Hibernate example source code file (EntityDeleteAction.java)

This example Hibernate source code file (EntityDeleteAction.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Hibernate tags/keywords

entitydeleteaction, entitypersister, eventlistenergroup, eventlistenergroup, hibernateexception, io, object, object, override, postdeleteevent, postdeleteevent, postdeleteeventlistener, predeleteevent, sessionimplementor, sessionimplementor

The Hibernate EntityDeleteAction.java source code

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2008-2011, Red Hat Inc. or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat Inc.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.hibernate.action.internal;

import java.io.Serializable;

import org.hibernate.AssertionFailure;
import org.hibernate.HibernateException;
import org.hibernate.cache.spi.CacheKey;
import org.hibernate.cache.spi.access.SoftLock;
import org.hibernate.engine.spi.EntityEntry;
import org.hibernate.engine.spi.PersistenceContext;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.event.spi.EventType;
import org.hibernate.event.spi.PostDeleteEvent;
import org.hibernate.event.spi.PostDeleteEventListener;
import org.hibernate.event.spi.PreDeleteEvent;
import org.hibernate.event.spi.PreDeleteEventListener;
import org.hibernate.persister.entity.EntityPersister;
import org.hibernate.event.service.spi.EventListenerGroup;

public final class EntityDeleteAction extends EntityAction {
	private final Object version;
	private final boolean isCascadeDeleteEnabled;
	private final Object[] state;

	private SoftLock lock;

	public EntityDeleteAction(
			final Serializable id,
	        final Object[] state,
	        final Object version,
	        final Object instance,
	        final EntityPersister persister,
	        final boolean isCascadeDeleteEnabled,
	        final SessionImplementor session) {
		super( session, id, instance, persister );
		this.version = version;
		this.isCascadeDeleteEnabled = isCascadeDeleteEnabled;
		this.state = state;
	}

	@Override
	public void execute() throws HibernateException {
		Serializable id = getId();
		EntityPersister persister = getPersister();
		SessionImplementor session = getSession();
		Object instance = getInstance();

		boolean veto = preDelete();

		Object version = this.version;
		if ( persister.isVersionPropertyGenerated() ) {
			// we need to grab the version value from the entity, otherwise
			// we have issues with generated-version entities that may have
			// multiple actions queued during the same flush
			version = persister.getVersion( instance );
		}

		final CacheKey ck;
		if ( persister.hasCache() ) {
			ck = session.generateCacheKey( id, persister.getIdentifierType(), persister.getRootEntityName() );
			lock = persister.getCacheAccessStrategy().lockItem( ck, version );
		}
		else {
			ck = null;
		}

		if ( !isCascadeDeleteEnabled && !veto ) {
			persister.delete( id, version, instance, session );
		}
		
		//postDelete:
		// After actually deleting a row, record the fact that the instance no longer 
		// exists on the database (needed for identity-column key generation), and
		// remove it from the session cache
		final PersistenceContext persistenceContext = session.getPersistenceContext();
		EntityEntry entry = persistenceContext.removeEntry( instance );
		if ( entry == null ) {
			throw new AssertionFailure( "possible nonthreadsafe access to session" );
		}
		entry.postDelete();

		persistenceContext.removeEntity( entry.getEntityKey() );
		persistenceContext.removeProxy( entry.getEntityKey() );
		
		if ( persister.hasCache() ) {
			persister.getCacheAccessStrategy().remove( ck );
		}

		postDelete();

		if ( getSession().getFactory().getStatistics().isStatisticsEnabled() && !veto ) {
			getSession().getFactory().getStatisticsImplementor().deleteEntity( getPersister().getEntityName() );
		}
	}

	private boolean preDelete() {
		boolean veto = false;
		EventListenerGroup<PreDeleteEventListener> listenerGroup = listenerGroup( EventType.PRE_DELETE );
		if ( listenerGroup.isEmpty() ) {
			return veto;
		}
		final PreDeleteEvent event = new PreDeleteEvent( getInstance(), getId(), state, getPersister(), eventSource() );
		for ( PreDeleteEventListener listener : listenerGroup.listeners() ) {
			veto |= listener.onPreDelete( event );
		}
		return veto;
	}

	private void postDelete() {
		EventListenerGroup<PostDeleteEventListener> listenerGroup = listenerGroup( EventType.POST_DELETE );
		if ( listenerGroup.isEmpty() ) {
			return;
		}
		final PostDeleteEvent event = new PostDeleteEvent(
				getInstance(),
				getId(),
				state,
				getPersister(),
				eventSource()
		);
		for ( PostDeleteEventListener listener : listenerGroup.listeners() ) {
			listener.onPostDelete( event );
		}
	}

	private void postCommitDelete() {
		EventListenerGroup<PostDeleteEventListener> listenerGroup = listenerGroup( EventType.POST_COMMIT_DELETE );
		if ( listenerGroup.isEmpty() ) {
			return;
		}
		final PostDeleteEvent event = new PostDeleteEvent(
				getInstance(),
				getId(),
				state,
				getPersister(),
				eventSource()
		);
		for( PostDeleteEventListener listener : listenerGroup.listeners() ){
			listener.onPostDelete( event );
		}
	}

	@Override
	public void doAfterTransactionCompletion(boolean success, SessionImplementor session) throws HibernateException {
		if ( getPersister().hasCache() ) {
			final CacheKey ck = getSession().generateCacheKey(
					getId(),
					getPersister().getIdentifierType(),
					getPersister().getRootEntityName()
			);
			getPersister().getCacheAccessStrategy().unlockItem( ck, lock );
		}
		postCommitDelete();
	}

	@Override
	protected boolean hasPostCommitEventListeners() {
		return ! listenerGroup( EventType.POST_COMMIT_DELETE ).isEmpty();
	}
}