--- a/src/main/java/de/mpiwg/itgroup/ismi/browse/FullEntityRepositoryBean.java	Fri Jun 08 18:59:49 2018 +0200
+++ b/src/main/java/de/mpiwg/itgroup/ismi/browse/FullEntityRepositoryBean.java	Wed Jun 13 14:57:13 2018 +0200
@@ -9,6 +9,8 @@
 import org.mpi.openmind.cache.WrapperService;
 import org.mpi.openmind.repository.bo.Attribute;
 import org.mpi.openmind.repository.bo.Entity;
+import org.mpi.openmind.repository.bo.Relation;
+import org.mpi.openmind.repository.services.utils.RelationFilter;
 
 /**
  * EntityRepositoryBean for full Entities with Attributes and Relations loaded.
@@ -24,8 +26,9 @@
 
     protected boolean sortAttributeNumerically = false;
 
-    /*
-     * (non-Javadoc)
+    /**
+     * updateAdvancedEntities() method that makes sure that the current Entities
+     * are not lightweight.
      * 
      * @see de.mpiwg.itgroup.ismi.browse.AbstractEntityRepositoryBean#
      * updateAdvancedEntities()
@@ -71,7 +74,15 @@
         return GOTO_ENTITY_REPOSITORY;
     }
 
+    /**
+     * Loads all entities of this.objectClass and sorts by this.sortAttributeName.
+     * 
+     * Sort attributes as integer if this.sortAttributeNumerically.
+     *  
+     * @throws Exception
+     */
     public void sortByAttributes() throws Exception {
+        logger.debug("Start sortByAttributes...");
         this.resultMode = MODE_ADVANCED;
         this.setPage("");
         this.entities = new ArrayList<Entity>();
@@ -83,7 +94,7 @@
          * run search and sort result (by attribute)
          */
         List<Entity> resultList = getWrapper().getEntitiesByDef(this.objectClass);
-        // sort List (by ownvalue)
+        // sort List (by attribute)
         Collections.sort(resultList,
                 getEntityAttributeComparator(this.sortAttributeName, this.sortAttributeNumerically));
         this.entities = resultList;
@@ -97,8 +108,18 @@
         } else {
             this.resultSummaryMsg = "No items were found!";
         }
+        logger.debug("Done sortByAttributes.");
     }
 
+    /**
+     * Returns Comparator for Entities that uses the Attribute attname.
+     * 
+     * Sorts as integer if numerically.
+     * 
+     * @param attName
+     * @param numerically
+     * @return
+     */
     public Comparator<Entity> getEntityAttributeComparator(final String attName, final boolean numerically) {
         return new Comparator<Entity>() {
             @Override
@@ -143,6 +164,84 @@
             }
         };
     }
+    
+    /**
+     * Loads all entities of this.objectClass matching the given RelationFilters.
+     * 
+     * Filters Relations by relObjectClass and either srcObjectClass or tarObjectClass.
+     * 
+     * Requires all RelationFilters to match.
+     *  
+     * @throws Exception
+     */
+    public void searchByRelations(List<RelationFilter> relationFilters) {
+        logger.debug("Start searchByRelations...");
+        this.resultMode = MODE_ADVANCED;
+        this.setPage("");
+        this.entities = new ArrayList<Entity>();
+        this.currentEntities = new ArrayList<Entity>();
+        this.resultSummaryMsg = "";        
+        
+        /*
+         * get all entities and filter result (by relation)
+         */
+        List<Entity> resultList = getWrapper().getEntitiesByDef(this.objectClass);
+        for (Entity entity : resultList) {
+        	if (entity.isLightweight()) {
+        		entity = getWrapper().getEntityContent(entity);
+        	}
+        	boolean condFailed = false;
+        	for (RelationFilter filter :relationFilters) {
+        		if (filter.tarObjectClass != null) {
+            		List<Relation> rels = entity.getSourceRelations(filter.relObjectClass, filter.tarObjectClass);
+            		if (filter.relationMissing) {
+            			// is the relation missing?
+            			if (!rels.isEmpty()) {
+            				condFailed = true;
+            				break;
+            			}
+            		} else {
+            			if (rels.isEmpty()) {
+            				condFailed = true;
+            				break;
+            			}
+            		}
+        		} else if (filter.srcObjectClass != null) {
+            		List<Relation> rels = entity.getTargetRelations(filter.relObjectClass, filter.srcObjectClass);
+            		if (filter.relationMissing) {
+            			// is the relation missing?
+            			if (!rels.isEmpty()) {
+            				condFailed = true;
+            				break;
+            			}
+            		} else {
+            			if (rels.isEmpty()) {
+            				condFailed = true;
+            				break;
+            			}
+            		}
+        		}
+        	}
+        	if (!condFailed) {
+        		// all conditions matched
+        		entities.add(entity);
+        	}
+        }
+        
+        // sort List (by ownValue)
+        Collections.sort(entities);
+
+        if (entities.size() > 0) {
+            int entitiesCount = entities.size();
+            this.resultSummaryMsg = entitiesCount + " items were found!";
+            this.advancedPaginator.setCurrentPage(0);
+            this.advancedPaginator.resetNumberOfPages(entitiesCount);
+            this.updateAdvancedEntities();
+        } else {
+            this.resultSummaryMsg = "No items were found!";
+        }
+        logger.debug("Done searchByRelations.");
+    }
 
     /**
      * @return the sortAttributeName