SpringBoot学习笔记之事务管理

新建SpringBoot项目SpringDataTransaction

新建个数据库db_bank  模拟银行转账，张三账户给李四转账，那么张三账户金额要减少，李四账户金额要增加，且张三减少的金额等于李四增加的金额

1.新建个Account.java账户实体 

package com.guo.entity;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity     // 实体
@Table(name="t_count")   // 表
public class Account {
    @Id      // 组件
    @GeneratedValue   //表 自增
    private Integer id;    // 主键
    @Column(length=50)   // 对应字符串   长度100(自定义)
    private String userName;  //用户名
    private Integer count;  // 存款金额

    
    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }



    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public Integer getCount() {
        return count;
    }

    public void setCount(Integer count) {
        this.count = count;
    }    

}

 

2.新建AccountDao 接口

package com.guo.dao;


import org.springframework.data.jpa.repository.JpaRepository;


import com.guo.entity.Account;

                                
public interface AccountDao extends JpaRepository<Account,Integer>{
  
}

3.这把多了个service接口

package com.guo.service;

public interface AccountService {
    
    //声明个客户转账的方法
    public void tranMoney(int fromUser,int toUser,int count);

}

 

4.service接口实现类

package com.guo.service.impl;

import javax.annotation.Resource;
import javax.transaction.Transactional;

import org.springframework.stereotype.Service;

import com.guo.dao.AccountDao;
import com.guo.entity.Account;
import com.guo.service.AccountService;
@Service("AccountService")
public class AccountServiceImpl implements AccountService{
    @Resource
    private AccountDao accountDao;
    
    @Transactional
    public void tranMoney(int fromUser, int toUser, int count) {
        Account fromAccount=accountDao.getOne(fromUser);
        fromAccount.setCount(fromAccount.getCount()-count);
        accountDao.save(fromAccount);
        Account toAccount=accountDao.getOne(toUser);
        toAccount.setCount(toAccount.getCount()+count);
        int zero=1/0;  // 加的异常
        accountDao.save(toAccount);
        
    }

}

 

5.新建个AccountController

package com.guo.service.impl;
 
import javax.annotation.Resource;
import javax.transaction.Transactional;
 
import org.springframework.stereotype.Service;
 
import com.guo.dao.AccountDao;
import com.guo.entity.Account;
import com.guo.service.AccountService;
@Service("AccountService")
public class AccountServiceImpl implements AccountService{
    @Resource
         private AccountDao accountDao;
         
    @Transactional
         public void tranMoney(int fromUser, int toUser, int count) {
             Account fromAccount=accountDao.getOne(fromUser);
                   fromAccount.setCount(fromAccount.getCount()-count);
                   accountDao.save(fromAccount);
                   Account toAccount=accountDao.getOne(toUser);
                   toAccount.setCount(toAccount.getCount()+count);
                   //搞个异常int zero=1/0;
                   accountDao.save(toAccount);
                   
         }
 
}

6.测试

刚开始张三和李四 账户各有500

如果加个异常int zero=1/0;

Service.impl不加 @Transactional标签时 会报异常

运行结果为NO，此时张三账户少了200，但是李四账户并没多200

加个@Transactional，运行虽结果虽为NO 但是张三少200，同时李四多200，体现了事务的一致性