Merge remote-tracking branch 'origin/coar-notify-7' into coar-notify-7-part-two

# Conflicts:
#	dspace-api/src/main/java/org/dspace/app/ldn/service/LDNMessageService.java
#	dspace-api/src/main/java/org/dspace/app/ldn/service/impl/LDNMessageServiceImpl.java

.github/workflows/build.yml

@@ -21,11 +21,11 @@ jobs:
       # Also specify version of Java to use (this can allow us to optionally run tests on multiple JDKs in future)
       matrix:
         include:
-          # NOTE: Unit Tests include deprecated REST API v6 (as it has unit tests)
+          # NOTE: Unit Tests include a retry for occasionally failing tests
           #  - surefire.rerunFailingTestsCount => try again for flakey tests, and keep track of/report on number of retries
           - type: "Unit Tests"
             java: 11
-            mvnflags: "-DskipUnitTests=false -Pdspace-rest -Dsurefire.rerunFailingTestsCount=2"
+            mvnflags: "-DskipUnitTests=false -Dsurefire.rerunFailingTestsCount=2"
             resultsdir: "**/target/surefire-reports/**"
           # NOTE: ITs skip all code validation checks, as they are already done by Unit Test job.
           #  - enforcer.skip     => Skip maven-enforcer-plugin rules

.github/workflows/docker.yml

@@ -102,6 +102,8 @@ jobs:
       build_id: dspace-solr
       image_name: dspace/dspace-solr
       dockerfile_path: ./dspace/src/main/docker/dspace-solr/Dockerfile
+      # Must pass solrconfigs to the Dockerfile so that it can find the required Solr config files
+      dockerfile_additional_contexts: 'solrconfigs=./dspace/solr/'
     secrets:
       DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
       DOCKER_ACCESS_TOKEN: ${{ secrets.DOCKER_ACCESS_TOKEN }}

.github/workflows/reusable-docker-build.yml

@@ -24,6 +24,12 @@ on:
       dockerfile_context:
         required: false
         type: string
+        default: '.'
+      # Optionally a list of "additional_contexts" to pass to Dockerfile. Defaults to empty
+      dockerfile_additional_contexts:
+        required: false
+        type: string
+        default: ''
       # If Docker image should have additional tag flavor details (e.g. a suffix), it may be passed in.
       tags_flavor:
         required: false
@@ -123,7 +129,9 @@ jobs:
         id: docker_build
         uses: docker/build-push-action@v5
         with:
-          context: ${{ inputs.dockerfile_context || '.' }}
+          build-contexts: |
+            ${{ inputs.dockerfile_additional_contexts }}
+          context: ${{ inputs.dockerfile_context }}
           file: ${{ inputs.dockerfile_path }}
           platforms: ${{ matrix.arch }}
           # For pull requests, we run the Docker build (to ensure no PR changes break the build),

Dockerfile

@@ -19,7 +19,7 @@ RUN mkdir /install \
 USER dspace
 # Copy the DSpace source code (from local machine) into the workdir (excluding .dockerignore contents)
 ADD --chown=dspace . /app/
-# Build DSpace (note: this build doesn't include the optional, deprecated "dspace-rest" webapp)
+# Build DSpace
 # Copy the dspace-installer directory to /install.  Clean up the build to keep the docker image small
 # Maven flags here ensure that we skip building test environment and skip all code verification checks.
 # These flags speed up this compilation as much as reasonably possible.

Dockerfile.test

@@ -21,9 +21,9 @@ RUN mkdir /install \
 USER dspace
 # Copy the DSpace source code (from local machine) into the workdir (excluding .dockerignore contents)
 ADD --chown=dspace . /app/
-# Build DSpace (INCLUDING the optional, deprecated "dspace-rest" webapp)
+# Build DSpace
 # Copy the dspace-installer directory to /install.  Clean up the build to keep the docker image small
-RUN mvn --no-transfer-progress package -Pdspace-rest && \
+RUN mvn --no-transfer-progress package && \
   mv /app/dspace/target/${TARGET_DIR}/* /install && \
   mvn clean
 
@@ -67,17 +67,10 @@ ENV CATALINA_OPTS=-Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=*:800
 
 # Link the DSpace 'server' webapp into Tomcat's webapps directory.
 # This ensures that when we start Tomcat, it runs from /server path (e.g. http://localhost:8080/server/)
-# Also link the v6.x (deprecated) REST API off the "/rest" path
-RUN ln -s $DSPACE_INSTALL/webapps/server   /usr/local/tomcat/webapps/server   && \
-    ln -s $DSPACE_INSTALL/webapps/rest          /usr/local/tomcat/webapps/rest
+RUN ln -s $DSPACE_INSTALL/webapps/server   /usr/local/tomcat/webapps/server
 # If you wish to run "server" webapp off the ROOT path, then comment out the above RUN, and uncomment the below RUN.
 # You also MUST update the 'dspace.server.url' configuration to match.
 # Please note that server webapp should only run on one path at a time.
 #RUN mv /usr/local/tomcat/webapps/ROOT /usr/local/tomcat/webapps/ROOT.bk && \
-#    ln -s $DSPACE_INSTALL/webapps/server   /usr/local/tomcat/webapps/ROOT && \
-#    ln -s $DSPACE_INSTALL/webapps/rest          /usr/local/tomcat/webapps/rest
+#    ln -s $DSPACE_INSTALL/webapps/server   /usr/local/tomcat/webapps/ROOT
 
-# Overwrite the v6.x (deprecated) REST API's web.xml, so that we can run it on HTTP (defaults to requiring HTTPS)
-# WARNING: THIS IS OBVIOUSLY INSECURE. NEVER DO THIS IN PRODUCTION.
-COPY dspace/src/main/docker/test/rest_web.xml $DSPACE_INSTALL/webapps/rest/WEB-INF/web.xml
-RUN sed -i -e "s|\${dspace.dir}|$DSPACE_INSTALL|" $DSPACE_INSTALL/webapps/rest/WEB-INF/web.xml

docker-compose-cli.yml

@@ -1,5 +1,10 @@
 version: "3.7"
-
+networks:
+  # Default to using network named 'dspacenet' from docker-compose.yml.
+  # Its full name will be prepended with the project name (e.g. "-p d7" means it will be named "d7_dspacenet")
+  default:
+    name: ${COMPOSE_PROJECT_NAME}_dspacenet
+    external: true
 services:
   dspace-cli:
     image: "${DOCKER_OWNER:-dspace}/dspace-cli:${DSPACE_VER:-latest}"
@@ -26,13 +31,8 @@ services:
     - ./dspace/config:/dspace/config
     entrypoint: /dspace/bin/dspace
     command: help
-    networks:
-      - dspacenet
     tty: true
     stdin_open: true
 
 volumes:
   assetstore:
-
-networks:
-  dspacenet:

docker-compose.yml

@@ -36,7 +36,7 @@ services:
     depends_on:
     - dspacedb
     networks:
-      dspacenet:
+      - dspacenet
     ports:
     - published: 8080
       target: 8080
@@ -89,8 +89,10 @@ services:
     container_name: dspacesolr
     image: "${DOCKER_OWNER:-dspace}/dspace-solr:${DSPACE_VER:-latest}"
     build:
-      context: .
-      dockerfile: ./dspace/src/main/docker/dspace-solr/Dockerfile
+      context: ./dspace/src/main/docker/dspace-solr/
+      # Provide path to Solr configs necessary to build Docker image
+      additional_contexts:
+        solrconfigs: ./dspace/solr/
       args:
         SOLR_VERSION: "${SOLR_VER:-8.11}"
     networks:
@@ -123,6 +125,8 @@ services:
       cp -r /opt/solr/server/solr/configsets/statistics/* statistics
       precreate-core qaevent /opt/solr/server/solr/configsets/qaevent
       cp -r /opt/solr/server/solr/configsets/qaevent/* qaevent
+      precreate-core suggestion /opt/solr/server/solr/configsets/suggestion
+      cp -r /opt/solr/server/solr/configsets/suggestion/* suggestion
       exec solr -f
 volumes:
   assetstore:

dspace-api/pom.xml

@@ -379,22 +379,6 @@
             <artifactId>jackson-datatype-jsr310</artifactId>
             <version>2.13.5</version>
         </dependency>
-        <dependency>
-            <groupId>org.springframework.boot</groupId>
-            <artifactId>spring-boot-starter-web</artifactId>
-            <version>${spring-boot.version}</version>
-            <exclusions>
-                <!-- Later version provided by dspace-api -->
-                <exclusion>
-                    <groupId>org.hibernate.validator</groupId>
-                    <artifactId>hibernate-validator</artifactId>
-                </exclusion>
-                <exclusion>
-                    <groupId>com.fasterxml.jackson.datatype</groupId>
-            		<artifactId>jackson-datatype-jsr310</artifactId>
-                </exclusion>
-            </exclusions>
-        </dependency>
         <dependency>
             <groupId>javax.cache</groupId>
             <artifactId>cache-api</artifactId>
@@ -549,7 +533,7 @@
         </dependency>
         <dependency>
             <groupId>org.hamcrest</groupId>
-            <artifactId>hamcrest-all</artifactId>
+            <artifactId>hamcrest</artifactId>
             <scope>test</scope>
         </dependency>
         <dependency>
@@ -641,7 +625,7 @@
         <dependency>
             <groupId>com.maxmind.geoip2</groupId>
             <artifactId>geoip2</artifactId>
-            <version>2.11.0</version>
+            <version>2.17.0</version>
         </dependency>
         <dependency>
             <groupId>org.apache.ant</groupId>
@@ -805,7 +789,7 @@
         <dependency>
             <groupId>com.opencsv</groupId>
             <artifactId>opencsv</artifactId>
-            <version>5.7.1</version>
+            <version>5.9</version>
         </dependency>
 
         <!-- Email templating -->
@@ -892,32 +876,32 @@
           <dependency>
             <groupId>io.netty</groupId>
             <artifactId>netty-buffer</artifactId>
-            <version>4.1.94.Final</version>
+            <version>4.1.106.Final</version>
           </dependency>
           <dependency>
             <groupId>io.netty</groupId>
             <artifactId>netty-transport</artifactId>
-            <version>4.1.94.Final</version>
+            <version>4.1.106.Final</version>
           </dependency>
           <dependency>
             <groupId>io.netty</groupId>
             <artifactId>netty-transport-native-unix-common</artifactId>
-            <version>4.1.94.Final</version>
+            <version>4.1.106.Final</version>
            </dependency>
           <dependency>
             <groupId>io.netty</groupId>
             <artifactId>netty-common</artifactId>
-            <version>4.1.94.Final</version>
+            <version>4.1.106.Final</version>
           </dependency>
           <dependency>
             <groupId>io.netty</groupId>
             <artifactId>netty-handler</artifactId>
-            <version>4.1.94.Final</version>
+            <version>4.1.106.Final</version>
           </dependency>
           <dependency>
             <groupId>io.netty</groupId>
             <artifactId>netty-codec</artifactId>
-            <version>4.1.94.Final</version>
+            <version>4.1.106.Final</version>
           </dependency>
           <dependency>
             <groupId>org.apache.velocity</groupId>
@@ -927,7 +911,7 @@
           <dependency>
               <groupId>org.xmlunit</groupId>
               <artifactId>xmlunit-core</artifactId>
-              <version>2.8.0</version>
+              <version>2.9.1</version>
               <scope>test</scope>
           </dependency>
           <dependency>

dspace-api/src/main/java/org/dspace/administer/CreateAdministrator.java

@@ -116,6 +116,17 @@ public final class CreateAdministrator {
     protected CreateAdministrator()
             throws Exception {
         context = new Context();
+        try {
+            context.getDBConfig();
+        } catch (NullPointerException npr) {
+            // if database is null, there is no point in continuing. Prior to this exception and catch,
+            // NullPointerException was thrown, that wasn't very helpful.
+            throw new IllegalStateException("Problem connecting to database. This " +
+                    "indicates issue with either network or version (or possibly some other). " +
+                    "If you are running this in docker-compose, please make sure dspace-cli was " +
+                    "built from the same sources as running dspace container AND that they are in " +
+                    "the same project/network.");
+        }
         groupService = EPersonServiceFactory.getInstance().getGroupService();
         ePersonService = EPersonServiceFactory.getInstance().getEPersonService();
     }

dspace-api/src/main/java/org/dspace/app/ldn/LDNMessageQueueStatus.java

@@ -7,7 +7,7 @@
  */
 package org.dspace.app.ldn;
 
-public enum QueueStatus {
+public enum LDNMessageQueueStatus {
 
     /**
      * Resulting processing status of an LDN Message (aka queue management)

dspace-api/src/main/java/org/dspace/app/ldn/LDNMetadataFields.java

@@ -8,7 +8,9 @@
 package org.dspace.app.ldn;
 
 /**
- *
+ * Constants for LDN metadata fields
+ * 
+ * @author Francesco Bacchelli (francesco.bacchelli at 4science.com)
  */
 public final class LDNMetadataFields {
 

dspace-api/src/main/java/org/dspace/app/ldn/LDNQueueExtractor.java

@@ -7,7 +7,6 @@
  */
 package org.dspace.app.ldn;
 
-import java.io.IOException;
 import java.sql.SQLException;
 
 import org.apache.logging.log4j.Logger;
@@ -32,17 +31,23 @@ public class LDNQueueExtractor {
     private LDNQueueExtractor() {
     }
 
-    public static int extractMessageFromQueue() throws IOException, SQLException {
-        log.info("START LDNQueueExtractor.extractMessageFromQueue()");
+    /**
+     * invokes
+     * @see org.dspace.app.ldn.service.impl.LDNMessageServiceImpl#extractAndProcessMessageFromQueue(Context)
+     * to process the oldest ldn messages from the queue. An LdnMessage is processed when is routed to a
+     * @see org.dspace.app.ldn.processor.LDNProcessor
+     * Also a +1 is added to the ldnMessage entity
+     * @see org.dspace.app.ldn.LDNMessageEntity#getQueueAttempts()
+     * @return the number of processed ldnMessages.
+     * @throws SQLException
+     */
+    public static int extractMessageFromQueue() throws SQLException {
         Context context = new Context(Context.Mode.READ_WRITE);
         int processed_messages = ldnMessageService.extractAndProcessMessageFromQueue(context);
-        if (processed_messages >= 0) {
+        if (processed_messages > 0) {
             log.info("Processed Messages x" + processed_messages);
-        } else {
-            log.error("Errors happened during the extract operations. Check the log above!");
         }
         context.complete();
-        log.info("END LDNQueueExtractor.extractMessageFromQueue()");
         return processed_messages;
     }
 

dspace-api/src/main/java/org/dspace/app/ldn/LDNQueueTimeoutChecker.java

@@ -7,7 +7,6 @@
  */
 package org.dspace.app.ldn;
 
-import java.io.IOException;
 import java.sql.SQLException;
 
 import org.apache.logging.log4j.Logger;
@@ -32,17 +31,22 @@ public class LDNQueueTimeoutChecker {
     private LDNQueueTimeoutChecker() {
     }
 
-    public static int checkQueueMessageTimeout() throws IOException, SQLException {
-        log.info("START LDNQueueTimeoutChecker.checkQueueMessageTimeout()");
+    /**
+     * invokes
+     * @see org.dspace.app.ldn.service.impl.LDNMessageServiceImpl#checkQueueMessageTimeout(Context)
+     * to refresh the queue status of timed-out and in progressing status ldn messages:
+     * according to their attempts put them back in queue or set their status as failed if maxAttempts
+     * reached.
+     * @return the number of managed ldnMessages.
+     * @throws SQLException
+     */
+    public static int checkQueueMessageTimeout() throws SQLException {
         Context context = new Context(Context.Mode.READ_WRITE);
         int fixed_messages = 0;
         fixed_messages = ldnMessageService.checkQueueMessageTimeout(context);
-        if (fixed_messages >= 0) {
+        if (fixed_messages > 0) {
             log.info("Managed Messages x" + fixed_messages);
-        } else {
-            log.error("Errors happened during the check operation. Check the log above!");
         }
-        log.info("END LDNQueueTimeoutChecker.checkQueueMessageTimeout()");
         context.complete();
         return fixed_messages;
     }

dspace-api/src/main/java/org/dspace/app/ldn/LDNRouter.java

@@ -32,11 +32,11 @@ public class LDNRouter {
      */
     public LDNProcessor route(LDNMessageEntity ldnMessage) {
         if (ldnMessage == null) {
-            log.warn("an null LDNMessage is received for routing!");
+            log.warn("A null LDNMessage was received and could not be routed.");
             return null;
         }
         if (StringUtils.isEmpty(ldnMessage.getType())) {
-            log.warn("LDNMessage " + ldnMessage + " has no type!");
+            log.warn("LDNMessage " + ldnMessage + " was received. It has no type, so it couldn't be routed.");
             return null;
         }
         Set<String> ldnMessageTypeSet = new HashSet<String>();

dspace-api/src/main/java/org/dspace/app/ldn/RdfMediaType.java

@@ -1,36 +0,0 @@
-/**
- * The contents of this file are subject to the license and copyright
- * detailed in the LICENSE and NOTICE files at the root of the source
- * tree and available online at
- *
- * http://www.dspace.org/license/
- */
-package org.dspace.app.ldn;
-
-import static java.nio.charset.Charset.defaultCharset;
-
-import org.springframework.http.MediaType;
-
-/**
- *
- */
-public class RdfMediaType {
-
-    public final static MediaType APPLICATION_JSON_LD = new MediaType("application", "ld+json", defaultCharset());
-    public final static MediaType APPLICATION_N_TRIPLES = new MediaType("application", "n-triples", defaultCharset());
-    public final static MediaType APPLICATION_RDF_XML = new MediaType("application", "rdf+xml", defaultCharset());
-    public final static MediaType APPLICATION_RDF_JSON = new MediaType("application", "rdf+json", defaultCharset());
-    public final static MediaType APPLICATION_X_TURTLE = new MediaType("application", "x-turtle", defaultCharset());
-
-    public final static MediaType TEXT_TURTLE = new MediaType("text", "turtle", defaultCharset());
-    public final static MediaType TEXT_N3 = new MediaType("text", "n3", defaultCharset());
-    public final static MediaType TEXT_RDF_N3 = new MediaType("text", "rdf+n3", defaultCharset());
-
-    /**
-     * 
-     */
-    private RdfMediaType() {
-
-    }
-
-}

dspace-api/src/main/java/org/dspace/app/ldn/action/LDNAction.java

@@ -26,6 +26,6 @@ public interface LDNAction {
      * @return ActionStatus the resulting status of the action
      * @throws Exception general exception that can be thrown while executing action
      */
-    public ActionStatus execute(Context context, Notification notification, Item item) throws Exception;
+    public LDNActionStatus execute(Context context, Notification notification, Item item) throws Exception;
 
 }

dspace-api/src/main/java/org/dspace/app/ldn/action/LDNActionStatus.java

@@ -10,6 +10,6 @@ package org.dspace.app.ldn.action;
 /**
  * Resulting status of an execution of an action.
  */
-public enum ActionStatus {
+public enum LDNActionStatus {
     CONTINUE, ABORT;
 }

dspace-api/src/main/java/org/dspace/app/ldn/action/LDNCorrectionAction.java

@@ -11,7 +11,7 @@ import java.math.BigDecimal;
 import java.sql.SQLException;
 import java.util.Date;
 
-import com.github.jsonldjava.utils.JsonUtils;
+import com.fasterxml.jackson.databind.ObjectMapper;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.dspace.app.ldn.NotifyServiceEntity;
@@ -51,8 +51,8 @@ public class LDNCorrectionAction implements LDNAction {
     private HandleService handleService;
 
     @Override
-    public ActionStatus execute(Context context, Notification notification, Item item) throws Exception {
-        ActionStatus result = ActionStatus.ABORT;
+    public LDNActionStatus execute(Context context, Notification notification, Item item) throws Exception {
+        LDNActionStatus result = LDNActionStatus.ABORT;
         String itemName = itemService.getName(item);
         QAEvent qaEvent = null;
         if (notification.getObject() != null) {
@@ -69,15 +69,14 @@ public class LDNCorrectionAction implements LDNAction {
             }
             BigDecimal score = getScore(context, notification);
             double doubleScoreValue = score != null ? score.doubleValue() : 0d;
-            /* String fullHandleUrl = configurationService.getProperty("dspace.ui.url") + "/handle/"
-                + handleService.findHandle(context, item); */
+            ObjectMapper mapper = new ObjectMapper();
             qaEvent = new QAEvent(QAEvent.COAR_NOTIFY_SOURCE,
                 handleService.findHandle(context, item), item.getID().toString(), itemName,
                 this.getQaEventTopic(), doubleScoreValue,
-                JsonUtils.toString(message)
-                , new Date());
+                mapper.writeValueAsString(message),
+                new Date());
             qaEventService.store(context, qaEvent);
-            result = ActionStatus.CONTINUE;
+            result = LDNActionStatus.CONTINUE;
         }
 
         return result;

dspace-api/src/main/java/org/dspace/app/ldn/action/LDNEmailAction.java

@@ -70,7 +70,7 @@ public class LDNEmailAction implements LDNAction {
      * @throws Exception
      */
     @Override
-    public ActionStatus execute(Context context, Notification notification, Item item) throws Exception {
+    public LDNActionStatus execute(Context context, Notification notification, Item item) throws Exception {
         try {
             Locale supportedLocale = I18nUtil.getEPersonLocale(context.getCurrentUser());
             Email email = Email.getEmail(I18nUtil.getEmailFilename(supportedLocale, actionSendEmailTextFile));
@@ -85,7 +85,8 @@ public class LDNEmailAction implements LDNAction {
             email.addArgument(notification.getActor().getName());
             email.addArgument(item.getName());
             email.addArgument(notification.getActor().getId());
-            email.addArgument(notification.getContext().getId());
+            email.addArgument(notification.getContext() != null ?
+                notification.getContext().getId() : notification.getObject().getId());
             email.addArgument(item.getSubmitter().getFullName());
             email.addArgument(date);
             email.addArgument(notification);
@@ -96,7 +97,7 @@ public class LDNEmailAction implements LDNAction {
             log.error("An Error Occurred while sending a notification email", e);
         }
 
-        return ActionStatus.CONTINUE;
+        return LDNActionStatus.CONTINUE;
     }
 
     /**

dspace-api/src/main/java/org/dspace/app/ldn/action/LDNRelationCorrectionAction.java

@@ -11,7 +11,7 @@ import java.math.BigDecimal;
 import java.sql.SQLException;
 import java.util.Date;
 
-import com.github.jsonldjava.utils.JsonUtils;
+import com.fasterxml.jackson.databind.ObjectMapper;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.dspace.app.ldn.NotifyServiceEntity;
@@ -51,14 +51,12 @@ public class LDNRelationCorrectionAction implements LDNAction {
     private HandleService handleService;
 
     @Override
-    public ActionStatus execute(Context context, Notification notification, Item item) throws Exception {
-        ActionStatus result = ActionStatus.ABORT;
+    public LDNActionStatus execute(Context context, Notification notification, Item item) throws Exception {
+        LDNActionStatus result = LDNActionStatus.ABORT;
         String itemName = itemService.getName(item);
         QAEvent qaEvent = null;
         if (notification.getObject() != null) {
             NotifyMessageDTO message = new NotifyMessageDTO();
-            /*relationFormat.replace("[0]", notification.getObject().getAsRelationship());
-            hrefValue = hrefValue.replace("[1]", notification.getObject().getAsSubject());*/
             message.setHref(notification.getObject().getAsSubject());
             message.setRelationship(notification.getObject().getAsRelationship());
             if (notification.getOrigin() != null) {
@@ -67,13 +65,14 @@ public class LDNRelationCorrectionAction implements LDNAction {
             }
             BigDecimal score = getScore(context, notification);
             double doubleScoreValue = score != null ? score.doubleValue() : 0d;
+            ObjectMapper mapper = new ObjectMapper();
             qaEvent = new QAEvent(QAEvent.COAR_NOTIFY_SOURCE,
                 handleService.findHandle(context, item), item.getID().toString(), itemName,
                 this.getQaEventTopic(), doubleScoreValue,
-                JsonUtils.toString(message)
-                , new Date());
+                mapper.writeValueAsString(message),
+                new Date());
             qaEventService.store(context, qaEvent);
-            result = ActionStatus.CONTINUE;
+            result = LDNActionStatus.CONTINUE;
         }
 
         return result;

dspace-api/src/main/java/org/dspace/app/ldn/action/SendLDNMessageAction.java

@@ -7,23 +7,23 @@
  */
 package org.dspace.app.ldn.action;
 
-import static org.dspace.app.ldn.RdfMediaType.APPLICATION_JSON_LD;
-
-import java.util.ArrayList;
-import java.util.List;
+import java.net.URI;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.apache.http.Header;
+import org.apache.http.HttpException;
+import org.apache.http.HttpHeaders;
+import org.apache.http.HttpStatus;
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.client.methods.HttpPost;
+import org.apache.http.entity.StringEntity;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.impl.client.HttpClientBuilder;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
-import org.dspace.app.ldn.converter.JsonLdHttpMessageConverter;
 import org.dspace.app.ldn.model.Notification;
 import org.dspace.content.Item;
 import org.dspace.core.Context;
-import org.springframework.http.HttpEntity;
-import org.springframework.http.HttpHeaders;
-import org.springframework.http.HttpStatus;
-import org.springframework.http.ResponseEntity;
-import org.springframework.http.converter.HttpMessageConverter;
-import org.springframework.web.client.RestTemplate;
 
 /**
  * Action to send LDN Message
@@ -34,75 +34,85 @@ public class SendLDNMessageAction implements LDNAction {
 
     private static final Logger log = LogManager.getLogger(SendLDNMessageAction.class);
 
-    private final RestTemplate restTemplate;
+    private CloseableHttpClient client = null;
 
     public SendLDNMessageAction() {
-        restTemplate = new RestTemplate();
-        List<HttpMessageConverter<?>> messageConverters = new ArrayList<HttpMessageConverter<?>>();
-        messageConverters.add(new JsonLdHttpMessageConverter());
-        messageConverters.addAll(restTemplate.getMessageConverters());
-        restTemplate.setMessageConverters(messageConverters);
+        HttpClientBuilder builder = HttpClientBuilder.create();
+        client = builder
+            .disableAutomaticRetries()
+            .setMaxConnTotal(5)
+            .build();
     }
 
-    @Override
-    public ActionStatus execute(Context context, Notification notification, Item item) throws Exception {
-        //TODO authorization with Bearer token should be supported.
-
-        HttpHeaders headers = new HttpHeaders();
-        headers.add("Content-Type", APPLICATION_JSON_LD.toString());
-
-        HttpEntity<Notification> request = new HttpEntity<>(notification, headers);
-
-        log.info("Announcing notification {}", request);
-
-        try {
-            //Server-side request forgery Critical check gitHub failure is a false positive,
-            //because the LDN Service URL is configured by the user from DSpace
-            //frontend configuration at /admin/ldn/services
-            ResponseEntity<String> response = restTemplate.postForEntity(
-                notification.getTarget().getInbox(),
-                request,
-                String.class);
-
-            if (isSuccessful(response.getStatusCode())) {
-                return ActionStatus.CONTINUE;
-            } else if (isRedirect(response.getStatusCode())) {
-                return handleRedirect(response, request);
-            } else {
-                return ActionStatus.ABORT;
-            }
-        } catch (Exception e) {
-            log.error(e);
-            return ActionStatus.ABORT;
+    public SendLDNMessageAction(CloseableHttpClient client) {
+        this();
+        if (client != null) {
+            this.client = client;
         }
     }
 
-    private boolean isSuccessful(HttpStatus statusCode) {
-        return statusCode == HttpStatus.ACCEPTED ||
-            statusCode == HttpStatus.CREATED;
+    @Override
+    public LDNActionStatus execute(Context context, Notification notification, Item item) throws Exception {
+        //TODO authorization with Bearer token should be supported.
+
+        String url = notification.getTarget().getInbox();
+
+        HttpPost httpPost = new HttpPost(url);
+        httpPost.addHeader("Content-Type", "application, ld+json");
+        ObjectMapper mapper = new ObjectMapper();
+        httpPost.setEntity(new StringEntity(mapper.writeValueAsString(notification), "UTF-8"));
+
+        LDNActionStatus result = LDNActionStatus.ABORT;
+        // NOTE: Github believes there is a "Potential server-side request forgery due to a user-provided value"
+        // This is a false positive because the LDN Service URL is configured by the user from DSpace.
+        // See the frontend configuration at [dspace.ui.url]/admin/ldn/services
+        try (
+            CloseableHttpResponse response = client.execute(httpPost);
+            ) {
+            if (isSuccessful(response.getStatusLine().getStatusCode())) {
+                result = LDNActionStatus.CONTINUE;
+            } else if (isRedirect(response.getStatusLine().getStatusCode())) {
+                result = handleRedirect(response, httpPost);
+            }
+        } catch (Exception e) {
+            log.error(e);
+        }
+        return result;
     }
 
-    private boolean isRedirect(HttpStatus statusCode) {
-        return statusCode == HttpStatus.PERMANENT_REDIRECT ||
-            statusCode == HttpStatus.TEMPORARY_REDIRECT;
+    private boolean isSuccessful(int statusCode) {
+        return statusCode == HttpStatus.SC_ACCEPTED ||
+            statusCode == HttpStatus.SC_CREATED;
     }
 
-    private ActionStatus handleRedirect(ResponseEntity<String> response,
-                                        HttpEntity<Notification> request) {
-
-        String url = response.getHeaders().getFirst(HttpHeaders.LOCATION);
+    private boolean isRedirect(int statusCode) {
+        //org.apache.http.HttpStatus has no enum value for 308!
+        return statusCode == (HttpStatus.SC_TEMPORARY_REDIRECT + 1) ||
+            statusCode == HttpStatus.SC_TEMPORARY_REDIRECT;
+    }
 
+    private LDNActionStatus handleRedirect(CloseableHttpResponse oldresponse,
+                                        HttpPost request) throws HttpException {
+        Header[] urls = oldresponse.getHeaders(HttpHeaders.LOCATION);
+        String url = urls.length > 0 && urls[0] != null ? urls[0].getValue() : null;
+        if (url == null) {
+            throw new HttpException("Error following redirect, unable to reach"
+                + " the correct url.");
+        }
+        LDNActionStatus result = LDNActionStatus.ABORT;
         try {
-            ResponseEntity<String> responseEntity =
-                restTemplate.postForEntity(url, request, String.class);
-
-            if (isSuccessful(responseEntity.getStatusCode())) {
-                return ActionStatus.CONTINUE;
+            request.setURI(new URI(url));
+            try (
+                CloseableHttpResponse response = client.execute(request);
+                ) {
+                if (isSuccessful(response.getStatusLine().getStatusCode())) {
+                    return LDNActionStatus.CONTINUE;
+                }
             }
         } catch (Exception e) {
             log.error("Error following redirect:", e);
         }
 
-        return ActionStatus.ABORT;
+        return LDNActionStatus.ABORT;
     }
 }

dspace-api/src/main/java/org/dspace/app/ldn/converter/JsonLdHttpMessageConverter.java

