More errorprone warnings. #3061

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

@@ -81,7 +81,7 @@ public class MetadataImporter {
      * @throws SQLException                 if database error
      * @throws IOException                  if IO error
      * @throws TransformerException         if transformer error
-     * @throws ParserConfigurationException if config error
+     * @throws ParserConfigurationException if configuration error
      * @throws AuthorizeException           if authorization error
      * @throws SAXException                 if parser error
      * @throws NonUniqueMetadataException   if duplicate metadata
@@ -91,7 +91,6 @@ public class MetadataImporter {
         throws ParseException, SQLException, IOException, TransformerException,
         ParserConfigurationException, AuthorizeException, SAXException,
         NonUniqueMetadataException, RegistryImportException {
-        boolean forceUpdate = false;
 
         // create an options object and populate it
         CommandLineParser parser = new DefaultParser();
@@ -100,16 +99,14 @@ public class MetadataImporter {
         options.addOption("u", "update", false, "update an existing schema");
         CommandLine line = parser.parse(options, args);
 
-        String file = null;
         if (line.hasOption('f')) {
-            file = line.getOptionValue('f');
+            String file = line.getOptionValue('f');
+            boolean forceUpdate = line.hasOption('u');
+            loadRegistry(file, forceUpdate);
         } else {
             usage();
-            System.exit(0);
+            System.exit(1);
         }
-
-        forceUpdate = line.hasOption('u');
-        loadRegistry(file, forceUpdate);
     }
 
     /**
@@ -120,7 +117,7 @@ public class MetadataImporter {
      * @throws SQLException                 if database error
      * @throws IOException                  if IO error
      * @throws TransformerException         if transformer error
-     * @throws ParserConfigurationException if config error
+     * @throws ParserConfigurationException if configuration error
      * @throws AuthorizeException           if authorization error
      * @throws SAXException                 if parser error
      * @throws NonUniqueMetadataException   if duplicate metadata
@@ -227,7 +224,7 @@ public class MetadataImporter {
     /**
      * Process a node in the metadata registry XML file. The node must
      * be a "dc-type" node.  If the type already exists, then it
-     * will not be reimported
+     * will not be re-imported.
      *
      * @param context DSpace context object
      * @param node    the node in the DOM tree

dspace-api/src/main/java/org/dspace/app/bulkedit/DSpaceCSV.java

@@ -138,7 +138,7 @@ public class DSpaceCSV implements Serializable {
     /**
      * Create a new instance, reading the lines in from file
      *
-     * @param inputStream the inputstream to read from
+     * @param inputStream the input stream to read from
      * @param c The DSpace Context
      * @throws Exception thrown if there is an error reading or processing the file
      */
@@ -159,7 +159,7 @@ public class DSpaceCSV implements Serializable {
                 columnCounter++;
 
                 // Remove surrounding quotes if there are any
-                if ((element.startsWith("\"")) && (element.endsWith("\""))) {
+                if (element.startsWith("\"") && element.endsWith("\"")) {
                     element = element.substring(1, element.length() - 1);
                 }
 
@@ -334,15 +334,15 @@ public class DSpaceCSV implements Serializable {
     /**
      * Set the value separator for multiple values stored in one csv value.
      *
-     * Is set in bulkedit.cfg as valueseparator
+     * Is set in {@code bulkedit.cfg} as {@code valueseparator}.
      *
-     * If not set, defaults to double pipe '||'
+     * If not set, defaults to double pipe '||'.
      */
     private void setValueSeparator() {
         // Get the value separator
         valueSeparator = DSpaceServicesFactory.getInstance().getConfigurationService()
                                               .getProperty("bulkedit.valueseparator");
-        if ((valueSeparator != null) && (!"".equals(valueSeparator.trim()))) {
+        if ((valueSeparator != null) && !valueSeparator.trim().isEmpty()) {
             valueSeparator = valueSeparator.trim();
         } else {
             valueSeparator = "||";
@@ -357,7 +357,7 @@ public class DSpaceCSV implements Serializable {
     /**
      * Set the field separator use to separate fields in the csv.
      *
-     * Is set in bulkedit.cfg as fieldseparator
+     * Is set in {@code bulkedit.cfg} as {@code fieldseparator}.
      *
      * If not set, defaults to comma ','.
      *
@@ -368,7 +368,7 @@ public class DSpaceCSV implements Serializable {
         // Get the value separator
         fieldSeparator = DSpaceServicesFactory.getInstance().getConfigurationService()
                                               .getProperty("bulkedit.fieldseparator");
-        if ((fieldSeparator != null) && (!"".equals(fieldSeparator.trim()))) {
+        if ((fieldSeparator != null) && !fieldSeparator.trim().isEmpty()) {
             fieldSeparator = fieldSeparator.trim();
             if ("tab".equals(fieldSeparator)) {
                 fieldSeparator = "\t";
@@ -392,15 +392,15 @@ public class DSpaceCSV implements Serializable {
     /**
      * Set the authority separator for value with authority data.
      *
-     * Is set in dspace.cfg as bulkedit.authorityseparator
+     * Is set in {@code dspace.cfg} as {@code bulkedit.authorityseparator}.
      *
-     * If not set, defaults to double colon '::'
+     * If not set, defaults to double colon '::'.
      */
     private void setAuthoritySeparator() {
         // Get the value separator
         authoritySeparator = DSpaceServicesFactory.getInstance().getConfigurationService()
                                                   .getProperty("bulkedit.authorityseparator");
-        if ((authoritySeparator != null) && (!"".equals(authoritySeparator.trim()))) {
+        if ((authoritySeparator != null) && !authoritySeparator.trim().isEmpty()) {
             authoritySeparator = authoritySeparator.trim();
         } else {
             authoritySeparator = "::";
@@ -505,7 +505,7 @@ public class DSpaceCSV implements Serializable {
             int i = 0;
             for (String part : bits) {
                 int bitcounter = part.length() - part.replaceAll("\"", "").length();
-                if ((part.startsWith("\"")) && ((!part.endsWith("\"")) || ((bitcounter & 1) == 1))) {
+                if (part.startsWith("\"") && (!part.endsWith("\"") || ((bitcounter & 1) == 1))) {
                     found = true;
                     String add = bits.get(i) + fieldSeparator + bits.get(i + 1);
                     bits.remove(i);
@@ -521,7 +521,7 @@ public class DSpaceCSV implements Serializable {
         // Deal with quotes around the elements
         int i = 0;
         for (String part : bits) {
-            if ((part.startsWith("\"")) && (part.endsWith("\""))) {
+            if (part.startsWith("\"") && part.endsWith("\"")) {
                 part = part.substring(1, part.length() - 1);
                 bits.set(i, part);
             }
@@ -561,7 +561,7 @@ public class DSpaceCSV implements Serializable {
         for (String part : bits) {
             if (i > 0) {
                 // Is this a last empty item?
-                if ((last) && (i == headings.size())) {
+                if (last && (i == headings.size())) {
                     part = "";
                 }
 
@@ -574,7 +574,7 @@ public class DSpaceCSV implements Serializable {
                 csvLine.add(headings.get(i - 1), null);
                 String[] elements = part.split(escapedValueSeparator);
                 for (String element : elements) {
-                    if ((element != null) && (!"".equals(element))) {
+                    if ((element != null) && !"".equals(element)) {
                         csvLine.add(headings.get(i - 1), element);
                     }
                 }
@@ -626,18 +626,18 @@ public class DSpaceCSV implements Serializable {
     public InputStream getInputStream() {
         StringBuilder stringBuilder = new StringBuilder();
         for (String csvLine : getCSVLinesAsStringArray()) {
-            stringBuilder.append(csvLine + "\n");
+            stringBuilder.append(csvLine).append("\n");
         }
         return IOUtils.toInputStream(stringBuilder.toString(), StandardCharsets.UTF_8);
     }
 
     /**
-     * Is it Ok to export this value? When exportAll is set to false, we don't export
+     * Is it okay to export this value? When exportAll is set to false, we don't export
      * some of the metadata elements.
      *
-     * The list can be configured via the key ignore-on-export in bulkedit.cfg
+     * The list can be configured via the key ignore-on-export in {@code bulkedit.cfg}.
      *
-     * @param md The Metadatum to examine
+     * @param md The MetadataField to examine
      * @return Whether or not it is OK to export this element
      */
     protected boolean okToExport(MetadataField md) {
@@ -646,12 +646,8 @@ public class DSpaceCSV implements Serializable {
         if (md.getQualifier() != null) {
             key += "." + md.getQualifier();
         }
-        if (ignore.get(key) != null) {
-            return false;
-        }
-
         // Must be OK, so don't ignore
-        return true;
+        return ignore.get(key) == null;
     }
 
     /**

dspace-api/src/main/java/org/dspace/app/itemupdate/DtoMetadata.java

@@ -120,6 +120,7 @@ class DtoMetadata {
         return true;
     }
 
+    @Override
     public String toString() {
         String s = "\tSchema: " + schema + " Element: " + element;
         if (qualifier != null) {

dspace-api/src/main/java/org/dspace/app/itemupdate/ItemArchive.java

@@ -17,6 +17,7 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.PrintWriter;
+import java.nio.charset.StandardCharsets;
 import java.sql.SQLException;
 import java.util.ArrayList;
 import java.util.Iterator;
@@ -55,7 +56,7 @@ public class ItemArchive {
     protected Transformer transformer = null;
 
     protected List<DtoMetadata> dtomList = null;
-    protected List<DtoMetadata> undoDtomList = new ArrayList<DtoMetadata>();
+    protected List<DtoMetadata> undoDtomList = new ArrayList<>();
 
     protected List<UUID> undoAddContents = new ArrayList<>(); // for undo of add
 
@@ -325,7 +326,7 @@ public class ItemArchive {
                 PrintWriter pw = null;
                 try {
                     File f = new File(dir, ItemUpdate.DELETE_CONTENTS_FILE);
-                    pw = new PrintWriter(new BufferedWriter(new FileWriter(f)));
+                    pw = new PrintWriter(new BufferedWriter(new FileWriter(f, StandardCharsets.UTF_8)));
                     for (UUID i : undoAddContents) {
                         pw.println(i);
                     }

dspace-api/src/main/java/org/dspace/app/sherpa/SHERPAResponse.java

@@ -8,12 +8,13 @@
 package org.dspace.app.sherpa;
 
 import java.io.InputStream;
-import java.util.LinkedList;
+import java.util.ArrayList;
 import java.util.List;
 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.DocumentBuilderFactory;
 
 import org.apache.commons.lang3.StringUtils;
+import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.dspace.app.util.XMLUtils;
 import org.w3c.dom.Document;
@@ -25,7 +26,7 @@ import org.w3c.dom.Element;
  * @author Andrea Bollini
  */
 public class SHERPAResponse {
-    private static final Logger log = org.apache.logging.log4j.LogManager.getLogger(SHERPAResponse.class);
+    private static final Logger log = LogManager.getLogger(SHERPAResponse.class);
 
     private int numHits;
 
@@ -81,7 +82,7 @@ public class SHERPAResponse {
                 publishersElement, "publisher");
 
             if (journalsList != null) {
-                journals = new LinkedList<SHERPAJournal>();
+                journals = new ArrayList<>(journalsList.size());
                 for (Element journalElement : journalsList) {
                     journals.add(new SHERPAJournal(
                         XMLUtils.getElementValue(journalElement, "jtitle"),
@@ -92,7 +93,7 @@ public class SHERPAResponse {
             }
 
             if (publishersList != null) {
-                publishers = new LinkedList<SHERPAPublisher>();
+                publishers = new ArrayList<>(publishersList.size());
                 for (Element publisherElement : publishersList) {
                     Element preprintsElement = XMLUtils.getSingleElement(
                         publisherElement, "preprints");

dspace-api/src/main/java/org/dspace/app/statistics/CreateStatReport.java

@@ -64,10 +64,6 @@ public class CreateStatReport {
      */
     private static Context context;
 
-    /**
-     * the config file from which to configure the analyser
-     */
-
     /**
      * Default constructor
      */
@@ -170,22 +166,19 @@ public class CreateStatReport {
         String myLogDir = null;
         String myFileTemplate = null;
         String myConfigFile = null;
-        StringBuffer myOutFile = null;
-        Date myStartDate = null;
-        Date myEndDate = null;
         boolean myLookUp = false;
 
         Calendar start = new GregorianCalendar(calendar.get(Calendar.YEAR),
                                                calendar.get(Calendar.MONTH),
                                                calendar.getActualMinimum(Calendar.DAY_OF_MONTH));
-        myStartDate = start.getTime();
+        Date myStartDate = start.getTime();
 
         Calendar end = new GregorianCalendar(calendar.get(Calendar.YEAR),
                                              calendar.get(Calendar.MONTH),
                                              calendar.getActualMaximum(Calendar.DAY_OF_MONTH));
-        myEndDate = end.getTime();
+        Date myEndDate = end.getTime();
 
-        myOutFile = new StringBuffer(outputLogDirectory);
+        StringBuilder myOutFile = new StringBuilder(outputLogDirectory);
         myOutFile.append(outputPrefix);
         myOutFile.append(calendar.get(Calendar.YEAR));
         myOutFile.append("-");
@@ -211,12 +204,11 @@ public class CreateStatReport {
         String myLogDir = null;
         String myFileTemplate = null;
         String myConfigFile = null;
-        StringBuffer myOutFile = null;
         Date myStartDate = null;
         Date myEndDate = null;
         boolean myLookUp = false;
 
-        myOutFile = new StringBuffer(outputLogDirectory);
+        StringBuilder myOutFile = new StringBuilder(outputLogDirectory);
         myOutFile.append(outputPrefix);
         myOutFile.append(calendar.get(Calendar.YEAR));
         myOutFile.append("-");
@@ -245,9 +237,6 @@ public class CreateStatReport {
         String myLogDir = null;
         String myFileTemplate = null;
         String myConfigFile = null;
-        StringBuffer myOutFile = null;
-        Date myStartDate = null;
-        Date myEndDate = null;
         boolean myLookUp = false;
 
