mysql事务管理及spring声明式事务中主动异常抛出使数据库回滚

原文： http://www.cnblogs.com/wanglonghai/p/4866512.html

  mysql的引擎常用的有两个，一个MyISAM，另一个是InnoDB，mysql默认的为MyISAM,而InnoDB才是支持事务的。所以一般需要修改下，如何修改就不说了。

   事务需要依赖数据库，好久没使用声明式事务，今天试了下。关键配置如下。

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<tx:advice id="transactionAdvice" transaction-manager="transactionManager">         <tx:attributes>             <tx:method name="add*" propagation="REQUIRED" />             <tx:method name="append*" propagation="REQUIRED" />             <tx:method name="insert*" propagation="REQUIRED" />             <tx:method name="save*" propagation="REQUIRED" />             <tx:method name="update*" propagation="REQUIRED" />             <tx:method name="modify*" propagation="REQUIRED" />             <tx:method name="edit*" propagation="REQUIRED" />             <tx:method name="delete*" propagation="REQUIRED" />             <tx:method name="remove*" propagation="REQUIRED" />             <tx:method name="tx*" propagation="REQUIRED" />             <tx:method name="repair" propagation="REQUIRED" />             <tx:method name="delAndRepair" propagation="REQUIRED"   />               <tx:method name="get*" propagation="SUPPORTS" />             <tx:method name="find*" propagation="SUPPORTS" />             <tx:method name="load*" propagation="SUPPORTS" />             <tx:method name="search*" propagation="SUPPORTS" />             <tx:method name="datagrid*" propagation="SUPPORTS" />               <tx:method name="*" propagation="SUPPORTS" />         </tx:attributes>     </tx:advice>     <aop:config>         <aop:pointcut id="transactionPointcut" expression="execution(* com.wondersgroup.employeeBenefits.*.*.service..*Impl.*(..))" />                   <!-- com.wondersgroup.benefit.*.core.service..*Impl.*(..) -->         <aop:advisor pointcut-ref="transactionPointcut" advice-ref="transactionAdvice" />     </aop:config>

　　事务配置好之后再service中手动抛了个exception，结果没有回滚，service方法如下

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@Override    public int saveBudgetApplyInfo(BudgetApplyInfo budgetApplyInfo) throws Exception {         budgetApplyInfoMapper.insert(budgetApplyInfo);        if(1==1){              throw new Exception();        }        return 1;    }

　　跟着断点一步步进去查看原因

在

TransactionAspectSupport中发现这样一个方法

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/**      * Handle a throwable, completing the transaction.      * We may commit or roll back, depending on the configuration.      * @param txInfo information about the current transaction      * @param ex throwable encountered      */     protected void completeTransactionAfterThrowing(TransactionInfo txInfo, Throwable ex) {         if (txInfo != null && txInfo.hasTransaction()) {             if (logger.isTraceEnabled()) {                 logger.trace("Completing transaction for [" + txInfo.getJoinpointIdentification() +                         "] after exception: " + ex);             }             if (txInfo.transactionAttribute.rollbackOn(ex)) {                 try {                     txInfo.getTransactionManager().rollback(txInfo.getTransactionStatus());                 }                 catch (TransactionSystemException ex2) {                     logger.error("Application exception overridden by rollback exception", ex);                     ex2.initApplicationException(ex);                     throw ex2;                 }                 catch (RuntimeException ex2) {                     logger.error("Application exception overridden by rollback exception", ex);                     throw ex2;                 }                 catch (Error err) {                     logger.error("Application exception overridden by rollback error", ex);                     throw err;                 }             }             else {                 // We don't roll back on this exception.                 // Will still roll back if TransactionStatus.isRollbackOnly() is true.                 try {                     txInfo.getTransactionManager().commit(txInfo.getTransactionStatus());                 }                 catch (TransactionSystemException ex2) {                     logger.error("Application exception overridden by commit exception", ex);                     ex2.initApplicationException(ex);                     throw ex2;                 }                 catch (RuntimeException ex2) {                     logger.error("Application exception overridden by commit exception", ex);                     throw ex2;                 }                 catch (Error err) {                     logger.error("Application exception overridden by commit error", ex);                     throw err;                 }             }         }     }

