DS-4096 paginated methods for relationships

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

@@ -38,8 +38,15 @@ public class EntityServiceImpl implements EntityService {
 
     @Override
     public Entity findByItemId(Context context, UUID itemId) throws SQLException {
+
+        return findByItemId(context, itemId, -1, -1);
+    }
+
+    @Override
+    public Entity findByItemId(Context context, UUID itemId, Integer limit, Integer offset) throws SQLException {
+
         Item item = itemService.find(context, itemId);
-        List<Relationship> relationshipList = relationshipService.findByItem(context, item);
+        List<Relationship> relationshipList = relationshipService.findByItem(context, item, limit, offset);
         return new Entity(item, relationshipList);
     }
 
@@ -80,8 +87,16 @@ public class EntityServiceImpl implements EntityService {
 
     @Override
     public List<Relationship> getRelationsByLabel(Context context, String label) throws SQLException {
+
+        return getRelationsByLabel(context, label, -1, -1);
+    }
+
+    @Override
+    public List<Relationship> getRelationsByLabel(Context context, String label, Integer limit, Integer offset)
+            throws SQLException {
+
         List<Relationship> listToReturn = new LinkedList<>();
-        List<Relationship> relationshipList = relationshipService.findAll(context);
+        List<Relationship> relationshipList = relationshipService.findAll(context, limit, offset);
         for (Relationship relationship : relationshipList) {
             RelationshipType relationshipType = relationship.getRelationshipType();
             if (StringUtils.equals(relationshipType.getLeftwardType(),label) ||
@@ -94,12 +109,20 @@ public class EntityServiceImpl implements EntityService {
 
     @Override
     public List<RelationshipType> getAllRelationshipTypes(Context context, Entity entity) throws SQLException {
+
+        return getAllRelationshipTypes(context, entity, -1, -1);
+    }
+
+    @Override
+    public List<RelationshipType> getAllRelationshipTypes(Context context, Entity entity, Integer limit, Integer offset)
+            throws SQLException {
+
         EntityType entityType = this.getType(context, entity);
         if (entityType == null) {
             return Collections.emptyList();
         }
         List<RelationshipType> listToReturn = new LinkedList<>();
-        for (RelationshipType relationshipType : relationshipTypeService.findAll(context)) {
+        for (RelationshipType relationshipType : relationshipTypeService.findAll(context, limit, offset)) {
             if (relationshipType.getLeftType().getID() == entityType.getID() ||
                 relationshipType.getRightType().getID() == entityType.getID()) {
                 listToReturn.add(relationshipType);
@@ -110,9 +133,17 @@ public class EntityServiceImpl implements EntityService {
 
     @Override
     public List<RelationshipType> getLeftRelationshipTypes(Context context, Entity entity) throws SQLException {
+
+        return getLeftRelationshipTypes(context, entity, -1, -1);
+    }
+
+    @Override
+    public List<RelationshipType> getLeftRelationshipTypes(Context context, Entity entity,
+                                                           Integer limit, Integer offset) throws SQLException {
+
         EntityType entityType = this.getType(context, entity);
         List<RelationshipType> listToReturn = new LinkedList<>();
-        for (RelationshipType relationshipType : relationshipTypeService.findAll(context)) {
+        for (RelationshipType relationshipType : relationshipTypeService.findAll(context, limit, offset)) {
             if (relationshipType.getLeftType().getID() == entityType.getID()) {
                 listToReturn.add(relationshipType);
             }
@@ -122,9 +153,17 @@ public class EntityServiceImpl implements EntityService {
 
     @Override
     public List<RelationshipType> getRightRelationshipTypes(Context context, Entity entity) throws SQLException {
+
+        return getRightRelationshipTypes(context, entity, -1, -1);
+    }
+
+    @Override
+    public List<RelationshipType> getRightRelationshipTypes(Context context, Entity entity,
+                                                            Integer limit, Integer offset) throws SQLException {
+
         EntityType entityType = this.getType(context, entity);
         List<RelationshipType> listToReturn = new LinkedList<>();
-        for (RelationshipType relationshipType : relationshipTypeService.findAll(context)) {
+        for (RelationshipType relationshipType : relationshipTypeService.findAll(context, limit, offset)) {
             if (relationshipType.getRightType().getID() == entityType.getID()) {
                 listToReturn.add(relationshipType);
             }
@@ -133,9 +172,16 @@ public class EntityServiceImpl implements EntityService {
     }
 