@@ -1,101 +0,0 @@
-/**
- * The contents of this file are subject to the license and copyright
- * detailed in the LICENSE and NOTICE files at the root of the source
- * tree and available online at
- *
- * http://www.dspace.org/license/
- */
-package org.dspace.app.ldn.converter;
-
-import static org.dspace.app.ldn.RdfMediaType.APPLICATION_JSON_LD;
-
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStreamWriter;
-
-import com.fasterxml.jackson.databind.DeserializationFeature;
-import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.SerializationFeature;
-import com.github.jsonldjava.utils.JsonUtils;
-import org.dspace.app.ldn.model.Notification;
-import org.springframework.http.HttpInputMessage;
-import org.springframework.http.HttpOutputMessage;
-import org.springframework.http.converter.AbstractHttpMessageConverter;
-import org.springframework.http.converter.HttpMessageNotReadableException;
-import org.springframework.http.converter.HttpMessageNotWritableException;
-
-/**
- * Message converter for JSON-LD notification request body.
- */
-public class JsonLdHttpMessageConverter extends AbstractHttpMessageConverter<Notification> {
-
-    private final ObjectMapper objectMapper;
-
-    /**
-     * Initialize object mapper to normalize arrays on
-     * serialization/deserialization.
-     */
-    public JsonLdHttpMessageConverter() {
-        super(APPLICATION_JSON_LD);
-        objectMapper = new ObjectMapper();
-        objectMapper.enable(SerializationFeature.INDENT_OUTPUT);
-        objectMapper.enable(SerializationFeature.WRITE_SINGLE_ELEM_ARRAYS_UNWRAPPED);
-        objectMapper.enable(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY);
-    }
-
-    /**
-     * Instruct message converter to convert notification object.
-     *
-     * @param clazz current class pending conversion
-     * @return boolean whether to convert the object with this converter
-     */
-    @Override
-    protected boolean supports(Class<?> clazz) {
-        return Notification.class.isAssignableFrom(clazz);
-    }
-
-    /**
-     * Convert input stream, primarily request body, to notification.
-     *
-     * @param clazz        notification class
-     * @param inputMessage input message with body to convert
-     *
-     * @return Notification deserialized notification
-     *
-     * @throws IOException                     failed to convert input stream
-     * @throws HttpMessageNotReadableException something wrong with the input
-     *                                         message
-     */
-    @Override
-    protected Notification readInternal(Class<? extends Notification> clazz, HttpInputMessage inputMessage)
-            throws IOException, HttpMessageNotReadableException {
-        try (InputStream in = inputMessage.getBody()) {
-            return objectMapper.convertValue(JsonUtils.fromInputStream(in), Notification.class);
-        }
-    }
-
-    /**
-     * Convert notification to output stream, primarily response body.
-     *
-     * @param notification  notification to convert
-     * @param outputMessage output message with serialized notification
-     * @throws IOException                     failed to convert notification
-     * @throws HttpMessageNotWritableException something wrong with the output
-     *                                         message
-     */
-    @Override
-    protected void writeInternal(Notification notification, HttpOutputMessage outputMessage)
-            throws IOException, HttpMessageNotWritableException {
-        try (OutputStreamWriter out = new OutputStreamWriter(outputMessage.getBody())) {
-            JsonUtils.write(out, notification);
-        }
-    }
-
-    /**
-     * @return String
-     */
-    public String getRdfType() {
-        return "JSON-LD";
-    }
-
-}

dspace-api/src/main/java/org/dspace/app/ldn/dao/LDNMessageDao.java

@@ -25,13 +25,44 @@ import org.dspace.core.GenericDAO;
  */
 public interface LDNMessageDao extends GenericDAO<LDNMessageEntity> {
 
+    /**
+     * load the oldest ldn messages considering their {@link org.dspace.app.ldn.LDNMessageEntity#queueLastStartTime}
+     * @param context
+     * @param max_attempts consider ldn_message entity with queue_attempts <= max_attempts
+     * @return ldn message entities to be routed
+     * @throws SQLException
+     */
     public List<LDNMessageEntity> findOldestMessageToProcess(Context context, int max_attempts) throws SQLException;
 
+    /**
+     * find ldn message entties in processing status and already timed out.
+     * @param context
+     * @param max_attempts consider ldn_message entity with queue_attempts <= max_attempts
+     * @return ldn message entities
+     * @throws SQLException
+     */
     public List<LDNMessageEntity> findProcessingTimedoutMessages(Context context, int max_attempts) throws SQLException;
 
+    /**
+     * find all ldn messages related to an item
+     * @param context
+     * @param item item related to the returned ldn messages
+     * @param activities involves only this specific group of activities
+     * @return all ldn messages related to the given item
+     * @throws SQLException
+     */
     public List<LDNMessageEntity> findAllMessagesByItem(
         Context context, Item item, String... activities) throws SQLException;
 
+    /**
+     * find all ldn messages related to an item and to a specific ldn message
+     * @param context
+     * @param msg the referring ldn message
+     * @param item the referring repository item
+     * @param relatedTypes filter for @see org.dspace.app.ldn.LDNMessageEntity#activityStreamType
+     * @return all related ldn messages
+     * @throws SQLException
+     */
     public List<LDNMessageEntity> findAllRelatedMessagesByItem(
         Context context, LDNMessageEntity msg, Item item, String... relatedTypes) throws SQLException;
 

dspace-api/src/main/java/org/dspace/app/ldn/dao/impl/LDNMessageDaoImpl.java

@@ -39,7 +39,6 @@ public class LDNMessageDaoImpl extends AbstractHibernateDAO<LDNMessageEntity> im
 
     @Override
     public List<LDNMessageEntity> findOldestMessageToProcess(Context context, int max_attempts) throws SQLException {
-        // looking for oldest failed-processed message
         CriteriaBuilder criteriaBuilder = getCriteriaBuilder(context);
         CriteriaQuery<LDNMessageEntity> criteriaQuery = getCriteriaQuery(criteriaBuilder, LDNMessageEntity.class);
         Root<LDNMessageEntity> root = criteriaQuery.from(LDNMessageEntity.class);
@@ -54,7 +53,6 @@ public class LDNMessageDaoImpl extends AbstractHibernateDAO<LDNMessageEntity> im
         orderList.add(criteriaBuilder.desc(root.get(LDNMessageEntity_.queueAttempts)));
         orderList.add(criteriaBuilder.asc(root.get(LDNMessageEntity_.queueLastStartTime)));
         criteriaQuery.orderBy(orderList);
-        // setHint("org.hibernate.cacheable", Boolean.FALSE);
         List<LDNMessageEntity> result = list(context, criteriaQuery, false, LDNMessageEntity.class, -1, -1);
         if (result == null || result.isEmpty()) {
             log.debug("No LDN messages found to be processed");
@@ -102,7 +100,6 @@ public class LDNMessageDaoImpl extends AbstractHibernateDAO<LDNMessageEntity> im
         orderList.add(criteriaBuilder.desc(root.get(LDNMessageEntity_.queueAttempts)));
         orderList.add(criteriaBuilder.asc(root.get(LDNMessageEntity_.queueLastStartTime)));
         criteriaQuery.orderBy(orderList);
-        // setHint("org.hibernate.cacheable", Boolean.FALSE);
         List<LDNMessageEntity> result = list(context, criteriaQuery, false, LDNMessageEntity.class, -1, -1);
         if (result == null || result.isEmpty()) {
             log.debug("No LDN messages found to be processed");
@@ -121,8 +118,6 @@ public class LDNMessageDaoImpl extends AbstractHibernateDAO<LDNMessageEntity> im
         Predicate relatedtypePredicate = null;
         andPredicates.add(
             criteriaBuilder.equal(root.get(LDNMessageEntity_.queueStatus), LDNMessageEntity.QUEUE_STATUS_PROCESSED));
-        /*andPredicates.add(
-            criteriaBuilder.equal(root.get(LDNMessageEntity_.object), item));*/
         andPredicates.add(
             criteriaBuilder.isNull(root.get(LDNMessageEntity_.target)));
         andPredicates.add(
@@ -136,7 +131,6 @@ public class LDNMessageDaoImpl extends AbstractHibernateDAO<LDNMessageEntity> im
         orderList.add(criteriaBuilder.asc(root.get(LDNMessageEntity_.queueLastStartTime)));
         orderList.add(criteriaBuilder.desc(root.get(LDNMessageEntity_.queueAttempts)));
         criteriaQuery.orderBy(orderList);
-        // setHint("org.hibernate.cacheable", Boolean.FALSE);
         List<LDNMessageEntity> result = list(context, criteriaQuery, false, LDNMessageEntity.class, -1, -1);
         if (result == null || result.isEmpty()) {
             log.debug("No LDN messages ACK found to be processed");
@@ -157,8 +151,6 @@ public class LDNMessageDaoImpl extends AbstractHibernateDAO<LDNMessageEntity> im
             criteriaBuilder.equal(root.get(LDNMessageEntity_.queueStatus), LDNMessageEntity.QUEUE_STATUS_PROCESSED));
         andPredicates.add(
             criteriaBuilder.equal(root.get(LDNMessageEntity_.object), item));
-        andPredicates.add(
-            criteriaBuilder.isNull(root.get(LDNMessageEntity_.origin)));
         if (activities != null && activities.length > 0) {
             activityPredicate = root.get(LDNMessageEntity_.activityStreamType).in(activities);
             andPredicates.add(activityPredicate);
@@ -168,7 +160,6 @@ public class LDNMessageDaoImpl extends AbstractHibernateDAO<LDNMessageEntity> im
         orderList.add(criteriaBuilder.asc(root.get(LDNMessageEntity_.queueLastStartTime)));
         orderList.add(criteriaBuilder.desc(root.get(LDNMessageEntity_.queueAttempts)));
         criteriaQuery.orderBy(orderList);
-        // setHint("org.hibernate.cacheable", Boolean.FALSE);
         List<LDNMessageEntity> result = list(context, criteriaQuery, false, LDNMessageEntity.class, -1, -1);
         if (result == null || result.isEmpty()) {
             log.debug("No LDN messages found");

dspace-api/src/main/java/org/dspace/app/ldn/model/Actor.java

@@ -10,7 +10,7 @@ package org.dspace.app.ldn.model;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
 /**
- *
+ * used to map @see org.dspace.app.ldn.model.Notification
  */
 public class Actor extends Base {
 

dspace-api/src/main/java/org/dspace/app/ldn/model/Base.java

@@ -17,7 +17,7 @@ import com.fasterxml.jackson.annotation.JsonInclude.Include;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
 /**
- *
+ * used to map @see org.dspace.app.ldn.model.Notification
  */
 @JsonInclude(Include.NON_EMPTY)
 @JsonIgnoreProperties(ignoreUnknown = true)

dspace-api/src/main/java/org/dspace/app/ldn/model/Citation.java

@@ -9,8 +9,9 @@ package org.dspace.app.ldn.model;
 
 import com.fasterxml.jackson.annotation.JsonProperty;
 
+
 /**
- *
+ * used to map @see org.dspace.app.ldn.model.Notification
  */
 public class Citation extends Base {
 

dspace-api/src/main/java/org/dspace/app/ldn/model/Context.java

@@ -11,8 +11,9 @@ import java.util.List;
 
 import com.fasterxml.jackson.annotation.JsonProperty;
 
+
 /**
- *
+ * used to map @see org.dspace.app.ldn.model.Notification
  */
 public class Context extends Citation {
 

dspace-api/src/main/java/org/dspace/app/ldn/model/Notification.java

@@ -11,7 +11,8 @@ import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 
 /**
- *
+ * the json object from witch @see org.dspace.app.ldn.LDNMessageEntity are created.
+ * <a href="https://notify.coar-repositories.org/patterns/">see official coar doc</a>
  */
 @JsonPropertyOrder(value = {
     "@context",

dspace-api/src/main/java/org/dspace/app/ldn/model/Object.java

@@ -10,7 +10,7 @@ package org.dspace.app.ldn.model;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
 /**
- *
+ * used to map @see org.dspace.app.ldn.model.Notification
  */
 public class Object extends Citation {
 

dspace-api/src/main/java/org/dspace/app/ldn/model/Service.java

@@ -10,7 +10,7 @@ package org.dspace.app.ldn.model;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
 /**
- *
+ * used to map @see org.dspace.app.ldn.model.Notification
  */
 public class Service extends Base {
 

dspace-api/src/main/java/org/dspace/app/ldn/model/Url.java

@@ -10,7 +10,7 @@ package org.dspace.app.ldn.model;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
 /**
- *
+ * used to map @see org.dspace.app.ldn.model.Citation
  */
 public class Url extends Base {
 

dspace-api/src/main/java/org/dspace/app/ldn/processor/LDNContextRepeater.java

@@ -50,7 +50,7 @@ public class LDNContextRepeater {
 
     /**
      * @param  notification
-     * @return              Iterator<Notification>
+     * @return Iterator<Notification>
      */
     public Iterator<Notification> iterator(Notification notification) {
         return new NotificationIterator(notification, repeatOver);
@@ -79,7 +79,7 @@ public class LDNContextRepeater {
 
                 JsonNode notificationNode = objectMapper.valueToTree(notification);
 
-                log.info("Notification {}", notificationNode);
+                log.debug("Notification {}", notificationNode);
 
                 JsonNode topContextNode = notificationNode.get(CONTEXT);
                 if (topContextNode.isNull()) {

dspace-api/src/main/java/org/dspace/app/ldn/processor/LDNMetadataProcessor.java

@@ -15,10 +15,12 @@ import java.util.List;
 import java.util.Objects;
 import java.util.UUID;
 
+import org.apache.http.HttpStatus;
+import org.apache.http.client.HttpResponseException;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
-import org.dspace.app.ldn.action.ActionStatus;
 import org.dspace.app.ldn.action.LDNAction;
+import org.dspace.app.ldn.action.LDNActionStatus;
 import org.dspace.app.ldn.model.Notification;
 import org.dspace.app.ldn.utility.LDNUtils;
 import org.dspace.content.DSpaceObject;
@@ -28,8 +30,6 @@ import org.dspace.core.Constants;
 import org.dspace.core.Context;
 import org.dspace.handle.service.HandleService;
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.http.HttpStatus;
-import org.springframework.web.server.ResponseStatusException;
 
 /**
  * Linked Data Notification metadata processor for consuming notifications. The
@@ -79,8 +79,8 @@ public class LDNMetadataProcessor implements LDNProcessor {
      *
      * @throws Exception failed execute the action
      */
-    private ActionStatus runActions(Context context, Notification notification, Item item) throws Exception {
-        ActionStatus operation = ActionStatus.CONTINUE;
+    private LDNActionStatus runActions(Context context, Notification notification, Item item) throws Exception {
+        LDNActionStatus operation = LDNActionStatus.CONTINUE;
         for (LDNAction action : actions) {
             log.info("Running action {} for notification {} {}",
                     action.getClass().getSimpleName(),
@@ -88,7 +88,7 @@ public class LDNMetadataProcessor implements LDNProcessor {
                     notification.getType());
 
             operation = action.execute(context, notification, item);
-            if (operation == ActionStatus.ABORT) {
+            if (operation == LDNActionStatus.ABORT) {
                 break;
             }
         }
@@ -134,8 +134,9 @@ public class LDNMetadataProcessor implements LDNProcessor {
      * @return Item associated item
      *
      * @throws SQLException failed to lookup item
+     * @throws HttpResponseException redirect failure
      */
-    private Item lookupItem(Context context, Notification notification) throws SQLException {
+    private Item lookupItem(Context context, Notification notification) throws SQLException, HttpResponseException {
         Item item = null;
 
         String url = null;
@@ -153,7 +154,7 @@ public class LDNMetadataProcessor implements LDNProcessor {
             item = itemService.find(context, uuid);
 
             if (Objects.isNull(item)) {
-                throw new ResponseStatusException(HttpStatus.NOT_FOUND,
+                throw new HttpResponseException(HttpStatus.SC_NOT_FOUND,
                         format("Item with uuid %s not found", uuid));
             }
 
@@ -161,21 +162,21 @@ public class LDNMetadataProcessor implements LDNProcessor {
             String handle = handleService.resolveUrlToHandle(context, url);
 
             if (Objects.isNull(handle)) {
-                throw new ResponseStatusException(HttpStatus.NOT_FOUND,
+                throw new HttpResponseException(HttpStatus.SC_NOT_FOUND,
                         format("Handle not found for %s", url));
             }
 
             DSpaceObject object = handleService.resolveToObject(context, handle);
 
             if (Objects.isNull(object)) {
-                throw new ResponseStatusException(HttpStatus.NOT_FOUND,
+                throw new HttpResponseException(HttpStatus.SC_NOT_FOUND,
                         format("Item with handle %s not found", handle));
             }
 
             if (object.getType() == Constants.ITEM) {
                 item = (Item) object;
             } else {
-                throw new ResponseStatusException(HttpStatus.UNPROCESSABLE_ENTITY,
+                throw new HttpResponseException(HttpStatus.SC_UNPROCESSABLE_ENTITY,
                         format("Handle %s does not resolve to an item", handle));
             }
         }

dspace-api/src/main/java/org/dspace/app/ldn/service/LDNMessageService.java

@@ -128,6 +128,7 @@ public interface LDNMessageService {
      * @throws SQLException If something goes wrong in the database
      */
     public NotifyRequestStatus findRequestsByItem(Context context, Item item) throws SQLException;
+
     /**
      * delete the provided ldn message
      *
@@ -144,4 +145,13 @@ public interface LDNMessageService {
      * @throws SQLException if something goes wrong
      */
     public List<LDNMessageEntity> findMessagesToBeReprocessed(Context context) throws SQLException;
+
+    /**
+     * check if IP number is included in the configured ip-range on the Notify
+     * Service
+     * 
+     * @param origin   the Notify Service entity
+     * @param sourceIp the ip to evaluate
+     */
+    public boolean isValidIp(NotifyServiceEntity origin, String sourceIp);
 }

dspace-api/src/main/java/org/dspace/app/ldn/service/impl/LDNMessageServiceImpl.java

@@ -20,6 +20,7 @@ import java.util.UUID;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.google.gson.JsonSyntaxException;
+
 import org.apache.commons.lang.time.DateUtils;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.logging.log4j.Logger;
@@ -93,6 +94,10 @@ public class LDNMessageServiceImpl implements LDNMessageService {
 
     @Override
     public LDNMessageEntity create(Context context, String id) throws SQLException {
+        LDNMessageEntity result = ldnMessageDao.findByID(context, LDNMessageEntity.class, id);
+        if (result != null) {
+            throw new SQLException("Duplicate LDN Message ID [" + id + "] detected. This message is rejected.");
+        }
         return ldnMessageDao.create(context, new LDNMessageEntity(id));
     }
 
@@ -104,7 +109,6 @@ public class LDNMessageServiceImpl implements LDNMessageService {
             ldnMessage.setContext(findDspaceObjectByUrl(context, notification.getContext().getId()));
         }
         ldnMessage.setOrigin(findNotifyService(context, notification.getOrigin()));
-        ldnMessage.setTarget(findNotifyService(context, notification.getTarget()));
         ldnMessage.setInReplyTo(find(context, notification.getInReplyTo()));
         ObjectMapper mapper = new ObjectMapper();
         String message = null;
@@ -130,38 +134,30 @@ public class LDNMessageServiceImpl implements LDNMessageService {
             ldnMessage.setCoarNotifyType(notificationTypeArrayList.get(1));
         }
         ldnMessage.setQueueStatus(LDNMessageEntity.QUEUE_STATUS_QUEUED);
-        //CST-12126 if source is untrusted, set the queue_status of the
-        //ldnMsgEntity to UNTRUSTED
+        ldnMessage.setSourceIp(sourceIp);
         if (ldnMessage.getOrigin() == null && !"Offer".equalsIgnoreCase(ldnMessage.getActivityStreamType())) {
             ldnMessage.setQueueStatus(LDNMessageEntity.QUEUE_STATUS_UNTRUSTED);
+        } else {
+
+            boolean ipCheckRangeEnabled = configurationService.getBooleanProperty("ldn.ip-range.enabled", true);
+            if (ipCheckRangeEnabled && !isValidIp(ldnMessage.getOrigin(), sourceIp)) {
+                ldnMessage.setQueueStatus(LDNMessageEntity.QUEUE_STATUS_UNTRUSTED_IP);
+            }
         }
         ldnMessage.setQueueTimeout(new Date());
-        ldnMessage.setSourceIp(sourceIp);
-
-        if (!isValidIp(ldnMessage)) {
-            ldnMessage.setQueueStatus(LDNMessageEntity.QUEUE_STATUS_UNTRUSTED_IP);
-        }
 
         update(context, ldnMessage);
         return ldnMessage;
     }
 
-    private boolean isValidIp(LDNMessageEntity message) {
+    @Override
+    public boolean isValidIp(NotifyServiceEntity origin, String sourceIp) {
 
-        boolean enabled = configurationService.getBooleanProperty("coar-notify.ip-range.enabled", true);
-
-        if (!enabled) {
-            return true;
-        }
-
-        NotifyServiceEntity notifyService =
-            message.getOrigin() == null ? message.getTarget() : message.getOrigin();
-
-        String lowerIp = notifyService.getLowerIp();
-        String upperIp = notifyService.getUpperIp();
+        String lowerIp = origin.getLowerIp();
+        String upperIp = origin.getUpperIp();
 
         try {
-            InetAddress ip = InetAddress.getByName(message.getSourceIp());
+            InetAddress ip = InetAddress.getByName(sourceIp);
             InetAddress lowerBoundAddress = InetAddress.getByName(lowerIp);
             InetAddress upperBoundAddress = InetAddress.getByName(upperIp);
 
@@ -322,7 +318,7 @@ public class LDNMessageServiceImpl implements LDNMessageService {
         }
         log.debug("Using parameters: [timeoutInMinutes]=" + timeoutInMinutes + ",[maxAttempts]=" + maxAttempts);
         /*
-         * CST-10631 put failed on processing messages with timed-out timeout and
+         * put failed on processing messages with timed-out timeout and
          * attempts >= configured_max_attempts put queue on processing messages with
          * timed-out timeout and attempts < configured_max_attempts
          */
@@ -335,7 +331,6 @@ public class LDNMessageServiceImpl implements LDNMessageService {
             return result;
         }
         if (msgsToCheck == null || msgsToCheck.isEmpty()) {
-            log.info("No timedout LDN messages found in queue.");
             return result;
         }
         for (int i = 0; i < msgsToCheck.size() && msgsToCheck.get(i) != null; i++) {
@@ -365,8 +360,8 @@ public class LDNMessageServiceImpl implements LDNMessageService {
         if (msgs != null && !msgs.isEmpty()) {
             for (LDNMessageEntity msg : msgs) {
                 RequestStatus offer = new RequestStatus();
-                offer.setServiceName(msg.getTarget() == null ? "Unknown Service" : msg.getTarget().getName());
-                offer.setServiceUrl(msg.getTarget() == null ? "" : msg.getTarget().getUrl());
+                offer.setServiceName(msg.getOrigin() == null ? "Unknown Service" : msg.getOrigin().getName());
+                offer.setServiceUrl(msg.getOrigin() == null ? "" : msg.getOrigin().getUrl());
                 offer.setOfferType(LDNUtils.getNotifyType(msg.getCoarNotifyType()));
                 List<LDNMessageEntity> acks = ldnMessageDao.findAllRelatedMessagesByItem(
                     context, msg, item, "Accept", "TentativeReject", "TentativeAccept", "Announce");

dspace-api/src/main/java/org/dspace/app/suggestion/SolrSuggestionProvider.java

@@ -129,7 +129,7 @@ public abstract class SolrSuggestionProvider implements SuggestionProvider {
     }
 
     /**
-     *
+     * check if the externalDataObject may have suggestion
      * @param context
      * @param externalDataObject
      * @return true if the externalDataObject could be suggested by this provider

dspace-api/src/main/java/org/dspace/app/suggestion/SolrSuggestionStorageServiceImpl.java

@@ -10,18 +10,23 @@ package org.dspace.app.suggestion;
 import static org.apache.commons.collections.CollectionUtils.isEmpty;
 
 import java.io.IOException;
-import java.lang.reflect.Type;
 import java.sql.SQLException;
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.UUID;
 import java.util.stream.Collectors;
 
-import com.google.gson.Gson;
-import com.google.gson.reflect.TypeToken;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.DeserializationFeature;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.json.JsonMapper;
 import org.apache.commons.lang3.StringUtils;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.apache.solr.client.solrj.SolrClient;
 import org.apache.solr.client.solrj.SolrQuery;
 import org.apache.solr.client.solrj.SolrQuery.SortClause;
@@ -33,6 +38,7 @@ import org.apache.solr.client.solrj.response.QueryResponse;
 import org.apache.solr.common.SolrDocument;
 import org.apache.solr.common.SolrDocumentList;
 import org.apache.solr.common.SolrInputDocument;
+import org.apache.solr.common.params.FacetParams;
 import org.dspace.content.Item;
 import org.dspace.content.dto.MetadataValueDTO;
 import org.dspace.content.service.ItemService;
@@ -41,6 +47,7 @@ import org.dspace.services.factory.DSpaceServicesFactory;
 import org.dspace.util.UUIDUtils;
 import org.springframework.beans.factory.annotation.Autowired;
 
+
 /**
  * Service to deal with the local suggestion solr core used by the
  * SolrSuggestionProvider(s)
@@ -50,6 +57,8 @@ import org.springframework.beans.factory.annotation.Autowired;
  */
 public class SolrSuggestionStorageServiceImpl implements SolrSuggestionStorageService {
 
+    private static final Logger log = LogManager.getLogger(SolrSuggestionStorageServiceImpl.class);
+
     protected SolrClient solrSuggestionClient;
 
     @Autowired
@@ -73,9 +82,12 @@ public class SolrSuggestionStorageServiceImpl implements SolrSuggestionStorageSe
     public void addSuggestion(Suggestion suggestion, boolean force, boolean commit)
             throws SolrServerException, IOException {
         if (force || !exist(suggestion)) {
-            Gson gson = new Gson();
+            ObjectMapper jsonMapper = new JsonMapper();
+            jsonMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
             SolrInputDocument document = new SolrInputDocument();
             document.addField(SOURCE, suggestion.getSource());
+            // suggestion id is written as concatenation of
+            // source + ":" + targetID + ":" + idPart (of externalDataObj)
             String suggestionFullID = suggestion.getID();
             document.addField(SUGGESTION_FULLID, suggestionFullID);
             document.addField(SUGGESTION_ID, suggestionFullID.split(":", 3)[2]);
@@ -89,7 +101,7 @@ public class SolrSuggestionStorageServiceImpl implements SolrSuggestionStorageSe
             document.addField(EXTERNAL_URI, suggestion.getExternalSourceUri());
             document.addField(SCORE, suggestion.getScore());
             document.addField(PROCESSED, false);
-            document.addField(EVIDENCES, gson.toJson(suggestion.getEvidences()));
+            document.addField(EVIDENCES, jsonMapper.writeValueAsString(suggestion.getEvidences()));
             getSolr().add(document);
             if (commit) {
                 getSolr().commit();
@@ -240,16 +252,13 @@ public class SolrSuggestionStorageServiceImpl implements SolrSuggestionStorageSe
         solrQuery.setFacet(true);
         solrQuery.setFacetMinCount(1);
         solrQuery.addFacetField(TARGET_ID);
-        solrQuery.setFacetLimit((int) (pageSize + offset));
+        solrQuery.setParam(FacetParams.FACET_OFFSET, String.valueOf(offset));
+        solrQuery.setFacetLimit((int) (pageSize));
         QueryResponse response = getSolr().query(solrQuery);
         FacetField facetField = response.getFacetField(TARGET_ID);
         List<SuggestionTarget> suggestionTargets = new ArrayList<SuggestionTarget>();
         int idx = 0;
         for (Count c : facetField.getValues()) {
-            if (idx < offset) {
-                idx++;
-                continue;
-            }
             SuggestionTarget target = new SuggestionTarget();
             target.setSource(source);
             target.setTotal((int) c.getCount());
@@ -326,9 +335,14 @@ public class SolrSuggestionStorageServiceImpl implements SolrSuggestionStorageSe
             }
         }
         String evidencesJson = (String) solrDoc.getFieldValue(EVIDENCES);
-        Type listType = new TypeToken<ArrayList<SuggestionEvidence>>() {
-        }.getType();
-        List<SuggestionEvidence> evidences = new Gson().fromJson(evidencesJson, listType);
+        ObjectMapper jsonMapper = new JsonMapper();
+        jsonMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+        List<SuggestionEvidence> evidences = new LinkedList<SuggestionEvidence>();
+        try {
+            evidences = jsonMapper.readValue(evidencesJson, new TypeReference<List<SuggestionEvidence>>() {});
+        } catch (JsonProcessingException e) {
+            log.error(e);
+        }
         suggestion.getEvidences().addAll(evidences);
         return suggestion;
     }

dspace-api/src/main/java/org/dspace/app/suggestion/Suggestion.java

@@ -14,26 +14,36 @@ import org.dspace.content.Item;
 import org.dspace.content.dto.MetadataValueDTO;
 
 /**
- * 
+ * This entity contains metadatas that should be added to the targeted Item
  *
  * @author Andrea Bollini (andrea.bollini at 4science.it)
  */
 public class Suggestion {
 
+    /** id of the suggestion */
     private String id;
 
+    /** the dc.title of the item */
     private String display;
 
+    /** the external source name the suggestion comes from */
     private String source;
 
+    /** external uri of the item */
     private String externalSourceUri;
 
+    /** item targeted by this suggestion */
     private Item target;
 
     private List<SuggestionEvidence> evidences = new LinkedList<SuggestionEvidence>();
 
     private List<MetadataValueDTO> metadata = new LinkedList<MetadataValueDTO>();
 
+    /** suggestion creation
+     * @param source name of the external source
+     * @param target the targeted item in repository
+     * @param idPart external item id, used mainly for suggestion @see #id creation
+     * */
     public Suggestion(String source, Item target, String idPart) {
         this.source = source;
         this.target = target;

dspace-api/src/main/java/org/dspace/app/suggestion/SuggestionEvidence.java

@@ -8,16 +8,21 @@
 package org.dspace.app.suggestion;
 
 /**
- * 
+ * This DTO class is returned by an {@link org.dspace.app.suggestion.openaire.EvidenceScorer} to model the concept of
+ * an evidence / fact that has been used to evaluate the precision of a suggestion increasing or decreasing the score
+ * of the suggestion.
  *
  * @author Andrea Bollini (andrea.bollini at 4science.it)
  */
 public class SuggestionEvidence {
 
+    /** name of the evidence */
     private String name;
 
+    /** positive or negative value to influence the score of the suggestion */
     private double score;
 
+    /** additional notes */
     private String notes;
 
     public SuggestionEvidence() {

dspace-api/src/main/java/org/dspace/app/suggestion/SuggestionProvider.java

@@ -13,22 +13,42 @@ import java.util.UUID;
 import org.dspace.core.Context;
 import org.dspace.external.model.ExternalDataObject;
 
+/**
+ * 
+ * Interface for suggestion management like finding and counting.
+ * @see org.dspace.app.suggestion.SuggestionTarget
+ * @author Francesco Bacchelli (francesco.bacchelli at 4science.com)
+ *
+ */
 public interface SuggestionProvider {
+
+    /** find all suggestion targets
+     * @see org.dspace.app.suggestion.SuggestionTarget
+     * */
     public List<SuggestionTarget> findAllTargets(Context context, int pageSize, long offset);
 
+    /** count all suggestion targets */
     public long countAllTargets(Context context);
 
+    /** find a suggestion target by UUID */
     public SuggestionTarget findTarget(Context context, UUID target);
 
+    /** find unprocessed suggestions (paged) by target UUID
+     * @see org.dspace.app.suggestion.Suggestion
+     * */
     public List<Suggestion> findAllUnprocessedSuggestions(Context context, UUID target, int pageSize, long offset,
             boolean ascending);
 
+    /** find unprocessed suggestions by target UUID */
     public long countUnprocessedSuggestionByTarget(Context context, UUID target);
 
+    /** find an unprocessed suggestion by target UUID and suggestion id */
     public Suggestion findUnprocessedSuggestion(Context context, UUID target, String id);
 
+    /** reject a specific suggestion by target @param target and by suggestion id @param idPart */
     public void rejectSuggestion(Context context, UUID target, String idPart);
 
+    /** flag a suggestion as processed */
     public void flagRelatedSuggestionsAsProcessed(Context context, ExternalDataObject externalDataObject);
 
 }

dspace-api/src/main/java/org/dspace/app/suggestion/SuggestionService.java

@@ -13,36 +13,49 @@ import java.util.UUID;
 import org.dspace.core.Context;
 
 /**
- * 
+ * Service that handles {@link Suggestion}.
  *
  * @author Andrea Bollini (andrea.bollini at 4science.it)
  */
 public interface SuggestionService {
 
+    /** find a {@link SuggestionTarget } by source name and suggestion id */
     public SuggestionTarget find(Context context, String source, UUID id);
 
+    /** count all suggetion targets by suggestion source */
     public long countAll(Context context, String source);
 
+    /** find all suggestion targets by source (paged) */
     public List<SuggestionTarget> findAllTargets(Context context, String source, int pageSize, long offset);
 
+    /** count all (unprocessed) suggestions by the given target uuid */
     public long countAllByTarget(Context context, UUID target);
 
+    /** find suggestion target by targeted item (paged) */
     public List<SuggestionTarget> findByTarget(Context context, UUID target, int pageSize, long offset);
 