         Calendar reportEndDate = new GregorianCalendar(calendar.get(Calendar.YEAR),
@@ -260,14 +249,14 @@ public class CreateStatReport {
             Calendar start = new GregorianCalendar(currentMonth.get(Calendar.YEAR),
                                                    currentMonth.get(Calendar.MONTH),
                                                    currentMonth.getActualMinimum(Calendar.DAY_OF_MONTH));
-            myStartDate = start.getTime();
+            Date myStartDate = start.getTime();
 
             Calendar end = new GregorianCalendar(currentMonth.get(Calendar.YEAR),
                                                  currentMonth.get(Calendar.MONTH),
                                                  currentMonth.getActualMaximum(Calendar.DAY_OF_MONTH));
-            myEndDate = end.getTime();
+            Date myEndDate = end.getTime();
 
-            myOutFile = new StringBuffer(outputLogDirectory);
+            StringBuilder myOutFile = new StringBuilder(outputLogDirectory);
             myOutFile.append(outputPrefix);
             myOutFile.append(currentMonth.get(Calendar.YEAR));
             myOutFile.append("-");
@@ -293,11 +282,9 @@ public class CreateStatReport {
         String outputPrefix = "report-general-";
 
         String myFormat = "html";
-        StringBuffer myInput = null;
-        StringBuffer myOutput = null;
         String myMap = null;
 
-        myInput = new StringBuffer(outputLogDirectory);
+        StringBuilder myInput = new StringBuilder(outputLogDirectory);
         myInput.append(inputPrefix);
         myInput.append(calendar.get(Calendar.YEAR));
         myInput.append("-");
@@ -306,7 +293,7 @@ public class CreateStatReport {
         myInput.append(calendar.get(Calendar.DAY_OF_MONTH));
         myInput.append(outputSuffix);
 
-        myOutput = new StringBuffer(outputReportDirectory);
+        StringBuilder myOutput = new StringBuilder(outputReportDirectory);
         myOutput.append(outputPrefix);
         myOutput.append(calendar.get(Calendar.YEAR));
         myOutput.append("-");
@@ -332,8 +319,6 @@ public class CreateStatReport {
         String outputPrefix = "report-";
 
         String myFormat = "html";
-        StringBuffer myInput = null;
-        StringBuffer myOutput = null;
         String myMap = null;
 
         Calendar reportEndDate = new GregorianCalendar(calendar.get(Calendar.YEAR),
@@ -344,14 +329,14 @@ public class CreateStatReport {
 
         while (currentMonth.before(reportEndDate)) {
 
-            myInput = new StringBuffer(outputLogDirectory);
+            StringBuilder myInput = new StringBuilder(outputLogDirectory);
             myInput.append(inputPrefix);
             myInput.append(currentMonth.get(Calendar.YEAR));
             myInput.append("-");
             myInput.append(currentMonth.get(Calendar.MONTH) + 1);
             myInput.append(outputSuffix);
 
-            myOutput = new StringBuffer(outputReportDirectory);
+            StringBuilder myOutput = new StringBuilder(outputReportDirectory);
             myOutput.append(outputPrefix);
             myOutput.append(currentMonth.get(Calendar.YEAR));
             myOutput.append("-");
@@ -376,18 +361,16 @@ public class CreateStatReport {
         String outputPrefix = "report-";
 
         String myFormat = "html";
-        StringBuffer myInput = null;
-        StringBuffer myOutput = null;
         String myMap = null;
 
-        myInput = new StringBuffer(outputLogDirectory);
+        StringBuilder myInput = new StringBuilder(outputLogDirectory);
         myInput.append(inputPrefix);
         myInput.append(calendar.get(Calendar.YEAR));
         myInput.append("-");
         myInput.append(calendar.get(Calendar.MONTH) + 1);
         myInput.append(outputSuffix);
 
-        myOutput = new StringBuffer(outputReportDirectory);
+        StringBuilder myOutput = new StringBuilder(outputReportDirectory);
         myOutput.append(outputPrefix);
         myOutput.append(calendar.get(Calendar.YEAR));
         myOutput.append("-");

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

@@ -58,6 +58,7 @@ public class WebApp implements ReloadableEntity<Integer> {
 
     }
 
+    @Override
     public Integer getID() {
         return id;
     }

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

@@ -8,7 +8,6 @@
 package org.dspace.app.util;
 
 import java.util.ArrayList;
-import java.util.LinkedList;
 import java.util.List;
 
 import org.apache.commons.lang3.StringUtils;
@@ -29,13 +28,13 @@ public class XMLUtils {
 
     /**
      * @param dataRoot the starting node
-     * @param name     the name of the subelement to find
+     * @param name     the tag name of the child element to find.
      * @return the list of all DOM Element with the provided name direct child
      * of the starting node
      */
     public static List<Element> getElementList(Element dataRoot, String name) {
         NodeList list = dataRoot.getElementsByTagName(name);
-        List<Element> listElements = new ArrayList<Element>();
+        List<Element> listElements = new ArrayList<>();
         for (int i = 0; i < list.getLength(); i++) {
             Element item = (Element) list.item(i);
             if (item.getParentNode().equals(dataRoot)) {
@@ -105,7 +104,7 @@ public class XMLUtils {
 
     /**
      * @param rootElement    the starting node
-     * @param subElementName the name of the subelement to find
+     * @param subElementName the tag name of the child element to find.
      * @return a list of string including all the text contents of the sub
      * element with the specified name. If there are not sub element
      * with the supplied name the method will return null
@@ -121,7 +120,7 @@ public class XMLUtils {
             return null;
         }
 
-        List<String> result = new LinkedList<String>();
+        List<String> result = new ArrayList<>();
         for (Element el : subElements) {
             if (StringUtils.isNotBlank(el.getTextContent())) {
                 result.add(el.getTextContent().trim());
@@ -152,7 +151,7 @@ public class XMLUtils {
             return null;
         }
 
-        List<String[]> result = new LinkedList<String[]>();
+        List<String[]> result = new ArrayList<>();
         for (Element el : subElements) {
             String[] tmp = new String[fieldsName.length];
             for (int idx = 0; idx < fieldsName.length; idx++) {

dspace-api/src/main/java/org/dspace/authenticate/PasswordAuthentication.java

@@ -41,7 +41,6 @@ import org.dspace.services.factory.DSpaceServicesFactory;
  * Basic Auth username and password to the <code>AuthenticationManager</code>.
  *
  * @author Larry Stone
- * @version $Revision$
  */
 public class PasswordAuthentication
     implements AuthenticationMethod {
@@ -49,7 +48,7 @@ public class PasswordAuthentication
     /**
      * log4j category
      */
-    private static Logger log = org.apache.logging.log4j.LogManager.getLogger(PasswordAuthentication.class);
+    private static final Logger log = org.apache.logging.log4j.LogManager.getLogger(PasswordAuthentication.class);
 
 
     /**
@@ -142,7 +141,7 @@ public class PasswordAuthentication
                                      .toString())) {
                 String groupName = DSpaceServicesFactory.getInstance().getConfigurationService()
                                                         .getProperty("authentication-password.login.specialgroup");
-                if ((groupName != null) && (!groupName.trim().equals(""))) {
+                if ((groupName != null) && !groupName.trim().isEmpty()) {
                     Group specialGroup = EPersonServiceFactory.getInstance().getGroupService()
                                                               .findByName(context, groupName);
                     if (specialGroup == null) {
@@ -195,9 +194,8 @@ public class PasswordAuthentication
                             HttpServletRequest request)
         throws SQLException {
         if (username != null && password != null) {
-            EPerson eperson = null;
             log.info(LogManager.getHeader(context, "authenticate", "attempting password auth of user=" + username));
-            eperson = EPersonServiceFactory.getInstance().getEPersonService()
+            EPerson eperson = EPersonServiceFactory.getInstance().getEPersonService()
                                            .findByEmail(context, username.toLowerCase());
 
             if (eperson == null) {

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

@@ -11,7 +11,6 @@ import java.sql.SQLException;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Date;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.UUID;
 
@@ -228,7 +227,7 @@ public class AuthorizeServiceImpl implements AuthorizeService {
         // If authorization was given before and cached
         Boolean cachedResult = c.getCachedAuthorizationResult(o, action, e);
         if (cachedResult != null) {
-            return cachedResult.booleanValue();
+            return cachedResult;
         }
 
         // is eperson set? if not, userToCheck = null (anonymous)
@@ -293,7 +292,7 @@ public class AuthorizeServiceImpl implements AuthorizeService {
                 }
 
                 if ((rp.getGroup() != null)
-                    && (groupService.isMember(c, e, rp.getGroup()))) {
+                    && groupService.isMember(c, e, rp.getGroup())) {
                     // group was set, and eperson is a member
                     // of that group
                     c.cacheAuthorizedAction(o, action, e, true, rp);
@@ -351,7 +350,7 @@ public class AuthorizeServiceImpl implements AuthorizeService {
 
         Boolean cachedResult = c.getCachedAuthorizationResult(o, Constants.ADMIN, e);
         if (cachedResult != null) {
-            return cachedResult.booleanValue();
+            return cachedResult;
         }
 
         //
@@ -368,7 +367,7 @@ public class AuthorizeServiceImpl implements AuthorizeService {
                 }
 
                 if ((rp.getGroup() != null)
-                    && (groupService.isMember(c, e, rp.getGroup()))) {
+                    && groupService.isMember(c, e, rp.getGroup())) {
                     // group was set, and eperson is a member
                     // of that group
                     c.cacheAuthorizedAction(o, Constants.ADMIN, e, true, rp);
@@ -428,6 +427,7 @@ public class AuthorizeServiceImpl implements AuthorizeService {
         }
     }
 
+    @Override
     public boolean isCommunityAdmin(Context c) throws SQLException {
         EPerson e = c.getCurrentUser();
         return isCommunityAdmin(c, e);
@@ -448,6 +448,7 @@ public class AuthorizeServiceImpl implements AuthorizeService {
         return false;
     }
 
+    @Override
     public boolean isCollectionAdmin(Context c) throws SQLException {
         EPerson e = c.getCurrentUser();
         return isCollectionAdmin(c, e);
@@ -527,7 +528,7 @@ public class AuthorizeServiceImpl implements AuthorizeService {
         List<ResourcePolicy> policies = getPolicies(c, src);
 
         //Only inherit non-ADMIN policies (since ADMIN policies are automatically inherited)
-        List<ResourcePolicy> nonAdminPolicies = new ArrayList<ResourcePolicy>();
+        List<ResourcePolicy> nonAdminPolicies = new ArrayList<>();
         for (ResourcePolicy rp : policies) {
             if (rp.getAction() != Constants.ADMIN) {
                 nonAdminPolicies.add(rp);
@@ -550,7 +551,7 @@ public class AuthorizeServiceImpl implements AuthorizeService {
     public void addPolicies(Context c, List<ResourcePolicy> policies, DSpaceObject dest)
         throws SQLException, AuthorizeException {
         // now add them to the destination object
-        List<ResourcePolicy> newPolicies = new LinkedList<>();
+        List<ResourcePolicy> newPolicies = new ArrayList<>(policies.size());
 
         for (ResourcePolicy srp : policies) {
             ResourcePolicy rp = resourcePolicyService.create(c);
@@ -625,7 +626,7 @@ public class AuthorizeServiceImpl implements AuthorizeService {
                                            int actionID) throws java.sql.SQLException {
         List<ResourcePolicy> policies = getPoliciesActionFilter(c, o, actionID);
 
-        List<Group> groups = new ArrayList<Group>();
+        List<Group> groups = new ArrayList<>();
         for (ResourcePolicy resourcePolicy : policies) {
             if (resourcePolicy.getGroup() != null && resourcePolicyService.isDateValid(resourcePolicy)) {
                 groups.add(resourcePolicy.getGroup());

dspace-api/src/main/java/org/dspace/checker/MostRecentChecksum.java

@@ -170,7 +170,7 @@ public class MostRecentChecksum implements Serializable {
             return true;
         }
 
-        if (o == null || getClass() != o.getClass()) {
+        if (o == null || !(o instanceof MostRecentChecksum)) {
             return false;
         }
 

dspace-api/src/main/java/org/dspace/checker/ResultsLogger.java

@@ -109,7 +109,7 @@ public class ResultsLogger implements ChecksumResultsCollector {
             "unknown"));
         LOG.info(msg("new-checksum") + ": " + info.getCurrentChecksum());
         LOG.info(msg("checksum-comparison-result") + ": "
-                     + (info.getChecksumResult().getResultCode()));
+                     + info.getChecksumResult().getResultCode());
         LOG.info("\n\n");
     }
 }

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

@@ -9,7 +9,7 @@ package org.dspace.content;
 
 import java.io.Serializable;
 import java.sql.SQLException;
-import java.util.LinkedList;
+import java.util.ArrayList;
 import java.util.List;
 import javax.persistence.CollectionTable;
 import javax.persistence.Column;
@@ -111,7 +111,7 @@ public class BitstreamFormat implements Serializable, ReloadableEntity<Integer>
      * {@link org.dspace.content.service.BitstreamFormatService#create(Context)}
      */
     protected BitstreamFormat() {
-        fileExtensions = new LinkedList<>();
+        fileExtensions = new ArrayList<>();
     }
 
     /**

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

@@ -9,7 +9,6 @@ package org.dspace.content;
 
 import java.sql.SQLException;
 import java.util.ArrayList;
-import java.util.LinkedList;
 import java.util.List;
 import javax.persistence.Column;
 import javax.persistence.Entity;
@@ -138,7 +137,7 @@ public class Bundle extends DSpaceObject implements DSpaceObjectLegacySupport {
      * @return the bitstreams
      */
     public List<Bitstream> getBitstreams() {
-        List<Bitstream> bitstreamList = new LinkedList<>(this.bitstreams);
+        List<Bitstream> bitstreamList = new ArrayList<>(this.bitstreams);
         return bitstreamList;
     }
 
@@ -191,7 +190,7 @@ public class Bundle extends DSpaceObject implements DSpaceObjectLegacySupport {
 
