001/*
002 * Copyright 2002-2012 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.orm.hibernate3.support;
018
019import java.io.Serializable;
020import java.util.Map;
021
022import org.hibernate.engine.SessionImplementor;
023import org.hibernate.event.MergeEvent;
024import org.hibernate.event.def.DefaultMergeEventListener;
025import org.hibernate.persister.entity.EntityPersister;
026
027/**
028 * Extension of Hibernate's DefaultMergeEventListener, transferring the ids
029 * of newly saved objects to the corresponding original objects (that are part
030 * of the detached object graph passed into the {@code merge} method).
031 *
032 * <p>Transferring newly assigned ids to the original graph allows for continuing
033 * to use the original object graph, despite merged copies being registered with
034 * the current Hibernate Session. This is particularly useful for web applications
035 * that might want to store an object graph and then render it in a web view,
036 * with links that include the id of certain (potentially newly saved) objects.
037 *
038 * <p>The merge behavior given by this MergeEventListener is nearly identical
039 * to TopLink's merge behavior. See PetClinic for an example, which relies on
040 * ids being available for newly saved objects: the {@code HibernateClinic}
041 * and {@code TopLinkClinic} DAO implementations both use straight merge
042 * calls, with the Hibernate SessionFactory configuration specifying an
043 * {@code IdTransferringMergeEventListener}.
044 *
045 * <p>Typically specified as entry for LocalSessionFactoryBean's "eventListeners"
046 * map, with key "merge".
047 *
048 * @author Juergen Hoeller
049 * @since 1.2
050 * @see org.springframework.orm.hibernate3.LocalSessionFactoryBean#setEventListeners(java.util.Map)
051 * @deprecated as of Spring 4.3, in favor of Hibernate 4.x/5.x
052 */
053@Deprecated
054@SuppressWarnings({"serial", "rawtypes"})
055public class IdTransferringMergeEventListener extends DefaultMergeEventListener {
056
057        /**
058         * Hibernate 3.1 implementation of ID transferral.
059         */
060        @Override
061        protected void entityIsTransient(MergeEvent event, Map copyCache) {
062                super.entityIsTransient(event, copyCache);
063                SessionImplementor session = event.getSession();
064                EntityPersister persister = session.getEntityPersister(event.getEntityName(), event.getEntity());
065                // Extract id from merged copy (which is currently registered with Session).
066                Serializable id = persister.getIdentifier(event.getResult(), session.getEntityMode());
067                // Set id on original object (which remains detached).
068                persister.setIdentifier(event.getOriginal(), id, session.getEntityMode());
069        }
070
071}