+    /** find suggestion source by source name */
     public SuggestionSource findSource(Context context, String source);
 
+    /** count all suggestion sources */
     public long countSources(Context context);
 
+    /** find all suggestion sources (paged) */
     public List<SuggestionSource> findAllSources(Context context, int pageSize, long offset);
 
+    /** find unprocessed suggestion by id */
     public Suggestion findUnprocessedSuggestion(Context context, String id);
 
+    /** reject a specific suggestion by its id */
     public void rejectSuggestion(Context context, String id);
 
+    /** find all suggestions by targeted item and external source */
     public List<Suggestion> findByTargetAndSource(Context context, UUID target, String source, int pageSize,
             long offset, boolean ascending);
 
+    /** count all suggestions by targeted item id and source name */
     public long countAllByTargetAndSource(Context context, String source, UUID target);
 
+    /** returns all suggestion providers */
     public List<SuggestionProvider> getSuggestionProviders();
 }

dspace-api/src/main/java/org/dspace/app/suggestion/SuggestionServiceImpl.java

@@ -76,6 +76,7 @@ public class SuggestionServiceImpl implements SuggestionService {
     public List<SuggestionTarget> findByTarget(Context context, UUID target, int pageSize, long offset) {
         List<SuggestionTarget> fullSourceTargets = new ArrayList<SuggestionTarget>();
         for (String source : providersMap.keySet()) {
+            // all the suggestion target will be related to the same target (i.e. the same researcher - person item)
             SuggestionTarget sTarget = providersMap.get(source).findTarget(context, target);
             if (sTarget != null && sTarget.getTotal() > 0) {
                 fullSourceTargets.add(sTarget);
@@ -88,6 +89,8 @@ public class SuggestionServiceImpl implements SuggestionService {
             }
         }
         );
+        // this list will be as large as the number of sources available in the repository so it is unlikely that
+        // real pagination will occur
         return fullSourceTargets.stream().skip(offset).limit(pageSize).collect(Collectors.toList());
     }
 

dspace-api/src/main/java/org/dspace/app/suggestion/SuggestionSource.java

@@ -8,14 +8,17 @@
 package org.dspace.app.suggestion;
 
 /**
- * 
+ * This DTO class is used to pass around the number of items interested by suggestion provided by a specific source
+ * (i.e. openaire)
  *
  * @author Andrea Bollini (andrea.bollini at 4science.it)
  */
 public class SuggestionSource {
 
+    /** source name of the suggestion */
     private String name;
 
+    /** number of targeted items */
     private int total;
 
     public SuggestionSource() {

dspace-api/src/main/java/org/dspace/app/suggestion/SuggestionTarget.java

@@ -10,23 +10,27 @@ package org.dspace.app.suggestion;
 import org.dspace.content.Item;
 
 /**
- * 
+ * This DTO class is used to pass around the number of suggestions available from a specific source for a target
+ * repository item
  *
  * @author Andrea Bollini (andrea.bollini at 4science.it)
  */
 public class SuggestionTarget {
 
+    /** the item targeted */
     private Item target;
 
+    /** source name of the suggestion */
     private String source;
 
+    /** total count of suggestions for same target and source */
     private int total;
 
     public SuggestionTarget() {
     }
 
     /**
-     * Wrap a target person into a suggestion target.
+     * Wrap a target repository item (usually a person item) into a suggestion target.
      * 
      * @param item must be not null
      */
@@ -41,11 +45,7 @@ public class SuggestionTarget {
      * @return the source:uuid of the wrapped item
      */
     public String getID() {
-        if (target != null) {
-            return source + ":" + target.getID();
-        } else {
-            return source + ":null";
-        }
+        return source + ":" + (target != null ? target.getID() : "");
     }
 
     public Item getTarget() {

dspace-api/src/main/java/org/dspace/app/suggestion/openaire/AuthorNamesScorer.java

@@ -5,7 +5,7 @@
  *
  * http://www.dspace.org/license/
  */
-package org.dspace.app.suggestion.oaire;
+package org.dspace.app.suggestion.openaire;
 
 import static org.dspace.app.suggestion.SuggestionUtils.getAllEntriesByMetadatum;
 
@@ -130,6 +130,11 @@ public class AuthorNamesScorer implements EvidenceScorer {
         return authors;
     }
 
+    /**
+     * cleans up undesired characters
+     * @param value the string to clean up
+     * @return cleaned up string
+     * */
     private String normalize(String value) {
         String norm = Normalizer.normalize(value, Normalizer.NFD);
         CharsetDetector cd = new CharsetDetector();

dspace-api/src/main/java/org/dspace/app/suggestion/openaire/DateScorer.java

@@ -5,7 +5,7 @@
  *
  * http://www.dspace.org/license/
  */
-package org.dspace.app.suggestion.oaire;
+package org.dspace.app.suggestion.openaire;
 
 import java.util.Calendar;
 import java.util.Collections;
@@ -31,23 +31,50 @@ import org.springframework.beans.factory.annotation.Autowired;
  */
 public class DateScorer implements EvidenceScorer {
 
+    /**
+     * if available it should contains the metadata field key in the form (schema.element[.qualifier]) that contains
+     * the birth date of the researcher
+     */
     private String birthDateMetadata;
 
+    /**
+     * if available it should contains the metadata field key in the form (schema.element[.qualifier]) that contains
+     * the date of graduation of the researcher. If the metadata has multiple values the min will be used
+     */
     private String educationDateMetadata;
 
-    private String minDateMetadata;
-
-    private String maxDateMetadata;
-
+    /**
+     * The minimal age that is expected for a researcher to be a potential author of a scholarly contribution
+     * (i.e. the minimum delta from the publication date and the birth date)
+     */
     private int birthDateDelta = 20;
+
+    /**
+     * The maximum age that is expected for a researcher to be a potential author of a scholarly contribution
+     * (i.e. the maximum delta from the publication date and the birth date)
+     */
     private int birthDateRange = 50;
 
+    /**
+     * The number of year from/before the graduation that is expected for a researcher to be a potential
+     * author of a scholarly contribution (i.e. the minimum delta from the publication date and the first
+     * graduation date)
+     */
     private int educationDateDelta = -3;
+
+    /**
+     * The maximum scientific longevity that is expected for a researcher from its graduation to be a potential
+     * author of a scholarly contribution (i.e. the maximum delta from the publication date and the first
+     * graduation date)
+     */
     private int educationDateRange = 50;
 
     @Autowired
     private ItemService itemService;
 
+    /**
+     * the metadata used in the publication to track the publication date (i.e. dc.date.issued)
+     */
     private String publicationDateMetadata;
 
     public void setItemService(ItemService itemService) {
@@ -86,14 +113,6 @@ public class DateScorer implements EvidenceScorer {
         this.educationDateRange = educationDateRange;
     }
 
-    public void setMaxDateMetadata(String maxDateMetadata) {
-        this.maxDateMetadata = maxDateMetadata;
-    }
-
-    public void setMinDateMetadata(String minDateMetadata) {
-        this.minDateMetadata = minDateMetadata;
-    }
-
     public void setPublicationDateMetadata(String publicationDateMetadata) {
         this.publicationDateMetadata = publicationDateMetadata;
     }
@@ -101,6 +120,7 @@ public class DateScorer implements EvidenceScorer {
     /**
      * Method which is responsible to evaluate ImportRecord based on the publication date.
      * ImportRecords which have a date outside the defined or calculated expected range will be discarded.
+     * {@link DateScorer#birthDateMetadata}, {@link DateScorer#educationDateMetadata}
      * 
      * @param importRecord the ExternalDataObject to check
      * @param researcher DSpace item
@@ -113,8 +133,7 @@ public class DateScorer implements EvidenceScorer {
             return new SuggestionEvidence(this.getClass().getSimpleName(),
                     0,
                     "No assumption was possible about the publication year range. "
-                    + "Please consider to set a min/max date in the profile, specify the birthday "
-                    + "or education achievements");
+                    + "Please consider setting your birthday in your profile.");
         } else {
             String optDate = SuggestionUtils.getFirstEntryByMetadatum(importRecord, publicationDateMetadata);
             int year = getYear(optDate);
@@ -139,34 +158,29 @@ public class DateScorer implements EvidenceScorer {
         }
     }
 
+    /**
+     * returns min and max year interval in between it's probably that the researcher
+     * actually contributed to the suggested item
+     * @param researcher
+     * @return
+     */
     private Integer[] calculateRange(Item researcher) {
-        String minDateStr = getSingleValue(researcher, minDateMetadata);
-        int minYear = getYear(minDateStr);
-        String maxDateStr = getSingleValue(researcher, maxDateMetadata);
-        int maxYear = getYear(maxDateStr);
-        if (minYear > 0 && maxYear > 0) {
-            return new Integer[] { minYear, maxYear };
+        String birthDateStr = getSingleValue(researcher, birthDateMetadata);
+        int birthDateYear = getYear(birthDateStr);
+        int educationDateYear = getListMetadataValues(researcher, educationDateMetadata).stream()
+                .mapToInt(x -> getYear(x.getValue())).filter(d -> d > 0).min().orElse(-1);
+        if (educationDateYear > 0) {
+            return new Integer[] {
+                educationDateYear + educationDateDelta,
+                educationDateYear + educationDateDelta + educationDateRange
+            };
+        } else if (birthDateYear > 0) {
+            return new Integer[] {
+                birthDateYear + birthDateDelta,
+                birthDateYear + birthDateDelta + birthDateRange
+            };
         } else {
-            String birthDateStr = getSingleValue(researcher, birthDateMetadata);
-            int birthDateYear = getYear(birthDateStr);
-            int educationDateYear = getListMetadataValues(researcher, educationDateMetadata)
-                      .stream()
-                      .mapToInt(x -> getYear(x.getValue()))
-                      .filter(d -> d > 0)
-                      .min().orElse(-1);
-            if (educationDateYear > 0) {
-                return new Integer[] {
-                    minYear > 0 ? minYear : educationDateYear + educationDateDelta,
-                    maxYear > 0 ? maxYear : educationDateYear + educationDateDelta + educationDateRange
-                };
-            } else if (birthDateYear > 0) {
-                return new Integer[] {
-                    minYear > 0 ? minYear : birthDateYear + birthDateDelta,
-                    maxYear > 0 ? maxYear : birthDateYear + birthDateDelta + birthDateRange
-                };
-            } else {
-                return null;
-            }
+            return null;
         }
     }
 

dspace-api/src/main/java/org/dspace/app/suggestion/openaire/EvidenceScorer.java

@@ -5,14 +5,14 @@
  *
  * http://www.dspace.org/license/
  */
-package org.dspace.app.suggestion.oaire;
+package org.dspace.app.suggestion.openaire;
 
 import org.dspace.app.suggestion.SuggestionEvidence;
 import org.dspace.content.Item;
 import org.dspace.external.model.ExternalDataObject;
 
 /**
- * Interface used in {@see org.dspace.app.suggestion.oaire.OAIREPublicationApproverServiceImpl}
+ * Interface used in {@see org.dspace.app.suggestion.oaire.PublicationApproverServiceImpl}
  * to construct filtering pipeline.
  * 
  * For each EvidenceScorer, the service call computeEvidence method.

dspace-api/src/main/java/org/dspace/app/suggestion/openaire/PublicationLoader.java

@@ -5,7 +5,7 @@
  *
  * http://www.dspace.org/license/
  */
-package org.dspace.app.suggestion.oaire;
+package org.dspace.app.suggestion.openaire;
 
 import static org.dspace.app.suggestion.SuggestionUtils.getAllEntriesByMetadatum;
 import static org.dspace.app.suggestion.SuggestionUtils.getFirstEntryByMetadatum;
@@ -33,7 +33,7 @@ import org.springframework.beans.factory.annotation.Autowired;
  * @author Pasquale Cavallo (pasquale.cavallo at 4science dot it)
  *
  */
-public class OAIREPublicationLoader extends SolrSuggestionProvider {
+public class PublicationLoader extends SolrSuggestionProvider {
 
     private List<String> names;
 
@@ -66,7 +66,7 @@ public class OAIREPublicationLoader extends SolrSuggestionProvider {
      * This method filter a list of ImportRecords using a pipeline of AuthorNamesApprover
      * and return a filtered list of ImportRecords.
      * 
-     * @see org.dspace.app.suggestion.oaire.AuthorNamesScorer
+     * @see org.dspace.app.suggestion.openaire.AuthorNamesScorer
      * @param researcher the researcher Item
      * @param importRecords List of import record
      * @return a list of filtered import records
@@ -105,10 +105,22 @@ public class OAIREPublicationLoader extends SolrSuggestionProvider {
      */
     public void importAuthorRecords(Context context, Item researcher)
             throws SolrServerException, IOException {
-        List<ExternalDataObject> metadata = getImportRecords(researcher);
-        List<Suggestion> records = reduceAndTransform(researcher, metadata);
-        for (Suggestion record : records) {
-            solrSuggestionStorageService.addSuggestion(record, false, false);
+        int offset = 0;
+        int limit = 10;
+        int loaded = limit;
+        List<String> searchValues = searchMetadataValues(researcher);
+        while (loaded > 0) {
+            List<ExternalDataObject> metadata = getImportRecords(searchValues, researcher, offset, limit);
+            if (metadata.isEmpty()) {
+                loaded = 0;
+                continue;
+            }
+            offset += limit;
+            loaded = metadata.size();
+            List<Suggestion> records = reduceAndTransform(researcher, metadata);
+            for (Suggestion record : records) {
+                solrSuggestionStorageService.addSuggestion(record, false, false);
+            }
         }
         solrSuggestionStorageService.commit();
     }
@@ -154,14 +166,18 @@ public class OAIREPublicationLoader extends SolrSuggestionProvider {
      * get from metadata key defined in class level variable names as author to query OpenAIRE.
      * 
      * @see org.dspace.importer.external.openaire.service.OpenAireImportMetadataSourceServiceImpl
+     * @param searchValues query
      * @param researcher item to extract metadata from
+     * @param limit for pagination purpose
+     * @param offset for pagination purpose
      * @return list of ImportRecord
      */
-    private List<ExternalDataObject> getImportRecords(Item researcher) {
-        List<String> searchValues = searchMetadataValues(researcher);
+    private List<ExternalDataObject> getImportRecords(List<String> searchValues,
+        Item researcher, int offset, int limit) {
         List<ExternalDataObject> matchingRecords = new ArrayList<>();
         for (String searchValue : searchValues) {
-            matchingRecords.addAll(primaryProvider.searchExternalDataObjects(searchValue, 0, 9999));
+            matchingRecords.addAll(
+                primaryProvider.searchExternalDataObjects(searchValue, offset, limit));
         }
         List<ExternalDataObject> toReturn = removeDuplicates(matchingRecords);
         return toReturn;

dspace-api/src/main/java/org/dspace/app/suggestion/openaire/PublicationLoaderCliScriptConfiguration.java

@@ -5,17 +5,17 @@
  *
  * http://www.dspace.org/license/
  */
-package org.dspace.app.suggestion;
+package org.dspace.app.suggestion.openaire;
 
 import org.apache.commons.cli.Options;
 
 /**
- * Extension of {@link OAIREPublicationLoaderScriptConfiguration} for CLI.
+ * Extension of {@link PublicationLoaderScriptConfiguration} for CLI.
  *
  * @author Alessandro Martelli (alessandro.martelli at 4science.it)
  */
-public class OAIREPublicationLoaderCliScriptConfiguration<T extends OAIREPublicationLoaderRunnable>
-    extends OAIREPublicationLoaderScriptConfiguration<T> {
+public class PublicationLoaderCliScriptConfiguration<T extends PublicationLoaderRunnable>
+    extends PublicationLoaderScriptConfiguration<T> {
 
     @Override
     public Options getOptions() {

dspace-api/src/main/java/org/dspace/app/suggestion/openaire/PublicationLoaderRunnable.java

@@ -5,19 +5,23 @@
  *
  * http://www.dspace.org/license/
  */
-package org.dspace.app.suggestion;
+package org.dspace.app.suggestion.openaire;
 
 import java.util.ArrayList;
+import java.util.Iterator;
 import java.util.List;
-import java.util.UUID;
 
 import org.apache.commons.cli.ParseException;
-import org.dspace.app.suggestion.oaire.OAIREPublicationLoader;
 import org.dspace.content.Item;
 import org.dspace.core.Context;
-import org.dspace.discovery.IndexableObject;
+import org.dspace.discovery.DiscoverQuery;
 import org.dspace.discovery.SearchService;
+import org.dspace.discovery.SearchServiceException;
+import org.dspace.discovery.SearchUtils;
+import org.dspace.discovery.utils.DiscoverQueryBuilder;
+import org.dspace.discovery.utils.parameter.QueryBuilderSearchFilter;
 import org.dspace.scripts.DSpaceRunnable;
+import org.dspace.sort.SortOption;
 import org.dspace.utils.DSpace;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -32,12 +36,12 @@ import org.slf4j.LoggerFactory;
  * 
  * @author Alessandro Martelli (alessandro.martelli at 4science.it)
  */
-public class OAIREPublicationLoaderRunnable
-    extends DSpaceRunnable<OAIREPublicationLoaderScriptConfiguration<OAIREPublicationLoaderRunnable>> {
+public class PublicationLoaderRunnable
+    extends DSpaceRunnable<PublicationLoaderScriptConfiguration<PublicationLoaderRunnable>> {
 
-    private static final Logger LOGGER = LoggerFactory.getLogger(OAIREPublicationLoaderRunnable.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(PublicationLoaderRunnable.class);
 
-    private OAIREPublicationLoader oairePublicationLoader = null;
+    private PublicationLoader oairePublicationLoader = null;
 
     protected Context context;
 
@@ -45,9 +49,9 @@ public class OAIREPublicationLoaderRunnable
 
     @Override
     @SuppressWarnings({ "rawtypes", "unchecked" })
-    public OAIREPublicationLoaderScriptConfiguration<OAIREPublicationLoaderRunnable> getScriptConfiguration() {
-        OAIREPublicationLoaderScriptConfiguration configuration = new DSpace().getServiceManager()
-                .getServiceByName("import-oaire-suggestions", OAIREPublicationLoaderScriptConfiguration.class);
+    public PublicationLoaderScriptConfiguration<PublicationLoaderRunnable> getScriptConfiguration() {
+        PublicationLoaderScriptConfiguration configuration = new DSpace().getServiceManager()
+                .getServiceByName("import-openaire-suggestions", PublicationLoaderScriptConfiguration.class);
         return configuration;
     }
 
@@ -55,7 +59,7 @@ public class OAIREPublicationLoaderRunnable
     public void setup() throws ParseException {
 
         oairePublicationLoader = new DSpace().getServiceManager().getServiceByName(
-                "OAIREPublicationLoader", OAIREPublicationLoader.class);
+                "OpenairePublicationLoader", PublicationLoader.class);
 
         profile = commandLine.getOptionValue("s");
         if (profile == null) {
@@ -70,10 +74,9 @@ public class OAIREPublicationLoaderRunnable
 
         context = new Context();
 
-        List<Item> researchers = getResearchers(profile);
-
-        for (Item researcher : researchers) {
-
+        Iterator<Item> researchers = getResearchers(profile);
+        while (researchers.hasNext()) {
+            Item researcher = researchers.next();
             oairePublicationLoader.importAuthorRecords(context, researcher);
         }
 
@@ -90,24 +93,23 @@ public class OAIREPublicationLoaderRunnable
      * @return             the researcher with specified UUID or all researchers
      */
     @SuppressWarnings("rawtypes")
-    private List<Item> getResearchers(String profileUUID) {
-        final UUID uuid = profileUUID != null ? UUID.fromString(profileUUID) : null;
+    private Iterator<Item> getResearchers(String profileUUID) {
         SearchService searchService = new DSpace().getSingletonService(SearchService.class);
-        List<IndexableObject> objects = null;
-        if (uuid != null) {
-            objects = searchService.search(context, "search.resourceid:" + uuid.toString(),
-                "lastModified", false, 0, 1000, "search.resourcetype:Item", "dspace.entity.type:Person");
-        } else {
-            objects = searchService.search(context, "*:*", "lastModified", false, 0, 1000, "search.resourcetype:Item",
-                    "dspace.entity.type:Person");
+        DiscoverQueryBuilder queryBuilder = SearchUtils.getQueryBuilder();
+        List<QueryBuilderSearchFilter> filters = new ArrayList<QueryBuilderSearchFilter>();
+        String query = "*:*";
+        if (profileUUID != null) {
+            query = "search.resourceid:" + profileUUID.toString();
         }
-        List<Item> items = new ArrayList<Item>();
-        if (objects != null) {
-            for (IndexableObject o : objects) {
-                items.add((Item) o.getIndexedObject());
-            }
+        try {
+            DiscoverQuery discoverQuery = queryBuilder.buildQuery(context, null,
+                SearchUtils.getDiscoveryConfigurationByName("person"),
+                query, filters,
+                "Item", 10, Long.getLong("0"), null, SortOption.DESCENDING);
+            return searchService.iteratorSearch(context, null, discoverQuery);
+        } catch (SearchServiceException e) {
+            LOGGER.error("Unable to read researcher on solr", e);
         }
-        LOGGER.info("Found " + items.size() + " researcher(s)");
-        return items;
+        return null;
     }
 }

dspace-api/src/main/java/org/dspace/app/suggestion/openaire/PublicationLoaderRunnableCli.java

@@ -5,19 +5,19 @@
  *
  * http://www.dspace.org/license/
  */
-package org.dspace.app.suggestion;
+package org.dspace.app.suggestion.openaire;
 
 import org.apache.commons.cli.HelpFormatter;
 import org.apache.commons.cli.ParseException;
 import org.dspace.utils.DSpace;
 
-public class OAIREPublicationLoaderRunnableCli extends OAIREPublicationLoaderRunnable {
+public class PublicationLoaderRunnableCli extends PublicationLoaderRunnable {
 
     @Override
     @SuppressWarnings({ "rawtypes", "unchecked" })
-    public OAIREPublicationLoaderCliScriptConfiguration getScriptConfiguration() {
-        OAIREPublicationLoaderCliScriptConfiguration configuration = new DSpace().getServiceManager()
-                .getServiceByName("import-oaire-suggestions", OAIREPublicationLoaderCliScriptConfiguration.class);
+    public PublicationLoaderCliScriptConfiguration getScriptConfiguration() {
+        PublicationLoaderCliScriptConfiguration configuration = new DSpace().getServiceManager()
+                .getServiceByName("import-openaire-suggestions", PublicationLoaderCliScriptConfiguration.class);
         return configuration;
     }
 
@@ -28,7 +28,7 @@ public class OAIREPublicationLoaderRunnableCli extends OAIREPublicationLoaderRun
         // in case of CLI we show the help prompt
         if (commandLine.hasOption('h')) {
             HelpFormatter formatter = new HelpFormatter();
-            formatter.printHelp("Import Readearchers Suggestions", getScriptConfiguration().getOptions());
+            formatter.printHelp("Import Researchers Suggestions", getScriptConfiguration().getOptions());
             System.exit(0);
         }
     }

dspace-api/src/main/java/org/dspace/app/suggestion/openaire/PublicationLoaderScriptConfiguration.java

@@ -5,12 +5,12 @@
  *
  * http://www.dspace.org/license/
  */
-package org.dspace.app.suggestion;
+package org.dspace.app.suggestion.openaire;
 
 import org.apache.commons.cli.Options;
 import org.dspace.scripts.configuration.ScriptConfiguration;
 
-public class OAIREPublicationLoaderScriptConfiguration<T extends OAIREPublicationLoaderRunnable>
+public class PublicationLoaderScriptConfiguration<T extends PublicationLoaderRunnable>
     extends ScriptConfiguration<T> {
 
     private Class<T> dspaceRunnableClass;
@@ -22,7 +22,7 @@ public class OAIREPublicationLoaderScriptConfiguration<T extends OAIREPublicatio
 
     /**
      * Generic setter for the dspaceRunnableClass
-     * @param dspaceRunnableClass   The dspaceRunnableClass to be set on this OAIREPublicationLoaderScriptConfiguration
+     * @param dspaceRunnableClass   The dspaceRunnableClass to be set on this PublicationLoaderScriptConfiguration
      */
     @Override
     public void setDspaceRunnableClass(Class<T> dspaceRunnableClass) {

dspace-api/src/main/java/org/dspace/app/util/AuthorizeUtil.java

@@ -628,12 +628,23 @@ public class AuthorizeUtil {
             // actually expected to be returning true.
             // For example the LDAP canSelfRegister will return true due to auto-register, while that
             // does not imply a new user can register explicitly
-            return AuthenticateServiceFactory.getInstance().getAuthenticationService()
-                                             .allowSetPassword(context, request, null);
+            return authorizePasswordChange(context, request);
         }
         return false;
     }
 
+    /**
+     * This method will return a boolean indicating whether the current user is allowed to reset the password
+     * or not
+     *
+     * @return          A boolean indicating whether the current user can reset its password or not
+     * @throws SQLException If something goes wrong
+     */
+    public static boolean authorizeForgotPassword() {
+        return DSpaceServicesFactory.getInstance().getConfigurationService()
+                             .getBooleanProperty("user.forgot-password", true);
+    }
+
     /**
      * This method will return a boolean indicating whether it's allowed to update the password for the EPerson
      * with the given email and canLogin property
@@ -647,8 +658,7 @@ public class AuthorizeUtil {
             if (eperson != null && eperson.canLogIn()) {
                 HttpServletRequest request = new DSpace().getRequestService().getCurrentRequest()
                                                          .getHttpServletRequest();
-                return AuthenticateServiceFactory.getInstance().getAuthenticationService()
-                                                 .allowSetPassword(context, request, null);
+                return authorizePasswordChange(context, request);
             }
         } catch (SQLException e) {
             log.error("Something went wrong trying to retrieve EPerson for email: " + email, e);
@@ -656,6 +666,19 @@ public class AuthorizeUtil {
         return false;
     }
 
+    /**
+     * Checks if the current configuration has at least one password based authentication method
+     *
+     * @param context Dspace Context
+     * @param request Current Request
+     * @return True if the password change is enabled
+     * @throws SQLException
+     */
+    protected static boolean authorizePasswordChange(Context context, HttpServletRequest request) throws SQLException {
+        return AuthenticateServiceFactory.getInstance().getAuthenticationService()
+                                         .allowSetPassword(context, request, null);
+    }
+
     /**
      * This method checks if the community Admin can manage accounts
      *

dspace-api/src/main/java/org/dspace/app/util/DCInputsReader.java

@@ -14,7 +14,6 @@ import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
-import javax.servlet.ServletException;
 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.DocumentBuilderFactory;
 import javax.xml.parsers.FactoryConfigurationError;
@@ -150,17 +149,16 @@ public class DCInputsReader {
      * Returns the set of DC inputs used for a particular collection, or the
      * default set if no inputs defined for the collection
      *
-     * @param collectionHandle collection's unique Handle
+     * @param collection collection for which search the set of DC inputs
      * @return DC input set
      * @throws DCInputsReaderException if no default set defined
-     * @throws ServletException
      */
-    public List<DCInputSet> getInputsByCollectionHandle(String collectionHandle)
+    public List<DCInputSet> getInputsByCollection(Collection collection)
         throws DCInputsReaderException {
         SubmissionConfig config;
         try {
             config = SubmissionServiceFactory.getInstance().getSubmissionConfigService()
-                        .getSubmissionConfigByCollection(collectionHandle);
+                        .getSubmissionConfigByCollection(collection);
             String formName = config.getSubmissionName();
             if (formName == null) {
                 throw new DCInputsReaderException("No form designated as default");
@@ -691,7 +689,7 @@ public class DCInputsReader {
 
     public String getInputFormNameByCollectionAndField(Collection collection, String field)
         throws DCInputsReaderException {
-        List<DCInputSet> inputSets = getInputsByCollectionHandle(collection.getHandle());
+        List<DCInputSet> inputSets = getInputsByCollection(collection);
         for (DCInputSet inputSet : inputSets) {
             String[] tokenized = Utils.tokenize(field);
             String schema = tokenized[0];

dspace-api/src/main/java/org/dspace/app/util/SubmissionConfigReader.java

@@ -11,6 +11,7 @@ import java.io.File;
 import java.sql.SQLException;
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
@@ -21,6 +22,7 @@ import javax.xml.parsers.FactoryConfigurationError;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.logging.log4j.Logger;
 import org.dspace.content.Collection;
+import org.dspace.content.Community;
 import org.dspace.content.DSpaceObject;
 import org.dspace.content.factory.ContentServiceFactory;
 import org.dspace.content.service.CollectionService;
@@ -90,6 +92,13 @@ public class SubmissionConfigReader {
      */
     private Map<String, String> collectionToSubmissionConfig = null;
 
+    /**
+     * Hashmap which stores which submission process configuration is used by
+     * which community, computed from the item submission config file
+     * (specifically, the 'submission-map' tag)
+     */
+    private Map<String, String> communityToSubmissionConfig = null;
+
     /**
      * Reference to the global submission step definitions defined in the
      * "step-definitions" section
@@ -127,6 +136,7 @@ public class SubmissionConfigReader {
 
     public void reload() throws SubmissionConfigReaderException {
         collectionToSubmissionConfig = null;
+        communityToSubmissionConfig = null;
         stepDefns = null;
         submitDefns = null;
         buildInputs(configDir + SUBMIT_DEF_FILE_PREFIX + SUBMIT_DEF_FILE_SUFFIX);
@@ -145,7 +155,8 @@ public class SubmissionConfigReader {
      */
     private void buildInputs(String fileName) throws SubmissionConfigReaderException {
         collectionToSubmissionConfig = new HashMap<String, String>();
-        submitDefns = new HashMap<String, List<Map<String, String>>>();
+        communityToSubmissionConfig = new HashMap<String, String>();
+        submitDefns = new LinkedHashMap<String, List<Map<String, String>>>();
 
         String uri = "file:" + new File(fileName).getAbsolutePath();
 
@@ -210,18 +221,41 @@ public class SubmissionConfigReader {
      * Returns the Item Submission process config used for a particular
      * collection, or the default if none is defined for the collection
      *
-     * @param collectionHandle collection's unique Handle
+     * @param col collection for which search Submission process config
      * @return the SubmissionConfig representing the item submission config
-     * @throws SubmissionConfigReaderException if no default submission process configuration defined
+     * @throws IllegalStateException if no default submission process configuration defined
      */
-    public SubmissionConfig getSubmissionConfigByCollection(String collectionHandle) {
-        // get the name of the submission process config for this collection
-        String submitName = collectionToSubmissionConfig
-            .get(collectionHandle);
-        if (submitName == null) {
+    public SubmissionConfig getSubmissionConfigByCollection(Collection col) {
+
+        String submitName;
+
+        if (col != null) {
+
+            // get the name of the submission process config for this collection
             submitName = collectionToSubmissionConfig
-                .get(DEFAULT_COLLECTION);
+                .get(col.getHandle());
+            if (submitName != null) {
+                return getSubmissionConfigByName(submitName);
+            }
+
+            if (!communityToSubmissionConfig.isEmpty()) {
+                try {
+                    List<Community> communities = col.getCommunities();
+                    for (Community com : communities) {
+                        submitName = getSubmissionConfigByCommunity(com);
+                        if (submitName != null) {
+                            return getSubmissionConfigByName(submitName);
+                        }
+                    }
+                } catch (SQLException sqle) {
+                    throw new IllegalStateException("Error occurred while getting item submission configured " +
+                                                    "by community", sqle);
+                }
+            }
         }
+
+        submitName = collectionToSubmissionConfig.get(DEFAULT_COLLECTION);
+
         if (submitName == null) {
             throw new IllegalStateException(
                 "No item submission process configuration designated as 'default' in 'submission-map' section of " +
@@ -230,6 +264,30 @@ public class SubmissionConfigReader {
         return getSubmissionConfigByName(submitName);
     }
 