     @Override
     public boolean equals(Object obj) {
-        if (obj == null) {
+        if (obj == null || !(obj instanceof Bundle)) {
             return false;
         }
         Class<?> objClass = HibernateProxyHelper.getClassWithoutInitializingProxy(obj);
@@ -202,10 +201,7 @@ public class Bundle extends DSpaceObject implements DSpaceObjectLegacySupport {
         if (this.getType() != other.getType()) {
             return false;
         }
-        if (!this.getID().equals(other.getID())) {
+        return this.getID().equals(other.getID());
-            return false;
-        }
-        return true;
     }
 
     @Override

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

@@ -34,8 +34,8 @@ import org.apache.logging.log4j.Logger;
  * There are four levels of granularity, depending on how much date information
  * is available: year, month, day, time.
  * <P>
- * Examples: <code>1994-05-03T15:30:24</code>,<code>1995-10-04</code>,
+ * Examples: {@code 1994-05-03T15:30:24}, {@code 1995-10-04},
- * <code>2001-10</code>,<code>1975</code>
+ * {@code 2001-10}, {@code 1975}
  *
  * @author Robert Tansley
  * @author Larry Stone
@@ -261,7 +261,7 @@ public class DCDate {
      * @return the year
      */
     public int getYear() {
-        return (!withinGranularity(DateGran.YEAR)) ? -1 : localCalendar.get(Calendar.YEAR);
+        return !withinGranularity(DateGran.YEAR) ? -1 : localCalendar.get(Calendar.YEAR);
     }
 
     /**
@@ -270,7 +270,7 @@ public class DCDate {
      * @return the month
      */
     public int getMonth() {
-        return (!withinGranularity(DateGran.MONTH)) ? -1 : localCalendar.get(Calendar.MONTH) + 1;
+        return !withinGranularity(DateGran.MONTH) ? -1 : localCalendar.get(Calendar.MONTH) + 1;
     }
 
     /**
@@ -279,7 +279,7 @@ public class DCDate {
      * @return the day
      */
     public int getDay() {
-        return (!withinGranularity(DateGran.DAY)) ? -1 : localCalendar.get(Calendar.DAY_OF_MONTH);
+        return !withinGranularity(DateGran.DAY) ? -1 : localCalendar.get(Calendar.DAY_OF_MONTH);
     }
 
     /**
@@ -288,7 +288,7 @@ public class DCDate {
      * @return the hour
      */
     public int getHour() {
-        return (!withinGranularity(DateGran.TIME)) ? -1 : localCalendar.get(Calendar.HOUR_OF_DAY);
+        return !withinGranularity(DateGran.TIME) ? -1 : localCalendar.get(Calendar.HOUR_OF_DAY);
     }
 
     /**
@@ -297,7 +297,7 @@ public class DCDate {
      * @return the minute
      */
     public int getMinute() {
-        return (!withinGranularity(DateGran.TIME)) ? -1 : localCalendar.get(Calendar.MINUTE);
+        return !withinGranularity(DateGran.TIME) ? -1 : localCalendar.get(Calendar.MINUTE);
     }
 
     /**
@@ -306,7 +306,7 @@ public class DCDate {
      * @return the second
      */
     public int getSecond() {
-        return (!withinGranularity(DateGran.TIME)) ? -1 : localCalendar.get(Calendar.SECOND);
+        return !withinGranularity(DateGran.TIME) ? -1 : localCalendar.get(Calendar.SECOND);
     }
 
     /**
@@ -315,7 +315,7 @@ public class DCDate {
      * @return the year
      */
     public int getYearUTC() {
-        return (!withinGranularity(DateGran.YEAR)) ? -1 : calendar.get(Calendar.YEAR);
+        return !withinGranularity(DateGran.YEAR) ? -1 : calendar.get(Calendar.YEAR);
     }
 
     /**
@@ -324,7 +324,7 @@ public class DCDate {
      * @return the month
      */
     public int getMonthUTC() {
-        return (!withinGranularity(DateGran.MONTH)) ? -1 : calendar.get(Calendar.MONTH) + 1;
+        return !withinGranularity(DateGran.MONTH) ? -1 : calendar.get(Calendar.MONTH) + 1;
     }
 
     /**
@@ -333,7 +333,7 @@ public class DCDate {
      * @return the day
      */
     public int getDayUTC() {
-        return (!withinGranularity(DateGran.DAY)) ? -1 : calendar.get(Calendar.DAY_OF_MONTH);
+        return !withinGranularity(DateGran.DAY) ? -1 : calendar.get(Calendar.DAY_OF_MONTH);
     }
 
     /**
@@ -342,7 +342,7 @@ public class DCDate {
      * @return the hour
      */
     public int getHourUTC() {
-        return (!withinGranularity(DateGran.TIME)) ? -1 : calendar.get(Calendar.HOUR_OF_DAY);
+        return !withinGranularity(DateGran.TIME) ? -1 : calendar.get(Calendar.HOUR_OF_DAY);
     }
 
     /**
@@ -351,7 +351,7 @@ public class DCDate {
      * @return the minute
      */
     public int getMinuteUTC() {
-        return (!withinGranularity(DateGran.TIME)) ? -1 : calendar.get(Calendar.MINUTE);
+        return !withinGranularity(DateGran.TIME) ? -1 : calendar.get(Calendar.MINUTE);
     }
 
     /**
@@ -360,10 +360,9 @@ public class DCDate {
      * @return the second
      */
     public int getSecondUTC() {
-        return (!withinGranularity(DateGran.TIME)) ? -1 : calendar.get(Calendar.SECOND);
+        return !withinGranularity(DateGran.TIME) ? -1 : calendar.get(Calendar.SECOND);
     }
 
-
     /**
      * Get the date as a string to put back in the Dublin Core. Use the UTC/GMT calendar version.
      *

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

@@ -8,10 +8,9 @@
 package org.dspace.content;
 
 /**
- * Series and report number, as stored in relation.ispartofseries
+ * Series and report number, as stored in {@code relation.ispartofseries}.
  *
  * @author Robert Tansley
- * @version $Id$
  */
 public class DCSeriesNumber {
     /**
@@ -70,6 +69,7 @@ public class DCSeriesNumber {
      *
      * @return the series and number as they should be stored in the DB
      */
+    @Override
     public String toString() {
         if (series == null) {
             return (null);

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

@@ -13,7 +13,6 @@ import java.util.Arrays;
 import java.util.Comparator;
 import java.util.HashMap;
 import java.util.Iterator;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.StringTokenizer;
@@ -450,7 +449,7 @@ public abstract class DSpaceObjectServiceImpl<T extends DSpaceObject> implements
             clearMetadata(context, dso, field.schema, field.element, field.qualifier,
                     language);
 
-            String newValueLanguage = (Item.ANY.equals(language)) ? null : language;
+            String newValueLanguage = Item.ANY.equals(language) ? null : language;
             addMetadata(context, dso, field.schema, field.element, field.qualifier,
                     newValueLanguage, value);
             dso.setMetadataModified();
@@ -595,7 +594,7 @@ public abstract class DSpaceObjectServiceImpl<T extends DSpaceObject> implements
              */
             // A map created to store the latest place for each metadata field
             Map<MetadataField, Integer> fieldToLastPlace = new HashMap<>();
-            List<MetadataValue> metadataValues = new LinkedList<>();
+            List<MetadataValue> metadataValues;
             if (dso.getType() == Constants.ITEM) {
                 metadataValues = getMetadata(dso, Item.ANY, Item.ANY, Item.ANY, Item.ANY);
             } else {
@@ -628,7 +627,7 @@ public abstract class DSpaceObjectServiceImpl<T extends DSpaceObject> implements
                     String authority = metadataValue.getAuthority();
                     String relationshipId = StringUtils.split(authority, "::")[1];
                     Relationship relationship = relationshipService.find(context, Integer.parseInt(relationshipId));
-                    if (relationship.getLeftItem() == (Item) dso) {
+                    if (relationship.getLeftItem().equals((Item) dso)) {
                         relationship.setLeftPlace(mvPlace);
                     } else {
                         relationship.setRightPlace(mvPlace);

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

@@ -78,6 +78,7 @@ public class EntityType implements ReloadableEntity<Integer> {
      *
      * @return The ID for this EntityType
      */
+    @Override
     public Integer getID() {
         return id;
     }
@@ -87,6 +88,7 @@ public class EntityType implements ReloadableEntity<Integer> {
      * @param obj   object to be compared
      * @return
      */
+    @Override
     public boolean equals(Object obj) {
         if (!(obj instanceof EntityType)) {
             return false;
@@ -97,10 +99,7 @@ public class EntityType implements ReloadableEntity<Integer> {
             return false;
         }
 
-        if (!StringUtils.equals(this.getLabel(), entityType.getLabel())) {
+        return StringUtils.equals(this.getLabel(), entityType.getLabel());
-            return false;
-        }
-        return true;
     }
 
     /**

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

@@ -218,6 +218,7 @@ public class Relationship implements ReloadableEntity<Integer> {
      * Standard getter for the ID for this Relationship
      * @return  The ID of this relationship
      */
+    @Override
     public Integer getID() {
         return id;
     }

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

@@ -201,7 +201,7 @@ public class RelationshipType implements ReloadableEntity<Integer> {
 
     /**
      * Standard setter for the leftMinCardinality Integer for this RelationshipType
-     * @param leftMinCardinality    The leftMinCardinality Integer that this RelationshipType should recieve
+     * @param leftMinCardinality    The leftMinCardinality Integer that this RelationshipType should receive
      */
     public void setLeftMinCardinality(Integer leftMinCardinality) {
         this.leftMinCardinality = leftMinCardinality;
@@ -217,7 +217,7 @@ public class RelationshipType implements ReloadableEntity<Integer> {
 
     /**
      * Standard setter for the leftMaxCardinality Integer for this RelationshipType
-     * @param leftMaxCardinality    The leftMaxCardinality Integer that this RelationshipType should recieve
+     * @param leftMaxCardinality    The leftMaxCardinality Integer that this RelationshipType should receive
      */
     public void setLeftMaxCardinality(Integer leftMaxCardinality) {
         this.leftMaxCardinality = leftMaxCardinality;
@@ -233,7 +233,7 @@ public class RelationshipType implements ReloadableEntity<Integer> {
 
     /**
      * Standard setter for the rightMinCardinality Integer for this RelationshipType
-     * @param rightMinCardinality    The rightMinCardinality Integer that this RelationshipType should recieve
+     * @param rightMinCardinality    The rightMinCardinality Integer that this RelationshipType should receive
      */
     public void setRightMinCardinality(Integer rightMinCardinality) {
         this.rightMinCardinality = rightMinCardinality;
@@ -249,7 +249,7 @@ public class RelationshipType implements ReloadableEntity<Integer> {
 
     /**
      * Standard setter for the rightMaxCardinality Integer for this RelationshipType
-     * @param rightMaxCardinality    The rightMaxCardinality Integer that this RelationshipType should recieve
+     * @param rightMaxCardinality    The rightMaxCardinality Integer that this RelationshipType should receive
      */
     public void setRightMaxCardinality(Integer rightMaxCardinality) {
         this.rightMaxCardinality = rightMaxCardinality;
@@ -291,6 +291,7 @@ public class RelationshipType implements ReloadableEntity<Integer> {
      * Standard getter for the ID of this RelationshipType
      * @return  The ID of this RelationshipType
      */
+    @Override
     public Integer getID() {
         return id;
     }

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

@@ -8,7 +8,7 @@
 package org.dspace.content.dao.impl;
 
 import java.sql.SQLException;
-import java.util.LinkedList;
+import java.util.ArrayList;
 import java.util.List;
 import javax.persistence.Query;
 import javax.persistence.criteria.CriteriaBuilder;
@@ -63,7 +63,7 @@ public class MetadataSchemaDAOImpl extends AbstractHibernateDAO<MetadataSchema>
         Root<MetadataSchema> metadataSchemaRoot = criteriaQuery.from(MetadataSchema.class);
         criteriaQuery.select(metadataSchemaRoot);
 
-        List<javax.persistence.criteria.Order> orderList = new LinkedList<>();
+        List<javax.persistence.criteria.Order> orderList = new ArrayList<>();
         orderList.add(criteriaBuilder.asc(metadataSchemaRoot.get(MetadataSchema_.id)));
         criteriaQuery.orderBy(orderList);
 

dspace-api/src/main/java/org/dspace/content/packager/PackageException.java

@@ -19,7 +19,6 @@ import org.apache.logging.log4j.Logger;
  * exceptions. This class is intended for declarations and catch clauses.
  *
  * @author Larry Stone
- * @version $Revision$
  */
 public class PackageException extends Exception {
     /**
@@ -76,10 +75,4 @@ public class PackageException extends Exception {
             log.error(sw.toString());
         }
     }
-
-    public String toString() {
-        String base = getClass().getName() + ": " + getMessage();
-        return (getCause() == null) ? base :
-            base + ", Reason: " + getCause().toString();
-    }
 }

dspace-api/src/main/java/org/dspace/content/packager/PackageParameters.java

@@ -57,7 +57,7 @@ public class PackageParameters extends Properties {
             } else if (v.length == 1) {
                 result.setProperty(name, v[0]);
             } else {
-                StringBuffer sb = new StringBuffer();
+                StringBuilder sb = new StringBuilder();
                 for (int i = 0; i < v.length; ++i) {
                     if (i > 0) {
                         sb.append(SEPARATOR);

dspace-api/src/main/java/org/dspace/content/virtual/UUIDValue.java

@@ -8,7 +8,6 @@
 package org.dspace.content.virtual;
 
 import java.sql.SQLException;
-import java.util.LinkedList;
 import java.util.List;
 
 import org.dspace.content.Item;
@@ -24,9 +23,7 @@ public class UUIDValue implements VirtualMetadataConfiguration {
 
     @Override
     public List<String> getValues(Context context, Item item) throws SQLException {
-        List<String> list = new LinkedList<>();
+        return List.of(String.valueOf(item.getID()));
-        list.add(String.valueOf(item.getID()));
-        return list;
     }
 
