Jboss Seam3 Weld Jpa在J2SE中使用之四[JPA]

转帖请标明此处地址：http://blog.csdn.net/FENGUFO/category/463623.aspx

 

前面配置完成以后，使用JPA需要在自己的类中注入

 

@Inject EntityManager em;

 

 

完成注入需要添加一个类，类名称随便，但unitName="??" ??需要按照自己的配置文件修改，对应即可。

 

package fm.biz.logic;import javax.enterprise.context.ApplicationScoped;import javax.enterprise.context.ConversationScoped;import javax.enterprise.inject.Default;import javax.enterprise.inject.Produces;import javax.inject.Named;import javax.persistence.EntityManagerFactory;import javax.persistence.PersistenceUnit;import org.jboss.seam.international.locale.DefaultLocale;import org.jboss.seam.solder.core.ExtensionManaged;@ApplicationScopedpublic class BizFactory{@ExtensionManaged@Produces@PersistenceUnit(unitName="biz")EntityManagerFactory entityManagerFactory;}

 

 

 

@Inject EntityManager em;

 

注入的em目前使用还是有问题，我代码里报错。看来在J2SE中使用EJB环境下个东西还真是麻烦。

 

原因是集成Seam3的事务出了问题，seam-persistence.jar 中的集成事务[EntityTransaction]会同步容器事务（JTA  synchronizations），可前面我没有使用JTA事务，默认TOMCAT也不支持JTA,怎么办？

 

只能取消同步了哈哈，用TOMCAT集成JTA事务插件也行，网上有教程，修改前面的JPA配置应该可以，我没有测试过。我还是选择了修改去掉同步代码，其实就几句。修改后

 

org.jboss.seam.transaction 文件。直接在自己的SRC目录添加即可，不能改包名称，可覆盖SEAM3中的JAR文件

 

/* * JBoss, Home of Professional Open Source * Copyright 2011, Red Hat, Inc. and/or its affiliates, and individual * contributors by the @authors tag. See the copyright.txt in the * distribution for a full listing of individual contributors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * http://www.apache.org/licenses/LICENSE-2.0 * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package org.jboss.seam.transaction;import javax.enterprise.context.RequestScoped;import javax.enterprise.inject.Instance;import javax.inject.Inject;import javax.persistence.EntityManager;import javax.transaction.HeuristicMixedException;import javax.transaction.HeuristicRollbackException;import javax.transaction.NotSupportedException;import javax.transaction.RollbackException;import javax.transaction.Status;import javax.transaction.Synchronization;import javax.transaction.SystemException;import org.jboss.logging.Logger;import org.jboss.seam.persistence.DefaultPersistenceProvider;import org.jboss.seam.solder.core.Veto;/** * Support for the JPA EntityTransaction API. * * Adapts JPA transaction management to a Seam UserTransaction interface.For use * in non-JTA-capable environments. * * @author Gavin King * */@RequestScoped@DefaultTransaction@Vetopublic class EntityTransaction extends AbstractUserTransaction{ private static final Logger log = Logger.getLogger(EntityTransaction.class); @Inject private EntityManager entityManager; @Inject private Instance<DefaultPersistenceProvider> persistenceProvider; @Inject public void init(Synchronizations sync) { setSynchronizations(sync); } public EntityTransaction() { } private javax.persistence.EntityTransaction getDelegate() { return entityManager.getTransaction(); } public void begin() throws NotSupportedException, SystemException { log.debug("beginning JPA resource-local transaction"); // TODO: translate exceptions that occur into the correct JTA exception try { getDelegate().begin(); log.debug("Ship getSynchronizations().afterTransactionBegin() in JPA(se)"); } catch (RuntimeException re) { throw re; } } public void commit() throws RollbackException, HeuristicMixedException, HeuristicRollbackException, SecurityException, IllegalStateException, SystemException { log.debug("committing JPA resource-local transaction"); javax.persistence.EntityTransaction delegate = getDelegate(); boolean success = false; try { if (delegate.getRollbackOnly()) { delegate.rollback(); throw new RollbackException(); } else { log.debug("Ship getSynchronizations().beforeTransactionCommit() in JPA(se)"); delegate.commit(); success = true; } } finally { log.debug("Ship getSynchronizations().afterTransactionCompletion(success) in JPA(se)"); } } public void rollback() throws IllegalStateException, SecurityException, SystemException { log.debug("rolling back JPA resource-local transaction"); // TODO: translate exceptions that occur into the correct JTA exception javax.persistence.EntityTransaction delegate = getDelegate(); try { delegate.rollback(); } finally { log.debug("Ship getSynchronizations().afterTransactionCompletion(false) in JPA(se)"); } } public void setRollbackOnly() throws IllegalStateException, SystemException { log.debug("marking JPA resource-local transaction for rollback"); getDelegate().setRollbackOnly(); } public int getStatus() throws SystemException { if (getDelegate().isActive()) { if (getDelegate().getRollbackOnly()) { return Status.STATUS_MARKED_ROLLBACK; } return Status.STATUS_ACTIVE; } else { return Status.STATUS_NO_TRANSACTION; } } public void setTransactionTimeout(int timeout) throws SystemException { throw new UnsupportedOperationException(); } @Override public void registerSynchronization(Synchronization sync) { /* if (log.isDebugEnabled()) { log.debug("registering synchronization: " + sync); } // try to register the synchronization directly with the // persistence provider, but if this fails, just hold // on to it myself if (!persistenceProvider.get().registerSynchronization(sync, entityManager)) { getSynchronizations().registerSynchronization(sync); } */ } @Override public boolean isConversationContextRequired() { return true; } @Override public void enlist(EntityManager entityManager) { // no-op }}

 

 

到此就可以正常使用JPA了，事务是JPA的手工事务，不过不需要在自己的代码中手工管理事务，交给SEAM3就行了，添加@Transactional标记即可