+    /**
+     * Recursive function to return the Item Submission process config
+     * used for a community or the closest community parent, or null
+     * if none is defined
+     *
+     * @param com community for which search Submission process config
+     * @return the SubmissionConfig representing the item submission config
+     */
+    private String getSubmissionConfigByCommunity(Community com) {
+        String submitName = communityToSubmissionConfig
+                .get(com.getHandle());
+        if (submitName != null) {
+            return submitName;
+        }
+        List<Community> communities = com.getParentCommunities();
+        for (Community parentCom : communities) {
+            submitName = getSubmissionConfigByCommunity(parentCom);
+            if (submitName != null) {
+                return submitName;
+            }
+        }
+        return null;
+    }
+
     /**
      * Returns the Item Submission process config
      *
@@ -357,13 +415,14 @@ public class SubmissionConfigReader {
             Node nd = nl.item(i);
             if (nd.getNodeName().equals("name-map")) {
                 String id = getAttribute(nd, "collection-handle");
+                String communityId = getAttribute(nd, "community-handle");
                 String entityType = getAttribute(nd, "collection-entity-type");
                 String value = getAttribute(nd, "submission-name");
                 String content = getValue(nd);
-                if (id == null && entityType == null) {
+                if (id == null && communityId == null && entityType == null) {
                     throw new SAXException(
-                        "name-map element is missing collection-handle or collection-entity-type attribute " +
-                            "in 'item-submission.xml'");
+                        "name-map element is missing collection-handle or community-handle or collection-entity-type " +
+                            "attribute in 'item-submission.xml'");
                 }
                 if (value == null) {
                     throw new SAXException(
@@ -375,7 +434,8 @@ public class SubmissionConfigReader {
                 }
                 if (id != null) {
                     collectionToSubmissionConfig.put(id, value);
-
+                } else if (communityId != null) {
+                    communityToSubmissionConfig.put(communityId, value);
                 } else {
                     // get all collections for this entity-type
                     List<Collection> collections = collectionService.findAllCollectionsByEntityType( context,

dspace-api/src/main/java/org/dspace/app/util/Util.java

@@ -405,21 +405,13 @@ public class Util {
         DCInput myInputs = null;
         boolean myInputsFound = false;
         String formFileName = I18nUtil.getInputFormsFileName(locale);
-        String col_handle = "";
 
         Collection collection = item.getOwningCollection();
 
-        if (collection == null) {
-            // set an empty handle so to get the default input set
-            col_handle = "";
-        } else {
-            col_handle = collection.getHandle();
-        }
-
         // Read the input form file for the specific collection
         DCInputsReader inputsReader = new DCInputsReader(formFileName);
 
-        List<DCInputSet> inputSets = inputsReader.getInputsByCollectionHandle(col_handle);
+        List<DCInputSet> inputSets = inputsReader.getInputsByCollection(collection);
 
         // Replace the values of Metadatum[] with the correct ones in case
         // of
@@ -500,8 +492,8 @@ public class Util {
     public static List<String> differenceInSubmissionFields(Collection fromCollection, Collection toCollection)
         throws DCInputsReaderException {
         DCInputsReader reader = new DCInputsReader();
-        List<DCInputSet> from = reader.getInputsByCollectionHandle(fromCollection.getHandle());
-        List<DCInputSet> to = reader.getInputsByCollectionHandle(toCollection.getHandle());
+        List<DCInputSet> from = reader.getInputsByCollection(fromCollection);
+        List<DCInputSet> to = reader.getInputsByCollection(toCollection);
 
         Set<String> fromFieldName = new HashSet<>();
         Set<String> toFieldName = new HashSet<>();

dspace-api/src/main/java/org/dspace/authority/indexer/DSpaceAuthorityIndexer.java

@@ -80,7 +80,15 @@ public class DSpaceAuthorityIndexer implements AuthorityIndexerInterface, Initia
             throws SQLException, AuthorizeException {
         List<AuthorityValue> values = new ArrayList<>();
         for (String metadataField : metadataFields) {
-            List<MetadataValue> metadataValues = itemService.getMetadataByMetadataString(item, metadataField);
+
+            String[] fieldParts = metadataField.split("\\.");
+            String schema = (fieldParts.length > 0 ? fieldParts[0] : null);
+            String element = (fieldParts.length > 1 ? fieldParts[1] : null);
+            String qualifier = (fieldParts.length > 2 ? fieldParts[2] : null);
+
+            // Get metadata values without virtual metadata
+            List<MetadataValue> metadataValues = itemService.getMetadata(item, schema, element, qualifier, Item.ANY,
+                false);
             for (MetadataValue metadataValue : metadataValues) {
                 String content = metadataValue.getValue();
                 String authorityKey = metadataValue.getAuthority();

dspace-api/src/main/java/org/dspace/authorize/AuthorizeServiceImpl.java

@@ -895,7 +895,7 @@ public class AuthorizeServiceImpl implements AuthorizeService {
                 return true;
             }
         } catch (SearchServiceException e) {
-            log.error("Failed getting getting community/collection admin status for "
+            log.error("Failed getting community/collection admin status for "
                 + context.getCurrentUser().getEmail() + " The search error is: " + e.getMessage()
                 + " The search resourceType filter was: " + query);
         }

dspace-api/src/main/java/org/dspace/coarnotify/NotifyConfigurationService.java

@@ -15,19 +15,19 @@ import java.util.Map;
  *
  * @author Mohamed Eskander (mohamed.eskander at 4science.com)
  */
-public class COARNotifyConfigurationService {
+public class NotifyConfigurationService {
 
     /**
      * Mapping the submission step process identifier with the configuration
      * (see configuration at coar-notify.xml)
      */
-    private Map<String, List<LDNPattern>> patterns;
+    private Map<String, List<NotifyPattern>> patterns;
 
-    public Map<String, List<LDNPattern>> getPatterns() {
+    public Map<String, List<NotifyPattern>> getPatterns() {
         return patterns;
     }
 
-    public void setPatterns(Map<String, List<LDNPattern>> patterns) {
+    public void setPatterns(Map<String, List<NotifyPattern>> patterns) {
         this.patterns = patterns;
     }
 

dspace-api/src/main/java/org/dspace/coarnotify/NotifyPattern.java

@@ -12,16 +12,16 @@ package org.dspace.coarnotify;
  *
  * @author Mohamed Eskander (mohamed.eskander at 4science.com)
  */
-public class LDNPattern {
+public class NotifyPattern {
 
     private String pattern;
     private boolean multipleRequest;
 
-    public LDNPattern() {
+    public NotifyPattern() {
 
     }
 
-    public LDNPattern(String pattern, boolean multipleRequest) {
+    public NotifyPattern(String pattern, boolean multipleRequest) {
         this.pattern = pattern;
         this.multipleRequest = multipleRequest;
     }

dspace-api/src/main/java/org/dspace/coarnotify/NotifySubmissionConfiguration.java

@@ -14,7 +14,7 @@ import java.util.List;
  *
  * @author Mohamed Eskander (mohamed.eskander at 4science.com)
  */
-public class COARNotifySubmissionConfiguration {
+public class NotifySubmissionConfiguration {
 
     /**
      * the map key of configured bean of COARNotifyConfigurationService
@@ -26,13 +26,13 @@ public class COARNotifySubmissionConfiguration {
      * the map values of configured bean of COARNotifyConfigurationService
      * in coar-notify.xml
      */
-    private List<LDNPattern> patterns;
+    private List<NotifyPattern> patterns;
 
-    public COARNotifySubmissionConfiguration() {
+    public NotifySubmissionConfiguration() {
 
     }
 
-    public COARNotifySubmissionConfiguration(String id, List<LDNPattern> patterns) {
+    public NotifySubmissionConfiguration(String id, List<NotifyPattern> patterns) {
         super();
         this.id = id;
         this.patterns = patterns;
@@ -51,7 +51,7 @@ public class COARNotifySubmissionConfiguration {
      *
      * @return the list of configured COAR Notify Patterns
      */
-    public List<LDNPattern> getPatterns() {
+    public List<NotifyPattern> getPatterns() {
         return patterns;
     }
 
@@ -59,7 +59,7 @@ public class COARNotifySubmissionConfiguration {
      * Sets the list of configured COAR Notify Patterns
      * @param patterns
      */
-    public void setPatterns(final List<LDNPattern> patterns) {
+    public void setPatterns(final List<NotifyPattern> patterns) {
         this.patterns = patterns;
     }
 }

dspace-api/src/main/java/org/dspace/coarnotify/SubmissionNotifyServiceImpl.java

@@ -10,41 +10,41 @@ package org.dspace.coarnotify;
 import java.util.ArrayList;
 import java.util.List;
 
-import org.dspace.coarnotify.service.SubmissionCOARNotifyService;
+import org.dspace.coarnotify.service.SubmissionNotifyService;
 import org.springframework.beans.factory.annotation.Autowired;
 
 /**
- * Service implementation of {@link SubmissionCOARNotifyService}
+ * Service implementation of {@link SubmissionNotifyService}
  *
  * @author Mohamed Eskander (mohamed.eskander at 4science.com)
  */
-public class SubmissionCOARNotifyServiceImpl implements SubmissionCOARNotifyService {
+public class SubmissionNotifyServiceImpl implements SubmissionNotifyService {
 
     @Autowired(required = true)
-    private COARNotifyConfigurationService coarNotifyConfigurationService;
+    private NotifyConfigurationService coarNotifyConfigurationService;
 
-    protected SubmissionCOARNotifyServiceImpl() {
+    protected SubmissionNotifyServiceImpl() {
 
     }
 
     @Override
-    public COARNotifySubmissionConfiguration findOne(String id) {
-        List<LDNPattern> patterns =
+    public NotifySubmissionConfiguration findOne(String id) {
+        List<NotifyPattern> patterns =
             coarNotifyConfigurationService.getPatterns().get(id);
 
         if (patterns == null) {
             return null;
         }
 
-        return new COARNotifySubmissionConfiguration(id, patterns);
+        return new NotifySubmissionConfiguration(id, patterns);
     }
 
     @Override
-    public List<COARNotifySubmissionConfiguration> findAll() {
-        List<COARNotifySubmissionConfiguration> coarNotifies = new ArrayList<>();
+    public List<NotifySubmissionConfiguration> findAll() {
+        List<NotifySubmissionConfiguration> coarNotifies = new ArrayList<>();
 
         coarNotifyConfigurationService.getPatterns().forEach((id, patterns) ->
-            coarNotifies.add(new COARNotifySubmissionConfiguration(id, patterns)
+            coarNotifies.add(new NotifySubmissionConfiguration(id, patterns)
             ));
 
         return coarNotifies;

dspace-api/src/main/java/org/dspace/coarnotify/service/SubmissionNotifyService.java

@@ -9,7 +9,7 @@ package org.dspace.coarnotify.service;
 
 import java.util.List;
 
-import org.dspace.coarnotify.COARNotifySubmissionConfiguration;
+import org.dspace.coarnotify.NotifySubmissionConfiguration;
 
 /**
  * Service interface class for the Creative Submission COAR Notify.
@@ -18,7 +18,7 @@ import org.dspace.coarnotify.COARNotifySubmissionConfiguration;
  *
  * @author Mohamed Eskander (mohamed.eskander at 4science.com)
  */
-public interface SubmissionCOARNotifyService {
+public interface SubmissionNotifyService {
 
     /**
      * Find the COARE Notify corresponding to the provided ID
@@ -27,13 +27,13 @@ public interface SubmissionCOARNotifyService {
      * @param id - the ID of the COAR Notify to be found
      * @return the corresponding COAR Notify if found or null when not found
      */
-    public COARNotifySubmissionConfiguration findOne(String id);
+    public NotifySubmissionConfiguration findOne(String id);
 
     /**
      * Find all configured COAR Notifies
      *
      * @return all configured COAR Notifies
      */
-    public List<COARNotifySubmissionConfiguration> findAll();
+    public List<NotifySubmissionConfiguration> findAll();
 
 }

dspace-api/src/main/java/org/dspace/content/Bitstream.java

@@ -307,10 +307,18 @@ public class Bitstream extends DSpaceObject implements DSpaceObjectLegacySupport
         return collection;
     }
 
+    public void setCollection(Collection collection) {
+        this.collection = collection;
+    }
+
     public Community getCommunity() {
         return community;
     }
 
+    public void setCommunity(Community community) {
+        this.community = community;
+    }
+
     /**
      * Get the asset store number where this bitstream is stored
      *

dspace-api/src/main/java/org/dspace/content/BitstreamServiceImpl.java

@@ -458,10 +458,15 @@ public class BitstreamServiceImpl extends DSpaceObjectServiceImpl<Bitstream> imp
 
     @Override
     public Bitstream findByIdOrLegacyId(Context context, String id) throws SQLException {
-        if (StringUtils.isNumeric(id)) {
-            return findByLegacyId(context, Integer.parseInt(id));
-        } else {
-            return find(context, UUID.fromString(id));
+        try {
+            if (StringUtils.isNumeric(id)) {
+                return findByLegacyId(context, Integer.parseInt(id));
+            } else {
+                return find(context, UUID.fromString(id));
+            }
+        } catch (IllegalArgumentException e) {
+            // Not a valid legacy ID or valid UUID
+            return null;
         }
     }
 

dspace-api/src/main/java/org/dspace/content/BundleServiceImpl.java

@@ -562,10 +562,15 @@ public class BundleServiceImpl extends DSpaceObjectServiceImpl<Bundle> implement
 
     @Override
     public Bundle findByIdOrLegacyId(Context context, String id) throws SQLException {
-        if (StringUtils.isNumeric(id)) {
-            return findByLegacyId(context, Integer.parseInt(id));
-        } else {
-            return find(context, UUID.fromString(id));
+        try {
+            if (StringUtils.isNumeric(id)) {
+                return findByLegacyId(context, Integer.parseInt(id));
+            } else {
+                return find(context, UUID.fromString(id));
+            }
+        } catch (IllegalArgumentException e) {
+            // Not a valid legacy ID or valid UUID
+            return null;
         }
     }
 

dspace-api/src/main/java/org/dspace/content/Collection.java

@@ -135,6 +135,9 @@ public class Collection extends DSpaceObject implements DSpaceObjectLegacySuppor
 
     protected void setLogo(Bitstream logo) {
         this.logo = logo;
+        if (logo != null) {
+            logo.setCollection(this);
+        }
         setModified();
     }
 

dspace-api/src/main/java/org/dspace/content/CollectionServiceImpl.java

@@ -895,10 +895,15 @@ public class CollectionServiceImpl extends DSpaceObjectServiceImpl<Collection> i
 
     @Override
     public Collection findByIdOrLegacyId(Context context, String id) throws SQLException {
-        if (StringUtils.isNumeric(id)) {
-            return findByLegacyId(context, Integer.parseInt(id));
-        } else {
-            return find(context, UUID.fromString(id));
+        try {
+            if (StringUtils.isNumeric(id)) {
+                return findByLegacyId(context, Integer.parseInt(id));
+            } else {
+                return find(context, UUID.fromString(id));
+            }
+        } catch (IllegalArgumentException e) {
+            // Not a valid legacy ID or valid UUID
+            return null;
         }
     }
 

dspace-api/src/main/java/org/dspace/content/Community.java

@@ -123,6 +123,9 @@ public class Community extends DSpaceObject implements DSpaceObjectLegacySupport
 
     void setLogo(Bitstream logo) {
         this.logo = logo;
+        if (logo != null) {
+            logo.setCommunity(this);
+        }
         setModified();
     }
 

dspace-api/src/main/java/org/dspace/content/CommunityServiceImpl.java

@@ -694,10 +694,15 @@ public class CommunityServiceImpl extends DSpaceObjectServiceImpl<Community> imp
 
     @Override
     public Community findByIdOrLegacyId(Context context, String id) throws SQLException {
-        if (StringUtils.isNumeric(id)) {
-            return findByLegacyId(context, Integer.parseInt(id));
-        } else {
-            return find(context, UUID.fromString(id));
+        try {
+            if (StringUtils.isNumeric(id)) {
+                return findByLegacyId(context, Integer.parseInt(id));
+            } else {
+                return find(context, UUID.fromString(id));
+            }
+        } catch (IllegalArgumentException e) {
+            // Not a valid legacy ID or valid UUID
+            return null;
         }
     }
 

dspace-api/src/main/java/org/dspace/content/InstallItemServiceImpl.java

@@ -150,7 +150,6 @@ public class InstallItemServiceImpl implements InstallItemService {
         return finishItem(c, item, is);
     }
 
-
     protected void populateMetadata(Context c, Item item)
         throws SQLException, AuthorizeException {
         // create accession date
@@ -158,15 +157,6 @@ public class InstallItemServiceImpl implements InstallItemService {
         itemService.addMetadata(c, item, MetadataSchemaEnum.DC.getName(),
                                 "date", "accessioned", null, now.toString());
 
-        // add date available if not under embargo, otherwise it will
-        // be set when the embargo is lifted.
-        // this will flush out fatal embargo metadata
-        // problems before we set inArchive.
-        if (embargoService.getEmbargoTermsAsDate(c, item) == null) {
-            itemService.addMetadata(c, item, MetadataSchemaEnum.DC.getName(),
-                                    "date", "available", null, now.toString());
-        }
-
         // If issue date is set as "today" (literal string), then set it to current date
         // In the below loop, we temporarily clear all issued dates and re-add, one-by-one,
         // replacing "today" with today's date.

dspace-api/src/main/java/org/dspace/content/ItemFilterServiceImpl.java

@@ -8,6 +8,7 @@
 package org.dspace.content;
 
 import java.util.List;
+import java.util.Map;
 import java.util.stream.Collectors;
 
 import org.dspace.app.ldn.ItemFilter;
@@ -37,12 +38,21 @@ public class ItemFilterServiceImpl implements ItemFilterService {
 
     @Override
     public List<ItemFilter> findAll() {
-        return serviceManager.getServicesWithNamesByType(LogicalStatement.class)
-                             .keySet()
-                             .stream()
-                             .sorted()
-                             .map(ItemFilter::new)
-                             .collect(Collectors.toList());
+        Map<String, LogicalStatement> ldnFilters =
+            serviceManager.getServiceByName("ldnItemFilters", Map.class);
+        return ldnFilters.keySet()
+            .stream()
+            .sorted()
+            .map(ItemFilter::new)
+            .collect(Collectors.toList());
+    }
+
+    public ServiceManager getServiceManager() {
+        return serviceManager;
+    }
+
+    public void setServiceManager(ServiceManager serviceManager) {
+        this.serviceManager = serviceManager;
     }
 
 }

dspace-api/src/main/java/org/dspace/content/ItemServiceImpl.java

@@ -49,6 +49,7 @@ import org.dspace.content.service.MetadataSchemaService;
 import org.dspace.content.service.RelationshipService;
 import org.dspace.content.service.WorkspaceItemService;
 import org.dspace.content.virtual.VirtualMetadataPopulator;
+import org.dspace.contentreport.QueryPredicate;
 import org.dspace.core.Constants;
 import org.dspace.core.Context;
 import org.dspace.core.LogHelper;
@@ -175,7 +176,6 @@ public class ItemServiceImpl extends DSpaceObjectServiceImpl<Item> implements It
     private QAEventsDAO qaEventsDao;
 
     protected ItemServiceImpl() {
-        super();
     }
 
     @Override
@@ -275,9 +275,8 @@ public class ItemServiceImpl extends DSpaceObjectServiceImpl<Item> implements It
                                               + template.getID()));
 
             return template;
-        } else {
-            return collection.getTemplateItem();
         }
+        return collection.getTemplateItem();
     }
 
     @Override
@@ -1190,9 +1189,8 @@ public class ItemServiceImpl extends DSpaceObjectServiceImpl<Item> implements It
         if (item.getOwningCollection() == null) {
             if (!isInProgressSubmission(context, item)) {
                 return true;
-            } else {
-                return false;
             }
+            return false;
         }
 
         return collectionService.canEditBoolean(context, item.getOwningCollection(), false);
@@ -1284,8 +1282,8 @@ prevent the generation of resource policy entry values with null dspace_object a
             if (!authorizeService
                 .isAnIdenticalPolicyAlreadyInPlace(context, dso, defaultPolicy.getGroup(), Constants.READ,
                     defaultPolicy.getID()) &&
-                   (!appendMode && this.isNotAlreadyACustomRPOfThisTypeOnDSO(context, dso) ||
-                    appendMode && this.shouldBeAppended(context, dso, defaultPolicy))) {
+                   (!appendMode && isNotAlreadyACustomRPOfThisTypeOnDSO(context, dso) ||
+                    appendMode && shouldBeAppended(context, dso, defaultPolicy))) {
                 ResourcePolicy newPolicy = resourcePolicyService.clone(context, defaultPolicy);
                 newPolicy.setdSpaceObject(dso);
                 newPolicy.setAction(Constants.READ);
@@ -1384,9 +1382,8 @@ prevent the generation of resource policy entry values with null dspace_object a
 
         if (Item.ANY.equals(value)) {
             return itemDAO.findByMetadataField(context, mdf, null, true);
-        } else {
-            return itemDAO.findByMetadataField(context, mdf, value, true);
         }
+        return itemDAO.findByMetadataField(context, mdf, value, true);
     }
 
     @Override
@@ -1430,19 +1427,24 @@ prevent the generation of resource policy entry values with null dspace_object a
 
         if (Item.ANY.equals(value)) {
             return itemDAO.findByMetadataField(context, mdf, null, true);
-        } else {
-            return itemDAO.findByMetadataField(context, mdf, value, true);
         }
+        return itemDAO.findByMetadataField(context, mdf, value, true);
     }
 
     @Override
-    public Iterator<Item> findByMetadataQuery(Context context, List<List<MetadataField>> listFieldList,
-                                              List<String> query_op, List<String> query_val, List<UUID> collectionUuids,
-                                              String regexClause, int offset, int limit)
-        throws SQLException, AuthorizeException, IOException {
-        return itemDAO
-            .findByMetadataQuery(context, listFieldList, query_op, query_val, collectionUuids, regexClause, offset,
-                                 limit);
+    public List<Item> findByMetadataQuery(Context context, List<QueryPredicate> queryPredicates,
+            List<UUID> collectionUuids, long offset, int limit)
+            throws SQLException {
+        return itemDAO.findByMetadataQuery(context, queryPredicates, collectionUuids, "text_value ~ ?",
+                offset, limit);
+    }
+
+
+    @Override
+    public long countForMetadataQuery(Context context, List<QueryPredicate> queryPredicates,
+            List<UUID> collectionUuids)
+            throws SQLException {
+        return itemDAO.countForMetadataQuery(context, queryPredicates, collectionUuids, "text_value ~ ?");
     }
 
     @Override
@@ -1508,20 +1510,19 @@ prevent the generation of resource policy entry values with null dspace_object a
         Collection ownCollection = item.getOwningCollection();
         if (ownCollection != null) {
             return ownCollection;
-        } else {
-            InProgressSubmission inprogress = ContentServiceFactory.getInstance().getWorkspaceItemService()
-                                                                   .findByItem(context,
-                                                                               item);
-            if (inprogress == null) {
-                inprogress = WorkflowServiceFactory.getInstance().getWorkflowItemService().findByItem(context, item);
-            }
-
-            if (inprogress != null) {
-                return inprogress.getCollection();
-            }
-            // is a template item?
-            return item.getTemplateItemOf();
         }
+        InProgressSubmission inprogress = ContentServiceFactory.getInstance().getWorkspaceItemService()
+                                                               .findByItem(context,
+                                                                           item);
+        if (inprogress == null) {
+            inprogress = WorkflowServiceFactory.getInstance().getWorkflowItemService().findByItem(context, item);
+        }
+
+        if (inprogress != null) {
+            return inprogress.getCollection();
+        }
+        // is a template item?
+        return item.getTemplateItemOf();
     }
 
     @Override
@@ -1618,10 +1619,14 @@ prevent the generation of resource policy entry values with null dspace_object a
 
     @Override
     public Item findByIdOrLegacyId(Context context, String id) throws SQLException {
-        if (StringUtils.isNumeric(id)) {
-            return findByLegacyId(context, Integer.parseInt(id));
-        } else {
+        try {
+            if (StringUtils.isNumeric(id)) {
+                return findByLegacyId(context, Integer.parseInt(id));
+            }
             return find(context, UUID.fromString(id));
+        } catch (IllegalArgumentException e) {
+            // Not a valid legacy ID or valid UUID
+            return null;
         }
     }
 

dspace-api/src/main/java/org/dspace/content/QAEvent.java

@@ -13,6 +13,7 @@ import java.security.NoSuchAlgorithmException;
 import java.util.Date;
 
 import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import org.dspace.qaevent.service.dto.CorrectionTypeMessageDTO;
 import org.dspace.qaevent.service.dto.NotifyMessageDTO;
 import org.dspace.qaevent.service.dto.OpenaireMessageDTO;
 import org.dspace.qaevent.service.dto.QAMessageDTO;
@@ -32,6 +33,7 @@ public class QAEvent {
     public static final String DISCARDED = "discarded";
 
     public static final String OPENAIRE_SOURCE = "openaire";
+    public static final String DSPACE_USERS_SOURCE = "DSpaceUsers";
     public static final String COAR_NOTIFY_SOURCE = "coar-notify";
 
     private String source;
@@ -65,8 +67,7 @@ public class QAEvent {
 
     private String status = "PENDING";
 
-    public QAEvent() {
-    }
+    public QAEvent() {}
 
     public QAEvent(String source, String originalId, String target, String title,
         String topic, double trust, String message, Date lastUpdate) {
@@ -84,7 +85,6 @@ public class QAEvent {
         } catch (NoSuchAlgorithmException | UnsupportedEncodingException e) {
             throw new IllegalStateException(e);
         }
-
     }
 
     public String getOriginalId() {
@@ -205,18 +205,16 @@ public class QAEvent {
     }
 
     public Class<? extends QAMessageDTO> getMessageDtoClass() {
-        Class<? extends QAMessageDTO> result = null;
         switch (getSource()) {
             case OPENAIRE_SOURCE:
-                result = OpenaireMessageDTO.class;
-                break;
+                return OpenaireMessageDTO.class;
             case COAR_NOTIFY_SOURCE:
-                result = NotifyMessageDTO.class;
-                break;
+                return NotifyMessageDTO.class;
+            case DSPACE_USERS_SOURCE:
+                return CorrectionTypeMessageDTO.class;
             default:
                 throw new IllegalArgumentException("Unknown event's source: " + getSource());
         }
-        return result;
     }
 
 }

dspace-api/src/main/java/org/dspace/content/authority/ChoiceAuthorityServiceImpl.java

@@ -242,7 +242,7 @@ public final class ChoiceAuthorityServiceImpl implements ChoiceAuthorityService
             // check if it is the requested collection
             Map<String, ChoiceAuthority> controllerFormDef = controllerFormDefinitions.get(fieldKey);
             SubmissionConfig submissionConfig = submissionConfigService
-                    .getSubmissionConfigByCollection(collection.getHandle());
+                    .getSubmissionConfigByCollection(collection);
             String submissionName = submissionConfig.getSubmissionName();
             // check if the requested collection has a submission definition that use an authority for the metadata
             if (controllerFormDef.containsKey(submissionName)) {
@@ -495,7 +495,7 @@ public final class ChoiceAuthorityServiceImpl implements ChoiceAuthorityService
             try {
                 configReaderService = SubmissionServiceFactory.getInstance().getSubmissionConfigService();
                 SubmissionConfig submissionName = configReaderService
-                        .getSubmissionConfigByCollection(collection.getHandle());
+                        .getSubmissionConfigByCollection(collection);
                 ma = controllerFormDefinitions.get(fieldKey).get(submissionName.getSubmissionName());
             } catch (SubmissionConfigReaderException e) {
                 // the system is in an illegal state as the submission definition is not valid

dspace-api/src/main/java/org/dspace/content/authority/DCInputAuthority.java

@@ -156,7 +156,8 @@ public class DCInputAuthority extends SelfNamedPlugin implements ChoiceAuthority
         int found = 0;
         List<Choice> v = new ArrayList<Choice>();
         for (int i = 0; i < valuesLocale.length; ++i) {
-            if (query == null || StringUtils.containsIgnoreCase(valuesLocale[i], query)) {
+            // In a DCInputAuthority context, a user will want to query the labels, not the values
+            if (query == null || StringUtils.containsIgnoreCase(labelsLocale[i], query)) {
                 if (found >= start && v.size() < limit) {
                     v.add(new Choice(null, valuesLocale[i], labelsLocale[i]));
                     if (valuesLocale[i].equalsIgnoreCase(query)) {

dspace-api/src/main/java/org/dspace/content/authority/SHERPARoMEOJournalTitle.java

@@ -59,7 +59,37 @@ public class SHERPARoMEOJournalTitle implements ChoiceAuthority {
 
     @Override
     public Choices getBestMatch(String text, String locale) {
-        return getMatches(text, 0, 1, locale);
+        // punt if there is no query text
+        if (text == null || text.trim().length() == 0) {
+            return new Choices(true);
+        }
+        int limit = 10;
+        SHERPAService sherpaService = new DSpace().getSingletonService(SHERPAService.class);
+        SHERPAResponse sherpaResponse = sherpaService.performRequest("publication", "title",
+            "equals", text, 0, limit);
+        Choices result;
+        if (CollectionUtils.isNotEmpty(sherpaResponse.getJournals())) {
+            List<Choice> list = sherpaResponse
+                .getJournals().stream()
+                .map(sherpaJournal -> new Choice(sherpaJournal.getIssns().get(0),
+                    sherpaJournal.getTitles().get(0), sherpaJournal.getTitles().get(0)))
+                .collect(Collectors.toList());
+            int total = sherpaResponse.getJournals().size();
+
+            int confidence;
+            if (list.isEmpty()) {
+                confidence = Choices.CF_NOTFOUND;
+            } else if (list.size() == 1) {
+                confidence = Choices.CF_UNCERTAIN;
+            } else {
+                confidence = Choices.CF_AMBIGUOUS;
+            }
+            result = new Choices(list.toArray(new Choice[list.size()]), 0, total, confidence,
+                total > limit);
+        } else {
+            result = new Choices(false);
+        }
+        return result;
     }
 
     @Override

dspace-api/src/main/java/org/dspace/content/authority/SHERPARoMEOPublisher.java

@@ -60,7 +60,38 @@ public class SHERPARoMEOPublisher implements ChoiceAuthority {
 
     @Override
     public Choices getBestMatch(String text, String locale) {
-        return getMatches(text, 0, 1, locale);
+        // punt if there is no query text
+        if (text == null || text.trim().length() == 0) {
+            return new Choices(true);
+        }
+        int limit = 10;
+        SHERPAService sherpaService = new DSpace().getSingletonService(SHERPAService.class);
+        SHERPAPublisherResponse sherpaResponse = sherpaService.performPublisherRequest("publisher", "name",
+                "equals", text, 0, limit);
+        Choices result;
+        if (CollectionUtils.isNotEmpty(sherpaResponse.getPublishers())) {
+            List<Choice> list = sherpaResponse
+                    .getPublishers().stream()
+                    .map(sherpaPublisher ->
+                            new Choice(sherpaPublisher.getIdentifier(),
+                                    sherpaPublisher.getName(), sherpaPublisher.getName()))
+                    .collect(Collectors.toList());
+            int total = sherpaResponse.getPublishers().size();
+
+            int confidence;
+            if (list.isEmpty()) {
+                confidence = Choices.CF_NOTFOUND;
+            } else if (list.size() == 1) {
+                confidence = Choices.CF_UNCERTAIN;
+            } else {
+                confidence = Choices.CF_AMBIGUOUS;
+            }
+            result = new Choices(list.toArray(new Choice[list.size()]), 0, total, confidence,
+                    total > limit);
+        } else {
+            result = new Choices(false);
+        }
+        return result;
     }
 
     @Override

dspace-api/src/main/java/org/dspace/content/dao/ItemDAO.java

@@ -17,6 +17,7 @@ import org.dspace.content.Collection;
 import org.dspace.content.Community;
 import org.dspace.content.Item;
 import org.dspace.content.MetadataField;
+import org.dspace.contentreport.QueryPredicate;
 import org.dspace.core.Context;
 import org.dspace.eperson.EPerson;
 
@@ -28,12 +29,11 @@ import org.dspace.eperson.EPerson;
  * @author kevinvandevelde at atmire.com
  */
 public interface ItemDAO extends DSpaceObjectLegacySupportDAO<Item> {
-    public Iterator<Item> findAll(Context context, boolean archived) throws SQLException;
+    Iterator<Item> findAll(Context context, boolean archived) throws SQLException;
 
-    public Iterator<Item> findAll(Context context, boolean archived, int limit, int offset) throws SQLException;
+    Iterator<Item> findAll(Context context, boolean archived, int limit, int offset) throws SQLException;
 