     @Override
-    public List<RelationshipType> getRelationshipTypesByTypeName(Context context, String label) throws SQLException {
+    public List<RelationshipType> getRelationshipTypesByLabel(Context context, String label) throws SQLException {
+
+        return getRelationshipTypesByLabel(context, label, -1, -1);
+    }
+
+    @Override
+    public List<RelationshipType> getRelationshipTypesByTypeName(Context context, String label,
+                                                                 Integer limit, Integer offset) throws SQLException {
         List<RelationshipType> listToReturn = new LinkedList<>();
-        for (RelationshipType relationshipType : relationshipTypeService.findAll(context)) {
+        for (RelationshipType relationshipType : relationshipTypeService.findAll(context, limit, offset)) {
             if (StringUtils.equals(relationshipType.getLeftwardType(),label) ||
                 StringUtils.equals(relationshipType.getRightwardType(),label)) {
                 listToReturn.add(relationshipType);

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

@@ -28,13 +28,20 @@ public class EntityTypeServiceImpl implements EntityTypeService {
     protected AuthorizeService authorizeService;
 
     @Override
-    public EntityType findByEntityType(Context context,String entityType) throws SQLException {
+    public EntityType findByEntityType(Context context, String entityType) throws SQLException {
         return entityTypeDAO.findByEntityType(context, entityType);
     }
 
     @Override
     public List<EntityType> findAll(Context context) throws SQLException {
-        return entityTypeDAO.findAll(context, EntityType.class);
+
+        return findAll(context, -1, -1);
+    }
+
+    @Override
+    public List<EntityType> findAll(Context context, Integer limit, Integer offset) throws SQLException {
+
+        return entityTypeDAO.findAll(context, EntityType.class, limit, offset);
     }
 
     @Override

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

@@ -268,7 +268,14 @@ public class RelationshipServiceImpl implements RelationshipService {
     @Override
     public List<Relationship> findByItem(Context context, Item item) throws SQLException {
 
-        List<Relationship> list = relationshipDAO.findByItem(context, item);
+        return findByItem(context, item, -1, -1);
+    }
+
+    @Override
+    public List<Relationship> findByItem(Context context, Item item, Integer limit, Integer offset)
+            throws SQLException {
+
+        List<Relationship> list = relationshipDAO.findByItem(context, item, limit, offset);
 
         list.sort((o1, o2) -> {
             int relationshipType = o1.getRelationshipType().getLeftwardType()
@@ -288,7 +295,14 @@ public class RelationshipServiceImpl implements RelationshipService {
 
     @Override
     public List<Relationship> findAll(Context context) throws SQLException {
-        return relationshipDAO.findAll(context, Relationship.class);
+
+        return findAll(context, -1, -1);
+    }
+
+    @Override
+    public List<Relationship> findAll(Context context, Integer limit, Integer offset) throws SQLException {
+
+        return relationshipDAO.findAll(context, Relationship.class, limit, offset);
     }
 
     @Override
@@ -420,7 +434,15 @@ public class RelationshipServiceImpl implements RelationshipService {
     @Override
     public List<Relationship> findByRelationshipType(Context context, RelationshipType relationshipType)
         throws SQLException {
-        return relationshipDAO.findByRelationshipType(context, relationshipType);
+
+        return findByRelationshipType(context, relationshipType, -1, -1);
+    }
+
+    @Override
+    public List<Relationship> findByRelationshipType(Context context, RelationshipType relationshipType, Integer limit,
+                                                     Integer offset)
+        throws SQLException {
+        return relationshipDAO.findByRelationshipType(context, relationshipType, limit, offset);
     }
 
 

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

@@ -54,17 +54,35 @@ public class RelationshipTypeServiceImpl implements RelationshipTypeService {
 
