利用事务实现转账功能！！！（基础版）

搭建环境：利用下边环境即可！！！

Spring整合MyBatis框架！！！-CSDN博客

需要修改的文件：

applicationContext.xml:

<!---->

UserService:

package com.by.service;import com.by.pojo.User;/** * 
Project: Spring - UserService
 * 
Powered by scl On 2024-01-05 21:24:07
 * 
描述：
 * * @author 孙臣龙 [1846080280@qq.com] * @version 1.0 * @since 17 */public interface UserService {void addUser(User user);void updateUser(String source, String target, float money);}

UserServiceImpl:

package com.by.service;import com.by.mapper.UserMapper;import com.by.pojo.User;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Service;import org.springframework.transaction.PlatformTransactionManager;import org.springframework.transaction.TransactionDefinition;import org.springframework.transaction.TransactionStatus;@Servicepublic class UserServiceImpl implements UserService {@Autowiredprivate UserMapper userMapper;@Autowiredprivate PlatformTransactionManager platformTransactionManager;@Autowiredprivate TransactionDefinition transactionDefinition;@Overridepublic void addUser(User user) {userMapper.addUser(user);}@Overridepublic void updateUser(String source, String target, float money) {TransactionStatus transaction = platformTransactionManager.getTransaction(transactionDefinition);try {userMapper.subUserMoney(source,money);System.out.println(6/0);userMapper.addUserMoney(target,money);platformTransactionManager.commit(transaction);} catch (Exception e) {e.printStackTrace();platformTransactionManager.rollback(transaction);}}}

UserMapper:

package com.by.mapper;import com.by.pojo.User;import org.apache.ibatis.annotations.Param;public interface UserMapper {public void addUser(User user);void addUserMoney(@Param("target") String target, @Param("money") float money);void subUserMoney(@Param("source") String source, @Param("money") float money);}

UserMapper.xml:

insert into t_user(name, money)values (#{name}, #{money})update t_user set money=money+#{money} where name=#{target}update t_user set money=money-#{money} where name=#{source}

测试类：

/* * Copyright (c) 2020, 2024,All rights reserved. * */package com.by.web;import com.by.service.UserService;import org.junit.Test;import org.junit.runner.RunWith;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.test.context.ContextConfiguration;import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;/** * 
Project: Spring - ClientUserMoney
 * 
Powered by scl On 2024-01-06 11:08:15
 * 
描述：
 * * @author 孙臣龙 [1846080280@qq.com] * @version 1.0 * @since 17 */@RunWith(SpringJUnit4ClassRunner.class)@ContextConfiguration("classpath:applicationContext.xml")public class ClientUserMoney {@Autowiredprivate UserService userService;@Testpublic void updateUser(){userService.updateUser("宋远桥","李星云",5f);}}

注意：

要实现事务需要将事务交给ioc容器进行管理。配置bean的思路，用接口的实现类去配置

1、PlatformTransactionManager
作用：是一个事务管理器，负责开启、提交或回滚事务
实现类：DataSourceTransactionManager(sqlSession)
2、TransactionDefinition
作用：定义事务的属性
实现类：DefaultTransactionDefinition
属性：
1）隔离级别【有默认值】
DEFAULT：默认值，等价于REPEATABLE_READ
READ_UNCOMMITTED
READ_COMMITTED 脏读 x x
REPEATABLE_READ 脏读 不可重复度
SERIALIZABLE 脏读 不可重复度 幻读
2）事务的传播行为【有默认值】
REQUIRED：默认值，methodB()会加入到methodA()事务中
3）事务超时【有默认值】
默认-1：永不超时
4）是否只读【有默认值】
readOnly = false：默认值，适用于增删改
readOnly = true：不记录log(效率快)，适用于查询
5）回滚规则
可省略：运行时异常回滚，编译时异常不回滚