-    @Deprecated
-    public Iterator<Item> findAll(Context context, boolean archived, boolean withdrawn) throws SQLException;
+    @Deprecated Iterator<Item> findAll(Context context, boolean archived, boolean withdrawn) throws SQLException;
 
     /**
      * Find all items that are:
@@ -46,7 +46,7 @@ public interface ItemDAO extends DSpaceObjectLegacySupportDAO<Item> {
      * @return iterator over all regular items.
      * @throws SQLException if database error.
      */
-    public Iterator<Item> findAllRegularItems(Context context) throws SQLException;
+    Iterator<Item> findAllRegularItems(Context context) throws SQLException;
 
     /**
      * Find all Items modified since a Date.
@@ -56,10 +56,10 @@ public interface ItemDAO extends DSpaceObjectLegacySupportDAO<Item> {
      * @return iterator over items
      * @throws SQLException if database error
      */
-    public Iterator<Item> findByLastModifiedSince(Context context, Date since)
+    Iterator<Item> findByLastModifiedSince(Context context, Date since)
         throws SQLException;
 
-    public Iterator<Item> findBySubmitter(Context context, EPerson eperson) throws SQLException;
+    Iterator<Item> findBySubmitter(Context context, EPerson eperson) throws SQLException;
 
     /**
      * Find all the items by a given submitter. The order is
@@ -71,23 +71,40 @@ public interface ItemDAO extends DSpaceObjectLegacySupportDAO<Item> {
      * @return an iterator over the items submitted by eperson
      * @throws SQLException if database error
      */
-    public Iterator<Item> findBySubmitter(Context context, EPerson eperson, boolean retrieveAllItems)
+    Iterator<Item> findBySubmitter(Context context, EPerson eperson, boolean retrieveAllItems)
         throws SQLException;
 
-    public Iterator<Item> findBySubmitter(Context context, EPerson eperson, MetadataField metadataField, int limit)
+    Iterator<Item> findBySubmitter(Context context, EPerson eperson, MetadataField metadataField, int limit)
         throws SQLException;
 
-    public Iterator<Item> findByMetadataField(Context context, MetadataField metadataField, String value,
+    Iterator<Item> findByMetadataField(Context context, MetadataField metadataField, String value,
                                               boolean inArchive) throws SQLException;
 
-    public Iterator<Item> findByMetadataQuery(Context context, List<List<MetadataField>> listFieldList,
-                                              List<String> query_op, List<String> query_val, List<UUID> collectionUuids,
-                                              String regexClause, int offset, int limit) throws SQLException;
+    /**
+     * Returns all the Items that belong to the specified aollections (if any)
+     * and match the provided predicates.
+     * @param context The relevant DSpace context
+     * @param queryPredicates List of predicates that returned items are required to match
+     * @param collectionUuids UUIDs of the collections to search.
+     *        If none are provided, the entire repository will be searched.
+     * @param regexClause Syntactic expression used to query the database using a regular expression
+     *        (e.g.: "text_value ~ ?")
+     * @param offset The offset for the query
+     * @param limit Maximum number of items to return
+     * @return A list containing the items that match the provided criteria
+     * @throws SQLException if something goes wrong
+     */
+    List<Item> findByMetadataQuery(Context context, List<QueryPredicate> queryPredicates,
+                                          List<UUID> collectionUuids, String regexClause,
+                                          long offset, int limit) throws SQLException;
 
-    public Iterator<Item> findByAuthorityValue(Context context, MetadataField metadataField, String authority,
+    long countForMetadataQuery(Context context, List<QueryPredicate> queryPredicates,
+            List<UUID> collectionUuids, String regexClause) throws SQLException;
+
+    Iterator<Item> findByAuthorityValue(Context context, MetadataField metadataField, String authority,
                                                boolean inArchive) throws SQLException;
 
-    public Iterator<Item> findArchivedByCollection(Context context, Collection collection, Integer limit,
+    Iterator<Item> findArchivedByCollection(Context context, Collection collection, Integer limit,
                                                    Integer offset) throws SQLException;
 
     /**
@@ -100,7 +117,7 @@ public interface ItemDAO extends DSpaceObjectLegacySupportDAO<Item> {
      * @return              An iterator containing the items for which the constraints hold true
      * @throws SQLException If something goes wrong
      */
-    public Iterator<Item> findArchivedByCollectionExcludingOwning(Context context, Collection collection, Integer limit,
+    Iterator<Item> findArchivedByCollectionExcludingOwning(Context context, Collection collection, Integer limit,
                                                                   Integer offset) throws SQLException;
 
     /**
@@ -111,11 +128,11 @@ public interface ItemDAO extends DSpaceObjectLegacySupportDAO<Item> {
      * @return              The total amount of items that fit the constraints
      * @throws SQLException If something goes wrong
      */
-    public int countArchivedByCollectionExcludingOwning(Context context, Collection collection) throws SQLException;
+    int countArchivedByCollectionExcludingOwning(Context context, Collection collection) throws SQLException;
 
-    public Iterator<Item> findAllByCollection(Context context, Collection collection) throws SQLException;
+    Iterator<Item> findAllByCollection(Context context, Collection collection) throws SQLException;
 
-    public Iterator<Item> findAllByCollection(Context context, Collection collection, Integer limit, Integer offset)
+    Iterator<Item> findAllByCollection(Context context, Collection collection, Integer limit, Integer offset)
         throws SQLException;
 
     /**
@@ -128,7 +145,7 @@ public interface ItemDAO extends DSpaceObjectLegacySupportDAO<Item> {
      * @return item count
      * @throws SQLException if database error
      */
-    public int countItems(Context context, Collection collection, boolean includeArchived, boolean includeWithdrawn)
+    int countItems(Context context, Collection collection, boolean includeArchived, boolean includeWithdrawn)
         throws SQLException;
 
     /**
@@ -144,7 +161,7 @@ public interface ItemDAO extends DSpaceObjectLegacySupportDAO<Item> {
      * @return item count
      * @throws SQLException if database error
      */
-    public int countItems(Context context, List<Collection> collections, boolean includeArchived,
+    int countItems(Context context, List<Collection> collections, boolean includeArchived,
                           boolean includeWithdrawn) throws SQLException;
 
     /**
@@ -158,7 +175,7 @@ public interface ItemDAO extends DSpaceObjectLegacySupportDAO<Item> {
      * @return iterator over items
      * @throws SQLException if database error
      */
-    public Iterator<Item> findAll(Context context, boolean archived,
+    Iterator<Item> findAll(Context context, boolean archived,
                                   boolean withdrawn, boolean discoverable, Date lastModified)
         throws SQLException;
 
@@ -192,7 +209,7 @@ public interface ItemDAO extends DSpaceObjectLegacySupportDAO<Item> {
      * @return count of items
      * @throws SQLException if database error
      */
-    public int countItems(Context context, EPerson submitter, boolean includeArchived, boolean includeWithdrawn)
+    int countItems(Context context, EPerson submitter, boolean includeArchived, boolean includeWithdrawn)
         throws SQLException;
 
 }

dspace-api/src/main/java/org/dspace/content/dao/impl/ItemDAOImpl.java

@@ -8,6 +8,7 @@
 package org.dspace.content.dao.impl;
 
 import java.sql.SQLException;
+import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Date;
 import java.util.Iterator;
@@ -16,28 +17,27 @@ import java.util.UUID;
 import javax.persistence.Query;
 import javax.persistence.TemporalType;
 import javax.persistence.criteria.CriteriaBuilder;
+import javax.persistence.criteria.CriteriaBuilder.In;
 import javax.persistence.criteria.CriteriaQuery;
+import javax.persistence.criteria.Predicate;
 import javax.persistence.criteria.Root;
+import javax.persistence.criteria.Subquery;
 
 import org.apache.logging.log4j.Logger;
 import org.dspace.content.Collection;
+import org.dspace.content.DSpaceObject_;
 import org.dspace.content.Item;
 import org.dspace.content.Item_;
 import org.dspace.content.MetadataField;
 import org.dspace.content.MetadataValue;
+import org.dspace.content.MetadataValue_;
 import org.dspace.content.dao.ItemDAO;
+import org.dspace.contentreport.QueryOperator;
+import org.dspace.contentreport.QueryPredicate;
 import org.dspace.core.AbstractHibernateDSODAO;
 import org.dspace.core.Context;
 import org.dspace.eperson.EPerson;
-import org.hibernate.Criteria;
-import org.hibernate.criterion.Criterion;
-import org.hibernate.criterion.DetachedCriteria;
-import org.hibernate.criterion.Order;
-import org.hibernate.criterion.Projections;
-import org.hibernate.criterion.Property;
-import org.hibernate.criterion.Restrictions;
-import org.hibernate.criterion.Subqueries;
-import org.hibernate.type.StandardBasicTypes;
+import org.dspace.util.JpaCriteriaBuilderKit;
 
 /**
  * Hibernate implementation of the Database Access Object interface class for the Item object.
@@ -50,7 +50,6 @@ public class ItemDAOImpl extends AbstractHibernateDSODAO<Item> implements ItemDA
     private static final Logger log = org.apache.logging.log4j.LogManager.getLogger(ItemDAOImpl.class);
 
     protected ItemDAOImpl() {
-        super();
     }
 
     @Override
@@ -174,118 +173,103 @@ public class ItemDAOImpl extends AbstractHibernateDSODAO<Item> implements ItemDA
         return iterate(query);
     }
 
-    enum OP {
-        equals {
-            public Criterion buildPredicate(String val, String regexClause) {
-                return Property.forName("mv.value").eq(val);
-            }
-        },
-        not_equals {
-            public Criterion buildPredicate(String val, String regexClause) {
-                return OP.equals.buildPredicate(val, regexClause);
-            }
-        },
-        like {
-            public Criterion buildPredicate(String val, String regexClause) {
-                return Property.forName("mv.value").like(val);
-            }
-        },
-        not_like {
-            public Criterion buildPredicate(String val, String regexClause) {
-                return OP.like.buildPredicate(val, regexClause);
-            }
-        },
-        contains {
-            public Criterion buildPredicate(String val, String regexClause) {
-                return Property.forName("mv.value").like("%" + val + "%");
-            }
-        },
-        doesnt_contain {
-            public Criterion buildPredicate(String val, String regexClause) {
-                return OP.contains.buildPredicate(val, regexClause);
-            }
-        },
-        exists {
-            public Criterion buildPredicate(String val, String regexClause) {
-                return Property.forName("mv.value").isNotNull();
-            }
-        },
-        doesnt_exist {
-            public Criterion buildPredicate(String val, String regexClause) {
-                return OP.exists.buildPredicate(val, regexClause);
-            }
-        },
-        matches {
-            public Criterion buildPredicate(String val, String regexClause) {
-                return Restrictions.sqlRestriction(regexClause, val, StandardBasicTypes.STRING);
-            }
-        },
-        doesnt_match {
-            public Criterion buildPredicate(String val, String regexClause) {
-                return OP.matches.buildPredicate(val, regexClause);
-            }
-
-        };
-        public abstract Criterion buildPredicate(String val, String regexClause);
+    @Override
+    public List<Item> findByMetadataQuery(Context context, List<QueryPredicate> queryPredicates,
+            List<UUID> collectionUuids, String regexClause, long offset, int limit) throws SQLException {
+        CriteriaBuilder criteriaBuilder = getCriteriaBuilder(context);
+        CriteriaQuery<Item> criteriaQuery = getCriteriaQuery(criteriaBuilder, Item.class);
+        Root<Item> itemRoot = criteriaQuery.from(Item.class);
+        criteriaQuery.select(itemRoot);
+        List<Predicate> predicates = toPredicates(criteriaBuilder, criteriaQuery, itemRoot,
+                queryPredicates, collectionUuids, regexClause);
+        criteriaQuery.where(criteriaBuilder.and(predicates.stream().toArray(Predicate[]::new)));
+        criteriaQuery.orderBy(criteriaBuilder.asc(itemRoot.get(DSpaceObject_.id)));
+        criteriaQuery.groupBy(itemRoot.get(DSpaceObject_.id));
+        try {
+            return list(context, criteriaQuery, false, Item.class, limit, (int) offset);
+        } catch (Exception e) {
+            e.printStackTrace();
+            throw e;
+        }
     }
 
     @Override
-    @Deprecated
-    public Iterator<Item> findByMetadataQuery(Context context, List<List<MetadataField>> listFieldList,
-                                              List<String> query_op, List<String> query_val, List<UUID> collectionUuids,
-                                              String regexClause, int offset, int limit) throws SQLException {
+    public long countForMetadataQuery(Context context, List<QueryPredicate> queryPredicates,
+            List<UUID> collectionUuids, String regexClause) throws SQLException {
+        // Build the query infrastructure
+        CriteriaBuilder criteriaBuilder = getCriteriaBuilder(context);
+        CriteriaQuery<Item> criteriaQuery = getCriteriaQuery(criteriaBuilder, Item.class);
+        // Select
+        Root<Item> itemRoot = criteriaQuery.from(Item.class);
+        // Apply the selected predicates
+        List<Predicate> predicates = toPredicates(criteriaBuilder, criteriaQuery, itemRoot,
+                queryPredicates, collectionUuids, regexClause);
+        criteriaQuery.where(criteriaBuilder.and(predicates.stream().toArray(Predicate[]::new)));
+        // Execute the query
+        return countLong(context, criteriaQuery, criteriaBuilder, itemRoot);
+    }
 
-        Criteria criteria = getHibernateSession(context).createCriteria(Item.class, "item");
-        criteria.setFirstResult(offset);
-        criteria.setMaxResults(limit);
+    private <T> List<Predicate> toPredicates(CriteriaBuilder criteriaBuilder, CriteriaQuery<T> query,
+            Root<Item> root, List<QueryPredicate> queryPredicates,
+            List<UUID> collectionUuids, String regexClause) {
+        List<Predicate> predicates = new ArrayList<>();
 
         if (!collectionUuids.isEmpty()) {
-            DetachedCriteria dcollCriteria = DetachedCriteria.forClass(Collection.class, "coll");
-            dcollCriteria.setProjection(Projections.property("coll.id"));
-            dcollCriteria.add(Restrictions.eqProperty("coll.id", "item.owningCollection"));
-            dcollCriteria.add(Restrictions.in("coll.id", collectionUuids));
-            criteria.add(Subqueries.exists(dcollCriteria));
+            Subquery<Collection> scollQuery = query.subquery(Collection.class);
+            Root<Collection> collRoot = scollQuery.from(Collection.class);
+            In<UUID> inColls = criteriaBuilder.in(collRoot.get(DSpaceObject_.ID));
+            collectionUuids.forEach(inColls::value);
+            scollQuery.select(collRoot.get(DSpaceObject_.ID))
+                    .where(criteriaBuilder.and(
+                            criteriaBuilder.equal(collRoot.get(DSpaceObject_.ID),
+                                    root.get(Item_.OWNING_COLLECTION).get(DSpaceObject_.ID)),
+                            collRoot.get(DSpaceObject_.ID).in(collectionUuids)
+                    ));
+            predicates.add(criteriaBuilder.exists(scollQuery));
         }
 
-        int index = Math.min(listFieldList.size(), Math.min(query_op.size(), query_val.size()));
-        StringBuilder sb = new StringBuilder();
-
-        for (int i = 0; i < index; i++) {
-            OP op = OP.valueOf(query_op.get(i));
+        for (int i = 0; i < queryPredicates.size(); i++) {
+            QueryPredicate predicate = queryPredicates.get(i);
+            QueryOperator op = predicate.getOperator();
             if (op == null) {
-                log.warn("Skipping Invalid Operator: " + query_op.get(i));
+                log.warn("Skipping Invalid Operator: null");
                 continue;
             }
 
-            if (op == OP.matches || op == OP.doesnt_match) {
+            if (op.getUsesRegex()) {
                 if (regexClause.isEmpty()) {
-                    log.warn("Skipping Unsupported Regex Operator: " + query_op.get(i));
+                    log.warn("Skipping Unsupported Regex Operator: " + op);
                     continue;
                 }
             }
 
-            DetachedCriteria subcriteria = DetachedCriteria.forClass(MetadataValue.class, "mv");
-            subcriteria.add(Property.forName("mv.dSpaceObject").eqProperty("item.id"));
-            subcriteria.setProjection(Projections.property("mv.dSpaceObject"));
+            List<Predicate> mvPredicates = new ArrayList<>();
+            Subquery<MetadataValue> mvQuery = query.subquery(MetadataValue.class);
+            Root<MetadataValue> mvRoot = mvQuery.from(MetadataValue.class);
+            mvPredicates.add(criteriaBuilder.equal(
+                    mvRoot.get(MetadataValue_.D_SPACE_OBJECT), root.get(DSpaceObject_.ID)));
 
-            if (!listFieldList.get(i).isEmpty()) {
-                subcriteria.add(Restrictions.in("metadataField", listFieldList.get(i)));
+            if (!predicate.getFields().isEmpty()) {
+                In<MetadataField> inFields = criteriaBuilder.in(mvRoot.get(MetadataValue_.METADATA_FIELD));
+                predicate.getFields().forEach(inFields::value);
+                mvPredicates.add(inFields);
             }
 
-            subcriteria.add(op.buildPredicate(query_val.get(i), regexClause));
+            JpaCriteriaBuilderKit<MetadataValue> jpaKit = new JpaCriteriaBuilderKit<>(criteriaBuilder, mvQuery, mvRoot);
+            mvPredicates.add(op.buildJpaPredicate(predicate.getValue(), regexClause, jpaKit));
 
-            if (op == OP.exists || op == OP.equals || op == OP.like || op == OP.contains || op == OP.matches) {
-                criteria.add(Subqueries.exists(subcriteria));
+            mvQuery.select(mvRoot.get(MetadataValue_.D_SPACE_OBJECT))
+                    .where(mvPredicates.stream().toArray(Predicate[]::new));
+
+            if (op.getNegate()) {
+                predicates.add(criteriaBuilder.not(criteriaBuilder.exists(mvQuery)));
             } else {
-                criteria.add(Subqueries.notExists(subcriteria));
+                predicates.add(criteriaBuilder.exists(mvQuery));
             }
         }
-        criteria.addOrder(Order.asc("item.id"));
-
-        log.debug(String.format("Running custom query with %d filters", index));
-
-        return ((List<Item>) criteria.list()).iterator();
 
+        log.debug(String.format("Running custom query with %d filters", queryPredicates.size()));
+        return predicates;
     }
 
     @Override
@@ -322,22 +306,22 @@ public class ItemDAOImpl extends AbstractHibernateDSODAO<Item> implements ItemDA
     public Iterator<Item> findArchivedByCollectionExcludingOwning(Context context, Collection collection, Integer limit,
                                                                   Integer offset) throws SQLException {
         CriteriaBuilder criteriaBuilder = getCriteriaBuilder(context);
-        CriteriaQuery criteriaQuery = getCriteriaQuery(criteriaBuilder, Item.class);
+        CriteriaQuery<Item> criteriaQuery = getCriteriaQuery(criteriaBuilder, Item.class);
         Root<Item> itemRoot = criteriaQuery.from(Item.class);
         criteriaQuery.select(itemRoot);
         criteriaQuery.where(criteriaBuilder.and(
                 criteriaBuilder.notEqual(itemRoot.get(Item_.owningCollection), collection),
                 criteriaBuilder.isMember(collection, itemRoot.get(Item_.collections)),
                 criteriaBuilder.isTrue(itemRoot.get(Item_.inArchive))));
-        criteriaQuery.orderBy(criteriaBuilder.asc(itemRoot.get(Item_.id)));
-        criteriaQuery.groupBy(itemRoot.get(Item_.id));
+        criteriaQuery.orderBy(criteriaBuilder.asc(itemRoot.get(DSpaceObject_.id)));
+        criteriaQuery.groupBy(itemRoot.get(DSpaceObject_.id));
         return list(context, criteriaQuery, false, Item.class, limit, offset).iterator();
     }
 
     @Override
     public int countArchivedByCollectionExcludingOwning(Context context, Collection collection) throws SQLException {
         CriteriaBuilder criteriaBuilder = getCriteriaBuilder(context);
-        CriteriaQuery criteriaQuery = getCriteriaQuery(criteriaBuilder, Item.class);
+        CriteriaQuery<Item> criteriaQuery = getCriteriaQuery(criteriaBuilder, Item.class);
         Root<Item> itemRoot = criteriaQuery.from(Item.class);
         criteriaQuery.select(itemRoot);
         criteriaQuery.where(criteriaBuilder.and(

dspace-api/src/main/java/org/dspace/content/service/ItemService.java

@@ -23,10 +23,10 @@ import org.dspace.content.Collection;
 import org.dspace.content.Community;
 import org.dspace.content.EntityType;
 import org.dspace.content.Item;
-import org.dspace.content.MetadataField;
 import org.dspace.content.MetadataValue;
 import org.dspace.content.Thumbnail;
 import org.dspace.content.WorkspaceItem;
+import org.dspace.contentreport.QueryPredicate;
 import org.dspace.core.Context;
 import org.dspace.discovery.SearchServiceException;
 import org.dspace.eperson.EPerson;
@@ -42,7 +42,7 @@ import org.dspace.eperson.Group;
 public interface ItemService
         extends DSpaceObjectService<Item>, DSpaceObjectLegacySupportService<Item> {
 
-    public Thumbnail getThumbnail(Context context, Item item, boolean requireOriginal) throws SQLException;
+    Thumbnail getThumbnail(Context context, Item item, boolean requireOriginal) throws SQLException;
 
     /**
      * Create a new item, with a new internal ID. Authorization is done
@@ -54,7 +54,7 @@ public interface ItemService
      * @throws SQLException       if database error
      * @throws AuthorizeException if authorization error
      */
-    public Item create(Context context, WorkspaceItem workspaceItem) throws SQLException, AuthorizeException;
+    Item create(Context context, WorkspaceItem workspaceItem) throws SQLException, AuthorizeException;
 
     /**
      * Create a new item, with a provided ID. Authorisation is done
@@ -67,7 +67,7 @@ public interface ItemService
      * @throws SQLException if database error
      * @throws AuthorizeException if authorization error
      */
-    public Item create(Context context, WorkspaceItem workspaceItem, UUID uuid) throws SQLException, AuthorizeException;
+    Item create(Context context, WorkspaceItem workspaceItem, UUID uuid) throws SQLException, AuthorizeException;
 
     /**
      * Create an empty template item for this collection. If one already exists,
@@ -81,7 +81,7 @@ public interface ItemService
      * @throws SQLException       if database error
      * @throws AuthorizeException if authorization error
      */
-    public Item createTemplateItem(Context context, Collection collection) throws SQLException, AuthorizeException;
+    Item createTemplateItem(Context context, Collection collection) throws SQLException, AuthorizeException;
 
     /**
      * Get all the items in the archive. Only items with the "in archive" flag
@@ -91,7 +91,7 @@ public interface ItemService
      * @return an iterator over the items in the archive.
      * @throws SQLException if database error
      */
-    public Iterator<Item> findAll(Context context) throws SQLException;
+    Iterator<Item> findAll(Context context) throws SQLException;
 
     /**
      * Get all the items in the archive. Only items with the "in archive" flag
@@ -103,7 +103,7 @@ public interface ItemService
      * @return an iterator over the items in the archive.
      * @throws SQLException if database error
      */
-    public Iterator<Item> findAll(Context context, Integer limit, Integer offset) throws SQLException;
+    Iterator<Item> findAll(Context context, Integer limit, Integer offset) throws SQLException;
 
     /**
      * Get all "final" items in the archive, both archived ("in archive" flag) or
@@ -113,8 +113,7 @@ public interface ItemService
      * @return an iterator over the items in the archive.
      * @throws SQLException if database error
      */
-    @Deprecated
-    public Iterator<Item> findAllUnfiltered(Context context) throws SQLException;
+    @Deprecated Iterator<Item> findAllUnfiltered(Context context) throws SQLException;
 
     /**
      * Find all items that are:
@@ -127,7 +126,7 @@ public interface ItemService
      * @return iterator over all regular items.
      * @throws SQLException if database error.
      */
-    public Iterator<Item> findAllRegularItems(Context context) throws SQLException;
+    Iterator<Item> findAllRegularItems(Context context) throws SQLException;
 
     /**
      * Find all the items in the archive by a given submitter. The order is
@@ -138,7 +137,7 @@ public interface ItemService
      * @return an iterator over the items submitted by eperson
      * @throws SQLException if database error
      */
-    public Iterator<Item> findBySubmitter(Context context, EPerson eperson)
+    Iterator<Item> findBySubmitter(Context context, EPerson eperson)
         throws SQLException;
 
     /**
@@ -153,7 +152,7 @@ public interface ItemService
      * @return an iterator over the items submitted by eperson
      * @throws SQLException if database error
      */
-    public Iterator<Item> findBySubmitter(Context context, EPerson eperson, boolean retrieveAllItems)
+    Iterator<Item> findBySubmitter(Context context, EPerson eperson, boolean retrieveAllItems)
             throws SQLException;
 
     /**
@@ -165,7 +164,7 @@ public interface ItemService
      * @return an iterator over the items submitted by eperson
      * @throws SQLException if database error
      */
-    public Iterator<Item> findBySubmitterDateSorted(Context context, EPerson eperson, Integer limit)
+    Iterator<Item> findBySubmitterDateSorted(Context context, EPerson eperson, Integer limit)
         throws SQLException;
 
     /**
@@ -176,7 +175,7 @@ public interface ItemService
      * @return an iterator over the items in the collection.
      * @throws SQLException if database error
      */
-    public Iterator<Item> findByCollection(Context context, Collection collection) throws SQLException;
+    Iterator<Item> findByCollection(Context context, Collection collection) throws SQLException;
 
     /**
      * Get all the archived items in this collection. The order is indeterminate.
@@ -188,7 +187,7 @@ public interface ItemService
      * @return an iterator over the items in the collection.
      * @throws SQLException if database error
      */
-    public Iterator<Item> findByCollection(Context context, Collection collection, Integer limit, Integer offset)
+    Iterator<Item> findByCollection(Context context, Collection collection, Integer limit, Integer offset)
         throws SQLException;
 
     /**
@@ -201,7 +200,7 @@ public interface ItemService
      * @return an iterator over the items in the collection.
      * @throws SQLException if database error
      */
-    public Iterator<Item> findByCollectionMapping(Context context, Collection collection, Integer limit, Integer offset)
+    Iterator<Item> findByCollectionMapping(Context context, Collection collection, Integer limit, Integer offset)
             throws SQLException;
 
     /**
@@ -212,7 +211,7 @@ public interface ItemService
      * @return an iterator over the items in the collection.
      * @throws SQLException if database error
      */
-    public int countByCollectionMapping(Context context, Collection collection) throws SQLException;
+    int countByCollectionMapping(Context context, Collection collection) throws SQLException;
 
     /**
      * Get all the items (including private and withdrawn) in this collection. The order is indeterminate.
@@ -224,7 +223,7 @@ public interface ItemService
      * @param offset offset value
      * @throws SQLException if database error
      */
-    public Iterator<Item> findAllByCollection(Context context, Collection collection, Integer limit, Integer offset)
+    Iterator<Item> findAllByCollection(Context context, Collection collection, Integer limit, Integer offset)
         throws SQLException;
 
     /**
@@ -235,7 +234,7 @@ public interface ItemService
      * @return an iterator over the items in the collection.
      * @throws SQLException if database error
      */
-    public Iterator<Item> findInArchiveOrWithdrawnDiscoverableModifiedSince(Context context, Date since)
+    Iterator<Item> findInArchiveOrWithdrawnDiscoverableModifiedSince(Context context, Date since)
         throws SQLException;
 
     /**
@@ -245,7 +244,7 @@ public interface ItemService
      * @return an iterator over the items in the collection.
      * @throws SQLException if database error
      */
-    public Iterator<Item> findInArchiveOrWithdrawnNonDiscoverableModifiedSince(Context context, Date since)
+    Iterator<Item> findInArchiveOrWithdrawnNonDiscoverableModifiedSince(Context context, Date since)
         throws SQLException;
 
     /**
@@ -256,7 +255,7 @@ public interface ItemService
      * @return an iterator over the items in the collection.
      * @throws SQLException if database error
      */
-    public Iterator<Item> findAllByCollection(Context context, Collection collection) throws SQLException;
+    Iterator<Item> findAllByCollection(Context context, Collection collection) throws SQLException;
 
     /**
      * See whether this Item is contained by a given Collection.
@@ -266,7 +265,7 @@ public interface ItemService
      * @return true if {@code collection} contains this Item.
      * @throws SQLException if database error
      */
-    public boolean isIn(Item item, Collection collection) throws SQLException;
+    boolean isIn(Item item, Collection collection) throws SQLException;
 
     /**
      * Get the communities this item is in. Returns an unordered array of the
@@ -278,7 +277,7 @@ public interface ItemService
      * @return the communities this item is in.
      * @throws SQLException if database error
      */
-    public List<Community> getCommunities(Context context, Item item) throws SQLException;
+    List<Community> getCommunities(Context context, Item item) throws SQLException;
 
 
     /**
@@ -289,7 +288,7 @@ public interface ItemService
      * @return the bundles in an unordered array
      * @throws SQLException if database error
      */
-    public List<Bundle> getBundles(Item item, String name) throws SQLException;
+    List<Bundle> getBundles(Item item, String name) throws SQLException;
 
     /**
      * Add an existing bundle to this item. This has immediate effect.
@@ -300,7 +299,7 @@ public interface ItemService
      * @throws SQLException       if database error
      * @throws AuthorizeException if authorization error
      */
-    public void addBundle(Context context, Item item, Bundle bundle) throws SQLException, AuthorizeException;
+    void addBundle(Context context, Item item, Bundle bundle) throws SQLException, AuthorizeException;
 
     /**
      * Remove a bundle. This may result in the bundle being deleted, if the
@@ -313,7 +312,7 @@ public interface ItemService
      * @throws AuthorizeException if authorization error
      * @throws IOException        if IO error
      */
-    public void removeBundle(Context context, Item item, Bundle bundle) throws SQLException, AuthorizeException,
+    void removeBundle(Context context, Item item, Bundle bundle) throws SQLException, AuthorizeException,
         IOException;
 
     /**
@@ -326,7 +325,7 @@ public interface ItemService
      * @throws AuthorizeException if authorization error
      * @throws IOException        if IO error
      */
-    public void removeAllBundles(Context context, Item item) throws AuthorizeException, SQLException, IOException;
+    void removeAllBundles(Context context, Item item) throws AuthorizeException, SQLException, IOException;
 
     /**
      * Create a single bitstream in a new bundle. Provided as a convenience
@@ -341,7 +340,7 @@ public interface ItemService
      * @throws IOException        if IO error
      * @throws SQLException       if database error
      */
-    public Bitstream createSingleBitstream(Context context, InputStream is, Item item, String name)
+    Bitstream createSingleBitstream(Context context, InputStream is, Item item, String name)
         throws AuthorizeException, IOException, SQLException;
 
     /**
@@ -355,7 +354,7 @@ public interface ItemService
      * @throws IOException        if IO error
      * @throws SQLException       if database error
      */
-    public Bitstream createSingleBitstream(Context context, InputStream is, Item item)
+    Bitstream createSingleBitstream(Context context, InputStream is, Item item)
         throws AuthorizeException, IOException, SQLException;
 
     /**
@@ -368,7 +367,7 @@ public interface ItemService
      * @return non-internal bitstreams.
      * @throws SQLException if database error
      */
-    public List<Bitstream> getNonInternalBitstreams(Context context, Item item) throws SQLException;
+    List<Bitstream> getNonInternalBitstreams(Context context, Item item) throws SQLException;
 
     /**
      * Remove just the DSpace license from an item This is useful to update the
@@ -383,7 +382,7 @@ public interface ItemService
      * @throws AuthorizeException if authorization error
      * @throws IOException        if IO error
      */
-    public void removeDSpaceLicense(Context context, Item item) throws SQLException, AuthorizeException,
+    void removeDSpaceLicense(Context context, Item item) throws SQLException, AuthorizeException,
         IOException;
 
     /**
@@ -395,7 +394,7 @@ public interface ItemService
      * @throws AuthorizeException if authorization error
      * @throws IOException        if IO error
      */
-    public void removeLicenses(Context context, Item item) throws SQLException, AuthorizeException, IOException;
+    void removeLicenses(Context context, Item item) throws SQLException, AuthorizeException, IOException;
 