     @Override

dspace-api/src/main/java/org/dspace/core/Context.java

@@ -8,13 +8,13 @@
 package org.dspace.core;
 
 import java.sql.SQLException;
+import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.EmptyStackException;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Locale;
 import java.util.Set;
-import java.util.Stack;
 import java.util.UUID;
 import java.util.concurrent.atomic.AtomicBoolean;
 
@@ -79,13 +79,13 @@ public class Context implements AutoCloseable {
     /**
      * A stack with the history of authorisation system check modify
      */
-    private Stack<Boolean> authStateChangeHistory;
+    private ArrayDeque<Boolean> authStateChangeHistory;
 
     /**
      * A stack with the name of the caller class that modify authorisation
      * system check
      */
-    private Stack<String> authStateClassCallHistory;
+    private ArrayDeque<String> authStateClassCallHistory;
 
     /**
      * Group IDs of special groups user is a member of
@@ -115,7 +115,7 @@ public class Context implements AutoCloseable {
     /**
      * Cache that is only used the context is in READ_ONLY mode
      */
-    private ContextReadOnlyCache readOnlyCache = new ContextReadOnlyCache();
+    private final ContextReadOnlyCache readOnlyCache = new ContextReadOnlyCache();
 
     protected EventService eventService;
 
@@ -183,8 +183,8 @@ public class Context implements AutoCloseable {
 
         specialGroups = new ArrayList<>();
 
-        authStateChangeHistory = new Stack<>();
+        authStateChangeHistory = new ArrayDeque<>();
-        authStateClassCallHistory = new Stack<>();
+        authStateClassCallHistory = new ArrayDeque<>();
         setMode(this.mode);
     }
 
@@ -336,7 +336,7 @@ public class Context implements AutoCloseable {
                                       + previousCaller));
             }
         }
-        ignoreAuth = previousState.booleanValue();
+        ignoreAuth = previousState;
     }
 
     /**
@@ -488,7 +488,7 @@ public class Context implements AutoCloseable {
             throw new IllegalStateException("Attempt to mutate object in read-only context");
         }
         if (events == null) {
-            events = new LinkedList<Event>();
+            events = new LinkedList<>();
         }
 
         events.add(event);
@@ -622,11 +622,7 @@ public class Context implements AutoCloseable {
      * @return true if member
      */
     public boolean inSpecialGroup(UUID groupID) {
-        if (specialGroups.contains(groupID)) {
+        return specialGroups.contains(groupID);
-            return true;
-        }
-
-        return false;
     }
 
     /**
@@ -636,7 +632,7 @@ public class Context implements AutoCloseable {
      * @throws SQLException if database error
      */
     public List<Group> getSpecialGroups() throws SQLException {
-        List<Group> myGroups = new ArrayList<Group>();
+        List<Group> myGroups = new ArrayList<>();
         for (UUID groupId : specialGroups) {
             myGroups.add(EPersonServiceFactory.getInstance().getGroupService().find(this, groupId));
         }
@@ -661,7 +657,7 @@ public class Context implements AutoCloseable {
 
         currentUserPreviousState = currentUser;
         specialGroupsPreviousState = specialGroups;
-        specialGroups = new ArrayList<UUID>();
+        specialGroups = new ArrayList<>();
         currentUser = newUser;
     }
 
@@ -703,11 +699,13 @@ public class Context implements AutoCloseable {
 
 
     /**
-     * Returns the size of the cache of all object that have been read from the database so far. A larger number
+     * Returns the size of the cache of all object that have been read from the
-     * means that more memory is consumed by the cache. This also has a negative impact on the query performance. In
+     * database so far.  A larger number means that more memory is consumed by
-     * that case you should consider uncaching entities when they are no longer needed (see
+     * the cache. This also has a negative impact on the query performance. In
-     * {@link Context#uncacheEntity(ReloadableEntity)} () uncacheEntity}).
+     * that case you should consider uncaching entities when they are no longer
+     * needed (see {@link Context#uncacheEntity(ReloadableEntity)} () uncacheEntity}).
      *
+     * @return cache size.
      * @throws SQLException When connecting to the active cache fails.
      */
     public long getCacheSize() throws SQLException {

dspace-api/src/main/java/org/dspace/core/I18nUtil.java

@@ -320,11 +320,11 @@ public class I18nUtil {
             fileType = "";
         }
 
-        if (!("".equals(locale.getCountry()))) {
+        if (!"".equals(locale.getCountry())) {
             fileNameLC = fileName + "_" + locale.getLanguage() + "_"
                 + locale.getCountry();
 
-            if (!("".equals(locale.getVariant()))) {
+            if (!"".equals(locale.getVariant())) {
                 fileNameLCV = fileName + "_" + locale.getLanguage() + "_"
                     + locale.getCountry() + "_" + locale.getVariant();
             }

dspace-api/src/main/java/org/dspace/curate/FileTaskQueue.java

@@ -13,16 +13,17 @@ import java.io.File;
 import java.io.FileReader;
 import java.io.FileWriter;
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Set;
 
+import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.dspace.services.factory.DSpaceServicesFactory;
 
-
 /**
  * FileTaskQueue provides a TaskQueue implementation based on flat files
  * for the queues and semaphores.
@@ -30,14 +31,16 @@ import org.dspace.services.factory.DSpaceServicesFactory;
  * @author richardrodgers
  */
 public class FileTaskQueue implements TaskQueue {
-    private static Logger log = org.apache.logging.log4j.LogManager.getLogger(TaskQueue.class);
+    private static final Logger log = LogManager.getLogger(TaskQueue.class);
+
     // base directory for curation task queues
     protected String tqDir;
 
     // ticket for queue readers
     protected long readTicket = -1L;
+
     // list of queues owned by reader
-    protected List<Integer> readList = new ArrayList<Integer>();
+    protected List<Integer> readList = new ArrayList<>();
 
     public FileTaskQueue() {
         tqDir = DSpaceServicesFactory.getInstance().getConfigurationService().getProperty("curate.taskqueue.dir");
@@ -72,7 +75,7 @@ public class FileTaskQueue implements TaskQueue {
                 BufferedWriter writer = null;
                 try {
                     File queue = new File(qDir, "queue" + Integer.toString(queueIdx));
-                    writer = new BufferedWriter(new FileWriter(queue, true));
+                    writer = new BufferedWriter(new FileWriter(queue, StandardCharsets.UTF_8, true));
                     Iterator<TaskQueueEntry> iter = entrySet.iterator();
                     while (iter.hasNext()) {
                         writer.write(iter.next().toString());
@@ -96,7 +99,7 @@ public class FileTaskQueue implements TaskQueue {
     @Override
     public synchronized Set<TaskQueueEntry> dequeue(String queueName, long ticket)
         throws IOException {
-        Set<TaskQueueEntry> entrySet = new HashSet<TaskQueueEntry>();
+        Set<TaskQueueEntry> entrySet = new HashSet<>();
         if (readTicket == -1L) {
             // hold the ticket & copy all Ids available, locking queues
             // stop when no more queues or one found locked
@@ -113,8 +116,8 @@ public class FileTaskQueue implements TaskQueue {
                     // read contents from file
                     BufferedReader reader = null;
                     try {
-                        reader = new BufferedReader(new FileReader(queue));
+                        reader = new BufferedReader(new FileReader(queue, StandardCharsets.UTF_8));
-                        String entryStr = null;
+                        String entryStr;
                         while ((entryStr = reader.readLine()) != null) {
                             entryStr = entryStr.trim();
                             if (entryStr.length() > 0) {

dspace-api/src/main/java/org/dspace/curate/ResolvedTask.java

@@ -24,7 +24,7 @@ public class ResolvedTask {
     private CurationTask cTask;
     private ScriptedTask sTask;
     // local name of task
-    private String taskName;
+    private final String taskName;
     // annotation data
     private boolean distributive = false;
     private boolean mutative = false;
@@ -76,7 +76,7 @@ public class ResolvedTask {
      * @throws IOException if error
      */
     public int perform(DSpaceObject dso) throws IOException {
-        return (unscripted()) ? cTask.perform(dso) : sTask.performDso(dso);
+        return unscripted() ? cTask.perform(dso) : sTask.performDso(dso);
     }
 
     /**
@@ -88,7 +88,7 @@ public class ResolvedTask {
      * @throws IOException if error
      */
     public int perform(Context ctx, String id) throws IOException {
-        return (unscripted()) ? cTask.perform(ctx, id) : sTask.performId(ctx, id);
+        return unscripted() ? cTask.perform(ctx, id) : sTask.performId(ctx, id);
     }
 
     /**

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

@@ -33,9 +33,9 @@ public class DiscoverQuery {
      * Main attributes for the discovery query
      **/
     private String query;
-    private List<String> filterQueries;
+    private final List<String> filterQueries;
     private List<String> dspaceObjectFilters = new ArrayList<>();
-    private List<String> fieldPresentQueries;
+    private final List<String> fieldPresentQueries;
     private boolean spellCheck;
 
     private int start = 0;
@@ -55,36 +55,35 @@ public class DiscoverQuery {
     /**
      * Attributes required for the faceting of values
      **/
-    private List<DiscoverFacetField> facetFields;
+    private final List<DiscoverFacetField> facetFields;
-    private List<String> facetQueries;
+    private final List<String> facetQueries;
-    private int facetLimit = -1;
     private int facetMinCount = -1;
     private int facetOffset = 0;
-    private Map<String, DiscoverHitHighlightingField> hitHighlighting;
+    private final Map<String, DiscoverHitHighlightingField> hitHighlighting;
 
     /**
      * Used when you want to search for a specific field value
      **/
-    private List<String> searchFields;
+    private final List<String> searchFields;
 
     /**
      * Misc attributes can be implementation dependent
      **/
-    private Map<String, List<String>> properties;
+    private final Map<String, List<String>> properties;
 
     private String discoveryConfigurationName;
 
     public DiscoverQuery() {
         //Initialize all our lists
-        this.filterQueries = new ArrayList<String>();
+        this.filterQueries = new ArrayList<>();
-        this.fieldPresentQueries = new ArrayList<String>();
+        this.fieldPresentQueries = new ArrayList<>();
 
-        this.facetFields = new ArrayList<DiscoverFacetField>();
+        this.facetFields = new ArrayList<>();
-        this.facetQueries = new ArrayList<String>();
+        this.facetQueries = new ArrayList<>();
-        this.searchFields = new ArrayList<String>();
+        this.searchFields = new ArrayList<>();
-        this.hitHighlighting = new HashMap<String, DiscoverHitHighlightingField>();
+        this.hitHighlighting = new HashMap<>();
         //Use a linked hashmap since sometimes insertion order might matter
-        this.properties = new LinkedHashMap<String, List<String>>();
+        this.properties = new LinkedHashMap<>();
     }
 
 
@@ -309,7 +308,7 @@ public class DiscoverQuery {
     public void addProperty(String property, String value) {
         List<String> toAddList = properties.get(property);
         if (toAddList == null) {
-            toAddList = new ArrayList<String>();
+            toAddList = new ArrayList<>();
         }
 
         toAddList.add(value);
@@ -322,7 +321,7 @@ public class DiscoverQuery {
     }
 
     public List<DiscoverHitHighlightingField> getHitHighlightingFields() {
-        return new ArrayList<DiscoverHitHighlightingField>(hitHighlighting.values());
+        return new ArrayList<>(hitHighlighting.values());
     }
 
     public void addHitHighlightingField(DiscoverHitHighlightingField hitHighlighting) {
@@ -368,7 +367,7 @@ public class DiscoverQuery {
 
     private List<String> buildFacetQueriesWithGap(int newestYear, int oldestYear, String dateFacet, int gap,
                                                   int topYear, int facetLimit) {
-        List<String> facetQueries = new LinkedList<>();
+        List<String> facetQueries = new ArrayList<>();
         for (int year = topYear; year > oldestYear && (facetQueries.size() < facetLimit); year -= gap) {
             //Add a filter to remove the last year only if we aren't the last year
             int bottomYear = year - gap;
@@ -392,7 +391,7 @@ public class DiscoverQuery {
     }
 
     private int getTopYear(int newestYear, int gap) {
-        return (int) (Math.ceil((float) (newestYear) / gap) * gap);
+        return (int) (Math.ceil((float) newestYear / gap) * gap);
     }
 
     /**

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

@@ -179,6 +179,11 @@ public class FullTextContentStreams extends ContentStreamBase {
         }
     }
 
+    /**
+     * {@link Enumeration} is implemented because instances of this class are
+     * passed to a JDK class that requires this obsolete type.
+     */
+    @SuppressWarnings("JdkObsolete")
     private static class FullTextEnumeration implements Enumeration<InputStream> {
 
         private final Iterator<FullTextBitstream> fulltextIterator;

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

@@ -55,7 +55,7 @@ public class SolrServiceFileInfoPlugin implements SolrServiceIndexPlugin {
                                 document.addField(SOLR_FIELD_NAME_FOR_FILENAMES, bitstream.getName());
 
                                 String description = bitstream.getDescription();
-                                if ((description != null) && (!description.isEmpty())) {
+                                if ((description != null) && !description.isEmpty()) {
                                     document.addField(SOLR_FIELD_NAME_FOR_DESCRIPTIONS, description);
                                 }
                             }

dspace-api/src/main/java/org/dspace/discovery/indexobject/AbstractIndexableObject.java

@@ -14,10 +14,13 @@ import org.dspace.discovery.IndexableObject;
 
 /**
  * This class exists in order to provide a default implementation for the equals and hashCode methods.
- * Since IndexableObjects can be made multiple times for the same underlying object, we needed a more finetuned
+ * Since IndexableObjects can be made multiple times for the same underlying
- * equals and hashcode methods. We're simply checking that the underlying objects are equal and generating the hashcode
+ * object, we needed more finely-tuned {@link equals} and {@link hashCode} methods.
- * for the underlying object. This way, we'll always get a proper result when calling equals or hashcode on an
+ * We're simply checking that the underlying objects are equal and returning the
- * IndexableObject because it'll depend on the underlying object
+ * hash-code for the underlying object. This way, we'll always get a proper
+ * result when calling {@link equals} or {@link hashCode} on an IndexableObject
+ * because it'll depend on the underlying object.
+ *
  * @param <T>   Refers to the underlying entity that is linked to this object
  * @param <PK>  The type of ID that this entity uses
  */
@@ -30,7 +33,7 @@ public abstract class AbstractIndexableObject<T extends ReloadableEntity<PK>, PK
         if (!(obj instanceof AbstractIndexableObject)) {
             return false;
         }
-        IndexableDSpaceObject other = (IndexableDSpaceObject) obj;
+        AbstractIndexableObject other = (AbstractIndexableObject) obj;
         return other.getIndexedObject().equals(getIndexedObject());
     }
 

dspace-api/src/main/java/org/dspace/eperson/Subscription.java

@@ -53,6 +53,7 @@ public class Subscription implements ReloadableEntity<Integer> {
 