     @Override
     public List<RelationshipType> findAll(Context context) throws SQLException {
-        return relationshipTypeDAO.findAll(context, RelationshipType.class);
+        return findAll(context, -1, -1);
+    }
+
+    @Override
+    public List<RelationshipType> findAll(Context context, Integer limit, Integer offset) throws SQLException {
+
+        return relationshipTypeDAO.findAll(context, RelationshipType.class, limit, offset);
     }
 
     @Override
     public List<RelationshipType> findByLeftwardOrRightwardTypeName(Context context, String label) throws SQLException {
-        return relationshipTypeDAO.findByLeftwardOrRightwardTypeName(context, label);
+        return findByLeftOrRightLabel(context, label, -1, -1);
+    }
+
+    @Override
+    public List<RelationshipType> findByLeftwardOrRightwardTypeName(Context context, String label, Integer limit, Integer offset)
+            throws SQLException {
+        return relationshipTypeDAO.findByLeftOrRightLabel(context, label, limit, offset);
     }
 
     @Override
     public List<RelationshipType> findByEntityType(Context context, EntityType entityType) throws SQLException {
-        return relationshipTypeDAO.findByEntityType(context, entityType);
+        return findByEntityType(context, entityType, -1, -1);
+    }
+
+    @Override
+    public List<RelationshipType> findByEntityType(Context context, EntityType entityType,
+                                                   Integer limit, Integer offset) throws SQLException {
+        return relationshipTypeDAO.findByEntityType(context, entityType, limit, offset);
     }
 
     @Override

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

@@ -36,6 +36,20 @@ public interface RelationshipDAO extends GenericDAO<Relationship> {
      */
     List<Relationship> findByItem(Context context,Item item) throws SQLException;
 
+    /**
+     * This method returns a list of Relationship objects that have the given Item object
+     * as a leftItem or a rightItem
+     * @param context   The relevant DSpace context
+     * @param item      The item that should be either a leftItem or a rightItem of all
+     *                  the Relationship objects in the returned list
+     * @param limit     paging limit
+     * @param offset    paging offset
+     * @return          The list of Relationship objects that contain either a left or a
+     *                  right item that is equal to the given item
+     * @throws SQLException If something goes wrong
+     */
+    List<Relationship> findByItem(Context context, Item item, Integer limit, Integer offset) throws SQLException;
+
     /**
      * This method returns the highest leftplace integer for all the relationships where this
      * item is the leftitem so that we can set a proper leftplace attribute on the next relationship
@@ -69,4 +83,19 @@ public interface RelationshipDAO extends GenericDAO<Relationship> {
      * @throws SQLException If something goes wrong
      */
     List<Relationship> findByRelationshipType(Context context, RelationshipType relationshipType) throws SQLException;
+
+    /**
+     * This method returns a list of Relationship objects for the given RelationshipType object.
+     * It will construct a list of all Relationship objects that have the given RelationshipType object
+     * as the relationshipType property
+     * @param context           The relevant DSpace context
+     * @param relationshipType  The RelationshipType object to be checked on
+     * @param limit             paging limit
+     * @param offset            paging offset
+     * @return  A list of Relationship objects that have the given RelationshipType object as the
+     *          relationshipType property
+     * @throws SQLException If something goes wrong
+     */
+    List<Relationship> findByRelationshipType(Context context, RelationshipType relationshipType,
+                                              Integer limit, Integer offset) throws SQLException;
 }

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

@@ -50,6 +50,19 @@ public interface RelationshipTypeDAO extends GenericDAO<RelationshipType> {
      */
     List<RelationshipType> findByLeftwardOrRightwardTypeName(Context context, String type) throws SQLException;
 