     /**
      * Withdraw the item from the archive. It is kept in place, and the content
@@ -406,7 +405,7 @@ public interface ItemService
      * @throws SQLException       if database error
      * @throws AuthorizeException if authorization error
      */
-    public void withdraw(Context context, Item item) throws SQLException, AuthorizeException;
+    void withdraw(Context context, Item item) throws SQLException, AuthorizeException;
 
 
     /**
@@ -417,7 +416,7 @@ public interface ItemService
      * @throws SQLException       if database error
      * @throws AuthorizeException if authorization error
      */
-    public void reinstate(Context context, Item item) throws SQLException, AuthorizeException;
+    void reinstate(Context context, Item item) throws SQLException, AuthorizeException;
 
     /**
      * Return true if this Collection 'owns' this item
@@ -426,7 +425,7 @@ public interface ItemService
      * @param collection Collection
      * @return true if this Collection owns this item
      */
-    public boolean isOwningCollection(Item item, Collection collection);
+    boolean isOwningCollection(Item item, Collection collection);
 
     /**
      * remove all of the policies for item and replace them with a new list of
@@ -440,7 +439,7 @@ public interface ItemService
      * @throws SQLException       if database error
      * @throws AuthorizeException if authorization error
      */
-    public void replaceAllItemPolicies(Context context, Item item, List<ResourcePolicy> newpolicies)
+    void replaceAllItemPolicies(Context context, Item item, List<ResourcePolicy> newpolicies)
         throws SQLException,
         AuthorizeException;
 
@@ -456,7 +455,7 @@ public interface ItemService
      * @throws SQLException       if database error
      * @throws AuthorizeException if authorization error
      */
-    public void replaceAllBitstreamPolicies(Context context, Item item, List<ResourcePolicy> newpolicies)
+    void replaceAllBitstreamPolicies(Context context, Item item, List<ResourcePolicy> newpolicies)
         throws SQLException, AuthorizeException;
 
 
@@ -470,7 +469,7 @@ public interface ItemService
      * @throws SQLException       if database error
      * @throws AuthorizeException if authorization error
      */
-    public void removeGroupPolicies(Context context, Item item, Group group) throws SQLException, AuthorizeException;
+    void removeGroupPolicies(Context context, Item item, Group group) throws SQLException, AuthorizeException;
 
     /**
      * Remove all policies on an item and its contents, and replace them with
@@ -485,7 +484,7 @@ public interface ItemService
      *                            draconian, but default policies must be enforced.
      * @throws AuthorizeException if authorization error
      */
-    public void inheritCollectionDefaultPolicies(Context context, Item item, Collection collection)
+    void inheritCollectionDefaultPolicies(Context context, Item item, Collection collection)
         throws java.sql.SQLException, AuthorizeException;
 
     /**
@@ -504,7 +503,7 @@ public interface ItemService
      *                            draconian, but default policies must be enforced.
      * @throws AuthorizeException if authorization error
      */
-    public void inheritCollectionDefaultPolicies(Context context, Item item, Collection collection,
+    void inheritCollectionDefaultPolicies(Context context, Item item, Collection collection,
                                                  boolean overrideItemReadPolicies)
         throws java.sql.SQLException, AuthorizeException;
 
@@ -517,14 +516,14 @@ public interface ItemService
      * already applied to the bundle/bitstream. Collection's policies are inherited
      * if there are no other policies defined or if the append mode is defined by
      * the configuration via the core.authorization.installitem.inheritance-read.append-mode property
-     * 
+     *
      * @param context             DSpace context object
      * @param item                Item to adjust policies on
      * @param collection          Collection
      * @throws SQLException       If database error
      * @throws AuthorizeException If authorization error
      */
-    public void adjustBundleBitstreamPolicies(Context context, Item item, Collection collection)
+    void adjustBundleBitstreamPolicies(Context context, Item item, Collection collection)
         throws SQLException, AuthorizeException;
 
     /**
@@ -545,7 +544,7 @@ public interface ItemService
      * @throws SQLException       If database error
      * @throws AuthorizeException If authorization error
      */
-    public void adjustBundleBitstreamPolicies(Context context, Item item, Collection collection,
+    void adjustBundleBitstreamPolicies(Context context, Item item, Collection collection,
                                               boolean replaceReadRPWithCollectionRP)
         throws SQLException, AuthorizeException;
 
@@ -566,7 +565,7 @@ public interface ItemService
      * @throws SQLException       If database error
      * @throws AuthorizeException If authorization error
      */
-    public void adjustBitstreamPolicies(Context context, Item item, Collection collection, Bitstream bitstream)
+    void adjustBitstreamPolicies(Context context, Item item, Collection collection, Bitstream bitstream)
         throws SQLException, AuthorizeException;
 
     /**
@@ -588,7 +587,7 @@ public interface ItemService
      * @throws SQLException       If database error
      * @throws AuthorizeException If authorization error
      */
-    public void adjustBitstreamPolicies(Context context, Item item, Collection collection, Bitstream bitstream,
+    void adjustBitstreamPolicies(Context context, Item item, Collection collection, Bitstream bitstream,
                                         boolean replaceReadRPWithCollectionRP)
         throws SQLException, AuthorizeException;
 
@@ -600,14 +599,14 @@ public interface ItemService
      * inherited as appropriate. Collection's policies are inherited if there are no
      * other policies defined or if the append mode is defined by the configuration
      * via the core.authorization.installitem.inheritance-read.append-mode property
-     * 
+     *
      * @param context              DSpace context object
      * @param item                 Item to adjust policies on
      * @param collection           Collection
      * @throws SQLException        If database error
      * @throws AuthorizeException  If authorization error
      */
-    public void adjustItemPolicies(Context context, Item item, Collection collection)
+    void adjustItemPolicies(Context context, Item item, Collection collection)
         throws SQLException, AuthorizeException;
 
     /**
@@ -626,7 +625,7 @@ public interface ItemService
      * @throws SQLException        If database error
      * @throws AuthorizeException  If authorization error
      */
-    public void adjustItemPolicies(Context context, Item item, Collection collection,
+    void adjustItemPolicies(Context context, Item item, Collection collection,
                                    boolean replaceReadRPWithCollectionRP)
         throws SQLException, AuthorizeException;
 
@@ -641,7 +640,7 @@ public interface ItemService
      * @throws AuthorizeException if authorization error
      * @throws IOException        if IO error
      */
-    public void move(Context context, Item item, Collection from, Collection to)
+    void move(Context context, Item item, Collection from, Collection to)
         throws SQLException, AuthorizeException, IOException;
 
     /**
@@ -656,7 +655,7 @@ public interface ItemService
      * @throws AuthorizeException if authorization error
      * @throws IOException        if IO error
      */
-    public void move(Context context, Item item, Collection from, Collection to, boolean inheritDefaultPolicies)
+    void move(Context context, Item item, Collection from, Collection to, boolean inheritDefaultPolicies)
         throws SQLException, AuthorizeException, IOException;
 
     /**
@@ -667,7 +666,7 @@ public interface ItemService
      * bitstreams inside
      * @throws SQLException if database error
      */
-    public boolean hasUploadedFiles(Item item) throws SQLException;
+    boolean hasUploadedFiles(Item item) throws SQLException;
 
     /**
      * Get the collections this item is not in.
@@ -677,7 +676,7 @@ public interface ItemService
      * @return the collections this item is not in, if any.
      * @throws SQLException if database error
      */
-    public List<Collection> getCollectionsNotLinked(Context context, Item item) throws SQLException;
+    List<Collection> getCollectionsNotLinked(Context context, Item item) throws SQLException;
 
     /**
      * return TRUE if context's user can edit item, false otherwise
@@ -687,7 +686,7 @@ public interface ItemService
      * @return boolean true = current user can edit item
      * @throws SQLException if database error
      */
-    public boolean canEdit(Context context, Item item) throws java.sql.SQLException;
+    boolean canEdit(Context context, Item item) throws java.sql.SQLException;
 
     /**
      * return TRUE if context's user can create new version of the item, false
@@ -698,7 +697,7 @@ public interface ItemService
      * @return boolean true = current user can create new version of the item
      * @throws SQLException if database error
      */
-    public boolean canCreateNewVersion(Context context, Item item) throws SQLException;
+    boolean canCreateNewVersion(Context context, Item item) throws SQLException;
 
     /**
      * Returns an iterator of in archive items possessing the passed metadata field, or only
@@ -713,7 +712,7 @@ public interface ItemService
      * @throws SQLException       if database error
      * @throws AuthorizeException if authorization error
      */
-    public Iterator<Item> findArchivedByMetadataField(Context context, String schema,
+    Iterator<Item> findArchivedByMetadataField(Context context, String schema,
                                                       String element, String qualifier,
                                                       String value) throws SQLException, AuthorizeException;
 
@@ -728,7 +727,7 @@ public interface ItemService
      * @throws SQLException       if database error
      * @throws AuthorizeException if authorization error
      */
-    public Iterator<Item> findArchivedByMetadataField(Context context, String metadataField, String value)
+    Iterator<Item> findArchivedByMetadataField(Context context, String metadataField, String value)
             throws SQLException, AuthorizeException;
 
     /**
@@ -745,14 +744,41 @@ public interface ItemService
      * @throws AuthorizeException if authorization error
      * @throws IOException        if IO error
      */
-    public Iterator<Item> findByMetadataField(Context context,
+    Iterator<Item> findByMetadataField(Context context,
                                               String schema, String element, String qualifier, String value)
         throws SQLException, AuthorizeException, IOException;
 
-    public Iterator<Item> findByMetadataQuery(Context context, List<List<MetadataField>> listFieldList,
-                                              List<String> query_op, List<String> query_val, List<UUID> collectionUuids,
-                                              String regexClause, int offset, int limit)
-        throws SQLException, AuthorizeException, IOException;
+    /**
+     * Returns a list of items that match the given predicates, within the
+     * specified collections, if any. This querying method is used by the
+     * Filtered Items report functionality.
+     * @param context DSpace context object
+     * @param queryPredicates metadata field predicates
+     * @param collectionUuids UUIDs of the collections to search
+     * @param offset position in the list to start returning items
+     * @param limit maximum number of items to return
+     * @return a list of matching items in the specified collections,
+     * or in any collection if no collection UUIDs are provided
+     * @throws SQLException if a database error occurs
+     */
+    List<Item> findByMetadataQuery(Context context, List<QueryPredicate> queryPredicates,
+            List<UUID> collectionUuids, long offset, int limit)
+            throws SQLException;
+
+    /**
+     * Returns the total number of items that match the given predicates, within the
+     * specified collections, if any. This querying method is used for pagination by the
+     * Filtered Items report functionality.
+     * @param context DSpace context object
+     * @param queryPredicates metadata field predicates
+     * @param collectionUuids UUIDs of the collections to search
+     * @return the total number of matching items in the specified collections,
+     * or in any collection if no collection UUIDs are provided
+     * @throws SQLException if a database error occurs
+     */
+    long countForMetadataQuery(Context context, List<QueryPredicate> queryPredicates,
+            List<UUID> collectionUuids)
+            throws SQLException;
 
     /**
      * Find all the items in the archive with a given authority key value
@@ -768,12 +794,12 @@ public interface ItemService
      * @throws AuthorizeException if authorization error
      * @throws IOException        if IO error
      */
-    public Iterator<Item> findByAuthorityValue(Context context,
+    Iterator<Item> findByAuthorityValue(Context context,
                                                String schema, String element, String qualifier, String value)
         throws SQLException, AuthorizeException;
 
 
-    public Iterator<Item> findByMetadataFieldAuthority(Context context, String mdString, String authority)
+    Iterator<Item> findByMetadataFieldAuthority(Context context, String mdString, String authority)
         throws SQLException, AuthorizeException;
 
     /**
@@ -785,7 +811,7 @@ public interface ItemService
      * @param item    item
      * @return true or false
      */
-    public boolean isItemListedForUser(Context context, Item item);
+    boolean isItemListedForUser(Context context, Item item);
 
     /**
      * counts items in the given collection
@@ -795,7 +821,7 @@ public interface ItemService
      * @return total items
      * @throws SQLException if database error
      */
-    public int countItems(Context context, Collection collection) throws SQLException;
+    int countItems(Context context, Collection collection) throws SQLException;
 
     /**
      * counts all items in the given collection including withdrawn items
@@ -805,7 +831,7 @@ public interface ItemService
      * @return total items
      * @throws SQLException if database error
      */
-    public int countAllItems(Context context, Collection collection) throws SQLException;
+    int countAllItems(Context context, Collection collection) throws SQLException;
 
     /**
      * Find all Items modified since a Date.
@@ -815,7 +841,7 @@ public interface ItemService
      * @return iterator over items
      * @throws SQLException if database error
      */
-    public Iterator<Item> findByLastModifiedSince(Context context, Date last)
+    Iterator<Item> findByLastModifiedSince(Context context, Date last)
         throws SQLException;
 
     /**
@@ -826,7 +852,7 @@ public interface ItemService
      * @return total items
      * @throws SQLException if database error
      */
-    public int countItems(Context context, Community community) throws SQLException;
+    int countItems(Context context, Community community) throws SQLException;
 
     /**
      * counts all items in the given community including withdrawn
@@ -836,7 +862,7 @@ public interface ItemService
      * @return total items
      * @throws SQLException if database error
      */
-    public int countAllItems(Context context, Community community) throws SQLException;
+    int countAllItems(Context context, Community community) throws SQLException;
 
     /**
      * counts all items
@@ -883,7 +909,7 @@ public interface ItemService
       * @throws SQLException
       * @throws SearchServiceException
       */
-    public List<Item> findItemsWithEdit(Context context, int offset, int limit)
+    List<Item> findItemsWithEdit(Context context, int offset, int limit)
         throws SQLException, SearchServiceException;
 
     /**
@@ -893,7 +919,7 @@ public interface ItemService
     * @throws SQLException
     * @throws SearchServiceException
     */
-    public int countItemsWithEdit(Context context) throws SQLException, SearchServiceException;
+    int countItemsWithEdit(Context context) throws SQLException, SearchServiceException;
 
     /**
      * Check if the supplied item is an inprogress submission
@@ -953,7 +979,7 @@ public interface ItemService
      *                     relationships.
      * @return metadata fields that match the parameters
      */
-    public List<MetadataValue> getMetadata(Item item, String schema, String element, String qualifier,
+    List<MetadataValue> getMetadata(Item item, String schema, String element, String qualifier,
                                            String lang, boolean enableVirtualMetadata);
 
     /**
@@ -961,7 +987,7 @@ public interface ItemService
      * @param item the item.
      * @return the label of the entity type, taken from the item metadata, or null if not found.
      */
-    public String getEntityTypeLabel(Item item);
+    String getEntityTypeLabel(Item item);
 
     /**
      * Retrieve the entity type of the given item.
@@ -969,6 +995,6 @@ public interface ItemService
      * @param item the item.
      * @return the entity type of the given item, or null if not found.
      */
-    public EntityType getEntityType(Context context, Item item) throws SQLException;
+    EntityType getEntityType(Context context, Item item) throws SQLException;
 
 }

dspace-api/src/main/java/org/dspace/contentreport/ContentReportServiceImpl.java

@@ -0,0 +1,190 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+package org.dspace.contentreport;
+
+import java.sql.SQLException;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Set;
+import java.util.UUID;
+
+import org.apache.logging.log4j.Logger;
+import org.dspace.content.Collection;
+import org.dspace.content.Community;
+import org.dspace.content.Item;
+import org.dspace.content.MetadataField;
+import org.dspace.content.service.CollectionService;
+import org.dspace.content.service.ItemService;
+import org.dspace.content.service.MetadataFieldService;
+import org.dspace.contentreport.service.ContentReportService;
+import org.dspace.core.Context;
+import org.dspace.services.ConfigurationService;
+import org.springframework.beans.factory.annotation.Autowired;
+
+public class ContentReportServiceImpl implements ContentReportService {
+
+    private static final Logger log = org.apache.logging.log4j.LogManager
+            .getLogger(ContentReportServiceImpl.class);
+
+    @Autowired
+    protected ConfigurationService configurationService;
+    @Autowired
+    private CollectionService collectionService;
+    @Autowired
+    private ItemService itemService;
+    @Autowired
+    private MetadataFieldService metadataFieldService;
+
+    /**
+     * Returns <code>true<</code> if Content Reports are enabled.
+     * @return <code>true<</code> if Content Reports are enabled
+     */
+    @Override
+    public boolean getEnabled() {
+        return configurationService.getBooleanProperty("contentreport.enable");
+    }
+
+    /**
+     * Retrieves item statistics per collection according to a set of Boolean filters.
+     * @param context DSpace context
+     * @param filters Set of filters
+     * @return a list of collections with the requested statistics for each of them
+     */
+    @Override
+    public List<FilteredCollection> findFilteredCollections(Context context, java.util.Collection<Filter> filters) {
+        List<FilteredCollection> colls = new ArrayList<>();
+        try {
+            List<Collection> collections = collectionService.findAll(context);
+            for (Collection collection : collections) {
+                FilteredCollection coll = new FilteredCollection();
+                coll.setHandle(collection.getHandle());
+                coll.setLabel(collection.getName());
+                Community community = collection.getCommunities().stream()
+                        .findFirst()
+                        .orElse(null);
+                if (community != null) {
+                    coll.setCommunityLabel(community.getName());
+                    coll.setCommunityHandle(community.getHandle());
+                }
+                colls.add(coll);
+
+                Iterator<Item> items = itemService.findAllByCollection(context, collection);
+                int nbTotalItems = 0;
+                while (items.hasNext()) {
+                    Item item = items.next();
+                    nbTotalItems++;
+                    boolean matchesAllFilters = true;
+                    for (Filter filter : filters) {
+                        if (filter.testItem(context, item)) {
+                            coll.addValue(filter, 1);
+                        } else {
+                            // This ensures the requested filter is present in the collection record
+                            // even when there are no matching items.
+                            coll.addValue(filter, 0);
+                            matchesAllFilters = false;
+                        }
+                    }
+                    if (matchesAllFilters) {
+                        coll.addAllFiltersValue(1);
+                    }
+                }
+                coll.setTotalItems(nbTotalItems);
+                coll.seal();
+            }
+        } catch (SQLException e) {
+            log.error("SQLException trying to receive filtered collections statistics", e);
+        }
+        return colls;
+    }
+
+    /**
+     * Retrieves a list of items according to a set of criteria.
+     * @param context DSpace context
+     * @param query structured query to find items against
+     * @return a list of items filtered according to the provided query
+     */
+    @Override
+    public FilteredItems findFilteredItems(Context context, FilteredItemsQuery query) {
+        FilteredItems report = new FilteredItems();
+
+        List<QueryPredicate> predicates = query.getQueryPredicates();
+        List<UUID> collectionUuids = getUuidsFromStrings(query.getCollections());
+        Set<Filter> filters = query.getFilters();
+
+        try {
+            List<Item> items = itemService.findByMetadataQuery(context, predicates, collectionUuids,
+                    query.getOffset(), query.getPageLimit());
+            items.stream()
+                    .filter(item -> filters.stream().allMatch(f -> f.testItem(context, item)))
+                    .forEach(report::addItem);
+        } catch (SQLException e) {
+            log.error(e.getMessage(), e);
+        }
+        try {
+            long count = itemService.countForMetadataQuery(context, predicates, collectionUuids);
+            report.setItemCount(count);
+        } catch (SQLException e) {
+            log.error(e.getMessage(), e);
+        }
+
+        return report;
+    }
+
+    /**
+     * Converts a metadata field name to a list of {@link MetadataField} instances
+     * (one if no wildcards are used, possibly more otherwise).
+     * @param context DSpace context
+     * @param metadataField field to search for
+     * @return a corresponding list of {@link MetadataField} entries
+     */
+    @Override
+    public List<MetadataField> getMetadataFields(org.dspace.core.Context context, String metadataField)
+            throws SQLException {
+        List<MetadataField> fields = new ArrayList<>();
+        if ("*".equals(metadataField)) {
+            return fields;
+        }
+        String schema = "";
+        String element = "";
+        String qualifier = null;
+        String[] parts = metadataField.split("\\.");
+        if (parts.length > 0) {
+            schema = parts[0];
+        }
+        if (parts.length > 1) {
+            element = parts[1];
+        }
+        if (parts.length > 2) {
+            qualifier = parts[2];
+        }
+
+        if (Item.ANY.equals(qualifier)) {
+            fields.addAll(metadataFieldService.findFieldsByElementNameUnqualified(context, schema, element));
+        } else {
+            MetadataField mf = metadataFieldService.findByElement(context, schema, element, qualifier);
+            if (mf != null) {
+                fields.add(mf);
+            }
+        }
+        return fields;
+    }
+
+    private static List<UUID> getUuidsFromStrings(List<String> collSel) {
+        List<UUID> uuids = new ArrayList<>();
+        for (String s: collSel) {
+            try {
+                uuids.add(UUID.fromString(s));
+            } catch (IllegalArgumentException e) {
+                log.warn("Invalid collection UUID: " + s);
+            }
+        }
+        return uuids;
+    }
+
+}

dspace-api/src/main/java/org/dspace/contentreport/Filter.java

@@ -0,0 +1,399 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+package org.dspace.contentreport;
+
+import java.sql.SQLException;
+import java.util.Arrays;
+import java.util.EnumSet;
+import java.util.List;
+import java.util.Objects;
+import java.util.Optional;
+import java.util.Set;
+import java.util.function.BiPredicate;
+import java.util.stream.Collectors;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.dspace.authorize.factory.AuthorizeServiceFactory;
+import org.dspace.authorize.service.AuthorizeService;
+import org.dspace.content.Bundle;
+import org.dspace.content.Item;
+import org.dspace.contentreport.ItemFilterUtil.BundleName;
+import org.dspace.core.Context;
+import org.dspace.services.factory.DSpaceServicesFactory;
+
+/**
+ * Available filters for the Filtered Collections and Filtered Items reports.
+ * In this enum, each item corresponds to a separate property, not values of
+ * a single property, hence the @JsonProperty applied to each of them.
+ * For each item, the annotation value is read through reflection and copied into
+ * the id property, which eliminates repetitions, hence reducing the risk or errors.
+ *
+ * @author Jean-François Morin (Université Laval)
+ */
+public enum Filter {
+
+    @JsonProperty("is_item")
+    IS_ITEM(FilterCategory.PROPERTY, (context, item) -> true),
+    @JsonProperty("is_withdrawn")
+    IS_WITHDRAWN(FilterCategory.PROPERTY, (context, item) -> item.isWithdrawn()),
+    @JsonProperty("is_not_withdrawn")
+    IS_NOT_WITHDRAWN(FilterCategory.PROPERTY, (context, item) -> !item.isWithdrawn()),
+    @JsonProperty("is_discoverable")
+    IS_DISCOVERABLE(FilterCategory.PROPERTY, (context, item) -> item.isDiscoverable()),
+    @JsonProperty("is_not_discoverable")
+    IS_NOT_DISCOVERABLE(FilterCategory.PROPERTY, (context, item) -> !item.isDiscoverable()),
+
+    /**
+     * Matches items having multiple original bitstreams.
+     */
+    @JsonProperty("has_multiple_originals")
+    HAS_MULTIPLE_ORIGINALS(FilterCategory.BITSTREAM, (context, item) ->
+        ItemFilterUtil.countOriginalBitstream(item) > 1),
+    /**
+     * Matches items having no original bitstreams.
+     */
+    @JsonProperty("has_no_originals")
+    HAS_NO_ORIGINALS(FilterCategory.BITSTREAM, (context, item) -> ItemFilterUtil.countOriginalBitstream(item) == 0),
+    /**
+     * Matches items having exactly one original bitstream.
+     */
+    @JsonProperty("has_one_original")
+    HAS_ONE_ORIGINAL(FilterCategory.BITSTREAM, (context, item) -> ItemFilterUtil.countOriginalBitstream(item) == 1),
+
+    /**
+     * Matches items having bitstreams with a MIME type that matches one defined in the "rest.report-mime-document"
+     * configuration property.
+     */
+    @JsonProperty("has_doc_original")
+    HAS_DOC_ORIGINAL(FilterCategory.BITSTREAM_MIME, (context, item) ->
+        ItemFilterUtil.countOriginalBitstreamMime(context, item, ItemFilterUtil.getDocumentMimeTypes()) > 0),
+    /**
+     * Matches items having bitstreams with a MIME type starting with "image" (e.g., image/jpeg, image/png).
+     */
+    @JsonProperty("has_image_original")
+    HAS_IMAGE_ORIGINAL(FilterCategory.BITSTREAM_MIME, (context, item) ->
+        ItemFilterUtil.countOriginalBitstreamMimeStartsWith(context, item, "image") > 0),
+    /**
+     * Matches items having bitstreams with a MIME type other than document (cf. HAS_DOCUMENT above) or image
+     * (cf. HAS_IMAGE_ORIGINAL above).
+     */
+    @JsonProperty("has_unsupp_type")
+    HAS_UNSUPPORTED_TYPE(FilterCategory.BITSTREAM_MIME, (context, item) -> {
+        int bitCount = ItemFilterUtil.countOriginalBitstream(item);
+        if (bitCount == 0) {
+            return false;
+        }
+        int docCount = ItemFilterUtil.countOriginalBitstreamMime(context, item, ItemFilterUtil.getDocumentMimeTypes());
+        int imgCount = ItemFilterUtil.countOriginalBitstreamMimeStartsWith(context, item, "image");
+        return (bitCount - docCount - imgCount) > 0;
+    }),
+    /**
+     * Matches items having bitstreams of multiple types (document, image, other).
+     */
+    @JsonProperty("has_mixed_original")
+    HAS_MIXED_ORIGINAL(FilterCategory.BITSTREAM_MIME, (context, item) -> {
+        int countBit = ItemFilterUtil.countOriginalBitstream(item);
+        if (countBit <= 1) {
+            return false;
+        }
+        int countDoc = ItemFilterUtil.countOriginalBitstreamMime(context, item, ItemFilterUtil.getDocumentMimeTypes());
+        if (countDoc > 0) {
+            return countDoc != countBit;
+        }
+        int countImg = ItemFilterUtil.countOriginalBitstreamMimeStartsWith(context, item, "image");
+        if (countImg > 0) {
+            return countImg != countBit;
+        }
+        return false;
+    }),
+    @JsonProperty("has_pdf_original")
+    HAS_PDF_ORIGINAL(FilterCategory.BITSTREAM_MIME, (context, item) ->
+        ItemFilterUtil.countOriginalBitstreamMime(context, item, ItemFilterUtil.MIMES_PDF) > 0),
+    @JsonProperty("has_jpg_original")
+    HAS_JPEG_ORIGINAL(FilterCategory.BITSTREAM_MIME, (context, item) ->
+        ItemFilterUtil.countOriginalBitstreamMime(context, item, ItemFilterUtil.MIMES_JPG) > 0),
+    /**
+     * Matches items having at least one PDF of size less than 20 kb (configurable in rest.cfg).
+     */
+    @JsonProperty("has_small_pdf")
+    HAS_SMALL_PDF(FilterCategory.BITSTREAM_MIME, (context, item) ->
+        ItemFilterUtil.countBitstreamSmallerThanMinSize(
+                context, BundleName.ORIGINAL, item, ItemFilterUtil.MIMES_PDF, "rest.report-pdf-min-size") > 0),
+    /**
+     * Matches items having at least one PDF of size more than 25 Mb (configurable in rest.cfg).
+     */
+    @JsonProperty("has_large_pdf")
+    HAS_LARGE_PDF(FilterCategory.BITSTREAM_MIME, (context, item) ->
+        ItemFilterUtil.countBitstreamLargerThanMaxSize(
+                context, BundleName.ORIGINAL,  item, ItemFilterUtil.MIMES_PDF, "rest.report-pdf-max-size") > 0),
+    /**
+     * Matches items having at least one non-text bitstream.
+     */
+    @JsonProperty("has_doc_without_text")
+    HAS_DOC_WITHOUT_TEXT(FilterCategory.BITSTREAM_MIME, (context, item) -> {
+        int countDoc = ItemFilterUtil.countOriginalBitstreamMime(context, item, ItemFilterUtil.getDocumentMimeTypes());
+        if (countDoc == 0) {
+            return false;
+        }
+        int countText = ItemFilterUtil.countBitstream(BundleName.TEXT, item);
+        return countDoc > countText;
+    }),
+
+    /**
+     * Matches items having at least one image, but all of supported types.
+     */
+    @JsonProperty("has_only_supp_image_type")
+    HAS_ONLY_SUPPORTED_IMAGE_TYPE(FilterCategory.MIME, (context, item) -> {
+        int imageCount = ItemFilterUtil.countOriginalBitstreamMimeStartsWith(context, item, "image/");
+        if (imageCount == 0) {
+            return false;
+        }
+        int suppImageCount = ItemFilterUtil.countOriginalBitstreamMime(
+                context, item, ItemFilterUtil.getSupportedImageMimeTypes());
+        return (imageCount == suppImageCount);
+    }),
+    /**
+     * Matches items having at least one image of an unsupported type.
+     */
+    @JsonProperty("has_unsupp_image_type")
+    HAS_UNSUPPORTED_IMAGE_TYPE(FilterCategory.MIME, (context, item) -> {
+        int imageCount = ItemFilterUtil.countOriginalBitstreamMimeStartsWith(context, item, "image/");
+        if (imageCount == 0) {
+            return false;
+        }
+        int suppImageCount = ItemFilterUtil.countOriginalBitstreamMime(
+                context, item, ItemFilterUtil.getSupportedImageMimeTypes());
+        return (imageCount - suppImageCount) > 0;
+    }),
+    /**
+     * Matches items having at least one document, but all of supported types.
+     */
+    @JsonProperty("has_only_supp_doc_type")
+    HAS_ONLY_SUPPORTED_DOC_TYPE(FilterCategory.MIME, (context, item) -> {
+        int docCount = ItemFilterUtil.countOriginalBitstreamMime(context, item, ItemFilterUtil.getDocumentMimeTypes());
+        if (docCount == 0) {
+            return false;
+        }
+        int suppDocCount = ItemFilterUtil.countOriginalBitstreamMime(
+                context, item, ItemFilterUtil.getSupportedDocumentMimeTypes());
+        return docCount == suppDocCount;
+    }),
+    /**
+     * Matches items having at least one document of an unsupported type.
+     */
+    @JsonProperty("has_unsupp_doc_type")
+    HAS_UNSUPPORTED_DOC_TYPE(FilterCategory.MIME, (context, item) -> {
+        int docCount = ItemFilterUtil.countOriginalBitstreamMime(context, item, ItemFilterUtil.getDocumentMimeTypes());
+        if (docCount == 0) {
+            return false;
+        }
+        int suppDocCount = ItemFilterUtil.countOriginalBitstreamMime(
+                context, item, ItemFilterUtil.getSupportedDocumentMimeTypes());
+        return (docCount - suppDocCount) > 0;
+    }),
+
+    /**
+     * Matches items having at least one unsupported bundle.
+     */
+    @JsonProperty("has_unsupported_bundle")
+    HAS_UNSUPPORTED_BUNDLE(FilterCategory.BUNDLE, (context, item) -> {
+        String[] bundleList = DSpaceServicesFactory.getInstance().getConfigurationService()
+                .getArrayProperty("rest.report-supp-bundles");
+        return ItemFilterUtil.hasUnsupportedBundle(item, bundleList);
+    }),
+    /**
+     * Matches items having at least one thumbnail of size less than 400 bytes (configurable in rest.cfg).
+     */
+    @JsonProperty("has_small_thumbnail")
+    HAS_SMALL_THUMBNAIL(FilterCategory.BUNDLE, (context, item) ->
+        ItemFilterUtil.countBitstreamSmallerThanMinSize(
+                context, BundleName.THUMBNAIL, item, ItemFilterUtil.MIMES_JPG, "rest.report-thumbnail-min-size") > 0),
+    /**
+     * Matches items having at least one original without a thumbnail.
+     */
+    @JsonProperty("has_original_without_thumbnail")
+    HAS_ORIGINAL_WITHOUT_THUMBNAIL(FilterCategory.BUNDLE, (context, item) -> {
+        int countBit = ItemFilterUtil.countOriginalBitstream(item);
+        if (countBit == 0) {
+            return false;
+        }
+        int countThumb = ItemFilterUtil.countBitstream(BundleName.THUMBNAIL, item);
+        return countBit > countThumb;
+    }),
+    /**
+     * Matches items having at least one non-JPEG thumbnail.
+     */
+    @JsonProperty("has_invalid_thumbnail_name")
+    HAS_INVALID_THUMBNAIL_NAME(FilterCategory.BUNDLE, (context, item) -> {
+        List<String> originalNames = ItemFilterUtil.getBitstreamNames(BundleName.ORIGINAL, item);
+        List<String> thumbNames = ItemFilterUtil.getBitstreamNames(BundleName.THUMBNAIL, item);
+        if (thumbNames.size() != originalNames.size()) {
+            return false;
+        }
+        return originalNames.stream()
+                .anyMatch(name -> !thumbNames.contains(name + ".jpg") && !thumbNames.contains(name + ".jpeg"));
+    }),
+    /**
+     * Matches items having at least one non-generated thumbnail.
+     */
+    @JsonProperty("has_non_generated_thumb")
+    HAS_NON_GENERATED_THUMBNAIL(FilterCategory.BUNDLE, (context, item) -> {
+        String[] generatedThumbDesc = DSpaceServicesFactory.getInstance().getConfigurationService()
+                .getArrayProperty("rest.report-gen-thumbnail-desc");
+        int countThumb = ItemFilterUtil.countBitstream(BundleName.THUMBNAIL, item);
+        if (countThumb == 0) {
+            return false;
+        }
+        int countGen = ItemFilterUtil.countBitstreamByDesc(BundleName.THUMBNAIL, item, generatedThumbDesc);
+        return (countThumb > countGen);
+    }),
+    /**
+     * Matches items having no licence-typed bitstreams.
+     */
+    @JsonProperty("no_license")
+    NO_LICENSE(FilterCategory.BUNDLE, (context, item) ->
+        ItemFilterUtil.countBitstream(BundleName.LICENSE, item) == 0),
+    /**
+     * Matches items having licence documentation (a licence bitstream named other than license.txt).
+     */
+    @JsonProperty("has_license_documentation")
+    HAS_LICENSE_DOCUMENTATION(FilterCategory.BUNDLE, (context, item) -> {
+        List<String> names = ItemFilterUtil.getBitstreamNames(BundleName.LICENSE, item);
+        return names.stream()
+                .anyMatch(name -> !name.equals("license.txt"));
+    }),
+
+    /**
+     * Matches items having at least one original with restricted access.
+     */
+    @JsonProperty("has_restricted_original")
+    HAS_RESTRICTED_ORIGINAL(FilterCategory.PERMISSION, (context, item) -> {
+        return item.getBundles().stream()
+                .filter(bundle -> bundle.getName().equals(BundleName.ORIGINAL.name()))
+                .map(Bundle::getBitstreams)
+                .flatMap(List::stream)
+                .anyMatch(bit -> {
+                    try {
+                        if (!getAuthorizeService()
+                                .authorizeActionBoolean(getAnonymousContext(), bit, org.dspace.core.Constants.READ)) {
+                            return true;
+                        }
+                    } catch (SQLException e) {
+                        getLog().warn("SQL Exception testing original bitstream access " + e.getMessage(), e);
+                    }
+                    return false;
+                });
+    }),
+    /**
+     * Matches items having at least one thumbnail with restricted access.
+     */
+    @JsonProperty("has_restricted_thumbnail")
+    HAS_RESTRICTED_THUMBNAIL(FilterCategory.PERMISSION, (context, item) -> {
+        return item.getBundles().stream()
+                .filter(bundle -> bundle.getName().equals(BundleName.THUMBNAIL.name()))
+                .map(Bundle::getBitstreams)
+                .flatMap(List::stream)
+                .anyMatch(bit -> {
+                    try {
+                        if (!getAuthorizeService()
+                                .authorizeActionBoolean(getAnonymousContext(), bit, org.dspace.core.Constants.READ)) {
+                            return true;
+                        }
+                    } catch (SQLException e) {
+                        getLog().warn("SQL Exception testing thumbnail bitstream access " + e.getMessage(), e);
+                    }
+                    return false;
+                });
+    }),
+    /**
+     * Matches items having metadata with restricted access.
+     */
+    @JsonProperty("has_restricted_metadata")
+    HAS_RESTRICTED_METADATA(FilterCategory.PERMISSION, (context, item) -> {
+        try {
+            return !getAuthorizeService()
+                    .authorizeActionBoolean(getAnonymousContext(), item, org.dspace.core.Constants.READ);
+        } catch (SQLException e) {
+            getLog().warn("SQL Exception testing item metadata access " + e.getMessage(), e);
+            return false;
+        }
+    });
+
+    private static final Logger log = LogManager.getLogger();
+    private static AuthorizeService authorizeService;
+    private static Context anonymousContext;
+
+    private String id;
+    private FilterCategory category;
+    private BiPredicate<Context, Item> itemTester;
+
+    Filter(FilterCategory category, BiPredicate<Context, Item> itemTester) {
+        try {
+            JsonProperty jp = getClass().getField(name()).getAnnotation(JsonProperty.class);
+            id = Optional.ofNullable(jp).map(JsonProperty::value).orElse(name());
+        } catch (Exception e) {
+            id = name();
+        }
+        this.category = category;
+        this.itemTester = itemTester;
+    }
+
+    public String getId() {
+        return id;
+    }
+
+    public FilterCategory getCategory() {
+        return category;
+    }
+
+    public boolean testItem(Context context, Item item) {
+        return itemTester.test(context, item);
+    }
+
+    private static Logger getLog() {
+        return log;
+    }
+
+    private static AuthorizeService getAuthorizeService() {
+        if (authorizeService == null) {
+            authorizeService = AuthorizeServiceFactory.getInstance().getAuthorizeService();
+        }
+        return authorizeService;
+    }
+
+    private static Context getAnonymousContext() {
+        if (anonymousContext == null) {
+            anonymousContext = new Context();
+        }
+        return anonymousContext;
+    }
+
+    @JsonCreator
+    public static Filter get(String id) {
+        return Arrays.stream(values())
+                .filter(item -> Objects.equals(item.id, id))
+                .findFirst()
+                .orElse(null);
+    }
+
+    public static Set<Filter> getFilters(String filters) {
+        String[] ids = Optional.ofNullable(filters).orElse("").split("[^a-z_]+");
+        Set<Filter> set = Arrays.stream(ids)
+                .map(Filter::get)
+                .filter(f -> f != null)
+                .collect(Collectors.toCollection(() -> EnumSet.noneOf(Filter.class)));
+        if (set == null) {
+            set = EnumSet.noneOf(Filter.class);
+        }
+        return set;
+    }
+
+}

