Hibernate example source code file (CacheEntry.java)

This example Hibernate source code file (CacheEntry.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

cacheentry, cacheentry, entitypersister, eventlistenergroup, eventsource, hibernateexception, interceptor, io, object, object, preloadevent, serializable, serializable, string, string

The Hibernate CacheEntry.java source code

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2010, 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.cache.spi.entry;

import java.io.Serializable;

import org.hibernate.AssertionFailure;
import org.hibernate.HibernateException;
import org.hibernate.Interceptor;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.event.spi.EventSource;
import org.hibernate.event.spi.EventType;
import org.hibernate.event.spi.PreLoadEvent;
import org.hibernate.event.spi.PreLoadEventListener;
import org.hibernate.internal.util.collections.ArrayHelper;
import org.hibernate.persister.entity.EntityPersister;
import org.hibernate.event.service.spi.EventListenerGroup;
import org.hibernate.event.service.spi.EventListenerRegistry;
import org.hibernate.type.TypeHelper;

/**
 * A cached instance of a persistent class
 *
 * @author Gavin King
 */
public final class CacheEntry implements Serializable {

	private final Serializable[] disassembledState;
	private final String subclass;
	private final boolean lazyPropertiesAreUnfetched;
	private final Object version;
	
	public String getSubclass() {
		return subclass;
	}
	
	public boolean areLazyPropertiesUnfetched() {
		return lazyPropertiesAreUnfetched;
	}
	
	public CacheEntry(
			final Object[] state, 
			final EntityPersister persister, 
			final boolean unfetched, 
			final Object version,
			final SessionImplementor session, 
			final Object owner) 
	throws HibernateException {
		//disassembled state gets put in a new array (we write to cache by value!)
		this.disassembledState = TypeHelper.disassemble(
				state, 
				persister.getPropertyTypes(), 
				persister.isLazyPropertiesCacheable() ? 
					null : persister.getPropertyLaziness(),
				session, 
				owner 
			);
		subclass = persister.getEntityName();
		lazyPropertiesAreUnfetched = unfetched || !persister.isLazyPropertiesCacheable();
		this.version = version;
	}
	
	public Object getVersion() {
		return version;
	}

	CacheEntry(Serializable[] state, String subclass, boolean unfetched, Object version) {
		this.disassembledState = state;
		this.subclass = subclass;
		this.lazyPropertiesAreUnfetched = unfetched;
		this.version = version;
	}

	public Object[] assemble(
			final Object instance, 
			final Serializable id, 
			final EntityPersister persister, 
			final Interceptor interceptor, 
			final EventSource session) 
	throws HibernateException {

		if ( !persister.getEntityName().equals(subclass) ) {
			throw new AssertionFailure("Tried to assemble a different subclass instance");
		}

		return assemble(disassembledState, instance, id, persister, interceptor, session);

	}

	private static Object[] assemble(
			final Serializable[] values, 
			final Object result, 
			final Serializable id, 
			final EntityPersister persister, 
			final Interceptor interceptor, 
			final EventSource session) throws HibernateException {
			
		//assembled state gets put in a new array (we read from cache by value!)
		Object[] assembledProps = TypeHelper.assemble(
				values, 
				persister.getPropertyTypes(), 
				session, result 
			);

		//persister.setIdentifier(result, id); //before calling interceptor, for consistency with normal load

		//TODO: reuse the PreLoadEvent
		final PreLoadEvent preLoadEvent = new PreLoadEvent( session )
				.setEntity( result )
				.setState( assembledProps )
				.setId( id )
				.setPersister( persister );

		final EventListenerGroup<PreLoadEventListener> listenerGroup = session
				.getFactory()
				.getServiceRegistry()
				.getService( EventListenerRegistry.class )
				.getEventListenerGroup( EventType.PRE_LOAD );
		for ( PreLoadEventListener listener : listenerGroup.listeners() ) {
			listener.onPreLoad( preLoadEvent );
		}

		persister.setPropertyValues( result, assembledProps );

		return assembledProps;
	}

    public Serializable[] getDisassembledState() {
	    // todo: this was added to support initializing an entity's EntityEntry snapshot during reattach;
	    // this should be refactored to instead expose a method to assemble a EntityEntry based on this
	    // state for return.
	    return disassembledState;
    }

	public String toString() {
		return "CacheEntry(" + subclass + ')' + ArrayHelper.toString(disassembledState);
	}

}