     }
 
+    @Override
     public Integer getID() {
         return id;
     }

dspace-api/src/main/java/org/dspace/eperson/dao/impl/SubscriptionDAOImpl.java

@@ -8,6 +8,7 @@
 package org.dspace.eperson.dao.impl;
 
 import java.sql.SQLException;
+import java.util.ArrayList;
 import java.util.LinkedList;
 import java.util.List;
 import javax.persistence.Query;
@@ -97,7 +98,7 @@ public class SubscriptionDAOImpl extends AbstractHibernateDAO<Subscription> impl
         Root<Subscription> subscriptionRoot = criteriaQuery.from(Subscription.class);
         criteriaQuery.select(subscriptionRoot);
 
-        List<javax.persistence.criteria.Order> orderList = new LinkedList<>();
+        List<javax.persistence.criteria.Order> orderList = new ArrayList<>(1);
         orderList.add(criteriaBuilder.asc(subscriptionRoot.get(Subscription_.ePerson)));
         criteriaQuery.orderBy(orderList);
 

dspace-api/src/main/java/org/dspace/external/OrcidRestConnector.java

@@ -8,6 +8,7 @@
 package org.dspace.external;
 
 import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
 import java.util.Scanner;
 
 import org.apache.commons.lang3.StringUtils;
@@ -15,6 +16,7 @@ import org.apache.http.HttpResponse;
 import org.apache.http.client.HttpClient;
 import org.apache.http.client.methods.HttpGet;
 import org.apache.http.impl.client.HttpClientBuilder;
+import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
 /**
@@ -28,9 +30,9 @@ public class OrcidRestConnector {
     /**
      * log4j logger
      */
-    private static Logger log = org.apache.logging.log4j.LogManager.getLogger(OrcidRestConnector.class);
+    private static final Logger log = LogManager.getLogger(OrcidRestConnector.class);
 
-    private String url;
+    private final String url;
 
     public OrcidRestConnector(String url) {
         this.url = url;
@@ -73,7 +75,7 @@ public class OrcidRestConnector {
     }
 
     public static String convertStreamToString(InputStream is) {
-        Scanner s = new Scanner(is).useDelimiter("\\A");
+        Scanner s = new Scanner(is, StandardCharsets.UTF_8).useDelimiter("\\A");
         return s.hasNext() ? s.next() : "";
     }
 

dspace-api/src/main/java/org/dspace/external/model/ExternalDataObject.java

@@ -7,7 +7,7 @@
  */
 package org.dspace.external.model;
 
-import java.util.LinkedList;
+import java.util.ArrayList;
 import java.util.List;
 
 import org.dspace.content.dto.MetadataValueDTO;
@@ -32,7 +32,7 @@ public class ExternalDataObject {
     /**
      * The list of Metadata values. These our MetadataValueDTO because they won't exist in the DB
      */
-    private List<MetadataValueDTO> metadata = new LinkedList<>();
+    private List<MetadataValueDTO> metadata = new ArrayList<>();
     /**
      * The display value of the ExternalDataObject
      */
@@ -87,11 +87,11 @@ public class ExternalDataObject {
 
     /**
      * This method will add a Metadata value to the list of metadata values
-     * @param metadataValueDTO The metadatavalue to be added
+     * @param metadataValueDTO The metadata value to be added.
      */
     public void addMetadata(MetadataValueDTO metadataValueDTO) {
         if (metadata == null) {
-            metadata = new LinkedList<>();
+            metadata = new ArrayList<>();
         }
         metadata.add(metadataValueDTO);
     }

dspace-api/src/main/java/org/dspace/external/provider/orcid/xml/Converter.java

@@ -13,7 +13,6 @@ import javax.xml.bind.JAXBContext;
 import javax.xml.bind.JAXBException;
 import javax.xml.bind.Unmarshaller;
 
-import org.apache.logging.log4j.Logger;
 import org.xml.sax.SAXException;
 
 /**
@@ -25,11 +24,6 @@ import org.xml.sax.SAXException;
  */
 public abstract class Converter<T> {
 
-    /**
-     * log4j logger
-     */
-    private static Logger log = org.apache.logging.log4j.LogManager.getLogger(Converter.class);
-
     public abstract T convert(InputStream document);
 
     protected Object unmarshall(InputStream input, Class<?> type) throws SAXException, URISyntaxException {

dspace-api/src/main/java/org/dspace/harvest/HarvestedItem.java

@@ -56,6 +56,7 @@ public class HarvestedItem implements ReloadableEntity<Integer> {
     protected HarvestedItem() {
     }
 
+    @Override
     public Integer getID() {
         return id;
     }
@@ -89,7 +90,6 @@ public class HarvestedItem implements ReloadableEntity<Integer> {
      */
     public void setOaiID(String itemOaiID) {
         this.oaiId = itemOaiID;
-        return;
     }
 
 

dspace-api/src/main/java/org/dspace/identifier/DOI.java

@@ -62,6 +62,7 @@ public class DOI
     protected DOI() {
     }
 
+    @Override
     public Integer getID() {
         return id;
     }

dspace-api/src/main/java/org/dspace/identifier/dao/impl/DOIDAOImpl.java

@@ -8,7 +8,7 @@
 package org.dspace.identifier.dao.impl;
 
 import java.sql.SQLException;
-import java.util.LinkedList;
+import java.util.ArrayList;
 import java.util.List;
 import javax.persistence.criteria.CriteriaBuilder;
 import javax.persistence.criteria.CriteriaQuery;
@@ -24,7 +24,7 @@ import org.dspace.identifier.dao.DOIDAO;
 
 /**
  * Hibernate implementation of the Database Access Object interface class for the DOI object.
- * This class is responsible for all database calls for the DOI object and is autowired by spring
+ * This class is responsible for all database calls for the DOI object and is autowired by Spring.
  * This class should never be accessed directly.
  *
  * @author kevinvandevelde at atmire.com
@@ -52,7 +52,7 @@ public class DOIDAOImpl extends AbstractHibernateDAO<DOI> implements DOIDAO {
         Root<DOI> doiRoot = criteriaQuery.from(DOI.class);
         criteriaQuery.select(doiRoot);
 
-        List<Predicate> listToIncludeInOrPredicate = new LinkedList<>();
+        List<Predicate> listToIncludeInOrPredicate = new ArrayList<>(statusToExclude.size() + 1);
 
         for (Integer status : statusToExclude) {
             listToIncludeInOrPredicate.add(criteriaBuilder.notEqual(doiRoot.get(DOI_.status), status));
@@ -75,7 +75,7 @@ public class DOIDAOImpl extends AbstractHibernateDAO<DOI> implements DOIDAO {
         CriteriaQuery criteriaQuery = getCriteriaQuery(criteriaBuilder, DOI.class);
         Root<DOI> doiRoot = criteriaQuery.from(DOI.class);
         criteriaQuery.select(doiRoot);
-        List<Predicate> orPredicates = new LinkedList<>();
+        List<Predicate> orPredicates = new ArrayList<>(statuses.size());
         for (Integer status : statuses) {
             orPredicates.add(criteriaBuilder.equal(doiRoot.get(DOI_.status), status));
         }
@@ -92,13 +92,13 @@ public class DOIDAOImpl extends AbstractHibernateDAO<DOI> implements DOIDAO {
         Root<DOI> doiRoot = criteriaQuery.from(DOI.class);
         criteriaQuery.select(doiRoot);
 
-        List<Predicate> listToIncludeInOrPredicate = new LinkedList<>();
+        List<Predicate> listToIncludeInOrPredicate = new ArrayList<>(excludedStatuses.size());
 
         for (Integer status : excludedStatuses) {
             listToIncludeInOrPredicate.add(criteriaBuilder.notEqual(doiRoot.get(DOI_.status), status));
         }
 
-        List<Predicate> listToIncludeInAndPredicate = new LinkedList<>();
+        List<Predicate> listToIncludeInAndPredicate = new ArrayList<>();
 
         listToIncludeInAndPredicate.add(criteriaBuilder.like(doiRoot.get(DOI_.doi), doi));
         listToIncludeInAndPredicate.add(criteriaBuilder.or(listToIncludeInOrPredicate.toArray(new Predicate[] {})));
@@ -107,8 +107,6 @@ public class DOIDAOImpl extends AbstractHibernateDAO<DOI> implements DOIDAO {
         }
         criteriaQuery.where(listToIncludeInAndPredicate.toArray(new Predicate[] {}));
         return list(context, criteriaQuery, false, DOI.class, -1, -1);
-
-
     }
 
     @Override

dspace-api/src/main/java/org/dspace/importer/external/datamodel/ImportRecord.java

@@ -7,9 +7,9 @@
  */
 package org.dspace.importer.external.datamodel;
 
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.LinkedList;
 import java.util.List;
 
 import org.dspace.importer.external.metadatamapping.MetadatumDTO;
@@ -38,7 +38,7 @@ public class ImportRecord {
      */
     public ImportRecord(List<MetadatumDTO> valueList) {
         //don't want to alter the original list. Also now I can control the type of list
-        this.valueList = new LinkedList<>(valueList);
+        this.valueList = new ArrayList<>(valueList);
     }
 
     /**
@@ -81,7 +81,7 @@ public class ImportRecord {
      * @return the MetadatumDTO's that are related to a given schema/element/qualifier pair/triplet
      */
     public Collection<MetadatumDTO> getValue(String schema, String element, String qualifier) {
-        List<MetadatumDTO> values = new LinkedList<MetadatumDTO>();
+        List<MetadatumDTO> values = new ArrayList<MetadatumDTO>();
         for (MetadatumDTO value : valueList) {
             if (value.getSchema().equals(schema) && value.getElement().equals(element)) {
                 if (qualifier == null && value.getQualifier() == null) {

dspace-api/src/main/java/org/dspace/importer/external/metadatamapping/AbstractMetadataFieldMapping.java

@@ -7,18 +7,19 @@
  */
 package org.dspace.importer.external.metadatamapping;
 
+import java.util.ArrayList;
 import java.util.Collection;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 
+import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.dspace.importer.external.metadatamapping.contributor.MetadataContributor;
 import org.dspace.importer.external.metadatamapping.transform.MetadataProcessorService;
 
 /**
- * Abstract class that implements {@link MetadataFieldMapping}
+ * Abstract class that implements {@link MetadataFieldMapping}.
- * This class adds a default implementation for the MetadataFieldMapping methods
+ * This class adds a default implementation for the MetadataFieldMapping methods.
  *
  * @author Roeland Dillen (roeland at atmire dot com)
  */
@@ -30,7 +31,7 @@ public abstract class AbstractMetadataFieldMapping<RecordType>
     /**
      * log4j logger
      */
-    private static Logger log = org.apache.logging.log4j.LogManager.getLogger(AbstractMetadataFieldMapping.class);
+    private static final Logger log = LogManager.getLogger(AbstractMetadataFieldMapping.class);
 
     /* A map containing what processing has to be done on a given metadataFieldConfig.
      * The processing of a value is used to determine the actual value that will be returned used.
@@ -66,6 +67,7 @@ public abstract class AbstractMetadataFieldMapping<RecordType>
      * @param value The value to map to a MetadatumDTO
      * @return A metadatumDTO created from the field and value
      */
+    @Override
     public MetadatumDTO toDCValue(MetadataFieldConfig field, String value) {
         MetadatumDTO dcValue = new MetadatumDTO();
 
@@ -108,14 +110,15 @@ public abstract class AbstractMetadataFieldMapping<RecordType>
     }
 
     /**
-     * Loop over the MetadataContributors and return their concatenated retrieved metadatumDTO objects
+     * Loop over the MetadataContributors and return their concatenated
+     * retrieved metadatumDTO objects.
      *
      * @param record Used to retrieve the MetadatumDTO
      * @return Lit of metadatumDTO
      */
     @Override
     public Collection<MetadatumDTO> resultToDCValueMapping(RecordType record) {
-        List<MetadatumDTO> values = new LinkedList<MetadatumDTO>();
+        List<MetadatumDTO> values = new ArrayList<>();
 
         for (MetadataContributor<RecordType> query : getMetadataFieldMap().values()) {
             try {

dspace-api/src/main/java/org/dspace/importer/external/metadatamapping/MetadataFieldConfig.java

@@ -8,7 +8,7 @@
 package org.dspace.importer.external.metadatamapping;
 
 /**
- * A generalised configuration for metadatafields.
+ * A generalised configuration for metadata fields.
  * This is used to make the link between values and the actual MetadatumDTO object.
  *
  * @author Roeland Dillen (roeland at atmire dot com)
@@ -31,7 +31,7 @@ public class MetadataFieldConfig {
         if (this == o) {
             return true;
         }
-        if (o == null || getClass() != o.getClass()) {
+        if (o == null || !(o instanceof MetadataFieldConfig)) {
             return false;
         }
 
@@ -43,11 +43,7 @@ public class MetadataFieldConfig {
         if (qualifier != null ? !qualifier.equals(that.qualifier) : that.qualifier != null) {
             return false;
         }
-        if (!schema.equals(that.schema)) {
+        return schema.equals(that.schema);
-            return false;
-        }
-
-        return true;
     }
 
     /**

dspace-api/src/main/java/org/dspace/scripts/DSpaceCommandLineParameter.java

@@ -14,7 +14,8 @@ import org.apache.commons.lang3.StringUtils;
 import org.apache.commons.lang3.builder.HashCodeBuilder;
 