+    /**
+     * This method will return a list of RelationshipType objects for which the given label is equal to
+     * either the leftLabel or rightLabel.
+     * @param context   The relevant DSpace context
+     * @param label     The label that will be used to check on
+     * @param limit     paging limit
+     * @param offset    paging offset
+     * @return A list of RelationshipType objects that have the given label as either the leftLabel or rightLabel
+     * @throws SQLException If something goes wrong
+     */
+    List<RelationshipType> findByLeftwardOrRightwardTypeName(Context context, String label, Integer limit, Integer offset)
+            throws SQLException;
+
     /**
      * This method will return a list of RelationshipType objects for which the given EntityType object is equal
      * to the leftType or rightType
@@ -60,4 +73,18 @@ public interface RelationshipTypeDAO extends GenericDAO<RelationshipType> {
      * @throws SQLException If something goes wrong
      */
     List<RelationshipType> findByEntityType(Context context, EntityType entityType) throws SQLException;
+
+    /**
+     * This method will return a list of RelationshipType objects for which the given EntityType object is equal
+     * to the leftType or rightType
+     * @param context       The relevant DSpace context
+     * @param entityType    The EntityType object that will be used to check on
+     * @param limit         paging limit
+     * @param offset        paging offset
+     * @return  The list of RelationshipType objects that have the given EntityType object
+     *          as either a leftType or rightType
+     * @throws SQLException If something goes wrong
+     */
+    List<RelationshipType> findByEntityType(Context context, EntityType entityType, Integer limit, Integer offset)
+            throws SQLException;
 }

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

@@ -25,6 +25,14 @@ public class RelationshipDAOImpl extends AbstractHibernateDAO<Relationship> impl
 
     @Override
     public List<Relationship> findByItem(Context context, Item item) throws SQLException {
+
+        return findByItem(context, item, -1, -1);
+    }
+
+    @Override
+    public List<Relationship> findByItem(Context context, Item item, Integer limit, Integer offset)
+            throws SQLException {
+
         CriteriaBuilder criteriaBuilder = getCriteriaBuilder(context);
         CriteriaQuery criteriaQuery = getCriteriaQuery(criteriaBuilder, Relationship.class);
         Root<Relationship> relationshipRoot = criteriaQuery.from(Relationship.class);
@@ -32,7 +40,7 @@ public class RelationshipDAOImpl extends AbstractHibernateDAO<Relationship> impl
         criteriaQuery
             .where(criteriaBuilder.or(criteriaBuilder.equal(relationshipRoot.get(Relationship_.leftItem), item),
                                       criteriaBuilder.equal(relationshipRoot.get(Relationship_.rightItem), item)));
-        return list(context, criteriaQuery, false, Relationship.class, -1, -1);
+        return list(context, criteriaQuery, false, Relationship.class, limit, offset);
     }
 
     @Override
@@ -70,13 +78,21 @@ public class RelationshipDAOImpl extends AbstractHibernateDAO<Relationship> impl
     @Override
     public List<Relationship> findByRelationshipType(Context context, RelationshipType relationshipType)
         throws SQLException {
+
+        return findByRelationshipType(context, relationshipType, -1, -1);
+    }
+
+    @Override
+    public List<Relationship> findByRelationshipType(Context context, RelationshipType relationshipType,
+                                                     Integer limit, Integer offset) throws SQLException {
+
         CriteriaBuilder criteriaBuilder = getCriteriaBuilder(context);
         CriteriaQuery criteriaQuery = getCriteriaQuery(criteriaBuilder, Relationship.class);
         Root<Relationship> relationshipRoot = criteriaQuery.from(Relationship.class);
         criteriaQuery.select(relationshipRoot);
         criteriaQuery
             .where(criteriaBuilder.equal(relationshipRoot.get(Relationship_.relationshipType), relationshipType));
-        return list(context, criteriaQuery, true, Relationship.class, -1, -1);
+        return list(context, criteriaQuery, true, Relationship.class, limit, offset);
     }
 
 

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

@@ -41,6 +41,14 @@ public class RelationshipTypeDAOImpl extends AbstractHibernateDAO<RelationshipTy
 
