001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.camel.component.jpa;
018
019 import javax.persistence.EntityManager;
020 import javax.persistence.EntityManagerFactory;
021 import javax.persistence.EntityTransaction;
022
023 import org.apache.camel.impl.ServiceSupport;
024
025 import org.springframework.orm.jpa.JpaCallback;
026
027 import static org.apache.camel.util.ObjectHelper.notNull;
028
029 /**
030 * @version $Revision: 563665 $
031 */
032 public class DefaultTransactionStrategy extends ServiceSupport implements TransactionStrategy {
033 private EntityManagerFactory entityManagerFactory;
034 private EntityManager entityManager;
035
036 public DefaultTransactionStrategy(EntityManagerFactory entityManagerFactory) {
037 notNull(entityManagerFactory, "entityManagerFactory");
038 this.entityManagerFactory = entityManagerFactory;
039 }
040
041 public DefaultTransactionStrategy(EntityManager entityManager) {
042 notNull(entityManager, "entityManager");
043 this.entityManager = entityManager;
044 }
045
046 public Object execute(JpaCallback callback) {
047 EntityManager em = getEntityManager();
048 EntityTransaction transaction = em.getTransaction();
049 transaction.begin();
050
051 try {
052 Object answer = callback.doInJpa(em);
053 transaction.commit();
054 return answer;
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 }