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 }