     @Override
     public List<RelationshipType> findByLeftwardOrRightwardTypeName(Context context, String type) throws SQLException {
+
+        return findByLeftwardOrRightwardTypeName(context, type, -1, -1);
+    }
+
+    @Override
+    public List<RelationshipType> findByLeftwardOrRightwardTypeName(Context context, String type, Integer limit, Integer offset)
+            throws SQLException {
+
         CriteriaBuilder criteriaBuilder = getCriteriaBuilder(context);
         CriteriaQuery criteriaQuery = getCriteriaQuery(criteriaBuilder, RelationshipType.class);
         Root<RelationshipType> relationshipTypeRoot = criteriaQuery.from(RelationshipType.class);
@@ -51,11 +59,18 @@ public class RelationshipTypeDAOImpl extends AbstractHibernateDAO<RelationshipTy
                 criteriaBuilder.equal(relationshipTypeRoot.get(RelationshipType_.rightwardType), type)
             )
         );
-        return list(context, criteriaQuery, true, RelationshipType.class, -1, -1);
+        return list(context, criteriaQuery, true, RelationshipType.class, limit, offset);
     }
 
     @Override
     public List<RelationshipType> findByEntityType(Context context, EntityType entityType) throws SQLException {
+        return findByEntityType(context, entityType, -1, -1);
+    }
+
+    @Override
+    public List<RelationshipType> findByEntityType(Context context, EntityType entityType,
+                                                   Integer limit, Integer offset) throws SQLException {
+
         CriteriaBuilder criteriaBuilder = getCriteriaBuilder(context);
         CriteriaQuery criteriaQuery = getCriteriaQuery(criteriaBuilder, RelationshipType.class);
         Root<RelationshipType> relationshipTypeRoot = criteriaQuery.from(RelationshipType.class);
@@ -67,7 +82,7 @@ public class RelationshipTypeDAOImpl extends AbstractHibernateDAO<RelationshipTy
                                    .equal(relationshipTypeRoot.get(RelationshipType_.rightType), entityType)
             )
         );
-        return list(context, criteriaQuery, false, RelationshipType.class, -1, -1);
+        return list(context, criteriaQuery, false, RelationshipType.class, limit, offset);
     }
 
 }

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

@@ -36,6 +36,19 @@ public interface EntityService {
      */
     Entity findByItemId(Context context, UUID itemId) throws SQLException;
 
+    /**
+     * This will construct an Entity object that will be returned with the Item that matches the ItemID that was
+     * passed along
+     * as well as a list of relationships for that Item.
+     * @param context   The relevant DSpace context
+     * @param itemId    The ItemID for the Item that is to be used in the Entity object
+     * @param limit     paging limit
+     * @param offset    paging offset
+     * @return The constructed Entity object with the Item and the list of relationships
+     * @throws SQLException If something goes wrong
+     */
+    Entity findByItemId(Context context, UUID itemId, Integer limit, Integer offset) throws SQLException;
+
     /**
      * Returns the EntityType for the Item that is attached to the Entity that is passed along to this method.
      * The EntityType String logic is in the Metadata for that Item and will be searched on in the EntityTypeService
@@ -76,6 +89,20 @@ public interface EntityService {
      */
     List<Relationship> getRelationsByLabel(Context context, String label) throws SQLException;
 
+    /**
+     * Retrieves the list of relationships for which their relationshiptype has a left or right label that is
+     * equal to the passed along label String
+     * @param context   The relevant DSpace context
+     * @param label     The label that needs to be in the relationshiptype of the relationship
+     * @param limit     paging limit
+     * @param offset    paging offset
+     * @return The list of relationships that have a relationshiptype with a left or right label
+     *                  that is equal to the label param
+     * @throws SQLException If something goes wrong
+     */
+    List<Relationship> getRelationsByLabel(Context context, String label, Integer limit, Integer offset)
+            throws SQLException;
+
     /**
      * Retrieves the list of relationships that have a relationshiptype that contains the EntityType for the given
      * Entity
@@ -89,6 +116,22 @@ public interface EntityService {
      */
     List<RelationshipType> getAllRelationshipTypes(Context context, Entity entity) throws SQLException;
 
