//$Id: OnUpdateVisitor.java 10948 2006-12-07 21:53:10Z steve.ebersole@jboss.com $
package org.hibernate.event.def;
import java.io.Serializable;
import org.hibernate.HibernateException;
import org.hibernate.collection.PersistentCollection;
import org.hibernate.event.EventSource;
import org.hibernate.persister.collection.CollectionPersister;
import org.hibernate.type.CollectionType;
/**
* When an entity is passed to update(), we must inspect all its collections and
* 1. associate any uninitialized PersistentCollections with this session
* 2. associate any initialized PersistentCollections with this session, using the
* existing snapshot
* 3. execute a collection removal (SQL DELETE) for each null collection property
* or "new" collection
*
* @author Gavin King
*/
public class OnUpdateVisitor extends ReattachVisitor {
OnUpdateVisitor(EventSource session, Serializable key, Object owner) {
super( session, key, owner );
}
/**
* {@inheritDoc}
*/
Object processCollection(Object collection, CollectionType type) throws HibernateException {
if ( collection == CollectionType.UNFETCHED_COLLECTION ) {
return null;
}
EventSource session = getSession();
CollectionPersister persister = session.getFactory().getCollectionPersister( type.getRole() );
final Serializable collectionKey = extractCollectionKeyFromOwner( persister );
if ( collection!=null && (collection instanceof PersistentCollection) ) {
PersistentCollection wrapper = (PersistentCollection) collection;
if ( wrapper.setCurrentSession(session) ) {
//a "detached" collection!
if ( !isOwnerUnchanged( wrapper, persister, collectionKey ) ) {
// if the collection belonged to a different entity,
// clean up the existing state of the collection
removeCollection( persister, collectionKey, session );
}
reattachCollection(wrapper, type);
}
else {
// a collection loaded in the current session
// can not possibly be the collection belonging
// to the entity passed to update()
removeCollection(persister, collectionKey, session);
}
}
else {
// null or brand new collection
// this will also (inefficiently) handle arrays, which have
// no snapshot, so we can't do any better
removeCollection(persister, collectionKey, session);
}
return null;
}
}