mybatis开启spring事务代码解析

<!--事务管理器-->
  <bean id="springTransactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="dataSource" />
  </bean>
  <!--数据源-->
  <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="com.mysql.jdbc.Driver" />
    <property name="url" value="jdbc:mysql://127.0.0.1:3306/test?characterEncoding=utf8" />
    <property name="username" value="root" />
    <property name="password" value="123456" />
  </bean>
  <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <!-- 指定sqlMapConfig总配置文件，订制的environment在spring容器中不在生效-->
    <!--指定实体类映射文件，可以指定同时指定某一包以及子包下面的所有配置文件，mapperLocations和configLocation有一个即可，当需要为实体类指定别名时，可指定configLocation属性，再在mybatis总配置文件中采用mapper引入实体类映射文件 -->
    <!--<property name="configLocation" value="classpath:fwportal/beans/dbconfig/mybatis.xml" />-->
    <property name="mapperLocations" value="classpath:mapper/*.xml" />
  </bean>
  <!--将DAO接口注册为BEAN-->
  <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
    <property name="basePackage" value="TRANSACTION.DAO" />
  </bean>

@Test
  public void testDelete() throws Exception {
	ApplicationContext context = new ClassPathXmlApplicationContext("mysqltransaction.xml");
	DataSourceTransactionManager springTransactionManager = (DataSourceTransactionManager) context.getBean("springTransactionManager");
	DefaultTransactionDefinition def = new DefaultTransactionDefinition();
	def.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRED);
	//开启事务
	TransactionStatus status = springTransactionManager.getTransaction(def);
	final StudentDAO dao = (StudentDAO)context.getBean("studentDAO");
	try {
		dao.delete(2L);
	}
	catch (Exception ex) {
		springTransactionManager.rollback(status);
		//事务回滚
		throw ex;
	}
	springTransactionManager.commit(status);
	//事务提交
}