+    /**
+     * Retrieves the list of relationships that have a relationshiptype that contains the EntityType for the given
+     * Entity
+     * in either the leftEntityType or the rightEntityType variables
+     * @param context   The relevant DSpace context
+     * @param entity    The Entity for which the EntityType should be checked for relationships
+     * @param limit     paging limit
+     * @param offset    paging offset
+     * @return The list of relationships that each contain a relationshiptype in which there is a right or left
+     * entity type that
+     *                  is equal to the entity type for the given entity
+     * @throws SQLException If something goes wrong
+     */
+    List<RelationshipType> getAllRelationshipTypes(Context context, Entity entity, Integer limit, Integer offset)
+            throws SQLException;
+
     /**
      * Retrieves the list of relationships that have a relationshiptype that contains the EntityType for the given
      * Entity
@@ -101,6 +144,21 @@ public interface EntityService {
      */
     List<RelationshipType> getLeftRelationshipTypes(Context context, Entity entity) throws SQLException;
 
+    /**
+     * Retrieves the list of relationships that have a relationshiptype that contains the EntityType for the given
+     * Entity
+     * in the leftEntityType
+     * @param context   The relevant DSpace context
+     * @param entity    The Entity for which the EntityType should be checked for relationships
+     * @param limit     paging limit
+     * @param offset    paging offset
+     * @return The list of relationships that each contain a relationshiptype in which there is a left entity type that
+     *                  is equal to the entity type for the given entity
+     * @throws SQLException If something goes wrong
+     */
+    List<RelationshipType> getLeftRelationshipTypes(Context context, Entity entity,
+                                                    Integer limit, Integer offset) throws SQLException;
+
     /**
      * Retrieves the list of relationships that have a relationshiptype that contains the EntityType for the given
      * Entity
@@ -113,6 +171,21 @@ public interface EntityService {
      */
     List<RelationshipType> getRightRelationshipTypes(Context context, Entity entity) throws SQLException;
 
+    /**
+     * Retrieves the list of relationships that have a relationshiptype that contains the EntityType for the given
+     * Entity
+     * in the rightEntityType
+     * @param context   The relevant DSpace context
+     * @param entity    The Entity for which the EntityType should be checked for relationships
+     * @param limit     paging limit
+     * @param offset    paging offset
+     * @return The list of relationships that each contain a relationshiptype in which there is a right entity type that
+     *                  is equal to the entity type for the given entity
+     * @throws SQLException If something goes wrong
+     */
+    List<RelationshipType> getRightRelationshipTypes(Context context, Entity entity,
+                                                     Integer limit, Integer offset) throws SQLException;
+
     /**
      * Retrieves a list of RelationshipType objects for which either their left or right label is equal to the
      * label parameter that's being passed along
@@ -124,4 +197,18 @@ public interface EntityService {
      */
     List<RelationshipType> getRelationshipTypesByTypeName(Context context, String label) throws SQLException;
 
+    /**
+     * Retrieves a list of RelationshipType objects for which either their left or right label is equal to the
+     * label parameter that's being passed along
+     * @param context   The relevant DSpace context
+     * @param label     The label for which the relationshiptype's labels must be checked
+     * @param limit     paging limit
+     * @param offset    paging offset
+     * @return The list of relationshiptypes that each contain a left or right label that is equal
+     *                  to the given label parameter
+     * @throws SQLException If something goes wrong
+     */
+    List<RelationshipType> getRelationshipTypesByLabel(Context context, String label,
+                                                       Integer limit, Integer offset) throws SQLException;
+
 }

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

@@ -37,6 +37,16 @@ public interface EntityTypeService extends DSpaceCRUDService<EntityType> {
      */
     public List<EntityType> findAll(Context context) throws SQLException;
 
+    /**
+     * Retrieves all the EntityType objects currently in the system
+     * @param context   The relevant DSpace context
+     * @param limit     paging limit
+     * @param offset    paging offset
+     * @return          A list of all EntityType objects
+     * @throws SQLException If something goes wrong
+     */
+    List<EntityType> findAll(Context context, Integer limit, Integer offset) throws SQLException;
+
     /**
      * This method creates an EntityType object in the database with the given entityTypeString as it's label
      * @param context           The relevant DSpace context

