Spring使用注解方式处理事务

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
 http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
 http://www.springframework.org/schema/tx
 http://www.springframework.org/schema/tx/spring-tx-2.0.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">

<!--声明事务管理器-->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="myDataSource"/>
</bean>
<!--声明事务的注解驱动
  transaction-manager：事务管理器对象的id
-->
<tx:annotation-driven transaction-manager="transactionManager"/>

/**使用注解来设值事务的属性(传播行为,隔离等级,超时,当哪些异常发生的时候触发回滚事务)
 * 注意:该注解必须使用在公有函数上，而且抛出的异常必需继承RuntimeException
 * */
@Transactional(propagation = Propagation.REQUIRED,
isolation = Isolation.DEFAULT,timeout = 20,
rollbackFor = {NullPointerException.class,NotEnoughException.class})
public void buyGoods(int goodsId, int nums)
        throws NullPointerException, NotEnoughException{
    /**生成销售的订单
     * */
    Sale sale=new Sale();
    sale.setGid(goodsId);
    sale.setNum(nums);
    saleDao.insertSale(sale);

    /**修改库存
     * */
    Goods goods=goodsDao.selectGoodsById(goodsId);
    if(goods==null){
        throw new NullPointerException(goodsId+"没有该商品");
    }
    if(goods.getAmount()<nums){
        throw new NotEnoughException(goodsId+"库存不足");
    }

    /**操作库存
     * */
    goods.setAmount(nums);
    goodsDao.updateGoods(goods);
}