 /**
- * This class serves as a representation of a command line parameter by holding a String name and a String value
+ * This class serves as a representation of a command line parameter by holding
+ * a String name and a String value.
  */
 public class DSpaceCommandLineParameter {
     private String name;
@@ -23,7 +24,7 @@ public class DSpaceCommandLineParameter {
     public static String SEPARATOR = "|||";
 
     /**
-     * This constructor will take a String key and String value and store them in their appriopriate fields
+     * This constructor will take a String key and String value and store them in their appropriate fields.
      * @param key   The String value to be stored as the name of the parameter
      * @param value The String value to be stored as the value of the parameter
      */
@@ -64,9 +65,10 @@ public class DSpaceCommandLineParameter {
 
     /**
      * Converts the DSpaceCommandLineParameter into a String format by concatenating the value and the name String
-     * values by separating them with a space
+     * values by separating them with a space.
      * @return The String representation of a DSpaceCommandlineParameter object
      */
+    @Override
     public String toString() {
         String stringToReturn = "";
         stringToReturn += getName();
@@ -92,7 +94,7 @@ public class DSpaceCommandLineParameter {
     }
 
     /**
-     * Will return a boolean indicating whether the given param is equal to this object
+     * Will return a boolean indicating whether the given parameter is equal to this object.
      * @param other The other object
      * @return      A boolean indicating equality
      */
@@ -101,7 +103,7 @@ public class DSpaceCommandLineParameter {
         if (other == null) {
             return false;
         }
-        if (other.getClass() != DSpaceCommandLineParameter.class) {
+        if (!(other instanceof DSpaceCommandLineParameter)) {
             return false;
         }
         return StringUtils.equals(this.getName(), ((DSpaceCommandLineParameter) other).getName()) && StringUtils

dspace-api/src/main/java/org/dspace/scripts/DSpaceRunnable.java

@@ -8,7 +8,7 @@
 package org.dspace.scripts;
 
 import java.io.InputStream;
-import java.util.LinkedList;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.UUID;
 
@@ -37,7 +37,7 @@ public abstract class DSpaceRunnable<T extends ScriptConfiguration> implements R
     protected CommandLine commandLine;
 
     /**
-     * This EPerson identifier variable is the uuid of the eperson that's running the script
+     * This EPerson identifier variable is the UUID of the EPerson that's running the script
      */
     private UUID epersonIdentifier;
 
@@ -129,7 +129,7 @@ public abstract class DSpaceRunnable<T extends ScriptConfiguration> implements R
      * @return  The list of Strings representing filenames from the options given to the script
      */
     public List<String> getFileNamesFromInputStreamOptions() {
-        List<String> fileNames = new LinkedList<>();
+        List<String> fileNames = new ArrayList<>();
 
         for (Option option : getScriptConfiguration().getOptions().getOptions()) {
             if (option.getType() == InputStream.class &&
@@ -151,8 +151,8 @@ public abstract class DSpaceRunnable<T extends ScriptConfiguration> implements R
     }
 
     /**
-     * Generic setter for the epersonIdentifier
+     * Generic setter for the epersonIdentifier.
-     * This EPerson identifier variable is the uuid of the eperson that's running the script
+     * This EPerson identifier variable is the UUID of the EPerson that's running the script.
      * @param epersonIdentifier   The epersonIdentifier to be set on this DSpaceRunnable
      */
     public void setEpersonIdentifier(UUID epersonIdentifier) {

dspace-api/src/main/java/org/dspace/scripts/Process.java

@@ -7,8 +7,8 @@
  */
 package org.dspace.scripts;
 
+import java.util.Collections;
 import java.util.Date;
-import java.util.LinkedList;
 import java.util.List;
 import javax.persistence.Column;
 import javax.persistence.Entity;
@@ -91,6 +91,7 @@ public class Process implements ReloadableEntity<Integer> {
      * This method returns the ID that the Process holds within the Database
      * @return  The ID that the process holds within the database
      */
+    @Override
     public Integer getID() {
         return processId;
     }
@@ -162,7 +163,8 @@ public class Process implements ReloadableEntity<Integer> {
 
     /**
      * To get the parameters, use ProcessService.getParameters() to get a parsed list of DSpaceCommandLineParameters
-     * This String representation is the parameter in an unparsed fashion. For example "-c test"
+     * This String representation is the parameter in an unparsed fashion.For example "-c test"
+     * @return the raw parameter string.
      */
     protected String getParameters() {
         return parameters;
@@ -179,7 +181,7 @@ public class Process implements ReloadableEntity<Integer> {
      */
     public List<Bitstream> getBitstreams() {
         if (bitstreams == null) {
-            bitstreams = new LinkedList<>();
+            bitstreams = Collections.EMPTY_LIST;
         }
         return bitstreams;
     }

dspace-api/src/main/java/org/dspace/search/Harvest.java

@@ -11,7 +11,6 @@ import java.sql.SQLException;
 import java.text.ParseException;
 import java.util.ArrayList;
 import java.util.Iterator;
-import java.util.LinkedList;
 import java.util.List;
 
 import org.apache.logging.log4j.Logger;
@@ -129,7 +128,7 @@ public class Harvest {
         // several smaller operations (e.g. for OAI resumption tokens.)
         discoverQuery.setSortField("search.resourceid", DiscoverQuery.SORT_ORDER.asc);
 
-        List<HarvestedItemInfo> infoObjects = new LinkedList<HarvestedItemInfo>();
+        List<HarvestedItemInfo> infoObjects = new ArrayList<>();
 
         // Count of items read from the record set that match the selection criteria.
         // Note : Until 'index > offset' the records are not added to the output set.
@@ -155,7 +154,7 @@ public class Harvest {
 
                 if (collections) {
                     // Add collections data
-                    fillCollections(context, itemInfo);
+                    fillCollections(itemInfo);
                 }
 
                 if (items) {
@@ -163,7 +162,7 @@ public class Harvest {
                     itemInfo.item = itemService.find(context, itemInfo.itemID);
                 }
 
-                if ((nonAnon) || (itemInfo.item == null) || (withdrawn && itemInfo.withdrawn)) {
+                if (nonAnon || (itemInfo.item == null) || (withdrawn && itemInfo.withdrawn)) {
                     index++;
                     if (index > offset) {
                         infoObjects.add(itemInfo);
@@ -221,7 +220,7 @@ public class Harvest {
 
         // Get the sets
         if (collections) {
-            fillCollections(context, itemInfo);
+            fillCollections(itemInfo);
         }
 
         return itemInfo;
@@ -234,8 +233,7 @@ public class Harvest {
      * @param itemInfo HarvestedItemInfo object to fill out
      * @throws SQLException if database error
      */
-    private static void fillCollections(Context context,
+    private static void fillCollections(HarvestedItemInfo itemInfo) throws SQLException {
-                                        HarvestedItemInfo itemInfo) throws SQLException {
         // Get the collection Handles from DB
         List<Collection> collections = itemInfo.item.getCollections();
         itemInfo.collectionHandles = new ArrayList<>();

dspace-api/src/main/java/org/dspace/statistics/Dataset.java

@@ -18,6 +18,7 @@ import java.util.List;
 import java.util.Map;
 
 import au.com.bytecode.opencsv.CSVWriter;
+import java.nio.charset.StandardCharsets;
 import org.apache.commons.lang3.ArrayUtils;
 import org.apache.commons.lang3.StringUtils;
 
@@ -65,20 +66,20 @@ public class Dataset {
     }
 
     private void initRowLabels(int rows) {
-        rowLabels = new ArrayList<String>(rows);
+        rowLabels = new ArrayList<>(rows);
-        rowLabelsAttrs = new ArrayList<Map<String, String>>();
+        rowLabelsAttrs = new ArrayList<>();
         for (int i = 0; i < rows; i++) {
             rowLabels.add("Row " + (i + 1));
-            rowLabelsAttrs.add(new HashMap<String, String>());
+            rowLabelsAttrs.add(new HashMap<>());
         }
     }
 
     private void initColumnLabels(int nbCols) {
-        colLabels = new ArrayList<String>(nbCols);
+        colLabels = new ArrayList<>(nbCols);
-        colLabelsAttrs = new ArrayList<Map<String, String>>();
+        colLabelsAttrs = new ArrayList<>();
         for (int i = 0; i < nbCols; i++) {
             colLabels.add("Column " + (i + 1));
-            colLabelsAttrs.add(new HashMap<String, String>());
+            colLabelsAttrs.add(new HashMap<>());
         }
     }
 
@@ -232,7 +233,7 @@ public class Dataset {
 
     public ByteArrayOutputStream exportAsCSV() throws IOException {
         ByteArrayOutputStream baos = new ByteArrayOutputStream();
-        CSVWriter ecsvp = new CSVWriter(new OutputStreamWriter(baos), ';');
+        CSVWriter ecsvp = new CSVWriter(new OutputStreamWriter(baos, StandardCharsets.UTF_8), ';');
         //Generate the item row
         List<String> colLabels = getColLabels();
         colLabels.add(0, "");

dspace-api/src/main/java/org/dspace/statistics/SolrLoggerUsageEventListener.java

@@ -7,9 +7,10 @@
  */
 package org.dspace.statistics;
 
-import java.util.LinkedList;
+import java.util.ArrayList;
 import java.util.List;
 
+import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.dspace.eperson.EPerson;
 import org.dspace.services.model.Event;
@@ -28,7 +29,7 @@ import org.springframework.beans.factory.annotation.Autowired;
  */
 public class SolrLoggerUsageEventListener extends AbstractUsageEventListener {
 
-    private static Logger log = org.apache.logging.log4j.LogManager.getLogger(SolrLoggerUsageEventListener.class);
+    private static final Logger log = LogManager.getLogger(SolrLoggerUsageEventListener.class);
 
     protected SolrLoggerService solrLoggerService;
 
@@ -56,7 +57,7 @@ public class SolrLoggerUsageEventListener extends AbstractUsageEventListener {
                     }
                 } else if (UsageEvent.Action.SEARCH == ue.getAction()) {
                     UsageSearchEvent usageSearchEvent = (UsageSearchEvent) ue;
-                    List<String> queries = new LinkedList<>();
+                    List<String> queries = new ArrayList<>();
                     queries.add(usageSearchEvent.getQuery());
                     solrLoggerService.postSearch(usageSearchEvent.getObject(), usageSearchEvent.getRequest(),
                                     currentUser, queries, usageSearchEvent.getPage().getSize(),

dspace-api/src/main/java/org/dspace/statistics/content/StatisticsDataVisits.java

@@ -285,13 +285,8 @@ public class StatisticsDataVisits extends StatisticsData {
             DatasetQuery firsDataset = datasetQueries.get(0);
             //Do the first query
 
-            ObjectCount[] topCounts1 = null;
+            ObjectCount[] topCounts1 =
-//            if (firsDataset.getQueries().size() == 1) {
-            topCounts1 =
                 queryFacetField(firsDataset, firsDataset.getQueries().get(0).getQuery(), filterQuery, facetMinCount);
-//            } else {
-//                TODO: do this
-//            }
             // Check if we have more queries that need to be done
             if (datasetQueries.size() == 2) {
                 DatasetQuery secondDataSet = datasetQueries.get(1);
@@ -313,7 +308,6 @@ public class StatisticsDataVisits extends StatisticsData {
                 }
                 for (int i = 0; i < topCounts1.length; i++) {
                     ObjectCount count1 = topCounts1[i];
-                    ObjectCount[] currentResult = new ObjectCount[topCounts2.length];
 
                     // Make sure we have a dataSet
                     if (dataset == null) {
@@ -645,7 +639,7 @@ public class StatisticsDataVisits extends StatisticsData {
                     // be null if a handle has not yet been assigned. In this case reference the
                     // item its internal id. In the last case where the bitstream is not associated
                     // with an item (such as a community logo) then reference the bitstreamID directly.
-                    String identifier = null;
+                    String identifier;
                     if (owningItem != null && owningItem.getHandle() != null) {
                         identifier = "handle/" + owningItem.getHandle();
                     } else if (owningItem != null) {

dspace-api/src/main/java/org/dspace/submit/lookup/ValueConcatenationModifier.java

@@ -39,11 +39,11 @@ public class ValueConcatenationModifier extends AbstractModifier {
     public Record modify(MutableRecord rec) {
         List<Value> values = rec.getValues(field);
         if (values != null) {
-            List<String> converted_values = new ArrayList<String>();
+            List<String> converted_values = new ArrayList<>();
             for (Value val : values) {
                 converted_values.add(val.getAsString());
             }
-            List<Value> final_value = new ArrayList<Value>();
+            List<Value> final_value = new ArrayList<>();
             String v = StringUtils.join(converted_values.iterator(), separator
                 + (whitespaceAfter ? " " : ""));
             final_value.add(new StringValue(v));
@@ -89,9 +89,9 @@ public class ValueConcatenationModifier extends AbstractModifier {
     }
 
     /**
-     * @param whiteSpaceAfter the whiteSpaceAfter to set
+     * @param whitespaceAfter the whiteSpaceAfter to set
      */
-    public void setWhitespaceAfter(boolean whiteSpaceAfter) {
+    public void setWhitespaceAfter(boolean whitespaceAfter) {
-        this.whitespaceAfter = whiteSpaceAfter;
+        this.whitespaceAfter = whitespaceAfter;
     }
 }

dspace-api/src/main/java/org/dspace/submit/util/ItemSubmissionLookupDTO.java

@@ -30,11 +30,9 @@ public class ItemSubmissionLookupDTO implements Serializable {
 
     private static final String MERGED_PUBLICATION_PROVIDER = "merged";
 
-    private static final String UNKNOWN_PROVIDER_STRING = "UNKNOWN-PROVIDER";
+    private final List<Record> publications;
 