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

@@ -32,6 +32,18 @@ public interface RelationshipService extends DSpaceCRUDService<Relationship> {
      */
     public List<Relationship> findByItem(Context context,Item item) throws SQLException;
 
+    /**
+     * Retrieves the list of Relationships currently in the system for which the given Item is either
+     * a leftItem or a rightItem object
+     * @param context   The relevant DSpace context
+     * @param item      The Item that has to be the left or right item for the relationship to be included in the list
+     * @param limit     paging limit
+     * @param offset    paging offset
+     * @return          The list of relationships for which each relationship adheres to the above listed constraint
+     * @throws SQLException If something goes wrong
+     */
+    List<Relationship> findByItem(Context context, Item item, Integer limit, Integer offset) throws SQLException;
+
     /**
      * Retrieves the full list of relationships currently in the system
      * @param context   The relevant DSpace context
@@ -40,6 +52,16 @@ public interface RelationshipService extends DSpaceCRUDService<Relationship> {
      */
     public List<Relationship> findAll(Context context) throws SQLException;
 
+    /**
+     * Retrieves the full list of relationships currently in the system
+     * @param context   The relevant DSpace context
+     * @param limit     paging limit
+     * @param offset    paging offset
+     * @return  The list of all relationships currently in the system
+     * @throws SQLException If something goes wrong
+     */
+    List<Relationship> findAll(Context context, Integer limit, Integer offset) throws SQLException;
+
     /**
      * This method creates a relationship object in the database equal to the given relationship param
      * if this is a valid relationship
@@ -126,6 +148,20 @@ public interface RelationshipService extends DSpaceCRUDService<Relationship> {
      */
     List<Relationship> findByRelationshipType(Context context, RelationshipType relationshipType) throws SQLException;
 
+    /**
+     * This method returns a list of Relationship objets for which the relationshipType property is equal to the given
+     * RelationshipType object
+     * @param context           The relevant DSpace context
+     * @param relationshipType  The RelationshipType object that will be used to check the Relationship on
+     * @param limit             paging limit
+     * @param offset            paging offset
+     * @return  The list of Relationship objects for which the given RelationshipType object is equal
+     *          to the relationshipType property
+     * @throws SQLException If something goes wrong
+     */
+    List<Relationship> findByRelationshipType(Context context, RelationshipType relationshipType, Integer limit,
+                                              Integer offset) throws SQLException;
+
     /**
      * This method is used to construct a Relationship object with all it's variables
      * @param c                 The relevant DSpace context

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

@@ -23,26 +23,26 @@ public interface RelationshipTypeService extends DSpaceCRUDService<RelationshipT
 
     /**
      * This method creates the given RelationshipType object in the database and returns it
-     * @param context               The relevant DSpace context
+     * @param context           The relevant DSpace context
-     * @param relationshipType      The RelationshipType to be created in the database
+     * @param relationshipType  The RelationshipType to be created in the database
-     * @return                      The newly created RelationshipType
+     * @return                  The newly created RelationshipType
      * @throws SQLException         If something goes wrong
      * @throws AuthorizeException   If something goes wrong with authorizations
      */
-    RelationshipType create(Context context,RelationshipType relationshipType) throws SQLException, AuthorizeException;
+    RelationshipType create(Context context, RelationshipType relationshipType) throws SQLException, AuthorizeException;
 
     /**
      * Retrieves a RelationshipType for which the given parameters all match the one in the returned RelationshipType
-     * @param context           The relevant DSpace context
+     * @param context       The relevant DSpace context
-     * @param leftType          The rightType EntityType that needs to match for the returned RelationshipType
+     * @param leftType      The rightType EntityType that needs to match for the returned RelationshipType
-     * @param rightType         The rightType EntityType that needs to match for the returned RelationshipType
+     * @param rightType     The rightType EntityType that needs to match for the returned RelationshipType
-     * @param leftwardType      The leftwardType String that needs to match for the returned RelationshipType
+     * @param leftwardType     The leftLabel String that needs to match for the returned RelationshipType
-     * @param rightwardType     The rightwardType String that needs to match for the returned RelationshipType
+     * @param rightwardType    The rightLabel String that needs to match for the returned RelationshipType
      * @return
      * @throws SQLException If something goes wrong
      */
-    RelationshipType findbyTypesAndLabels(Context context,EntityType leftType,EntityType rightType,
+    RelationshipType findbyTypesAndLabels(Context context, EntityType leftType, EntityType rightType,
-                                          String leftwardType,String rightwardType)
+                                          String leftwardType, String rightwardType)
                                             throws SQLException;
 
