cdmlib-persistence/src/main/java/eu/etaxonomy/cdm/persistence/hibernate/PostMergeEntityListener.java

   1 /**
   2  * Copyright (C) 2015 EDIT
   3  * European Distributed Institute of Taxonomy
   4  * http://www.e-taxonomy.eu
   5  *
   6  * The contents of this file are subject to the Mozilla Public License Version 1.1
   7  * See LICENSE.TXT at the top of this package for the full license terms.
   8  */
   9 package eu.etaxonomy.cdm.persistence.hibernate;
  10
  11 import java.util.HashSet;
  12 import java.util.Map;
  13 import java.util.Set;
  14 import java.util.concurrent.ConcurrentHashMap;
  15
  16 import org.apache.logging.log4j.LogManager;
  17 import org.apache.logging.log4j.Logger;
  18 import org.hibernate.Hibernate;
  19 import org.hibernate.HibernateException;
  20 import org.hibernate.Session;
  21 import org.hibernate.event.spi.MergeEvent;
  22 import org.hibernate.event.spi.MergeEventListener;
  23
  24 import eu.etaxonomy.cdm.model.common.CdmBase;
  25 import eu.etaxonomy.cdm.model.common.ITreeNode;
  26 import eu.etaxonomy.cdm.model.description.PolytomousKeyNode;
  27
  28 /**
  29  * @author cmathew
  30  * @since 23 Sep 2015
  31  */
  32 public class PostMergeEntityListener implements MergeEventListener {
  33
  34     private static final long serialVersionUID = 1565797119368313987L;
  35     @SuppressWarnings("unused")
  36     private static final Logger logger = LogManager.getLogger(PostMergeEntityListener.class);
  37
  38     private static Map<Session, Set<CdmBase>> newEntitiesMap = new ConcurrentHashMap<>();
  39
  40     public static void addSession(Session session) {
  41         newEntitiesMap.put(session, new HashSet<>());
  42     }
  43
  44     public static void removeSession(Session session) {
  45         newEntitiesMap.remove(session);
  46     }
  47
  48     public static Set<CdmBase> getNewEntities(Session session) {
  49         return newEntitiesMap.get(session);
  50     }
  51
  52     @Override
  53     public void onMerge(MergeEvent event) throws HibernateException {
  54         //Note AM: TODO is there a reason wyh we neglect onMerge in this case?
  55         //         Shouldn't we do something like "onMerge(event, new HashMap<>());"
  56 //        Object entity = event.getEntity();
  57     }
  58
  59     @Override
  60     public void onMerge(MergeEvent event, Map copiedAlready) throws HibernateException {
  61         // any new entities are added to a map which is retrieved at the end of the
  62         // CdmEntityDaoBase.merge(T transientObject, boolean returnTransientEntity) call
  63         if(event.getOriginal() != null && CdmBase.class.isAssignableFrom(event.getOriginal().getClass()) &&
  64                 event.getResult() != null && CdmBase.class.isAssignableFrom(event.getResult().getClass())) {
  65             CdmBase original = (CdmBase) event.getOriginal();
  66             CdmBase result = (CdmBase) event.getResult();
  67             handleTreeNodes(result, original, event, copiedAlready);
  68             if(original != null && Hibernate.isInitialized(original) && original.getId() == 0 &&
  69                     result != null && Hibernate.isInitialized(result) && result.getId() > 0) {
  70                 //see IService#merge(detachedObject, returnTransientEntity)
  71                 original.setId(result.getId());
  72                 Set<CdmBase> newEntities = newEntitiesMap.get(event.getSession());
  73                 if(newEntities != null) {
  74                     newEntities.add(result);
  75                 }
  76             }
  77         }
  78     }
  79
  80     private static void handleTreeNodes(CdmBase result, CdmBase original, MergeEvent event, Map copiedAlready) {
  81         if (original != null){
  82             Class<?> entityClazz = original.getClass();
  83
  84             if (ITreeNode.class.isAssignableFrom(entityClazz)){  //TaxonNode or TermNode
  85                 //TODO #10101
  86             } else if (PolytomousKeyNode.class.isAssignableFrom(entityClazz)){
  87                 // #10101 the following code tried to handle orphanRemoval for key nodes that were
  88                 // really removed from the graph. Generally the removal worked but it was not possible at this
  89                 // place to guarantee that the node which was removed from the parent was not used elsewhere
  90                 // (has a new parent). For this one needs to retrieve the new state of the node (or of its new parent).
  91                 // But this is not difficult or impossible at this point as the node is not part of the graph to
  92                 // to be merged or if it is because its new parent is part of the graph also, it is not guaranteed
  93                 // that it has already treated so far.
  94                 // Maybe it can better be handled by another type of listener therefore I keep this code here.
  95                 // See #10101 for further information on this issue and how it was solved.
  96                 // The implementation was partly copied from https://stackoverflow.com/questions/812364/how-to-determine-collection-changes-in-a-hibernate-postupdateeventlistener
  97
  98 //                EventSource session = event.getSession();
  99 //                PolytomousKeyNode resultPkn = (PolytomousKeyNode)result;
 100 //                //copied from https://stackoverflow.com/questions/812364/how-to-determine-collection-changes-in-a-hibernate-postupdateeventlistener
 101 //                PersistenceContext pc = session.getPersistenceContext();
 102 //                CollectionEntry childrenEntry = pc.getCollectionEntry((PersistentCollection)resultPkn.getChildren());
 103 //                List<PolytomousKeyNode> childrenEntrySnapshot = (List<PolytomousKeyNode>)childrenEntry.getSnapshot();
 104 //                if (childrenEntrySnapshot != null) {
 105 //                    for (PolytomousKeyNode snapshotChild: childrenEntrySnapshot){
 106 //                        if (!resultPkn.getChildren().contains(snapshotChild)) {
 107 //                            EntityEntry currentChild = pc.getEntry(snapshotChild);
 108 //                            Object parent = currentChild == null ? null :
 109 //                                currentChild.getLoadedValue("parent");
 110 //                            if (parent == null || parent == resultPkn) {
 111 //                                session.delete(snapshotChild);
 112 //                            }
 113 //                        }
 114 //                   }
 115 //                }
 116             }
 117         }
 118     }
 119 }