首先建立一个简单的转账的代码模块

大概就是对一个数据库表account进行操作，如图

使用service层的transfer方法实现tom对lucy 转账500

package com.itheima.service.impl;

import com.itheima.dao.AccountDao;
import com.itheima.service.AccountService;

public class AccountServiceImpl implements AccountService {

    private AccountDao accountDao;
    public void setAccountDao(AccountDao accountDao) {
        this.accountDao = accountDao;
    }

    public void transfer(String outMan, String inMan, double money) {
        accountDao.out(outMan,money);
        accountDao.in(inMan,money);
    }
}

但是这肯定属于一个事务，在发生异常之后需要进行回滚。在spring中已经帮我们做好了相关的事务控制。

首先需要搞清楚那个是切点和增强，并且配置事务的aop织入。

applicationContext.xml内容如下

<?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:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="
       http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd
       http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd
">

    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="com.mysql.jdbc.Driver"/>
        <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/test"/>
        <property name="user" value="root"/>
        <property name="password" value="root"/>
    </bean>

    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <bean id="accountDao" class="com.itheima.dao.impl.AccountDaoImpl">
        <property name="jdbcTemplate" ref="jdbcTemplate"/>
    </bean>

    <!--目标对象 内部的方法就是切点-->
    <bean id="accountService" class="com.itheima.service.impl.AccountServiceImpl">
        <property name="accountDao" ref="accountDao"/>
    </bean>


    <!--配置一个平台事务管理器-->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>
    <!--通知 事务的增强-->
    <tx:advice id="txAdvice" transaction-manager="transactionManager">
        <!--设置事务的属性信息的-->
        <tx:attributes>
            <tx:method name="*"/>
        </tx:attributes>
    </tx:advice>

    <!--事务的aop织入-->
    <aop:config>
        <aop:advisor advice-ref="txAdvice" pointcut="execution(* com.itheima.service.impl.*.*(..))"></aop:advisor>
    </aop:config>
</beans>

基于注解的声明

package com.itheima.service.impl;

import com.itheima.dao.AccountDao;
import com.itheima.service.AccountService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Isolation;
import org.springframework.transaction.annotation.Transactional;

@Service("accountService")
public class AccountServiceImpl implements AccountService {
    @Autowired
    private AccountDao accountDao;
    public void setAccountDao(AccountDao accountDao) {
        this.accountDao = accountDao;
    }

    @Transactional(isolation = Isolation.DEFAULT)
    public void transfer(String outMan, String inMan, double money) {
        accountDao.out(outMan,money);
        accountDao.in(inMan,money);
    }
}

applicationContext.xml内容如下

<?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:context="http://www.springframework.org/schema/context"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="
       http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd
       http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd
       http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
">

    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="com.mysql.jdbc.Driver"/>
        <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/test"/>
        <property name="user" value="root"/>
        <property name="password" value="root"/>
    </bean>

    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"/>
    </bean>

<!--    组件扫描-->
    <context:component-scan base-package="com.itheima"/>


    <!--配置一个平台事务管理器-->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <!--事务的注解驱动-->
    <tx:annotation-driven transaction-manager="transactionManager"/>
</beans>