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Hibernate example source code file (EntityKey.java)

This example Hibernate source code file (EntityKey.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

classnotfoundexception, entitykey, entitykey, entitypersister, io, ioexception, override, serializable, serializable, sessionfactoryimplementor, sessionimplementor, string, string, type, type

The Hibernate EntityKey.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.engine.spi;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

import org.hibernate.AssertionFailure;
import org.hibernate.internal.util.compare.EqualsHelper;
import org.hibernate.persister.entity.EntityPersister;
import org.hibernate.pretty.MessageHelper;
import org.hibernate.type.Type;

/**
 * Uniquely identifies of an entity instance in a particular session by identifier.
 * <p/>
 * Information used to determine uniqueness consists of the entity-name and the identifier value (see {@link #equals}).
 *
 * @author Gavin King
 */
public final class EntityKey implements Serializable {
	private final Serializable identifier;
	private final String entityName;
	private final String rootEntityName;
	private final String tenantId;

	private final int hashCode;

	private final Type identifierType;
	private final boolean isBatchLoadable;
	private final SessionFactoryImplementor factory;

	/**
	 * Construct a unique identifier for an entity class instance.
	 * <p>
	 * NOTE : This signature has changed to accommodate both entity mode and multi-tenancy, both of which relate to
	 * the Session to which this key belongs.  To help minimize the impact of these changes in the future, the
	 * {@link SessionImplementor#generateEntityKey} method was added to hide the session-specific changes.
	 *
	 * @param id The entity id
	 * @param persister The entity persister
	 * @param tenantId The tenant identifier of the session to which this key belongs
	 */
	public EntityKey(Serializable id, EntityPersister persister, String tenantId) {
		if ( id == null ) {
			throw new AssertionFailure( "null identifier" );
		}
		this.identifier = id; 
		this.rootEntityName = persister.getRootEntityName();
		this.entityName = persister.getEntityName();
		this.tenantId = tenantId;

		this.identifierType = persister.getIdentifierType();
		this.isBatchLoadable = persister.isBatchLoadable();
		this.factory = persister.getFactory();
		this.hashCode = generateHashCode();
	}

	/**
	 * Used to reconstruct an EntityKey during deserialization.
	 *
	 * @param identifier The identifier value
	 * @param rootEntityName The root entity name
	 * @param entityName The specific entity name
	 * @param identifierType The type of the identifier value
	 * @param batchLoadable Whether represented entity is eligible for batch loading
	 * @param factory The session factory
	 * @param tenantId The entity's tenant id (from the session that loaded it).
	 */
	private EntityKey(
			Serializable identifier,
	        String rootEntityName,
	        String entityName,
	        Type identifierType,
	        boolean batchLoadable,
	        SessionFactoryImplementor factory,
			String tenantId) {
		this.identifier = identifier;
		this.rootEntityName = rootEntityName;
		this.entityName = entityName;
		this.identifierType = identifierType;
		this.isBatchLoadable = batchLoadable;
		this.factory = factory;
		this.tenantId = tenantId;
		this.hashCode = generateHashCode();
	}

	private int generateHashCode() {
		int result = 17;
		result = 37 * result + rootEntityName.hashCode();
		result = 37 * result + identifierType.getHashCode( identifier, factory );
		return result;
	}

	public boolean isBatchLoadable() {
		return isBatchLoadable;
	}

	public Serializable getIdentifier() {
		return identifier;
	}

	public String getEntityName() {
		return entityName;
	}

	@Override
	public boolean equals(Object other) {
		EntityKey otherKey = (EntityKey) other;
		return otherKey.rootEntityName.equals(this.rootEntityName) &&
				identifierType.isEqual(otherKey.identifier, this.identifier, factory) &&
				EqualsHelper.equals( tenantId, otherKey.tenantId );
	}

	@Override
	public int hashCode() {
		return hashCode;
	}

	@Override
	public String toString() {
		return "EntityKey" + 
			MessageHelper.infoString( factory.getEntityPersister( entityName ), identifier, factory );
	}

	/**
	 * Custom serialization routine used during serialization of a
	 * Session/PersistenceContext for increased performance.
	 *
	 * @param oos The stream to which we should write the serial data.
	 *
	 * @throws IOException Thrown by Java I/O
	 */
	public void serialize(ObjectOutputStream oos) throws IOException {
		oos.writeObject( identifier );
		oos.writeObject( rootEntityName );
		oos.writeObject( entityName );
		oos.writeObject( identifierType );
		oos.writeBoolean( isBatchLoadable );
		oos.writeObject( tenantId );
	}

	/**
	 * Custom deserialization routine used during deserialization of a
	 * Session/PersistenceContext for increased performance.
	 *
	 * @param ois The stream from which to read the entry.
	 * @param session The session being deserialized.
	 *
	 * @return The deserialized EntityEntry
	 *
	 * @throws IOException Thrown by Java I/O
	 * @throws ClassNotFoundException Thrown by Java I/O
	 */
	public static EntityKey deserialize(
			ObjectInputStream ois,
	        SessionImplementor session) throws IOException, ClassNotFoundException {
		return new EntityKey(
				( Serializable ) ois.readObject(),
		        (String) ois.readObject(),
				(String) ois.readObject(),
		        ( Type ) ois.readObject(),
		        ois.readBoolean(),
		        ( session == null ? null : session.getFactory() ),
				(String) ois.readObject()
		);
	}
}

Other Hibernate examples (source code examples)

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