-    private List<Record> publications;
+    private final String uuid;
-
-    private String uuid;
 
     public ItemSubmissionLookupDTO(List<Record> publications) {
         this.uuid = UUID.randomUUID().toString();
@@ -46,7 +44,7 @@ public class ItemSubmissionLookupDTO implements Serializable {
     }
 
     public Set<String> getProviders() {
-        Set<String> orderedProviders = new LinkedHashSet<String>();
+        Set<String> orderedProviders = new LinkedHashSet<>();
         for (Record p : publications) {
             orderedProviders.add(SubmissionLookupService.getProviderName(p));
         }

dspace-api/src/main/java/org/dspace/versioning/Version.java

@@ -77,6 +77,7 @@ public class Version implements ReloadableEntity<Integer> {
 
     }
 
+    @Override
     public Integer getID() {
         return id;
     }

dspace-api/src/main/java/org/dspace/versioning/VersionHistory.java

@@ -20,7 +20,6 @@ import javax.persistence.OrderBy;
 import javax.persistence.SequenceGenerator;
 import javax.persistence.Table;
 
-import org.apache.logging.log4j.Logger;
 import org.dspace.core.Context;
 import org.dspace.core.ReloadableEntity;
 import org.hibernate.proxy.HibernateProxyHelper;
@@ -35,8 +34,6 @@ import org.hibernate.proxy.HibernateProxyHelper;
 @Table(name = "versionhistory")
 public class VersionHistory implements ReloadableEntity<Integer> {
 
-    private static final Logger log = org.apache.logging.log4j.LogManager.getLogger(VersionHistory.class);
-
     @Id
     @Column(name = "versionhistory_id")
     @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "versionhistory_seq")
@@ -56,6 +53,7 @@ public class VersionHistory implements ReloadableEntity<Integer> {
 
     }
 
+    @Override
     public Integer getID() {
         return id;
     }
@@ -98,11 +96,7 @@ public class VersionHistory implements ReloadableEntity<Integer> {
         }
 
         final VersionHistory that = (VersionHistory) o;
-        if (!this.getID().equals(that.getID())) {
+        return this.getID().equals(that.getID());
-            return false;
-        }
-
-        return true;
     }
 
     @Override

dspace-api/src/main/java/org/dspace/workflow/WorkflowException.java

@@ -27,7 +27,8 @@ public class WorkflowException extends Exception {
         this.reason = reason;
     }
 
-    public String toString() {
+    @Override
+    public String getMessage() {
         return reason;
     }
 }

dspace-api/src/main/java/org/dspace/workflowbasic/BasicWorkflowItem.java

@@ -116,6 +116,7 @@ public class BasicWorkflowItem implements WorkflowItem {
      *
      * @return state
      */
+    @Override
     public int getState() {
         return state;
     }

dspace-api/src/main/java/org/dspace/workflowbasic/TaskListItem.java

@@ -73,6 +73,7 @@ public class TaskListItem implements ReloadableEntity<Integer> {
         this.workflowItem = workflowItem;
     }
 
+    @Override
     public Integer getID() {
         return taskListItemId;
     }

dspace-api/src/main/java/org/dspace/xmlworkflow/RoleMembers.java

@@ -30,8 +30,8 @@ import org.dspace.eperson.service.GroupService;
 public class RoleMembers {
 
     protected GroupService groupService = EPersonServiceFactory.getInstance().getGroupService();
-    private ArrayList<Group> groups;
+    private final ArrayList<Group> groups;
-    private ArrayList<EPerson> epersons;
+    private final ArrayList<EPerson> epersons;
 
     public RoleMembers() {
         this.groups = new ArrayList<>();
@@ -55,11 +55,7 @@ public class RoleMembers {
     }
 
     public void removeEperson(EPerson epersonToRemove) {
-        for (EPerson eperson : epersons) {
+        epersons.removeIf(eperson -> eperson.equals(epersonToRemove));
-            if (eperson.equals(epersonToRemove)) {
-                epersons.remove(eperson);
-            }
-        }
     }
 
     public ArrayList<EPerson> getAllUniqueMembers(Context context) throws SQLException {

dspace-api/src/main/java/org/dspace/xmlworkflow/WorkflowConfigurationException.java

@@ -8,7 +8,7 @@
 package org.dspace.xmlworkflow;
 
 /**
- * Exception for problems with the configuration xml
+ * Exception for problems with the configuration XML.
  *
  * @author Bram De Schouwer (bram.deschouwer at dot com)
  * @author Kevin Van de Velde (kevin at atmire dot com)
@@ -17,13 +17,14 @@ package org.dspace.xmlworkflow;
  */
 public class WorkflowConfigurationException extends Exception {
 
-    private String error;
+    private final String error;
 
     public WorkflowConfigurationException(String error) {
         this.error = error;
     }
 
-    public String toString() {
+    @Override
+    public String getMessage() {
         return this.error;
     }
 

dspace-api/src/main/java/org/dspace/xmlworkflow/storedcomponents/ClaimedTask.java

@@ -71,6 +71,7 @@ public class ClaimedTask implements ReloadableEntity<Integer> {
 
     }
 
+    @Override
     public Integer getID() {
         return id;
     }
@@ -91,24 +92,24 @@ public class ClaimedTask implements ReloadableEntity<Integer> {
         return workflowItem;
     }
 
-    public void setActionID(String actionID) {
+    public void setActionID(String actionId) {
-        this.actionId = actionID;
+        this.actionId = actionId;
     }
 
     public String getActionID() {
         return actionId;
     }
 
-    public void setStepID(String stepID) {
+    public void setStepID(String stepId) {
-        this.stepId = stepID;
+        this.stepId = stepId;
     }
 
     public String getStepID() {
         return stepId;
     }
 
-    public void setWorkflowID(String workflowID) {
+    public void setWorkflowID(String workflowId) {
-        this.workflowId = workflowID;
+        this.workflowId = workflowId;
     }
 
     public String getWorkflowID() {

dspace-api/src/main/java/org/dspace/xmlworkflow/storedcomponents/CollectionRole.java

@@ -91,6 +91,7 @@ public class CollectionRole implements ReloadableEntity<Integer> {
         return group;
     }
 
+    @Override
     public Integer getID() {
         return id;
     }

dspace-api/src/main/java/org/dspace/xmlworkflow/storedcomponents/PoolTask.java

@@ -78,12 +78,13 @@ public class PoolTask implements ReloadableEntity<Integer> {
 
     }
 
+    @Override
     public Integer getID() {
         return id;
     }
 
-    public void setEperson(EPerson eperson) {
+    public void setEperson(EPerson ePerson) {
-        this.ePerson = eperson;
+        this.ePerson = ePerson;
     }
 
     public EPerson getEperson() {
@@ -114,16 +115,16 @@ public class PoolTask implements ReloadableEntity<Integer> {
         return this.workflowItem;
     }
 
-    public void setStepID(String stepID) {
+    public void setStepID(String stepId) {
-        this.stepId = stepID;
+        this.stepId = stepId;
     }
 
     public String getStepID() {
         return stepId;
     }
 
-    public void setActionID(String actionID) {
+    public void setActionID(String actionId) {
-        this.actionId = actionID;
+        this.actionId = actionId;
     }
 
     public String getActionID() {

dspace-api/src/main/java/org/dspace/xmlworkflow/storedcomponents/WorkflowItemRole.java

@@ -69,7 +69,7 @@ public class WorkflowItemRole implements ReloadableEntity<Integer> {
 
     }
 
-
+    @Override
     public Integer getID() {
         return id;
     }
@@ -90,8 +90,8 @@ public class WorkflowItemRole implements ReloadableEntity<Integer> {
         return workflowItem;
     }
 
-    public void setEPerson(EPerson eperson) {
+    public void setEPerson(EPerson ePerson) {
-        this.ePerson = eperson;
+        this.ePerson = ePerson;
     }
 
     public EPerson getEPerson() throws SQLException {

dspace-api/src/test/java/org/dspace/AbstractIntegrationTest.java

@@ -12,6 +12,7 @@ import java.io.FileWriter;
 import java.io.IOException;
 import java.io.Writer;
 import java.nio.channels.FileChannel;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Paths;
 import java.nio.file.StandardOpenOption;
 
@@ -118,7 +119,8 @@ public class AbstractIntegrationTest extends AbstractUnitTest {
      */
     protected void appendToLocalConfiguration(String textToAppend) {
         String extraConfPath = getLocalConfigurationFilePath();
-        try (Writer output = new BufferedWriter(new FileWriter(extraConfPath, true))) {
+        try (Writer output = new BufferedWriter(
+                new FileWriter(extraConfPath, StandardCharsets.UTF_8, true))) {
             output.append("\n");
             output.append(textToAppend);
             output.flush();

dspace-api/src/test/java/org/dspace/app/bulkedit/MetadataImportIT.java

@@ -47,10 +47,12 @@ import org.junit.Test;
 
 public class MetadataImportIT extends AbstractIntegrationTestWithDatabase {
 
-    private ItemService itemService
+    private final ItemService itemService
             = ContentServiceFactory.getInstance().getItemService();
-    private EPersonService ePersonService = EPersonServiceFactory.getInstance().getEPersonService();
+    private final EPersonService ePersonService
-    private RelationshipService relationshipService = ContentServiceFactory.getInstance().getRelationshipService();
+            = EPersonServiceFactory.getInstance().getEPersonService();
+    private final RelationshipService relationshipService
+            = ContentServiceFactory.getInstance().getRelationshipService();
 
     Collection collection;
 
@@ -119,7 +121,7 @@ public class MetadataImportIT extends AbstractIntegrationTestWithDatabase {
         Item importedItem = findItemByName("Test Import 1");
 
 
-        assertEquals(relationshipService.findByItem(context, importedItem).size(), 1);
+        assertEquals(1, relationshipService.findByItem(context, importedItem).size());
         context.turnOffAuthorisationSystem();
         itemService.delete(context, itemService.find(context, importedItem.getID()));
         context.restoreAuthSystemState();
@@ -148,7 +150,7 @@ public class MetadataImportIT extends AbstractIntegrationTestWithDatabase {
         Item importedItem = findItemByName("Person1");
 
 
-        assertEquals(relationshipService.findByItem(context, importedItem).size(), 1);
+        assertEquals(1, relationshipService.findByItem(context, importedItem).size());
 
     }
 

dspace-api/src/test/java/org/dspace/app/csv/CSVMetadataImportReferenceIT.java

@@ -56,14 +56,16 @@ public class CSVMetadataImportReferenceIT extends AbstractIntegrationTestWithDat
     //Common collection to utilize for test
     private Collection col1;
 
-    private RelationshipService relationshipService = ContentServiceFactory.getInstance().getRelationshipService();
+    private final RelationshipService relationshipService
-    private ItemService itemService = ContentServiceFactory.getInstance().getItemService();
+            = ContentServiceFactory.getInstance().getRelationshipService();
-
+    private final ItemService itemService
+            = ContentServiceFactory.getInstance().getItemService();
 
     Community parentCommunity;
 
     /**
-     * Setup testing enviorment
+     * Setup testing environment.
+     * @throws java.sql.SQLException passed through.
      */
     @Before
     public void setup() throws SQLException {
@@ -80,7 +82,7 @@ public class CSVMetadataImportReferenceIT extends AbstractIntegrationTestWithDat
         EntityType publication = EntityTypeBuilder.createEntityTypeBuilder(context, "Publication").build();
         EntityType person = EntityTypeBuilder.createEntityTypeBuilder(context, "Person").build();
         EntityType project = EntityTypeBuilder.createEntityTypeBuilder(context, "Project").build();
-        EntityType orgUnit = EntityTypeBuilder.createEntityTypeBuilder(context, "OrgUnit").build();
+        EntityTypeBuilder.createEntityTypeBuilder(context, "OrgUnit").build();
 
         RelationshipTypeBuilder
             .createRelationshipTypeBuilder(context, publication, person, "isAuthorOfPublication",
@@ -350,11 +352,12 @@ public class CSVMetadataImportReferenceIT extends AbstractIntegrationTestWithDat
 
     /**
      * Test failure when referring to item by non unique metadata in the database.
+     * @throws java.lang.Exception passed through.
      */
     @Test(expected = MetadataImportException.class)
     public void testNonUniqueMDRefInDb() throws Exception {
         context.turnOffAuthorisationSystem();
-        Item person = ItemBuilder.createItem(context, col1)
+        ItemBuilder.createItem(context, col1)
                                  .withTitle("Person")
                                  .withIssueDate("2017-10-17")
                                  .withAuthor("Smith, Donald")
@@ -363,7 +366,7 @@ public class CSVMetadataImportReferenceIT extends AbstractIntegrationTestWithDat
                                  .withRelationshipType("Person")
                                  .withIdentifierOther("1")
                                  .build();
-        Item person2 = ItemBuilder.createItem(context, col1)
+        ItemBuilder.createItem(context, col1)
                                  .withTitle("Person2")
                                  .withIssueDate("2017-10-17")
                                  .withAuthor("Smith, John")
@@ -385,7 +388,7 @@ public class CSVMetadataImportReferenceIT extends AbstractIntegrationTestWithDat
     @Test(expected = MetadataImportException.class)
     public void testNonUniqueMDRefInBoth() throws Exception {
         context.turnOffAuthorisationSystem();
-        Item person = ItemBuilder.createItem(context, col1)
+        ItemBuilder.createItem(context, col1)
                                  .withTitle("Person")
                                  .withIssueDate("2017-10-17")
                                  .withAuthor("Smith, Donald")
@@ -402,7 +405,7 @@ public class CSVMetadataImportReferenceIT extends AbstractIntegrationTestWithDat
     }
 
     /**
-     * Test failure when refering to item by metadata that does not exist in the relation column
+     * Test failure when referring to item by metadata that does not exist in the relation column
      */
     @Test(expected = Exception.class)
     public void testNonExistMdRef() throws Exception {
@@ -413,7 +416,7 @@ public class CSVMetadataImportReferenceIT extends AbstractIntegrationTestWithDat
     }
 
     /**
-     * Test failure when refering to an item in the CSV that hasn't been created yet due to it's order in the CSV
+     * Test failure when referring to an item in the CSV that hasn't been created yet due to it's order in the CSV
      */
     @Test(expected = Exception.class)
     public void testCSVImportWrongOrder() throws Exception {
@@ -424,7 +427,7 @@ public class CSVMetadataImportReferenceIT extends AbstractIntegrationTestWithDat
     }
 
