Spring事务机制中@Transactional失效的原因

      最近项目中发现spring事务机制中@Transactional会失效，一个方法抛出异常，但是数据库中修改的数据并不会回滚，于是看了一些资料，发现以下情况@Transactional事务会失效。

1.首先检查配置，在项目的spring配置文件检查是否配置开启事务

        <bean id="transactionManager"class="org.springframework.jdbc.datasource.DataSourceTransactionManager"><property name="dataSource" ref="routeDataSource" /></bean><!-- 事务 --><tx:annotation-driven transaction-manager="transactionManager" proxy-target-class="true" />

2.同一个类中, 一个未标注@Transactional的方法去调用标有@Transactional的方法, 事务会失效

If you use (default) Spring Proxy AOP, then all AOP functionality provided by Spring (like @Transational) will only be taken into account if the call goes through the proxy. -- This is normally the case if the annotated method is invoked from another bean.

3. 在非public方法上标注@Transactional, 事务无效

When using proxies, you should apply the @Transactional annotation only to methods with public visibility. If you do annotate protected, private 

or package-visible methods with the @Transactional annotation, no error is raised, but the annotated method does not exhibit the configured

 transactional settings. Consider the use of AspectJ (see below) if you need to annotate non-public methods.