# spring-transcation

**Repository Path**: MarkPolaris/spring-transcation

## Basic Information

- **Project Name**: spring-transcation
- **Description**: spring通过注解实现事务
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2019-07-27
- **Last Updated**: 2020-12-19

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

#### 通过注解事务完成转账案例

##### 一、转账基本逻辑

1. 需要额外添加的xml配置有

```xml
 <!--配置声明式事务-->
    <context:annotation-config/>
    <context:component-scan base-package="com.neuedu"/>
    <!--配置事务管理器-->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>
    <!--开启注解事务-->
    <tx:annotation-driven/>
```

2. 写一个转账的小demo，定义相关实体类Account

![5d3cfe72530ca54136](https://i.loli.net/2019/07/28/5d3cfe72530ca54136.png)

```java
package com.neuedu.entity;

import lombok.Data;

import java.math.BigDecimal;

/**
 * @Author: MARK
 * @Date: 2019/7/27 16:07
 * @version: 1.0.0
 * @Description:
 */
@Data
public class Account {
    private Integer id;
    private String name;
    private BigDecimal money;
}

```

3. DAO层使用mybatis，写一个mapper，将id和金额传进去，通过map

```java
package com.neuedu.mapper;

import org.springframework.stereotype.Repository;

import java.util.Map;

/**
 * @Author: MARK
 * @Date: 2019/7/27 16:07
 * @version: 1.0.0
 * @Description:
 */
@Repository
public interface AccountMapper {
    //更新该账户的金额
    void update(Map map);
}

```

4. mapper的实现AccountMapper.xml

```xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.neuedu.mapper.AccountMapper">

    <update id="update" parameterType="Map">
        update account set money = money + #{money} where id=#{id}
    </update>

    <select id="findById" parameterType="Integer" resultType="com.neuedu.entity.Account">
        select id, name, money from account where id=#{id}
    </select>

</mapper>
```

5. 业务层，AccountService接口

```java
package com.neuedu.service;

import java.math.BigDecimal;

/**
 * @Author: MARK
 * @Date: 2019/7/27 16:07
 * @version: 1.0.0
 * @Description:
 */
public interface AccountService {
    //谁给谁转了多少钱
    void transfer(Integer id1, Integer id2, BigDecimal money);
}

```

6. 业务层接口的实现类AccountServiceImpl.java

```java
package com.neuedu.service.impl;

import com.neuedu.mapper.AccountMapper;
import com.neuedu.service.AccountService;
import jdk.management.resource.internal.inst.UnixAsynchronousServerSocketChannelImplRMHooks;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.math.BigDecimal;
import java.util.HashMap;
import java.util.Map;

/**
 * @Author: MARK
 * @Date: 2019/7/27 16:07
 * @version: 1.0.0
 * @Description:
 */
@Service
public class AccountServiceImpl implements AccountService {
    @Autowired
    private AccountMapper accountMapper;
    @Override
    public void transfer(Integer id1, Integer id2, BigDecimal money) {
        //两个账户分别更新
        //账户1减钱
        Map map1 = new HashMap<>();
        map1.put("id", id1);
        map1.put("money", money.multiply(new BigDecimal(-1)));
        accountMapper.update(map1);

        //账户2加钱
        Map map2 = new HashMap<>();
        map2.put("id", id2);
        map2.put("money", money);
        accountMapper.update(map2);
    }
}

```

环绕通知加不加都可以，加的话注意写上执行方法 proceedingJoinPoint.proceed();

7. 先对mapper进行测试，通过后再对service进行测试，service测试如下

```java
package com.neuedu.service;

import com.neuedu.AppTest;
import lombok.extern.slf4j.Slf4j;
import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;

import java.math.BigDecimal;

import static org.junit.Assert.*;

/**
 * @Author: MARK
 * @Date: 2019/7/28 09:15
 * @version: 1.0.0
 * @Description:
 */
@Slf4j
public class AccountServiceTest extends AppTest {
    @Autowired
    private AccountService accountService;
    @Test
    public void testService(){
        accountService.transfer(1, 2, new BigDecimal(500));
    }

}
```

8. 运行结果
   
   运行前数据库

![5d3d008f29b0785019](https://i.loli.net/2019/07/28/5d3d008f29b0785019.png)

        运行后数据库

![5d3d00dc139a325001](https://i.loli.net/2019/07/28/5d3d00dc139a325001.png)

基本逻辑完成，下面对事务进行测试

#### 二、事务处理

1. 在转账过程中添加异常

![5d3d01c4c08b671050](https://i.loli.net/2019/07/28/5d3d01c4c08b671050.png)

2. 再运行测试，抛出异常

![5d3d023e0649472428](https://i.loli.net/2019/07/28/5d3d023e0649472428.png)

3. 查看数据库, 发现id为1的money减少了500，而id为2的money没有变化，这就是要添加事务的原因

![5d3d025dcbd1c89661](https://i.loli.net/2019/07/28/5d3d025dcbd1c89661.png)

4. 添加事务注解

![5d3d031f378b536510](https://i.loli.net/2019/07/28/5d3d031f378b536510.png)

5. 再运行测试

![5d3d039075e9223220](https://i.loli.net/2019/07/28/5d3d039075e9223220.png)

同样抛出异常，但是由于添加了事务注解，出现异常全部回滚