     /**
@@ -53,6 +53,16 @@ public interface RelationshipTypeService extends DSpaceCRUDService<RelationshipT
      */
     List<RelationshipType> findAll(Context context) throws SQLException;
 
+    /**
+     * Retrieves all RelationshipType objects currently in the system
+     * @param context   The relevant DSpace context
+     * @param limit     paging limit
+     * @param offset    paging offset
+     * @return          The list of all RelationshipType objects currently in the system
+     * @throws SQLException If something goes wrong
+     */
+    List<RelationshipType> findAll(Context context, Integer limit, Integer offset) throws SQLException;
+
     /**
      * Retrieves all RelationshipType objects that have a left or right type that is
      * equal to the given String
@@ -64,6 +74,20 @@ public interface RelationshipTypeService extends DSpaceCRUDService<RelationshipT
      */
     List<RelationshipType> findByLeftwardOrRightwardTypeName(Context context, String label) throws SQLException;
 
+    /**
+     * Retrieves all RelationshipType objects that have a left or right label that is
+     * equal to the given String
+     * @param context   The relevant DSpace context
+     * @param label     The label that has to match
+     * @param limit     paging limit
+     * @param offset    paging offset
+     * @return          The list of all RelationshipType objects that have a left or right label
+     *                  that is equal to the given label param
+     * @throws SQLException If something goes wrong
+     */
+    List<RelationshipType> findByLeftOrRightLabel(Context context, String label, Integer limit, Integer offset)
+            throws SQLException;
+
     /**
      * Returns a list of RelationshipType objects for which the given EntityType is equal to either the leftType
      * or the rightType
@@ -75,6 +99,9 @@ public interface RelationshipTypeService extends DSpaceCRUDService<RelationshipT
      */
     List<RelationshipType> findByEntityType(Context context, EntityType entityType) throws SQLException;
 
+    List<RelationshipType> findByEntityType(Context context, EntityType entityType, Integer limit, Integer offset)
+            throws SQLException;
+
     /**
      * This method will support the creation of a RelationshipType object with the given parameters
      * @param context                       The relevant DSpace context

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

@@ -66,10 +66,16 @@ public abstract class AbstractHibernateDAO<T> implements GenericDAO<T> {
 
     @Override
     public List<T> findAll(Context context, Class<T> clazz) throws SQLException {
+
+        return findAll(context, clazz, -1, -1);
+    }
+
+    @Override
+    public List<T> findAll(Context context, Class<T> clazz, Integer limit, Integer offset) throws SQLException {
         CriteriaQuery criteriaQuery = getCriteriaQuery(getCriteriaBuilder(context), clazz);
         Root<T> root = criteriaQuery.from(clazz);
         criteriaQuery.select(root);
-        return executeCriteriaQuery(context, criteriaQuery, false, -1, -1);
+        return executeCriteriaQuery(context, criteriaQuery, false, limit, offset);
     }
 
     @Override

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

@@ -58,6 +58,18 @@ public interface GenericDAO<T> {
      */
     public List<T> findAll(Context context, Class<T> clazz) throws SQLException;
 
+    /**
+     * Fetch all persisted instances of a given object type.
+     *
+     * @param context The relevant DSpace Context.
+     * @param clazz   the desired type.
+     * @param limit   paging limit
+     * @param offset  paging offset
+     * @return list of DAOs of the same type as clazz
+     * @throws SQLException if database error
+     */
+    List<T> findAll(Context context, Class<T> clazz, Integer limit, Integer offset) throws SQLException;
+
     /**
      * Execute a JPQL query returning a unique result.
      *