　　上面的方法中有这么一段

1	txInfo.transactionAttribute.rollbackOn(ex)，这里是判断是否需要执行回滚操作的，跟踪rollbackOn方法最后会执行到

DefaultTransactionAttribute中的rollbackOn方法

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/**      * The default behavior is as with EJB: rollback on unchecked exception.      * Additionally attempt to rollback on Error.      * <p>This is consistent with TransactionTemplate's default behavior.      */     public boolean rollbackOn(Throwable ex) {         return (ex instanceof RuntimeException || ex instanceof Error);     }

　　看到这里，应该都清楚了。。。自己主动抛异常Exception是不对的。这里只捕获运行时异常

1	RuntimeException 及Error，所以我们测试时不可以直接抛Exception，而应该换成

1	RuntimeException 。当然。也可在xml中指定rollback-for

1	<tx:method name="add*" propagation="REQUIRED" rollback-for="Exception" />

　　最后：个人还是比较喜欢基于注解的事务处理

如果还不行，请接着看下面这篇：

最近做一个项目，项目的框架采用是Spring3MVC+MyBatis3.1。可是在开发过程中发现配置的事务不管用。

出现这个问题的现象是用Junit调试事务管用，而部署到Tomcat中就不管用了。先看看事务的配置：

<!--proxy-target-class="true"强制使用cglib代理   如果为false则spring会自动选择-->
<aop:aspectj-autoproxy proxy-target-class="true"/>

<!-- Transaction manager for a single JDBC DataSource -->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="dataSource" />
</bean>

<tx:advice id="txAdvice" transaction-manager="transactionManager">
    <tx:attributes>
        <tx:method name="save*" propagation="REQUIRED"/>
    </tx:attributes>
</tx:advice>


<aop:config>
<aop:pointcut expression="execution(public * com.luyou.platform.service.impl.*Impl.*(..))" id="pointcut"/>
<aop:advisor advice-ref="txAdvice" pointcut-ref="pointcut"/>
</aop:config>

采用以下两种方法调试：

一、Debug视图

 1、Junit下的

发现配置事务的AOP已经包进来了。再看看Tomcat中运行的Debug截图：

显然AOP没有被包进来。

二、Log4J的记录：

Junit下的记录：

Spring托管了事务。

Tomcat运行时的记录：

Spring没有托管事务。

从以上两种方法的调试说明了，事务的配置是正确的，只是在部署到Tomcat中，没有被托管。为什么会在Junit的时候就可以呢？得看看Junit的配置：

@RunWith(SpringJUnit4ClassRunner.class)
@TestExecutionListeners({DependencyInjectionTestExecutionListener.class})
@ContextConfiguration("classpath:applicationContext.xml")

这是Junit加载Spring容器的注解。ContextConfiguration会把applicationContext.xml的Bean都加载了，这就说明Tomcat在运行时没有将applicationContext.xml的Bean加载进来。问了前辈，前辈的回话是这样的：

切面配置在了root applicationContext的bean上了，而spring mvc会根据xxx-servelt.xml生成一个自己的applicationContext，他的父applicationContext为root applicatonContext，当mvc有自己的bean时便不再去向父context要bean，导致声明事务无效。

看了前辈的这个邮件，我将applicationContext.xml中配置事务的AOP复制到XXX-servlet.xml中。再调试，Tomcat中运行项目事务被Spring托管了，也就是问题解决了！！

问题解决后查看了Spring3.1的Docs发现了以下的内容：

These inherited beans can be overridden in the servlet-specific scope, and you can define new scope-specific beans local to a given Servlet instance.
Context hierarchy in Spring Web MVC Upon initialization of a DispatcherServlet, Spring MVC looks for a file named [servlet-name]-servlet.xml in the WEB-INF directory of your web application and creates the beans defined there, overriding the definitions of any beans defined with the same name in the global scope.

原文地址：https://my.oschina.net/xuqiang/blog/97633