dspace-api/src/main/java/org/dspace/contentreport/FilterCategory.java

@@ -0,0 +1,50 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+package org.dspace.contentreport;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+/**
+ * Identifies the category/section of filters defined in the {@link Filter} enum.
+ * This enum will be used when/if the structured filter definitions are returned to
+ * the Angular layer through a REST endpoint.
+ *
+ * @author Jean-François Morin (Université Laval)
+ */
+public enum FilterCategory {
+
+    PROPERTY("property"),
+    BITSTREAM("bitstream"),
+    BITSTREAM_MIME("bitstream_mime"),
+    MIME("mime"),
+    BUNDLE("bundle"),
+    PERMISSION("permission");
+
+    private String id;
+    private List<Filter> filters;
+
+    FilterCategory(String id) {
+        this.id = id;
+    }
+
+    public String getId() {
+        return id;
+    }
+
+    public List<Filter> getFilters() {
+        if (filters == null) {
+            filters = Arrays.stream(Filter.values())
+                    .filter(f -> f.getCategory() == this)
+                    .collect(Collectors.toUnmodifiableList());
+        }
+        return filters;
+    }
+
+}

dspace-api/src/main/java/org/dspace/contentreport/FilteredCollection.java

@@ -0,0 +1,219 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+package org.dspace.contentreport;
+
+import java.io.Serializable;
+import java.util.EnumMap;
+import java.util.Map;
+import java.util.Optional;
+
+/**
+ * This class represents an entry in the Filtered Collections report.
+ *
+ * @author Jean-François Morin (Université Laval)
+ */
+public class FilteredCollection implements Cloneable, Serializable {
+
+    private static final long serialVersionUID = -231735620268582719L;
+
+    /** Name of the collection */
+    private String label;
+    /** Handle of the collection, used to make it clickable from the generated report */
+    private String handle;
+    /** Name of the owning community */
+    private String communityLabel;
+    /** Handle of the owning community, used to make it clickable from the generated report */
+    private String communityHandle;
+    /** Total number of items in the collection */
+    private int totalItems;
+    /** Number of filtered items per requested filter in the collection */
+    private Map<Filter, Integer> values = new EnumMap<>(Filter.class);
+    /** Number of items in the collection that match all requested filters */
+    private int allFiltersValue;
+    /**
+     * Indicates whether this object is protected against further changes.
+     * This is used in computing summary data in the parent FilteredCollectionsRest class.
+     */
+    private boolean sealed;
+
+    /**
+     * Shortcut method that builds a FilteredCollectionRest instance
+     * from its building blocks.
+     * @param label Name of the collection
+     * @param handle Handle of the collection
+     * @param communityLabel Name of the owning community
+     * @param communityHandle Handle of the owning community
+     * @param totalItems Total number of items in the collection
+     * @param allFiltersValue Number of items in the collection that match all requested filters
+     * @param values Number of filtered items per requested filter in the collection
+     * @param doSeal true if the collection must be sealed immediately
+     * @return a FilteredCollectionRest instance built from the provided parameters
+     */
+    public static FilteredCollection of(String label, String handle,
+            String communityLabel, String communityHandle,
+            int totalItems, int allFiltersValue, Map<Filter, Integer> values, boolean doSeal) {
+        var coll = new FilteredCollection();
+        coll.label = label;
+        coll.handle = handle;
+        coll.communityLabel = communityLabel;
+        coll.communityHandle = communityHandle;
+        coll.totalItems = totalItems;
+        coll.allFiltersValue = allFiltersValue;
+        Optional.ofNullable(values).ifPresent(vs -> vs.forEach(coll::addValue));
+        if (doSeal) {
+            coll.seal();
+        }
+        return coll;
+    }
+
+    /**
+     * Returns the item counts per filter.
+     * If this object is sealed, a defensive copy will be returned.
+     *
+     * @return the item counts per filter
+     */
+    public Map<Filter, Integer> getValues() {
+        if (sealed) {
+            return new EnumMap<>(values);
+        }
+        return values;
+    }
+
+    /**
+     * Increments a filtered item count for a given filter.
+     *
+     * @param filter Filter to add to the requested filters in this collection
+     * @param delta Number by which the filtered item count must be incremented
+     * for the requested filter
+     */
+    public void addValue(Filter filter, int delta) {
+        checkSealed();
+        Integer oldValue = values.getOrDefault(filter, Integer.valueOf(0));
+        int newValue = oldValue.intValue() + delta;
+        values.put(filter, Integer.valueOf(newValue));
+    }
+
+    /**
+     * Sets all filtered item counts for this collection.
+     * The contents are copied into this object's internal Map, which is protected against
+     * further tampering with the provided Map.
+     *
+     * @param values Values that replace the current ones
+     */
+    public void setValues(Map<? extends Filter, ? extends Integer> values) {
+        checkSealed();
+        this.values.clear();
+        this.values.putAll(values);
+    }
+
+    public String getLabel() {
+        return label;
+    }
+
+    public void setLabel(String label) {
+        checkSealed();
+        this.label = label;
+    }
+
+    public String getHandle() {
+        return handle;
+    }
+
+    public void setHandle(String handle) {
+        checkSealed();
+        this.handle = handle;
+    }
+
+    public String getCommunityLabel() {
+        return communityLabel;
+    }
+
+    public void setCommunityLabel(String communityLabel) {
+        checkSealed();
+        this.communityLabel = communityLabel;
+    }
+
+    public String getCommunityHandle() {
+        return communityHandle;
+    }
+
+    public void setCommunityHandle(String communityHandle) {
+        checkSealed();
+        this.communityHandle = communityHandle;
+    }
+
+    public int getTotalItems() {
+        return totalItems;
+    }
+
+    public void setTotalItems(int totalItems) {
+        checkSealed();
+        this.totalItems = totalItems;
+    }
+
+    public int getAllFiltersValue() {
+        return allFiltersValue;
+    }
+
+    /**
+     * Increments the count of items matching all filters.
+     *
+     * @param delta Number by which the count must be incremented
+     */
+    public void addAllFiltersValue(int delta) {
+        checkSealed();
+        allFiltersValue++;
+    }
+
+    /**
+     * Replaces the count of items matching all filters.
+     *
+     * @param allFiltersValue Number that replaces the current item count
+     */
+    public void setAllFiltersValue(int allFiltersValue) {
+        checkSealed();
+        this.allFiltersValue = allFiltersValue;
+    }
+
+    public boolean getSealed() {
+        return sealed;
+    }
+
+    /**
+     * Seals this filtered collection object.
+     * No changes to this object can be made afterwards. Any attempt will throw
+     * an IllegalStateException.
+     */
+    public void seal() {
+        sealed = true;
+    }
+
+    private void checkSealed() {
+        if (sealed) {
+            throw new IllegalStateException("This filtered collection record is sealed"
+                    + " and cannot be modified anymore. You can apply changes to a non-sealed clone.");
+        }
+    }
+
+    /**
+     * Returns a non-sealed clone of this filtered collection record.
+     *
+     * @return a new non-sealed FilteredCollectionRest instance containing
+     * all attribute values of this object
+     */
+    @Override
+    public FilteredCollection clone() {
+        var clone = new FilteredCollection();
+        clone.label = label;
+        clone.handle = handle;
+        clone.values.putAll(values);
+        clone.allFiltersValue = allFiltersValue;
+        return clone;
+    }
+
+}

dspace-api/src/main/java/org/dspace/contentreport/FilteredCollections.java

@@ -0,0 +1,107 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+package org.dspace.contentreport;
+
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.Optional;
+
+/**
+ * This class represents the complete result of a Filtered Collections report query.
+ * In addition to the list of FilteredCollection entries, it contains the lazily computed
+ * summary to be included in the completed report.
+ *
+ * @author Jean-François Morin (Université Laval)
+ */
+public class FilteredCollections implements Serializable {
+
+    private static final long serialVersionUID = 3622651208704009095L;
+
+    /** Collections included in the report */
+    private List<FilteredCollection> collections = new ArrayList<>();
+    /**
+     * Summary generated by adding up data for each filter included in the report.
+     * It will be regenerated if any non-sealed collection item is found in
+     * the {@link #collections} collection attribute.
+     */
+    private FilteredCollection summary;
+
+    /**
+     * Shortcut method that builds a FilteredCollectionsRest instance
+     * from its building blocks.
+     * @param collections a list of FilteredCollectionRest instances
+     * @return a FilteredCollectionsRest instance built from the provided parameters
+     */
+    public static FilteredCollections of(Collection<FilteredCollection> collections) {
+        var colls = new FilteredCollections();
+        Optional.ofNullable(collections).ifPresent(cs -> cs.stream().forEach(colls::addCollection));
+        return colls;
+    }
+
+    /**
+     * Returns a defensive copy of the collections included in this report.
+     *
+     * @return the collections included in this report
+     */
+    public List<FilteredCollection> getCollections() {
+        return new ArrayList<>(collections);
+    }
+
+    /**
+     * Adds a {@link FilteredCollectionRest} object to this report.
+     *
+     * @param coll {@link FilteredCollectionRest} to add to this report
+     */
+    public void addCollection(FilteredCollection coll) {
+        summary = null;
+        collections.add(coll);
+    }
+
+    /**
+     * Sets all collections for this report.
+     * The contents are copied into this object's internal list, which is protected against
+     * further tampering with the provided list.
+     *
+     * @param collections Values that replace the current ones
+     */
+    public void setCollections(List<FilteredCollection> collections) {
+        summary = null;
+        this.collections.clear();
+        this.collections.addAll(collections);
+    }
+
+    /**
+     * Returns the report summary.
+     * If the summary has not been computed yet and/or the report includes non-sealed collections,
+     * it will be regenerated.
+     *
+     * @return the generated report summary
+     */
+    public FilteredCollection getSummary() {
+        boolean needsRefresh = summary == null || collections.stream().anyMatch(c -> !c.getSealed());
+        if (needsRefresh) {
+            summary = new FilteredCollection();
+            for (var coll : collections) {
+                coll.getValues().forEach(summary::addValue);
+            }
+            int total = collections.stream()
+                    .mapToInt(FilteredCollection::getTotalItems)
+                    .sum();
+            summary.setTotalItems(total);
+            int allFilters = collections.stream()
+                    .mapToInt(FilteredCollection::getAllFiltersValue)
+                    .sum();
+            summary.setAllFiltersValue(allFilters);
+            summary.seal();
+        }
+        return summary;
+    }
+
+}

dspace-api/src/main/java/org/dspace/contentreport/FilteredItems.java

@@ -0,0 +1,70 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+package org.dspace.contentreport;
+
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.dspace.content.Item;
+
+/**
+ * This class represents a list of items for a  Filtered Items report query.
+ * Since the underlying list should correspond to only a page of results,
+ * the total number of items found through the query is included in this report.
+ *
+ * @author Jean-François Morin (Université Laval)
+ */
+public class FilteredItems implements Serializable {
+
+    private static final long serialVersionUID = 7980375013177658249L;
+
+    /** Items included in the report */
+    private List<Item> items = new ArrayList<>();
+    /** Total item count (for pagination) */
+    private long itemCount;
+
+    /**
+     * Returns a defensive copy of the items included in this report.
+     *
+     * @return the items included in this report
+     */
+    public List<Item> getItems() {
+        return new ArrayList<>(items);
+    }
+
+    /**
+     * Adds an {@link ItemRest} object to this report.
+     *
+     * @param item {@link ItemRest} to add to this report
+     */
+    public void addItem(Item item) {
+        items.add(item);
+    }
+
+    /**
+     * Sets all items for this report.
+     * The contents are copied into this object's internal list, which is protected
+     * against further tampering with the provided list.
+     *
+     * @param items Values that replace the current ones
+     */
+    public void setItems(List<Item> items) {
+        this.items.clear();
+        this.items.addAll(items);
+    }
+
+    public long getItemCount() {
+        return itemCount;
+    }
+
+    public void setItemCount(long itemCount) {
+        this.itemCount = itemCount;
+    }
+
+}

dspace-api/src/main/java/org/dspace/contentreport/FilteredItemsQuery.java

@@ -0,0 +1,115 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+package org.dspace.contentreport;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.EnumSet;
+import java.util.List;
+import java.util.Optional;
+import java.util.Set;
+
+/**
+ * Structured query contents for the Filtered Items report
+ * @author Jean-François Morin (Université Laval)
+ */
+public class FilteredItemsQuery {
+
+    private List<String> collections = new ArrayList<>();
+    private List<QueryPredicate> queryPredicates = new ArrayList<>();
+    private long offset;
+    private int pageLimit;
+    private Set<Filter> filters = EnumSet.noneOf(Filter.class);
+    private List<String> additionalFields = new ArrayList<>();
+
+    /**
+     * Shortcut method that builds a FilteredItemsQuery instance
+     * from its building blocks.
+     * @param collectionUuids collection UUIDs to add
+     * @param predicates query predicates used to filter existing items
+     * @param pageLimit number of items per page
+     * @param filters filters to apply to existing items
+     * The filters mapping to true will be applied, others (either missing or
+     * mapping to false) will not.
+     * @param additionalFields additional fields to display in the resulting report
+     * @return a FilteredItemsQuery instance built from the provided parameters
+     */
+    public static FilteredItemsQuery of(Collection<String> collectionUuids,
+            Collection<QueryPredicate> predicates, long offset, int pageLimit,
+            Collection<Filter> filters, Collection<String> additionalFields) {
+        var query = new FilteredItemsQuery();
+        Optional.ofNullable(collectionUuids).ifPresent(query.collections::addAll);
+        Optional.ofNullable(predicates).ifPresent(query.queryPredicates::addAll);
+        query.offset = offset;
+        query.pageLimit = pageLimit;
+        Optional.ofNullable(filters).ifPresent(query.filters::addAll);
+        Optional.ofNullable(additionalFields).ifPresent(query.additionalFields::addAll);
+        return query;
+    }
+
+    public List<String> getCollections() {
+        return collections;
+    }
+
+    public void setCollections(List<String> collections) {
+        this.collections.clear();
+        if (collections != null) {
+            this.collections.addAll(collections);
+        }
+    }
+
+    public List<QueryPredicate> getQueryPredicates() {
+        return queryPredicates;
+    }
+
+    public void setQueryPredicates(List<QueryPredicate> queryPredicates) {
+        this.queryPredicates.clear();
+        if (queryPredicates != null) {
+            this.queryPredicates.addAll(queryPredicates);
+        }
+    }
+
+    public long getOffset() {
+        return offset;
+    }
+
+    public void setOffset(long offset) {
+        this.offset = offset;
+    }
+
+    public int getPageLimit() {
+        return pageLimit;
+    }
+
+    public void setPageLimit(int pageLimit) {
+        this.pageLimit = pageLimit;
+    }
+
+    public Set<Filter> getFilters() {
+        return filters;
+    }
+
+    public void setFilters(Set<Filter> filters) {
+        this.filters.clear();
+        if (filters != null) {
+            this.filters.addAll(filters);
+        }
+    }
+
+    public List<String> getAdditionalFields() {
+        return additionalFields;
+    }
+
+    public void setAdditionalFields(List<String> additionalFields) {
+        this.additionalFields.clear();
+        if (additionalFields != null) {
+            this.additionalFields.addAll(additionalFields);
+        }
+    }
+
+}

dspace-api/src/main/java/org/dspace/contentreport/ItemFilterUtil.java

@@ -0,0 +1,353 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+package org.dspace.contentreport;
+
+import static org.dspace.content.Item.ANY;
+
+import java.sql.SQLException;
+import java.util.Arrays;
+import java.util.Calendar;
+import java.util.List;
+import java.util.Set;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.dspace.content.Bitstream;
+import org.dspace.content.Bundle;
+import org.dspace.content.Item;
+import org.dspace.content.factory.ContentServiceFactory;
+import org.dspace.content.service.ItemService;
+import org.dspace.core.Context;
+import org.dspace.services.factory.DSpaceServicesFactory;
+
+/**
+ * Utility methods for applying some of the filters defined in the {@link Filter} enum.
+ *
+ * @author Jean-François Morin (Université Laval) (port to DSpace 7.x)
+ * @author Terry Brady, Georgetown University (original code in DSpace 6.x)
+ */
+public class ItemFilterUtil {
+
+    protected static ItemService itemService = ContentServiceFactory.getInstance().getItemService();
+    private static final Logger log = LogManager.getLogger(ItemFilterUtil.class);
+    public static final String[] MIMES_PDF = {"application/pdf"};
+    public static final String[] MIMES_JPG = {"image/jpeg"};
+
+    /**
+     * Supported bundle types.
+     * N.B.: Bundle names are used in metadata as they are named here.
+     * Do NOT change these names, the name() method is invoked at multiple
+     * locations in this class and enum Filter.
+     * If these names are to change, the name() invocations shall be changed
+     * so that they refer to these unchanged names, likely through a String property.
+     */
+    enum BundleName {
+        ORIGINAL, TEXT, LICENSE, THUMBNAIL;
+    }
+
+    private ItemFilterUtil() {}
+
+    static String[] getDocumentMimeTypes() {
+        return DSpaceServicesFactory.getInstance().getConfigurationService()
+                .getArrayProperty("rest.report-mime-document");
+    }
+
+    static String[] getSupportedDocumentMimeTypes() {
+        return DSpaceServicesFactory.getInstance().getConfigurationService()
+                .getArrayProperty("rest.report-mime-document-supported");
+    }
+
+    static String[] getSupportedImageMimeTypes() {
+        return DSpaceServicesFactory.getInstance().getConfigurationService()
+                .getArrayProperty("rest.report-mime-document-image");
+    }
+
+    /**
+     * Counts the original bitstreams of a given item.
+     * @param item Provided item
+     * @return the number of original bitstreams in the item
+     */
+    static int countOriginalBitstream(Item item) {
+        return countBitstream(BundleName.ORIGINAL, item);
+    }
+
+    /**
+     * Counts the bitstreams of a given item for a specific type.
+     * @param bundleName Type of bundle to filter bitstreams
+     * @param item Provided item
+     * @return the number of matching bitstreams in the item
+     */
+    static int countBitstream(BundleName bundleName, Item item) {
+        return item.getBundles().stream()
+                .filter(bundle -> bundle.getName().equals(bundleName.name()))
+                .mapToInt(bundle -> bundle.getBitstreams().size())
+                .sum();
+    }
+
+    /**
+     * Retrieves the bitstream names of an given item for a specific bundle type.
+     * @param bundleName Type of bundle to filter bitstreams
+     * @param item Provided item
+     * @return the names of matching bitstreams in the item
+     */
+    static List<String> getBitstreamNames(BundleName bundleName, Item item) {
+        return item.getBundles().stream()
+                .filter(bundle -> bundle.getName().equals(bundleName.name()))
+                .map(Bundle::getBitstreams)
+                .flatMap(List::stream)
+                .map(Bitstream::getName)
+                .collect(Collectors.toList());
+    }
+
+    /**
+     * Counts the original bitstreams of a given item matching one of a list of specific MIME types.
+     * @param context DSpace context
+     * @param item Provided item
+     * @param mimeList List of MIME types to filter bitstreams
+     * @return number of matching original bitstreams
+     */
+    static int countOriginalBitstreamMime(Context context, Item item, String[] mimeList) {
+        return countBitstreamMime(context, BundleName.ORIGINAL, item, mimeList);
+    }
+
+    /**
+     * Counts the bitstreams of a given item for a specific type matching one of a list of specific MIME types.
+     * @param context DSpace context
+     * @param bundleName Type of bundle to filter bitstreams
+     * @param item Provided item
+     * @param mimeList List of MIME types to filter bitstreams
+     * @return number of matching bitstreams
+     */
+    static int countBitstreamMime(Context context, BundleName bundleName, Item item, String[] mimeList) {
+        return item.getBundles().stream()
+                .filter(bundle -> bundle.getName().equals(bundleName.name()))
+                .map(Bundle::getBitstreams)
+                .flatMap(List::stream)
+                .mapToInt(bit -> {
+                    int count = 0;
+                    for (String mime : mimeList) {
+                        try {
+                            if (bit.getFormat(context).getMIMEType().equals(mime.trim())) {
+                                count++;
+                            }
+                        } catch (SQLException e) {
+                            log.error("Get format error for bitstream " + bit.getName());
+                        }
+                    }
+                    return count;
+                })
+                .sum();
+    }
+
+    /**
+     * Counts the bitstreams of a given item for a specific type matching one of a list of specific descriptions.
+     * @param bundleName Type of bundle to filter bitstreams
+     * @param item Provided item
+     * @param descList List of descriptions to filter bitstreams
+     * @return number of matching bitstreams
+     */
+    static int countBitstreamByDesc(BundleName bundleName, Item item, String[] descList) {
+        return item.getBundles().stream()
+                .filter(bundle -> bundle.getName().equals(bundleName.name()))
+                .map(Bundle::getBitstreams)
+                .flatMap(List::stream)
+                .filter(bit -> bit.getDescription() != null)
+                .mapToInt(bit -> {
+                    int count = 0;
+                    for (String desc : descList) {
+                        String bitDesc = bit.getDescription();
+                        if (bitDesc.equals(desc.trim())) {
+                            count++;
+                        }
+                    }
+                    return count;
+                })
+                .sum();
+    }
+
+    /**
+     * Counts the bitstreams of a given item smaller than a given size for a specific type
+     * matching one of a list of specific MIME types.
+     * @param context DSpace context
+     * @param bundleName Type of bundle to filter bitstreams
+     * @param item Provided item
+     * @param mimeList List of MIME types to filter bitstreams
+     * @param prop Configurable property providing the size to filter bitstreams
+     * @return number of matching bitstreams
+     */
+    static int countBitstreamSmallerThanMinSize(
+            Context context, BundleName bundleName, Item item, String[] mimeList, String prop) {
+        long size = DSpaceServicesFactory.getInstance().getConfigurationService().getLongProperty(prop);
+        return item.getBundles().stream()
+                .filter(bundle -> bundle.getName().equals(bundleName.name()))
+                .map(Bundle::getBitstreams)
+                .flatMap(List::stream)
+                .mapToInt(bit -> {
+                    int count = 0;
+                    for (String mime : mimeList) {
+                        try {
+                            if (bit.getFormat(context).getMIMEType().equals(mime.trim())) {
+                                if (bit.getSizeBytes() < size) {
+                                    count++;
+                                }
+                            }
+                        } catch (SQLException e) {
+                            log.error(e.getMessage(), e);
+                        }
+                    }
+                    return count;
+                })
+                .sum();
+    }
+
+    /**
+     * Counts the bitstreams of a given item larger than a given size for a specific type
+     * matching one of a list of specific MIME types.
+     * @param context DSpace context
+     * @param bundleName Type of bundle to filter bitstreams
+     * @param item Provided item
+     * @param mimeList List of MIME types to filter bitstreams
+     * @param prop Configurable property providing the size to filter bitstreams
+     * @return number of matching bitstreams
+     */
+    static int countBitstreamLargerThanMaxSize(
+            Context context, BundleName bundleName, Item item, String[] mimeList, String prop) {
+        long size = DSpaceServicesFactory.getInstance().getConfigurationService().getLongProperty(prop);
+        return item.getBundles().stream()
+                .filter(bundle -> bundle.getName().equals(bundleName.name()))
+                .map(Bundle::getBitstreams)
+                .flatMap(List::stream)
+                .mapToInt(bit -> {
+                    int count = 0;
+                    for (String mime : mimeList) {
+                        try {
+                            if (bit.getFormat(context).getMIMEType().equals(mime.trim())) {
+                                if (bit.getSizeBytes() > size) {
+                                    count++;
+                                }
+                            }
+                        } catch (SQLException e) {
+                            log.error(e.getMessage(), e);
+                        }
+                    }
+                    return count;
+                })
+                .sum();
+    }
+
+    /**
+     * Counts the original bitstreams of a given item whose MIME type starts with a specific prefix.
+     * @param context DSpace context
+     * @param item Provided item
+     * @param prefix Prefix to filter bitstreams
+     * @return number of matching original bitstreams
+     */
+    static int countOriginalBitstreamMimeStartsWith(Context context, Item item, String prefix) {
+        return countBitstreamMimeStartsWith(context, BundleName.ORIGINAL, item, prefix);
+    }
+
+    /**
+     * Counts the bitstreams of a given item for a specific type whose MIME type starts with a specific prefix.
+     * @param context DSpace context
+     * @param bundleName Type of bundle to filter bitstreams
+     * @param item Provided item
+     * @param prefix Prefix to filter bitstreams
+     * @return number of matching bitstreams
+     */
+    static int countBitstreamMimeStartsWith(Context context, BundleName bundleName, Item item, String prefix) {
+        return item.getBundles().stream()
+                .filter(bundle -> bundle.getName().equals(bundleName.name()))
+                .map(Bundle::getBitstreams)
+                .flatMap(List::stream)
+                .mapToInt(bit -> {
+                    int count = 0;
+                    try {
+                        if (bit.getFormat(context).getMIMEType().startsWith(prefix)) {
+                            count++;
+                        }
+                    } catch (SQLException e) {
+                        log.error(e.getMessage(), e);
+                    }
+                    return count;
+                })
+                .sum();
+    }
+
+    /**
+     * Returns true if a given item has a bundle not matching a specific list of bundles.
+     * @param item Provided item
+     * @param bundleList List of bundle names to filter bundles
+     * @return true if the item has a (non-)matching bundle
+     */
+    static boolean hasUnsupportedBundle(Item item, String[] bundleList) {
+        if (bundleList == null) {
+            return false;
+        }
+        Set<String> bundles = Arrays.stream(bundleList)
+                .collect(Collectors.toSet());
+        return item.getBundles().stream()
+                .anyMatch(bundle -> !bundles.contains(bundle.getName()));
+    }
+
+    static boolean hasOriginalBitstreamMime(Context context, Item item, String[] mimeList) {
+        return hasBitstreamMime(context, BundleName.ORIGINAL, item, mimeList);
+    }
+
+    static boolean hasBitstreamMime(Context context, BundleName bundleName, Item item, String[] mimeList) {
+        return countBitstreamMime(context, bundleName, item, mimeList) > 0;
+    }
+
+    /**
+     * Returns true if a given item has at least one field of a specific list whose value
+     * matches a provided regular expression.
+     * @param item Provided item
+     * @param fieldList List of fields to check
+     * @param regex Regular expression to check field values against
+     * @return true if there is at least one matching field, false otherwise
+     */
+    static boolean hasMetadataMatch(Item item, String fieldList, Pattern regex) {
+        if ("*".equals(fieldList)) {
+            return itemService.getMetadata(item, ANY, ANY, ANY, ANY).stream()
+                    .anyMatch(md -> regex.matcher(md.getValue()).matches());
+        }
+
+        return Arrays.stream(fieldList.split(","))
+                .map(field -> itemService.getMetadataByMetadataString(item, field.trim()))
+                .flatMap(List::stream)
+                .anyMatch(md -> regex.matcher(md.getValue()).matches());
+    }
+
+    /**
+     * Returns true if a given item has at all fields of a specific list whose values
+     * match a provided regular expression.
+     * @param item Provided item
+     * @param fieldList List of fields to check
+     * @param regex Regular expression to check field values against
+     * @return true if all specified fields match, false otherwise
+     */
+    static boolean hasOnlyMetadataMatch(Item item, String fieldList, Pattern regex) {
+        if ("*".equals(fieldList)) {
+            return itemService.getMetadata(item, ANY, ANY, ANY, ANY).stream()
+                    .allMatch(md -> regex.matcher(md.getValue()).matches());
+        }
+
+        return Arrays.stream(fieldList.split(","))
+                .map(field -> itemService.getMetadataByMetadataString(item, field.trim()))
+                .flatMap(List::stream)
+                .allMatch(md -> regex.matcher(md.getValue()).matches());
+    }
+
+    static boolean recentlyModified(Item item, int days) {
+        Calendar cal = Calendar.getInstance();
+        cal.add(Calendar.DATE, -days);
+        return cal.getTime().before(item.getLastModified());
+    }
+
+}

