使用MyBatisPlus+Spring实现声明式事务

超、凢脫俗 2024-03-26 19:46 92阅读 0赞

### 前言： ###

1.springboot使用事务需要引入sprint-tx,但是在结合mybatisplus时，mybatis-plus已经代为引入了，

2.在springboot的启动类或者某个@Configuration上，加上@EnableTransactionManagent开启事务的支持

3.在service中使用@Transactional就可以使用事务了，@Transactional添加在方法中，方法支持事务，如果将@Transactional添加在类上，则整个类的所有方法都默认支持事务

4.@Transactional默认回滚的是RuntimeExcaption，如果不是抛出的RuntimeException则不会被回滚，（在spring框架下，所有的异常都被org.springwork重写为RuntimeExcetpion）

5.@Transactional(rollbackFor=Excetpion.class)，在@Transactional注解中如果不配置rollbackFor属性,那么事物只会在遇到RuntimeException的时候才会回滚,加上rollbackFor=Exception.class,可以让事物在遇到非运行时异常时也回滚

6.使用try catch捕捉异常进行异常处理，除了throw异常，即抛出一场，才会回滚，否则不会触发回滚

### 步骤一:在pom.xml中导入依赖 ###

**导入MyBatisPlus相关依赖**

<dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-boot-starter</artifactId>
                <version>3.4.3.1</version>
            </dependency>
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>5.1.47</version>
            </dependency>
    
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <optional>true</optional>
            </dependency>

### 步骤二:application中 配置数据源 ###

spring:
      datasource:
        driver-class-name: com.mysql.jdbc.Driver
        url: jdbc:mysql://10.211.55.2:3306/jdbctest?useSSL=true&useUnicode=true&characterEncoding=utf-8
        username: root
        password: Aa123123.

### 步骤三: 创建实体类，service，mapper和controller ###

**3.1创建实体类**

package demo.entity;
    
    import com.baomidou.mybatisplus.annotation.IdType;
    import com.baomidou.mybatisplus.annotation.TableId;
    import com.baomidou.mybatisplus.annotation.TableName;
    import lombok.AllArgsConstructor;
    import lombok.Data;
    import lombok.NoArgsConstructor;
    
    import java.math.BigDecimal;
    
    @TableName("acount")
    @Data
    @AllArgsConstructor
    @NoArgsConstructor
    public class Account {
        @TableId(type = IdType.AUTO)
        private Integer id;
    
        private String name;
    
        private BigDecimal money;
    }

**3.2创建Mapper**\`\`\`java

package demo.mapper;
    
    import com.baomidou.mybatisplus.core.mapper.BaseMapper;
    import demo.entity.Account;
    import org.apache.ibatis.annotations.Mapper;
    
    @Mapper
    public interface AccountMapper extends BaseMapper<Account> {
    }

**3.3创建Service**

AccountService

package demo.service;
    
    import com.baomidou.mybatisplus.extension.service.IService;
    import demo.entity.Account;
    import java.math.BigDecimal;
    
    public interface AccountService extends IService<Account> {
    
        boolean transfer(String source, String target, BigDecimal money);
    }

AccountServiceImpl

package demo.service.impl;
    
    import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
    import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
    import demo.entity.Account;
    import demo.mapper.AccountMapper;
    import demo.service.AccountService;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    import org.springframework.transaction.annotation.Transactional;
    
    import java.math.BigDecimal;
    
    @Service
    public class AccountServiceImpl extends ServiceImpl<AccountMapper, Account> implements AccountService {
        @Autowired
        private AccountMapper accountMapper;
    
        private Integer i1;
        private Integer i2;
    
        //开启事务
        @Transactional
        public boolean transfer(String source, String target, BigDecimal money) {
            //获取汇款方
            QueryWrapper<Account> wrapper1 = new QueryWrapper<>();
            wrapper1.eq("name", source);
            Account one1 = accountMapper.selectOne(wrapper1);
    
            QueryWrapper<Account> wrapper2 = new QueryWrapper<>();
            wrapper2.eq("name", target);
            Account one2 = accountMapper.selectOne(wrapper2);
    
            one1.setMoney(one1.getMoney().subtract(money)); //十进制减法
            i1 = accountMapper.updateById(one1);
            //模拟转账异常
            int a=1/0;
    
            one2.setMoney(one2.getMoney().add(money)); //十进制加法
            i2 = accountMapper.updateById(one2);
            if (i1 > 0 && i2 > 0) {
                return true;
            }
            return false;
        }
    }

**3.4创建TestController**

package demo.controller;
    
    import demo.service.AccountService;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import java.math.BigDecimal;
    
    @RestController
    public class TestController {
    
        @Autowired
        private AccountService accountService;
    
        @RequestMapping("/test")
        public String test(){
            String result = null;
            boolean b = accountService.transfer("A", "B", BigDecimal.valueOf(700));
            if(b){
                result = "转账成功!";
            } else {
                result = "转账异常!";
            }
            return result;
        }
    }