如何确定Hibernate PostUpdateEventListener中的集合更改?

我想出了一个方法来做这件事,所以我会把它贴出来,以防它对其他人有用。这段代码循环遍历所有“旧状态”属性,对于任何持久集合,都会获取以前的内容“快照”。然后将其包装在一个不可修改的集合中,以便更好地度量:

public void onPostUpdate( PostUpdateEvent event )
{       
   for ( Object item: event.getOldState() )
   {
      Object previousContents = null;

      if ( item != null && item instanceof PersistentCollection )               
      {
         PersistentCollection pc = (PersistentCollection) item;
         PersistenceContext context = session.getPersistenceContext();            
         CollectionEntry entry = context.getCollectionEntry( pc );
         Object snapshot = entry.getSnapshot();

         if ( snapshot == null )
            continue;

         if ( pc instanceof List )
         {
            previousContents = Collections.unmodifiableList( (List) snapshot );
         }        
         else if ( pc instanceof Map )
         {
            previousContents = Collections.unmodifiableMap( (Map) snapshot );
         }
         else if ( pc instanceof Set )
         {  
            //Set snapshot is actually stored as a Map                
            Map snapshotMap = (Map) snapshot;
            previousContents = Collections.unmodifiableSet( new HashSet( snapshotMap.values() ) );          
         }
         else
           previousContents = pc;

      //Do something with previousContents here
  }   

似乎有一个专用于捕获集合更改的接口。

Audit Log implementation Full

 public void onPreUpdateCollection(PreCollectionUpdateEvent event) {
    if (bypass(event.getAffectedOwnerOrNull().getClass())) {
        return;
    }
    CollectionEntry collectionEntry = getCollectionEntry(event);    
 }


 protected CollectionEntry getCollectionEntry(AbstractCollectionEvent event) {
     return event.getSession().getPersistenceContext()
            .getCollectionEntry(event.getCollection());
 }