001 /**
002 *
003 * Licensed to the Apache Software Foundation (ASF) under one or more
004 * contributor license agreements. See the NOTICE file distributed with
005 * this work for additional information regarding copyright ownership.
006 * The ASF licenses this file to You under the Apache License, Version 2.0
007 * (the "License"); you may not use this file except in compliance with
008 * the License. You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018 package org.apache.camel.component.jpa;
019
020 import org.apache.camel.impl.ServiceSupport;
021 import static org.apache.camel.util.ObjectHelper.notNull;
022 import org.springframework.orm.jpa.JpaCallback;
023
024 import javax.persistence.EntityManager;
025 import javax.persistence.EntityManagerFactory;
026 import javax.persistence.EntityTransaction;
027
028 /**
029 * @version $Revision: 525537 $
030 */
031 public class DefaultTransactionStrategy extends ServiceSupport implements TransactionStrategy {
032 private EntityManagerFactory entityManagerFactory;
033 private EntityManager entityManager;
034
035 public DefaultTransactionStrategy(EntityManagerFactory entityManagerFactory) {
036 notNull(entityManagerFactory, "entityManagerFactory");
037 this.entityManagerFactory = entityManagerFactory;
038 }
039
040 public DefaultTransactionStrategy(EntityManager entityManager) {
041 notNull(entityManager, "entityManager");
042 this.entityManager = entityManager;
043 }
044
045 public Object execute(JpaCallback callback) {
046 EntityManager em = getEntityManager();
047 EntityTransaction transaction = em.getTransaction();
048 transaction.begin();
049
050 try {
051 Object answer = callback.doInJpa(em);
052 transaction.commit();
053 return answer;
054 }
055 catch (RuntimeException e) {
056 if (transaction != null) {
057 transaction.rollback();
058 }
059 throw e;
060 }
061 }
062
063 public EntityManager getEntityManager() {
064 if (entityManager == null) {
065 entityManager = entityManagerFactory.createEntityManager();
066 }
067 return entityManager;
068 }
069
070 protected void doStart() throws Exception {
071 // force lazy construction
072 getEntityManager();
073 }
074
075 protected void doStop() throws Exception {
076 if (entityManager != null) {
077 entityManager.close();
078 }
079 }
080 }