     /**
-     * Test failure when refering to an item in the CSV that hasn't been created yet due to it's order in the CSV
+     * Test failure when referring to an item in the CSV that hasn't been created yet due to it's order in the CSV
      */
     @Test(expected = Exception.class)
     public void testCSVImportWrongOrderRowName() throws Exception {
@@ -446,7 +449,7 @@ public class CSVMetadataImportReferenceIT extends AbstractIntegrationTestWithDat
     }
 
     /**
-     * Test relationship validation with invalid relationship definition and with an archived origin referer
+     * Test relationship validation with invalid relationship definition and with an archived origin referrer.
      */
     @Test(expected = MetadataImportInvalidHeadingException.class)
     public void testInvalidRelationshipArchivedOrigin() throws Exception {

dspace-api/src/test/java/org/dspace/builder/util/AbstractBuilderCleanupUtil.java

@@ -7,8 +7,8 @@
  */
 package org.dspace.builder.util;
 
+import java.util.ArrayList;
 import java.util.LinkedHashMap;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 
@@ -51,24 +51,24 @@ public class AbstractBuilderCleanupUtil {
     }
 
     private void initMap() {
-        map.put(RelationshipBuilder.class.getName(), new LinkedList<>());
+        map.put(RelationshipBuilder.class.getName(), new ArrayList<>());
-        map.put(RelationshipTypeBuilder.class.getName(), new LinkedList<>());
+        map.put(RelationshipTypeBuilder.class.getName(), new ArrayList<>());
-        map.put(EntityTypeBuilder.class.getName(), new LinkedList<>());
+        map.put(EntityTypeBuilder.class.getName(), new ArrayList<>());
-        map.put(PoolTaskBuilder.class.getName(), new LinkedList<>());
+        map.put(PoolTaskBuilder.class.getName(), new ArrayList<>());
-        map.put(WorkflowItemBuilder.class.getName(), new LinkedList<>());
+        map.put(WorkflowItemBuilder.class.getName(), new ArrayList<>());
-        map.put(WorkspaceItemBuilder.class.getName(), new LinkedList<>());
+        map.put(WorkspaceItemBuilder.class.getName(), new ArrayList<>());
-        map.put(BitstreamBuilder.class.getName(), new LinkedList<>());
+        map.put(BitstreamBuilder.class.getName(), new ArrayList<>());
-        map.put(BitstreamFormatBuilder.class.getName(), new LinkedList<>());
+        map.put(BitstreamFormatBuilder.class.getName(), new ArrayList<>());
-        map.put(ClaimedTaskBuilder.class.getName(), new LinkedList<>());
+        map.put(ClaimedTaskBuilder.class.getName(), new ArrayList<>());
-        map.put(CollectionBuilder.class.getName(), new LinkedList<>());
+        map.put(CollectionBuilder.class.getName(), new ArrayList<>());
-        map.put(CommunityBuilder.class.getName(), new LinkedList<>());
+        map.put(CommunityBuilder.class.getName(), new ArrayList<>());
-        map.put(EPersonBuilder.class.getName(), new LinkedList<>());
+        map.put(EPersonBuilder.class.getName(), new ArrayList<>());
-        map.put(GroupBuilder.class.getName(), new LinkedList<>());
+        map.put(GroupBuilder.class.getName(), new ArrayList<>());
-        map.put(ItemBuilder.class.getName(), new LinkedList<>());
+        map.put(ItemBuilder.class.getName(), new ArrayList<>());
-        map.put(MetadataFieldBuilder.class.getName(), new LinkedList<>());
+        map.put(MetadataFieldBuilder.class.getName(), new ArrayList<>());
-        map.put(MetadataSchemaBuilder.class.getName(), new LinkedList<>());
+        map.put(MetadataSchemaBuilder.class.getName(), new ArrayList<>());
-        map.put(SiteBuilder.class.getName(), new LinkedList<>());
+        map.put(SiteBuilder.class.getName(), new ArrayList<>());
-        map.put(ProcessBuilder.class.getName(), new LinkedList<>());
+        map.put(ProcessBuilder.class.getName(), new ArrayList<>());
     }
 
     /**
@@ -78,7 +78,7 @@ public class AbstractBuilderCleanupUtil {
      * @param abstractBuilder   The AbstractBuilder to be added
      */
     public void addToMap(AbstractBuilder abstractBuilder) {
-        map.computeIfAbsent(abstractBuilder.getClass().getName(), k -> new LinkedList<>()).add(abstractBuilder);
+        map.computeIfAbsent(abstractBuilder.getClass().getName(), k -> new ArrayList<>()).add(abstractBuilder);
     }
 
     /**

dspace-api/src/test/java/org/dspace/content/MetadataFieldNameTest.java

@@ -40,8 +40,9 @@ public class MetadataFieldNameTest {
     }
 
     @Test(expected = NullPointerException.class)
+    @SuppressWarnings("ResultOfObjectAllocationIgnored")
     public void testConstructNull() {
-        MetadataFieldName instance = new MetadataFieldName("one", null);
+        new MetadataFieldName("one", null);
     }
 
     /**
@@ -71,7 +72,7 @@ public class MetadataFieldNameTest {
      */
     @Test(expected = IllegalArgumentException.class)
     public void TestParse1() {
-        String[] results = MetadataFieldName.parse("one");
+        MetadataFieldName.parse("one");
     }
 
     /**
@@ -79,15 +80,16 @@ public class MetadataFieldNameTest {
      */
     @Test(expected = IllegalArgumentException.class)
     public void TestParse0() {
-        String[] results = MetadataFieldName.parse("");
+        MetadataFieldName.parse("");
     }
 
     /**
      * Test of parse method using an illegal null name.
      */
     @Test(expected = NullPointerException.class)
+    @SuppressWarnings("null")
     public void TestParseNull() {
-        String[] results = MetadataFieldName.parse(null);
+        MetadataFieldName.parse(null);
     }
 
     /**

dspace-api/src/test/java/org/dspace/content/authority/DSpaceControlledVocabularyTest.java

@@ -13,7 +13,6 @@ import static org.junit.Assert.assertNotNull;
 import java.io.IOException;
 
 import org.dspace.AbstractDSpaceTest;
-import org.dspace.content.Collection;
 import org.dspace.core.factory.CoreServiceFactory;
 import org.junit.After;
 import org.junit.AfterClass;
@@ -66,6 +65,8 @@ public class DSpaceControlledVocabularyTest extends AbstractDSpaceTest {
 
     /**
      * Test of getMatches method, of class DSpaceControlledVocabulary.
+     * @throws java.io.IOException passed through.
+     * @throws java.lang.ClassNotFoundException passed through.
      */
     @Test
     public void testGetMatches() throws IOException, ClassNotFoundException {
@@ -74,9 +75,7 @@ public class DSpaceControlledVocabularyTest extends AbstractDSpaceTest {
         final String PLUGIN_INTERFACE = "org.dspace.content.authority.ChoiceAuthority";
 
         // Ensure that 'id' attribute is optional
-        String field = null; // not used
         String text = "north 40";
-        Collection collection = null;
         int start = 0;
         int limit = 10;
         String locale = null;

dspace-api/src/test/java/org/dspace/license/MockCCLicenseConnectorServiceImpl.java

@@ -9,8 +9,8 @@ package org.dspace.license;
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.util.ArrayList;
 import java.util.HashMap;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 
@@ -51,7 +51,7 @@ public class MockCCLicenseConnectorServiceImpl extends CCLicenseConnectorService
     }
 
     private List<CCLicenseField> createMockLicenseFields(int count, int[] amountOfFieldsAndEnums) {
-        List<CCLicenseField> ccLicenseFields = new LinkedList<>();
+        List<CCLicenseField> ccLicenseFields = new ArrayList<>(amountOfFieldsAndEnums.length);
         for (int index = 0; index < amountOfFieldsAndEnums.length; index++) {
             String licenseFieldId = "license" + count + "-field" + index;
             String licenseFieldLabel = "License " + count + " - Field " + index + " - Label";
@@ -70,7 +70,7 @@ public class MockCCLicenseConnectorServiceImpl extends CCLicenseConnectorService
     }
 
     private List<CCLicenseFieldEnum> createMockLicenseFields(int count, int index, int amountOfEnums) {
-        List<CCLicenseFieldEnum> ccLicenseFieldEnumList = new LinkedList<>();
+        List<CCLicenseFieldEnum> ccLicenseFieldEnumList = new ArrayList<>(amountOfEnums);
         for (int i = 0; i < amountOfEnums; i++) {
             String enumId = "license" + count + "-field" + index + "-enum" + i;
             String enumLabel = "License " + count + " - Field " + index + " - Enum " + i + " - Label";

dspace-api/src/test/java/org/dspace/statistics/export/ITIrusExportUsageEventListener.java

@@ -65,7 +65,7 @@ import org.junit.Test;
 //@RunWith(MockitoJUnitRunner.class)
 public class ITIrusExportUsageEventListener extends AbstractIntegrationTestWithDatabase {
 
-    private static Logger log = Logger.getLogger(ITIrusExportUsageEventListener.class);
+    private static final Logger log = Logger.getLogger(ITIrusExportUsageEventListener.class);
 
 
     protected CommunityService communityService = ContentServiceFactory.getInstance().getCommunityService();
@@ -86,7 +86,7 @@ public class ITIrusExportUsageEventListener extends AbstractIntegrationTestWithD
                                                                  .getServiceByName("testProcessedUrls",
                                                                                    ArrayList.class);
 
-    private IrusExportUsageEventListener exportUsageEventListener =
+    private final IrusExportUsageEventListener exportUsageEventListener =
             DSpaceServicesFactory.getInstance()
                                  .getServiceManager()
                                  .getServicesByType(IrusExportUsageEventListener.class)
@@ -105,9 +105,11 @@ public class ITIrusExportUsageEventListener extends AbstractIntegrationTestWithD
 
 
     /**
-     * Initializes the test by setting up all objects needed to create a test item
+     * Initializes the test by setting up all objects needed to create a test item.
+     * @throws java.lang.Exception passed through.
      */
     @Before()
+    @Override
     public void setUp() throws Exception {
         super.setUp();
 
@@ -152,11 +154,12 @@ public class ITIrusExportUsageEventListener extends AbstractIntegrationTestWithD
     }
 
     /**
-     * Clean up the created objects
+     * Clean up the created objects.
-     * Empty the testProcessedUrls used to store succeeded urls
+     * Empty the testProcessedUrls used to store succeeded URLs.
-     * Empty the database table where the failed urls are logged
+     * Empty the database table where the failed URLs are logged.
      */
     @After
+    @Override
     public void destroy() throws Exception {
         try {
             context.turnOffAuthorisationSystem();
@@ -377,11 +380,13 @@ public class ITIrusExportUsageEventListener extends AbstractIntegrationTestWithD
 
     /**
      * Test that an object that is not an Item or Bitstream is not processed
+     * @throws java.sql.SQLException passed through.
      */
     @Test
+    @SuppressWarnings("ResultOfMethodCallIgnored")
     public void testReceiveEventOnNonRelevantObject() throws SQLException {
 
-        HttpServletRequest request = mock(HttpServletRequest.class);
+        mock(HttpServletRequest.class);
 
         UsageEvent usageEvent = mock(UsageEvent.class);
         when(usageEvent.getObject()).thenReturn(community);
@@ -394,7 +399,6 @@ public class ITIrusExportUsageEventListener extends AbstractIntegrationTestWithD
 
         assertEquals(0, all.size());
         assertEquals(0, testProcessedUrls.size());
-
     }
 
     /**
@@ -408,11 +412,6 @@ public class ITIrusExportUsageEventListener extends AbstractIntegrationTestWithD
 
         Pattern p = Pattern.compile(regex);
 
-        if (p.matcher(string).matches()) {
+        return p.matcher(string).matches();
-            return true;
     }
-        return false;
-    }
-
-
 }

dspace-api/src/test/java/org/dspace/statistics/export/processor/BitstreamEventProcessorTest.java

@@ -37,13 +37,13 @@ import org.junit.Test;
  */
 public class BitstreamEventProcessorTest extends AbstractIntegrationTestWithDatabase {
 
-    private ConfigurationService configurationService = DSpaceServicesFactory.getInstance().getConfigurationService();
+    private final ConfigurationService configurationService
-
+            = DSpaceServicesFactory.getInstance().getConfigurationService();
 
     private String encodedUrl;
 
-
     @Before
+    @Override
     public void setUp() throws Exception {
         super.setUp();
         configurationService.setProperty("irus.statistics.tracker.enabled", true);

dspace-api/src/test/java/org/dspace/statistics/export/service/MockOpenUrlServiceImpl.java

@@ -15,7 +15,8 @@ import org.apache.commons.lang.StringUtils;
 import org.springframework.beans.factory.annotation.Autowired;
 
 /**
- * Mock OpenUrlService that will ensure that IRUS tracker does need to be contacted in order to test the functionality
+ * Mock OpenUrlService that will ensure that IRUS tracker does need to be
+ * contacted in order to test the functionality.
  */
 public class MockOpenUrlServiceImpl extends OpenUrlServiceImpl {
 
@@ -23,13 +24,14 @@ public class MockOpenUrlServiceImpl extends OpenUrlServiceImpl {
     ArrayList testProcessedUrls;
 
     /**
-     * Returns a response code to simulate contact to the external url
+     * Returns a response code to simulate contact to the external URL.
-     * When the url contains "fail", a fail code 500 will be returned
+     * When the URL contains "fail", a fail code 500 will be returned.
-     * Otherwise the success code 200 will be returned
+     * Otherwise the success code 200 will be returned.
      * @param urlStr
-     * @return 200 or 500 depending on whether the "fail" keyword is present in the url
+     * @return 200 or 500 depending on whether the "fail" keyword is present in the URL.
      * @throws IOException
      */
+    @Override
     protected int getResponseCodeFromUrl(final String urlStr) throws IOException {
         if (StringUtils.contains(urlStr, "fail")) {
             return HttpURLConnection.HTTP_INTERNAL_ERROR;