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/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* License: GNU Lesser General Public License (LGPL), version 2.1 or later.
* See the lgpl.txt file in the root directory or .
*/
package org.hibernate.event.internal;
import java.io.Serializable;
import java.util.concurrent.TimeUnit;
import org.hibernate.HibernateException;
import org.hibernate.LockOptions;
import org.hibernate.WrongClassException;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.event.spi.EventSource;
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.persister.entity.UniqueKeyLoadable;
import org.hibernate.pretty.MessageHelper;
import org.hibernate.stat.spi.StatisticsImplementor;
/**
* 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();
if ( LOG.isTraceEnabled() ) {
LOG.tracev(
"Attempting to resolve: {0}#{1}",
MessageHelper.infoString( persister ),
event.getNaturalIdValues()
);
}
Serializable entityId = resolveFromCache( event );
if ( entityId != null ) {
if ( LOG.isTraceEnabled() ) {
LOG.tracev(
"Resolved object in cache: {0}#{1}",
MessageHelper.infoString( persister ),
event.getNaturalIdValues()
);
}
return entityId;
}
if ( LOG.isTraceEnabled() ) {
LOG.tracev(
"Object not resolved in any cache: {0}#{1}",
MessageHelper.infoString( persister ),
event.getNaturalIdValues()
);
}
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().getPersistenceContextInternal().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 EventSource session = event.getSession();
final SessionFactoryImplementor factory = session.getFactory();
final StatisticsImplementor statistics = factory.getStatistics();
final boolean stats = statistics.isStatisticsEnabled();
long startTime = 0;
if ( stats ) {
startTime = System.nanoTime();
}
Object[] naturalIdValues = event.getOrderedNaturalIdValues();
final Serializable pk;
EntityPersister persister = event.getEntityPersister();
LockOptions lockOptions = event.getLockOptions();
if ( persister instanceof UniqueKeyLoadable) {
UniqueKeyLoadable rootPersister = (UniqueKeyLoadable)
persister.getFactory().getMetamodel().entityPersister( persister.getRootEntityName() );
Object entity = rootPersister.loadByNaturalId( naturalIdValues, lockOptions, session );
if ( entity == null ) {
pk = null;
}
else {
if ( !persister.isInstance(entity) ) {
throw new WrongClassException(
"loaded object was of wrong class " + entity.getClass(),
naturalIdValues,
persister.getEntityName()
);
}
pk = persister.getIdentifier( entity, session );
}
}
else {
pk = persister.loadEntityIdByNaturalId( naturalIdValues, lockOptions, session );
}
if ( stats ) {
final long endTime = System.nanoTime();
final long milliseconds = TimeUnit.MILLISECONDS.convert( endTime - startTime, TimeUnit.NANOSECONDS );
statistics.naturalIdQueryExecuted(
persister.getRootEntityName(),
milliseconds
);
}
//PK can be null if the entity doesn't exist
if (pk != null) {
session.getPersistenceContextInternal().getNaturalIdHelper()
.cacheNaturalIdCrossReferenceFromLoad( persister, pk, naturalIdValues );
}
return pk;
}
}