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 }