dspace-api/src/main/java/org/dspace/contentreport/QueryOperator.java

@@ -0,0 +1,131 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+package org.dspace.contentreport;
+
+import java.util.Arrays;
+import java.util.function.BiFunction;
+import javax.persistence.criteria.CriteriaBuilder;
+import javax.persistence.criteria.Expression;
+import javax.persistence.criteria.Path;
+import javax.persistence.criteria.Predicate;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import org.apache.commons.lang3.function.TriFunction;
+import org.dspace.content.MetadataValue;
+import org.dspace.content.MetadataValue_;
+import org.dspace.util.DSpacePostgreSQLDialect;
+import org.dspace.util.JpaCriteriaBuilderKit;
+import org.hibernate.criterion.Criterion;
+import org.hibernate.criterion.Property;
+import org.hibernate.criterion.Restrictions;
+import org.hibernate.type.StandardBasicTypes;
+
+/**
+ * Operators available for creating predicates to query the
+ * Filtered Items report
+ * @author Jean-François Morin (Université Laval)
+ */
+public enum QueryOperator {
+
+    EXISTS("exists", true, false,
+        (val, regexClause) -> Property.forName("mv.value").isNotNull(),
+        (val, regexClause, jpaKit) -> jpaKit.criteriaBuilder().isNotNull(jpaKit.root().get(MetadataValue_.VALUE))),
+    DOES_NOT_EXIST("doesnt_exist", true, true,
+        (val, regexClause) -> EXISTS.buildPredicate(val, regexClause),
+        (val, regexClause, jpaKit) -> EXISTS.buildJpaPredicate(val, regexClause, jpaKit)),
+    EQUALS("equals", true, false,
+        (val, regexClause) -> Property.forName("mv.value").eq(val),
+        (val, regexClause, jpaKit) -> jpaKit.criteriaBuilder().equal(jpaKit.root().get(MetadataValue_.VALUE), val)),
+    DOES_NOT_EQUAL("not_equals", true, true,
+        (val, regexClause) -> EQUALS.buildPredicate(val, regexClause),
+        (val, regexClause, jpaKit) -> EQUALS.buildJpaPredicate(val, regexClause, jpaKit)),
+    LIKE("like", true, false,
+        (val, regexClause) -> Property.forName("mv.value").like(val),
+        (val, regexClause, jpaKit) -> jpaKit.criteriaBuilder().like(jpaKit.root().get(MetadataValue_.VALUE), val)),
+    NOT_LIKE("not_like", true, true,
+        (val, regexClause) -> LIKE.buildPredicate(val, regexClause),
+        (val, regexClause, jpaKit) -> LIKE.buildJpaPredicate(val, regexClause, jpaKit)),
+    CONTAINS("contains", true, false,
+        (val, regexClause) -> Property.forName("mv.value").like("%" + val + "%"),
+        (val, regexClause, jpaKit) -> LIKE.buildJpaPredicate("%" + val + "%", regexClause, jpaKit)),
+    DOES_NOT_CONTAIN("doesnt_contain", true, true,
+        (val, regexClause) -> CONTAINS.buildPredicate(val, regexClause),
+        (val, regexClause, jpaKit) -> CONTAINS.buildJpaPredicate(val, regexClause, jpaKit)),
+    MATCHES("matches", false, false,
+        (val, regexClause) -> Restrictions.sqlRestriction(regexClause, val, StandardBasicTypes.STRING),
+        (val, regexClause, jpaKit) -> regexPredicate(val, DSpacePostgreSQLDialect.REGEX_MATCHES, jpaKit)),
+    DOES_NOT_MATCH("doesnt_match", false, false,
+        (val, regexClause) -> Restrictions.not(Restrictions.sqlRestriction(
+                regexClause, val, StandardBasicTypes.STRING)),
+        (val, regexClause, jpaKit) -> regexPredicate(val, DSpacePostgreSQLDialect.REGEX_NOT_MATCHES, jpaKit));
+
+    private final String code;
+    /** Criteria builder for the old Hibernate API */
+    @Deprecated(forRemoval = true)
+    private final BiFunction<String, String, Criterion> criterionBuilder;
+    private final TriFunction<String, String, JpaCriteriaBuilderKit<MetadataValue>, Predicate> predicateBuilder;
+    private final boolean usesRegex;
+    private final boolean negate;
+
+    QueryOperator(String code, boolean usesRegex, boolean negate,
+            BiFunction<String, String, Criterion> criterionBuilder,
+            TriFunction<String, String, JpaCriteriaBuilderKit<MetadataValue>, Predicate> predicateBuilder) {
+        this.code = code;
+        this.usesRegex = usesRegex;
+        this.negate = negate;
+        this.criterionBuilder = criterionBuilder;
+        this.predicateBuilder = predicateBuilder;
+    }
+
+    @JsonProperty
+    public String getCode() {
+        return code;
+    }
+
+    public boolean getUsesRegex() {
+        return usesRegex;
+    }
+
+    public boolean getNegate() {
+        return negate;
+    }
+
+    public Criterion buildPredicate(String val, String regexClause) {
+        return criterionBuilder.apply(val, regexClause);
+    }
+
+    public Predicate buildJpaPredicate(String val, String regexClause, JpaCriteriaBuilderKit<MetadataValue> jpaKit) {
+        return predicateBuilder.apply(val, regexClause, jpaKit);
+    }
+
+    @JsonCreator
+    public static QueryOperator get(String code) {
+        return Arrays.stream(values())
+                .filter(item -> item.code.equalsIgnoreCase(code))
+                .findFirst()
+                .orElse(null);
+    }
+
+    public BiFunction<String, String, Criterion> getCriterionBuilder() {
+        return criterionBuilder;
+    }
+
+    private static Predicate regexPredicate(String val, String regexFunction,
+            JpaCriteriaBuilderKit<MetadataValue> jpaKit) {
+        // Source: https://stackoverflow.com/questions/24995881/use-regular-expressions-in-jpa-criteriabuilder
+        CriteriaBuilder builder = jpaKit.criteriaBuilder();
+        Expression<String> patternExpression = builder.<String>literal(val);
+        Path<String> path = jpaKit.root().get(MetadataValue_.VALUE);
+        // "matches" comes from the name of the regex function
+        // defined in class DSpacePostgreSQLDialect
+        return builder.equal(builder
+                .function(regexFunction, Boolean.class, path, patternExpression), Boolean.TRUE);
+    }
+
+}

dspace-api/src/main/java/org/dspace/contentreport/QueryPredicate.java

@@ -0,0 +1,69 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+package org.dspace.contentreport;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+
+import org.dspace.content.MetadataField;
+
+/**
+ * Data structure representing a query predicate used by the Filtered Items report
+ * to filter items to retrieve.
+ * @author Jean-François Morin (Université Laval)
+ */
+public class QueryPredicate {
+
+    private List<MetadataField> fields = new ArrayList<>();
+    private QueryOperator operator;
+    private String value;
+
+    /**
+     * Shortcut method that builds a QueryPredicate from a single field, an operator, and a value.
+     * @param field Predicate subject
+     * @param operator Predicate operator
+     * @param value Predicate object
+     * @return a QueryPredicate instance built from the provided parameters
+     */
+    public static QueryPredicate of(MetadataField field, QueryOperator operator, String value) {
+        var predicate = new QueryPredicate();
+        predicate.fields.add(field);
+        predicate.operator = operator;
+        predicate.value = value;
+        return predicate;
+    }
+
+    /**
+     * Shortcut method that builds a QueryPredicate from a list of fields, an operator, and a value.
+     * @param fields Fields that form the predicate subject
+     * @param operator Predicate operator
+     * @param value Predicate object
+     * @return a QueryPredicate instance built from the provided parameters
+     */
+    public static QueryPredicate of(Collection<MetadataField> fields, QueryOperator operator, String value) {
+        var predicate = new QueryPredicate();
+        predicate.fields.addAll(fields);
+        predicate.operator = operator;
+        predicate.value = value;
+        return predicate;
+    }
+
+    public List<MetadataField> getFields() {
+        return fields;
+    }
+
+    public QueryOperator getOperator() {
+        return operator;
+    }
+
+    public String getValue() {
+        return value;
+    }
+
+}

dspace-api/src/main/java/org/dspace/contentreport/service/ContentReportService.java

@@ -0,0 +1,55 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+package org.dspace.contentreport.service;
+
+import java.sql.SQLException;
+import java.util.Collection;
+import java.util.List;
+
+import org.dspace.content.MetadataField;
+import org.dspace.contentreport.Filter;
+import org.dspace.contentreport.FilteredCollection;
+import org.dspace.contentreport.FilteredItems;
+import org.dspace.contentreport.FilteredItemsQuery;
+import org.dspace.core.Context;
+
+public interface ContentReportService {
+
+    /**
+     * Returns <code>true<</code> if Content Reports are enabled.
+     * @return <code>true<</code> if Content Reports are enabled
+     */
+    boolean getEnabled();
+
+    /**
+     * Retrieves item statistics per collection according to a set of Boolean filters.
+     * @param context DSpace context
+     * @param filters Set of filters
+     * @return a list of collections with the requested statistics for each of them
+     */
+    List<FilteredCollection> findFilteredCollections(Context context, Collection<Filter> filters);
+
+    /**
+     * Retrieves a list of items according to a set of criteria.
+     * @param context DSpace context
+     * @param query structured query to find items against
+     * @return a list of items filtered according to the provided query
+     */
+    FilteredItems findFilteredItems(Context context, FilteredItemsQuery query);
+
+    /**
+     * Converts a metadata field name to a list of {@link MetadataField} instances
+     * (one if no wildcards are used, possibly more otherwise).
+     * @param context DSpace context
+     * @param metadataField field to search for
+     * @return a corresponding list of {@link MetadataField} entries
+     */
+    List<MetadataField> getMetadataFields(org.dspace.core.Context context, String metadataField)
+            throws SQLException;
+
+}

dspace-api/src/main/java/org/dspace/correctiontype/CorrectionType.java

@@ -0,0 +1,81 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+package org.dspace.correctiontype;
+
+import java.sql.SQLException;
+
+import org.dspace.authorize.AuthorizeException;
+import org.dspace.content.Item;
+import org.dspace.content.QAEvent;
+import org.dspace.core.Context;
+import org.dspace.qaevent.service.dto.QAMessageDTO;
+
+/**
+ * Interface class that model the CorrectionType.
+ *
+ * @author Mykhaylo Boychuk (mykhaylo.boychuk at 4science.com)
+ */
+public interface CorrectionType {
+
+    /**
+     * Retrieves the unique identifier associated to the CorrectionType.
+     */
+    public String getId();
+
+    /**
+     * Retrieves the topic associated with the to the CorrectionType.
+     */
+    public String getTopic();
+
+    /**
+     * Checks whether the CorrectionType required related item.
+     */
+    public boolean isRequiredRelatedItem();
+
+    /**
+     * Checks whether target item is allowed for current CorrectionType
+     * 
+     * @param context              Current DSpace session
+     * @param targetItem           Target item
+     * @throws AuthorizeException  if authorize error
+     * @throws SQLException        if there's a database problem
+     */
+    public boolean isAllowed(Context context, Item targetItem) throws AuthorizeException, SQLException;
+
+    /**
+     * Checks whether target item and related item are allowed for current CorrectionType
+     * 
+     * @param context               Current DSpace session
+     * @param targetItem            Target item
+     * @param relatedItem           Related item
+     * @throws AuthorizeException   if authorize error
+     * @throws SQLException         if there's a database problem
+     */
+    public boolean isAllowed(Context context, Item targetItem, Item relatedItem) throws AuthorizeException,SQLException;
+
+    /**
+     * Creates a QAEvent for a specific target item.
+     * 
+     * @param context      Current DSpace session
+     * @param targetItem   Target item
+     * @param reason       Reason
+     * @return             QAEvent
+     */
+    public QAEvent createCorrection(Context context, Item targetItem, QAMessageDTO reason);
+
+    /**
+     *  Creates a QAEvent for a target item and related item.
+     * @param context      Current DSpace session
+     * @param targetItem   Target item
+     * @param relatedItem  Related item
+     * @param reason       Reason
+     * @return             QAEvent
+     */
+    public QAEvent createCorrection(Context context, Item targetItem, Item relatedItem, QAMessageDTO reason);
+
+}

dspace-api/src/main/java/org/dspace/correctiontype/ReinstateCorrectionType.java

@@ -0,0 +1,141 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+package org.dspace.correctiontype;
+
+import static org.dspace.content.QAEvent.DSPACE_USERS_SOURCE;
+import static org.dspace.correctiontype.WithdrawnCorrectionType.WITHDRAWAL_REINSTATE_GROUP;
+
+import java.sql.SQLException;
+import java.util.Date;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import org.apache.commons.lang3.StringUtils;
+import org.dspace.authorize.AuthorizeException;
+import org.dspace.authorize.service.AuthorizeService;
+import org.dspace.content.Item;
+import org.dspace.content.QAEvent;
+import org.dspace.core.Context;
+import org.dspace.eperson.Group;
+import org.dspace.eperson.service.GroupService;
+import org.dspace.qaevent.service.QAEventService;
+import org.dspace.qaevent.service.dto.CorrectionTypeMessageDTO;
+import org.dspace.qaevent.service.dto.QAMessageDTO;
+import org.dspace.services.ConfigurationService;
+import org.springframework.beans.factory.InitializingBean;
+import org.springframework.beans.factory.annotation.Autowired;
+
+/**
+ * Implementation class for {@link CorrectionType}
+ * that will reinstate target item if it's withdrawn.
+ *
+ * @author Mykhaylo Boychuk (mykhaylo.boychuk@4science.com)
+ */
+public class ReinstateCorrectionType implements CorrectionType, InitializingBean {
+
+    private String id;
+    private String topic;
+    private String creationForm;
+
+    @Autowired
+    private GroupService groupService;
+    @Autowired
+    private QAEventService qaEventService;
+    @Autowired
+    private AuthorizeService authorizeService;
+    @Autowired
+    private ConfigurationService configurationService;
+
+    @Override
+    public boolean isAllowed(Context context, Item targetItem) throws SQLException {
+        if (!targetItem.isWithdrawn()) {
+            return false;
+        }
+        boolean isAdmin = authorizeService.isAdmin(context);
+        if (!currentUserIsMemberOfwithdrawalReinstateGroup(context) && !isAdmin) {
+            return false;
+        }
+        long tot = qaEventService.countSourcesByTarget(context, targetItem.getID());
+        return tot == 0;
+    }
+
+    private boolean currentUserIsMemberOfwithdrawalReinstateGroup(Context context) throws SQLException {
+        String groupName = configurationService.getProperty(WITHDRAWAL_REINSTATE_GROUP);
+        if (StringUtils.isBlank(groupName)) {
+            return false;
+        }
+        Group withdrawalReinstateGroup = groupService.findByName(context, groupName);
+        return withdrawalReinstateGroup != null && groupService.isMember(context, withdrawalReinstateGroup);
+    }
+
+    @Override
+    public boolean isAllowed(Context context, Item targetItem, Item relatedItem) throws AuthorizeException,
+        SQLException {
+        return isAllowed(context, targetItem);
+    }
+
+    @Override
+    public QAEvent createCorrection(Context context, Item targetItem, QAMessageDTO reason) {
+        ObjectNode reasonJson = createReasonJson(reason);
+        QAEvent qaEvent = new QAEvent(DSPACE_USERS_SOURCE,
+                                      context.getCurrentUser().getID().toString(),
+                                      targetItem.getID().toString(),
+                                      targetItem.getName(),
+                                      this.getTopic(),
+                                      1.0,
+                                      reasonJson.toString(),
+                                      new Date()
+                                      );
+
+        qaEventService.store(context, qaEvent);
+        return qaEvent;
+    }
+
+    private ObjectNode createReasonJson(QAMessageDTO reason) {
+        CorrectionTypeMessageDTO mesasge = (CorrectionTypeMessageDTO) reason;
+        ObjectNode jsonNode = new ObjectMapper().createObjectNode();
+        jsonNode.put("reason", mesasge.getReason());
+        return jsonNode;
+    }
+
+    @Override
+    public QAEvent createCorrection(Context context, Item targetItem, Item relatedItem, QAMessageDTO reason) {
+        return this.createCorrection(context, targetItem, reason);
+    }
+
+    @Override
+    public boolean isRequiredRelatedItem() {
+        return false;
+    }
+
+    @Override
+    public String getId() {
+        return id;
+    }
+
+    public void setId(String id) {
+        this.id = id;
+    }
+
+    @Override
+    public String getTopic() {
+        return topic;
+    }
+
+    public void setTopic(String topic) {
+        this.topic = topic;
+    }
+
+    @Override
+    public void afterPropertiesSet() throws Exception {}
+
+    public void setCreationForm(String creationForm) {
+        this.creationForm = creationForm;
+    }
+
+}

dspace-api/src/main/java/org/dspace/correctiontype/WithdrawnCorrectionType.java

@@ -0,0 +1,149 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+package org.dspace.correctiontype;
+
+import static org.dspace.content.QAEvent.DSPACE_USERS_SOURCE;
+import static org.dspace.core.Constants.READ;
+
+import java.sql.SQLException;
+import java.util.Date;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import org.apache.commons.lang3.StringUtils;
+import org.dspace.authorize.AuthorizeException;
+import org.dspace.authorize.service.AuthorizeService;
+import org.dspace.content.Item;
+import org.dspace.content.QAEvent;
+import org.dspace.core.Context;
+import org.dspace.eperson.Group;
+import org.dspace.eperson.service.GroupService;
+import org.dspace.qaevent.service.QAEventService;
+import org.dspace.qaevent.service.dto.CorrectionTypeMessageDTO;
+import org.dspace.qaevent.service.dto.QAMessageDTO;
+import org.dspace.services.ConfigurationService;
+import org.springframework.beans.factory.InitializingBean;
+import org.springframework.beans.factory.annotation.Autowired;
+
+/**
+ * Implementation class for {@link CorrectionType}
+ * that will withdrawn target item if it archived and wasn't withdrawn alredy.
+ *
+ * @author Mykhaylo Boychuk (mykhaylo.boychuk at 4science.com)
+ */
+public class WithdrawnCorrectionType implements CorrectionType, InitializingBean {
+
+    public static final String WITHDRAWAL_REINSTATE_GROUP = "qaevents.withdraw-reinstate.group";
+
+    private String id;
+    private String topic;
+    private String creationForm;
+
+    @Autowired
+    private GroupService groupService;
+    @Autowired
+    private QAEventService qaEventService;
+    @Autowired
+    private AuthorizeService authorizeService;
+    @Autowired
+    private ConfigurationService configurationService;
+
+
+    @Override
+    public boolean isAllowed(Context context, Item targetItem) throws SQLException {
+        if (targetItem.isWithdrawn() || !targetItem.isArchived()) {
+            return false;
+        }
+        try {
+            authorizeService.authorizeAction(context, targetItem, READ);
+        } catch (AuthorizeException e) {
+            return false;
+        }
+        boolean isAdmin = authorizeService.isAdmin(context);
+        if (!currentUserIsMemberOfwithdrawalReinstateGroup(context) && !isAdmin) {
+            return false;
+        }
+        long tot = qaEventService.countSourcesByTarget(context, targetItem.getID());
+        return tot == 0;
+    }
+
+    private boolean currentUserIsMemberOfwithdrawalReinstateGroup(Context context) throws SQLException {
+        String groupName = configurationService.getProperty(WITHDRAWAL_REINSTATE_GROUP);
+        if (StringUtils.isBlank(groupName)) {
+            return false;
+        }
+        Group withdrawalReinstateGroup = groupService.findByName(context, groupName);
+        return withdrawalReinstateGroup != null && groupService.isMember(context, withdrawalReinstateGroup);
+    }
+
+    @Override
+    public QAEvent createCorrection(Context context, Item targetItem, QAMessageDTO reason) {
+        ObjectNode reasonJson = createReasonJson(reason);
+        QAEvent qaEvent = new QAEvent(DSPACE_USERS_SOURCE,
+                                      context.getCurrentUser().getID().toString(),
+                                      targetItem.getID().toString(),
+                                      targetItem.getName(),
+                                      this.getTopic(),
+                                      1.0,
+                                      reasonJson.toString(),
+                                      new Date()
+                                      );
+
+        qaEventService.store(context, qaEvent);
+        return qaEvent;
+    }
+
+    private ObjectNode createReasonJson(QAMessageDTO reason) {
+        CorrectionTypeMessageDTO mesasge = (CorrectionTypeMessageDTO) reason;
+        ObjectNode jsonNode = new ObjectMapper().createObjectNode();
+        jsonNode.put("reason", mesasge.getReason());
+        return jsonNode;
+    }
+
+    @Override
+    public boolean isAllowed(Context context, Item targetItem, Item relatedItem)
+            throws AuthorizeException, SQLException {
+        return isAllowed(context, targetItem);
+    }
+
+    @Override
+    public QAEvent createCorrection(Context context, Item targetItem, Item relatedItem, QAMessageDTO reason) {
+        return createCorrection(context, targetItem, reason);
+    }
+
+    @Override
+    public boolean isRequiredRelatedItem() {
+        return false;
+    }
+
+    @Override
+    public String getId() {
+        return id;
+    }
+
+    public void setId(String id) {
+        this.id = id;
+    }
+
+    @Override
+    public String getTopic() {
+        return topic;
+    }
+
+    public void setTopic(String topic) {
+        this.topic = topic;
+    }
+
+    @Override
+    public void afterPropertiesSet() throws Exception {}
+
+    public void setCreationForm(String creationForm) {
+        this.creationForm = creationForm;
+    }
+
+}

dspace-api/src/main/java/org/dspace/correctiontype/service/CorrectionTypeService.java

@@ -0,0 +1,58 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+package org.dspace.correctiontype.service;
+
+import java.sql.SQLException;
+import java.util.List;
+
+import org.dspace.authorize.AuthorizeException;
+import org.dspace.content.Item;
+import org.dspace.core.Context;
+import org.dspace.correctiontype.CorrectionType;
+
+/**
+ * Service interface class for the CorrectionType object.
+ *
+ * @author Mohamed Eskander (mohamed.eskander at 4science.com)
+ */
+public interface CorrectionTypeService {
+
+    /**
+     * Retrieves a CorrectionType object from the system based on a unique identifier.
+     * 
+     * @param id The unique identifier of the CorrectionType object to be retrieved.
+     * @return   The CorrectionType object corresponding to the provided identifier,
+     *           or null if no object is found.
+     */
+    public CorrectionType findOne(String id);
+
+    /**
+     * Retrieves a list of all CorrectionType objects available in the system.
+     * 
+     * @return Returns a List containing all CorrectionType objects in the system.
+     */
+    public List<CorrectionType> findAll();
+
+    /**
+     * Retrieves a list of CorrectionType objects related to the provided Item.
+     * 
+     * @param context               Current DSpace session.
+     * @param item                  Target item
+     * @throws AuthorizeException   If authorize error
+     * @throws SQLException         If a database error occurs during the operation.
+     */
+    public List<CorrectionType> findByItem(Context context, Item item) throws AuthorizeException, SQLException;
+
+    /**
+     * Retrieves a CorrectionType object associated with a specific topic.
+     * 
+     * @param topic  The topic for which the CorrectionType object is to be retrieved.
+     */
+    public CorrectionType findByTopic(String topic);
+
+}

dspace-api/src/main/java/org/dspace/correctiontype/service/impl/CorrectionTypeServiceImpl.java

@@ -0,0 +1,64 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+package org.dspace.correctiontype.service.impl;
+
+import java.sql.SQLException;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.commons.collections4.CollectionUtils;
+import org.dspace.authorize.AuthorizeException;
+import org.dspace.content.Item;
+import org.dspace.core.Context;
+import org.dspace.correctiontype.CorrectionType;
+import org.dspace.correctiontype.service.CorrectionTypeService;
+import org.springframework.beans.factory.annotation.Autowired;
+
+/**
+ * Service implementation class for the CorrectionType object.
+ *
+ * @author Mohamed Eskander (mohamed.eskander at 4science.com)
+ */
+public class CorrectionTypeServiceImpl implements CorrectionTypeService {
+
+    @Autowired
+    private List<CorrectionType> correctionTypes;
+
+    @Override
+    public CorrectionType findOne(String id) {
+        return findAll().stream()
+                        .filter(correctionType -> correctionType.getId().equals(id))
+                        .findFirst()
+                        .orElse(null);
+    }
+
+    @Override
+    public List<CorrectionType> findAll() {
+        return CollectionUtils.isNotEmpty(correctionTypes) ? correctionTypes : List.of();
+    }
+
+    @Override
+    public List<CorrectionType> findByItem(Context context, Item item) throws AuthorizeException, SQLException {
+        List<CorrectionType> correctionTypes = new ArrayList<>();
+        for (CorrectionType correctionType : findAll()) {
+            if (correctionType.isAllowed(context, item)) {
+                correctionTypes.add(correctionType);
+            }
+        }
+        return correctionTypes;
+    }
+
+    @Override
+    public CorrectionType findByTopic(String topic) {
+        return findAll().stream()
+                        .filter(correctionType -> correctionType.getTopic().equals(topic))
+                        .findFirst()
+                        .orElse(null);
+    }
+
+}

dspace-api/src/main/java/org/dspace/ctask/general/RequiredMetadata.java

@@ -17,6 +17,7 @@ import org.dspace.app.util.DCInput;
 import org.dspace.app.util.DCInputSet;
 import org.dspace.app.util.DCInputsReader;
 import org.dspace.app.util.DCInputsReaderException;
+import org.dspace.content.Collection;
 import org.dspace.content.DSpaceObject;
 import org.dspace.content.Item;
 import org.dspace.content.MetadataValue;
@@ -69,7 +70,7 @@ public class RequiredMetadata extends AbstractCurationTask {
                     handle = "in workflow";
                 }
                 sb.append("Item: ").append(handle);
-                for (String req : getReqList(item.getOwningCollection().getHandle())) {
+                for (String req : getReqList(item.getOwningCollection())) {
                     List<MetadataValue> vals = itemService.getMetadataByMetadataString(item, req);
                     if (vals.size() == 0) {
                         sb.append(" missing required field: ").append(req);
@@ -91,14 +92,14 @@ public class RequiredMetadata extends AbstractCurationTask {
         }
     }
 
-    protected List<String> getReqList(String handle) throws DCInputsReaderException {
-        List<String> reqList = reqMap.get(handle);
+    protected List<String> getReqList(Collection collection) throws DCInputsReaderException {
+        List<String> reqList = reqMap.get(collection.getHandle());
         if (reqList == null) {
             reqList = reqMap.get("default");
         }
         if (reqList == null) {
             reqList = new ArrayList<String>();
-            List<DCInputSet> inputSet = reader.getInputsByCollectionHandle(handle);
+            List<DCInputSet> inputSet = reader.getInputsByCollection(collection);
             for (DCInputSet inputs : inputSet) {
                 for (DCInput[] row : inputs.getFields()) {
                     for (DCInput input : row) {

dspace-api/src/main/java/org/dspace/discovery/IndexClient.java

@@ -7,14 +7,20 @@
  */
 package org.dspace.discovery;
 
+import static org.dspace.discovery.IndexClientOptions.TYPE_OPTION;
+
 import java.io.IOException;
 import java.sql.SQLException;
+import java.util.Arrays;
 import java.util.Iterator;
+import java.util.List;
 import java.util.Optional;
 import java.util.UUID;
+import java.util.stream.Collectors;
 
 import org.apache.commons.cli.CommandLine;
 import org.apache.commons.cli.ParseException;
+import org.apache.commons.lang3.StringUtils;
 import org.dspace.content.Collection;
 import org.dspace.content.Community;
 import org.dspace.content.DSpaceObject;
@@ -51,6 +57,17 @@ public class IndexClient extends DSpaceRunnable<IndexDiscoveryScriptConfiguratio
             return;
         }
 
+        String type = null;
+        if (commandLine.hasOption(TYPE_OPTION)) {
+            List<String> indexableObjectTypes = IndexObjectFactoryFactory.getInstance().getIndexFactories().stream()
+                    .map((indexFactory -> indexFactory.getType())).collect(Collectors.toList());
+            type = commandLine.getOptionValue(TYPE_OPTION);
+            if (!indexableObjectTypes.contains(type)) {
+                handler.handleException(String.format("%s is not a valid indexable object type, options: %s",
+                        type, Arrays.toString(indexableObjectTypes.toArray())));
+            }
+        }
+
         /** Acquire from dspace-services in future */
         /**
          * new DSpace.getServiceManager().getServiceByName("org.dspace.discovery.SolrIndexer");
@@ -113,6 +130,10 @@ public class IndexClient extends DSpaceRunnable<IndexDiscoveryScriptConfiguratio
         } else if (indexClientOptions == IndexClientOptions.BUILD ||
             indexClientOptions == IndexClientOptions.BUILDANDSPELLCHECK) {
             handler.logInfo("(Re)building index from scratch.");
+            if (StringUtils.isNotBlank(type)) {
+                handler.logWarning(String.format("Type option, %s, not applicable for entire index rebuild option, b" +
+                        ", type will be ignored", TYPE_OPTION));
+            }
             indexer.deleteIndex();
             indexer.createIndex(context);
             if (indexClientOptions == IndexClientOptions.BUILDANDSPELLCHECK) {
@@ -133,14 +154,14 @@ public class IndexClient extends DSpaceRunnable<IndexDiscoveryScriptConfiguratio
         } else if (indexClientOptions == IndexClientOptions.UPDATE ||
             indexClientOptions == IndexClientOptions.UPDATEANDSPELLCHECK) {
             handler.logInfo("Updating Index");
-            indexer.updateIndex(context, false);
+            indexer.updateIndex(context, false, type);
             if (indexClientOptions == IndexClientOptions.UPDATEANDSPELLCHECK) {
                 checkRebuildSpellCheck(commandLine, indexer);
             }
         } else if (indexClientOptions == IndexClientOptions.FORCEUPDATE ||
             indexClientOptions == IndexClientOptions.FORCEUPDATEANDSPELLCHECK) {
             handler.logInfo("Updating Index");
-            indexer.updateIndex(context, true);
+            indexer.updateIndex(context, true, type);
             if (indexClientOptions == IndexClientOptions.FORCEUPDATEANDSPELLCHECK) {
                 checkRebuildSpellCheck(commandLine, indexer);
             }