DS-3533 Make bitstream subresource embeds optional

dspace-server-webapp/src/main/java/org/dspace/app/rest/converter/BitstreamConverter.java

@@ -48,11 +48,6 @@ public class BitstreamConverter extends DSpaceObjectConverter<Bitstream, Bitstre
         checksum.setCheckSumAlgorithm(obj.getChecksumAlgorithm());
         checksum.setValue(obj.getChecksum());
         b.setCheckSum(checksum);
-        try {
-            b.setFormat(converter.toRest(obj.getFormat(null), projection));
-        } catch (SQLException e) {
-            throw new RuntimeException(e);
-        }
         b.setSizeBytes(obj.getSizeBytes());
         return b;
     }

dspace-server-webapp/src/main/java/org/dspace/app/rest/model/BitstreamRest.java

@@ -15,17 +15,23 @@ import com.fasterxml.jackson.annotation.JsonProperty.Access;
  *
  * @author Andrea Bollini (andrea.bollini at 4science.it)
  */
+@LinksRest(links = {
+        @LinkRest(
+                name = BitstreamRest.FORMAT,
+                linkClass = BitstreamFormatRest.class,
+                method = "getFormat",
+                embedOptional = true
+        )
+})
 public class BitstreamRest extends DSpaceObjectRest {
     public static final String PLURAL_NAME = "bitstreams";
     public static final String NAME = "bitstream";
     public static final String CATEGORY = RestAddressableModel.CORE;
+
+    public static final String FORMAT = "format";
+
     private String bundleName;
 
-    // avoid to serialize this object inline as we want a full resource embedded
-    // TODO extends this annotation to provide information about lazy loading
-    // and projection behavior
-    @JsonProperty(access = Access.WRITE_ONLY)
-    private BitstreamFormatRest format;
     private Long sizeBytes;
     private CheckSumRest checkSum;
     // sequenceId is READ_ONLY because it is assigned by the ItemService (as it must be unique within an Item)
@@ -40,14 +46,6 @@ public class BitstreamRest extends DSpaceObjectRest {
         this.bundleName = bundleName;
     }
 
-    public BitstreamFormatRest getFormat() {
-        return format;
-    }
-
-    public void setFormat(BitstreamFormatRest format) {
-        this.format = format;
-    }
-
     public Long getSizeBytes() {
         return sizeBytes;
     }

dspace-server-webapp/src/main/java/org/dspace/app/rest/repository/BitstreamFormatLinkRepository.java

@@ -0,0 +1,51 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+package org.dspace.app.rest.repository;
+
+import java.sql.SQLException;
+import java.util.UUID;
+import javax.annotation.Nullable;
+import javax.servlet.http.HttpServletRequest;
+
+import org.dspace.app.rest.model.BitstreamFormatRest;
+import org.dspace.app.rest.model.BitstreamRest;
+import org.dspace.app.rest.projection.Projection;
+import org.dspace.content.Bitstream;
+import org.dspace.content.service.BitstreamService;
+import org.dspace.core.Context;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.data.domain.Pageable;
+import org.springframework.stereotype.Component;
+
+/**
+ * Link repository for "format" subresource of an individual bitstream.
+ */
+@Component(BitstreamRest.CATEGORY + "." + BitstreamRest.NAME + "." + BitstreamRest.FORMAT)
+public class BitstreamFormatLinkRepository extends AbstractDSpaceRestRepository
+        implements LinkRestRepository {
+
+    @Autowired
+    BitstreamService bitstreamService;
+
+    //@PreAuthorize("hasPermission(#bitstreamId, 'BITSTREAM', 'READ')")
+    public BitstreamFormatRest getFormat(@Nullable HttpServletRequest request,
+                                         UUID bitstreamId,
+                                         @Nullable Pageable optionalPageable,
+                                         Projection projection) {
+        try {
+            Context context = obtainContext();
+            Bitstream bitstream = bitstreamService.find(context, bitstreamId);
+            if (bitstream == null || bitstream.getFormat(context) == null) {
+                return null;
+            }
+            return converter.toRest(bitstream.getFormat(context), projection);
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        }
+    }
+}