/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2012, 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.event.internal;
import java.io.Serializable;
import org.hibernate.HibernateException;
import org.hibernate.cache.spi.access.NaturalIdRegionAccessStrategy;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.event.spi.ResolveNaturalIdEvent;
import org.hibernate.event.spi.ResolveNaturalIdEventListener;
import org.hibernate.internal.CoreLogging;
import org.hibernate.internal.CoreMessageLogger;
import org.hibernate.persister.entity.EntityPersister;
import org.hibernate.pretty.MessageHelper;
/**
* Defines the default load event listeners used by hibernate for loading entities
* in response to generated load events.
*
* @author Eric Dalquist
* @author Steve Ebersole
*/
public class DefaultResolveNaturalIdEventListener
extends AbstractLockUpgradeEventListener
implements ResolveNaturalIdEventListener {
public static final Object REMOVED_ENTITY_MARKER = new Object();
public static final Object INCONSISTENT_RTN_CLASS_MARKER = new Object();
private static final CoreMessageLogger LOG = CoreLogging.messageLogger( DefaultResolveNaturalIdEventListener.class );
@Override
public void onResolveNaturalId(ResolveNaturalIdEvent event) throws HibernateException {
final Serializable entityId = resolveNaturalId( event );
event.setEntityId( entityId );
}
/**
* Coordinates the efforts to load a given entity. First, an attempt is
* made to load the entity from the session-level cache. If not found there,
* an attempt is made to locate it in second-level cache. Lastly, an
* attempt is made to load it directly from the datasource.
*
* @param event The load event
*
* @return The loaded entity, or null.
*/
protected Serializable resolveNaturalId(final ResolveNaturalIdEvent event) {
final EntityPersister persister = event.getEntityPersister();
final boolean traceEnabled = LOG.isTraceEnabled();
if ( traceEnabled )
LOG.tracev( "Attempting to resolve: {0}",
MessageHelper.infoString( persister, event.getNaturalIdValues(), event.getSession().getFactory() ) );
Serializable entityId = resolveFromCache( event );
if ( entityId != null ) {
if ( traceEnabled )
LOG.tracev( "Resolved object in cache: {0}",
MessageHelper.infoString( persister, event.getNaturalIdValues(), event.getSession().getFactory() ) );
return entityId;
}
if ( traceEnabled )
LOG.tracev( "Object not resolved in any cache: {0}",
MessageHelper.infoString( persister, event.getNaturalIdValues(), event.getSession().getFactory() ) );
return loadFromDatasource( event );
}
/**
* Attempts to resolve the entity id corresponding to the event's natural id values from the session
*
* @param event The load event
*
* @return The entity from the cache, or null.
*/
protected Serializable resolveFromCache(final ResolveNaturalIdEvent event) {
return event.getSession().getPersistenceContext().getNaturalIdHelper().findCachedNaturalIdResolution(
event.getEntityPersister(),
event.getOrderedNaturalIdValues()
);
}
/**
* Performs the process of loading an entity from the configured
* underlying datasource.
*
* @param event The load event
*
* @return The object loaded from the datasource, or null if not found.
*/
protected Serializable loadFromDatasource(final ResolveNaturalIdEvent event) {
final SessionFactoryImplementor factory = event.getSession().getFactory();
final boolean stats = factory.getStatistics().isStatisticsEnabled();
long startTime = 0;
if ( stats ) {
startTime = System.currentTimeMillis();
}
final Serializable pk = event.getEntityPersister().loadEntityIdByNaturalId(
event.getOrderedNaturalIdValues(),
event.getLockOptions(),
event.getSession()
);
if ( stats ) {
final NaturalIdRegionAccessStrategy naturalIdCacheAccessStrategy = event.getEntityPersister().getNaturalIdCacheAccessStrategy();
final String regionName = naturalIdCacheAccessStrategy == null ? null : naturalIdCacheAccessStrategy.getRegion().getName();
factory.getStatisticsImplementor().naturalIdQueryExecuted(
regionName,
System.currentTimeMillis() - startTime );
}
//PK can be null if the entity doesn't exist
if (pk != null) {
event.getSession().getPersistenceContext().getNaturalIdHelper().cacheNaturalIdCrossReferenceFromLoad(
event.getEntityPersister(),
pk,
event.getOrderedNaturalIdValues()
);
}
return pk;
}
}