//$Id: DefaultEvictEventListener.java 15864 2009-02-03 01:16:57Z [email protected] $
package org.hibernate.event.def;
import java.io.Serializable;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.HibernateException;
import org.hibernate.engine.Cascade;
import org.hibernate.engine.CascadingAction;
import org.hibernate.engine.EntityEntry;
import org.hibernate.engine.EntityKey;
import org.hibernate.engine.PersistenceContext;
import org.hibernate.event.EventSource;
import org.hibernate.event.EvictEvent;
import org.hibernate.event.EvictEventListener;
import org.hibernate.persister.entity.EntityPersister;
import org.hibernate.pretty.MessageHelper;
import org.hibernate.proxy.HibernateProxy;
import org.hibernate.proxy.LazyInitializer;
/**
* Defines the default evict event listener used by hibernate for evicting entities
* in response to generated flush events. In particular, this implementation will
* remove any hard references to the entity that are held by the infrastructure
* (references held by application or other persistent instances are okay)
*
* @author Steve Ebersole
*/
public class DefaultEvictEventListener implements EvictEventListener {
private static final Log log = LogFactory.getLog(DefaultEvictEventListener.class);
/**
* Handle the given evict event.
*
* @param event The evict event to be handled.
* @throws HibernateException
*/
public void onEvict(EvictEvent event) throws HibernateException {
EventSource source = event.getSession();
final Object object = event.getObject();
final PersistenceContext persistenceContext = source.getPersistenceContext();
if ( object instanceof HibernateProxy ) {
LazyInitializer li = ( (HibernateProxy) object ).getHibernateLazyInitializer();
Serializable id = li.getIdentifier();
EntityPersister persister = source.getFactory().getEntityPersister( li.getEntityName() );
if ( id == null ) {
throw new IllegalArgumentException("null identifier");
}
EntityKey key = new EntityKey( id, persister, source.getEntityMode() );
persistenceContext.removeProxy( key );
if ( !li.isUninitialized() ) {
final Object entity = persistenceContext.removeEntity(key);
if ( entity != null ) {
EntityEntry e = event.getSession().getPersistenceContext().removeEntry(entity);
doEvict( entity, key, e.getPersister(), event.getSession() );
}
}
li.unsetSession();
}
else {
EntityEntry e = persistenceContext.removeEntry( object );
if ( e != null ) {
EntityKey key = new EntityKey( e.getId(), e.getPersister(), source.getEntityMode() );
persistenceContext.removeEntity( key );
doEvict( object, key, e.getPersister(), source );
}
}
}
protected void doEvict(
final Object object,
final EntityKey key,
final EntityPersister persister,
final EventSource session) throws HibernateException {
if ( log.isTraceEnabled() ) {
log.trace( "evicting " + MessageHelper.infoString(persister) );
}
// remove all collections for the entity from the session-level cache
if ( persister.hasCollections() ) {
new EvictVisitor( session ).process( object, persister );
}
new Cascade( CascadingAction.EVICT, Cascade.AFTER_EVICT, session )
.cascade( persister, object );
}
}
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