--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/main/java/edu/harvard/iq/dataverse/DataverseLinkingServiceBean.java	Tue Sep 08 17:00:21 2015 +0200
@@ -0,0 +1,69 @@
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+package edu.harvard.iq.dataverse;
+
+import java.util.ArrayList;
+import java.util.List;
+import javax.ejb.EJB;
+import javax.ejb.Stateless;
+import javax.inject.Named;
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import javax.persistence.Query;
+import javax.persistence.TypedQuery;
+
+/**
+ *
+ * @author skraffmiller
+ */
+@Stateless
+@Named
+public class DataverseLinkingServiceBean implements java.io.Serializable {
+
+    @PersistenceContext(unitName = "VDCNet-ejbPU")
+    private EntityManager em;
+    
+    @EJB
+    DataverseServiceBean dataverseService;
+    
+    
+    public List<Dataverse> findLinkedDataverses(Long linkingDataverseId) {
+        List<Dataverse> retList = new ArrayList();
+        Query query = em.createQuery("select object(o) from DataverseLinkingDataverse as o where o.linkingDataverse.id =:linkingDataverseId order by o.id");
+        query.setParameter("linkingDataverseId", linkingDataverseId);
+        for (Object o : query.getResultList()) {
+            DataverseLinkingDataverse convterted = (DataverseLinkingDataverse) o;
+            retList.add(convterted.getDataverse());
+        }
+        return retList;
+    }
+
+    public List<Dataverse> findLinkingDataverses(Long dataverseId) {
+        List<Dataverse> retList = new ArrayList();
+        Query query = em.createQuery("select object(o) from DataverseLinkingDataverse as o where o.dataverse.id =:dataverseId order by o.id");
+        query.setParameter("dataverseId", dataverseId);
+        for (Object o : query.getResultList()) {
+            DataverseLinkingDataverse convterted = (DataverseLinkingDataverse) o;
+            retList.add(convterted.getLinkingDataverse());
+        }
+        return retList;
+    }
+    
+    public void save(DataverseLinkingDataverse dataverseLinkingDataverse) {
+        if (dataverseLinkingDataverse.getId() == null) {
+            em.persist(dataverseLinkingDataverse);
+        } else {
+            em.merge(dataverseLinkingDataverse);
+        }
+    }
+
+    public boolean alreadyLinked(Dataverse definitionPoint, Dataverse dataverseToLinkTo) {
+        TypedQuery<DataverseLinkingDataverse> typedQuery = em.createQuery("SELECT OBJECT(o) FROM DataverseLinkingDataverse AS o WHERE o.linkingDataverse.id = :dataverseId AND o.dataverse.id = :dataverseToLinkTo", DataverseLinkingDataverse.class);
+        typedQuery.setParameter("dataverseId", definitionPoint.getId());
+        typedQuery.setParameter("dataverseToLinkTo", dataverseToLinkTo.getId());
+        return !typedQuery.getResultList().isEmpty();
+    }
+}