第10讲. SpringBoot事物管理

1.新建一个数据库，db_bank.编码集：utf8

2,复制9.3的项目，重命名为SpringDataTransaction，这一步主要是为了不影响之前的代码，更新一下项目：右键项目名->maven->Update Projec...，

3，新建一个实体，Account，指定表明为：t_account 加上注解。float不需要长度注解，修改配置文件，启动项目，查看是否生成表，如果生成了表t_account 则成功。为了不影响代码删除 t_book 表，。

package com.cruise.entity;

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

@Entity
@Table(name="t_account")
public class Account {

   @Id
   @GeneratedValue
   private Integer id;
   @Column(length=50)
   private String userName;

private float balance;

   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 float getBalance() {
       return balance;
   }
   public void setBalance(float balance) {
       this.balance = balance;
   }
}

配置文件：

server:
port: 8888

context-path: /
spring:
datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/db_bank
    password: root
    username: root
jpa:
    hibernate:
      ddl-auto: update
    show-sql: true

4，新建一个AccountDao，继承接口JpaRepository Integer 为主键的类型

package com.cruise.dao;

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

import com.cruise.entity.Account;

public interface AccountDao extends JpaRepository{

}

5，新建com.cruise.service包，新建AccountService接口，写一个转账接口

package com.cruise.service;

public interface AccountService {

public void transferAccounts(int fromUser,int toUser,float account);
}

6，写Service实现类，AccountServiceImpl，实现AccountService接口，加注解，注入dao接口,

从 fromAccount 转账到 toAccount ，fromAccount 减少account ， toAccount增加 account

package com.cruise.service.impl;

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

import org.springframework.stereotype.Service;

import com.cruise.dao.AccountDao;
import com.cruise.entity.Account;
import com.cruise.service.AccountService;

/**
*
* @author pengc
*
*/
@Service("accountService")
public class AccountServiceImpl implements AccountService {

   @Resource
   private AccountDao accountDao;

   public void transferAccounts(int fromUser, int toUser, float account) {

       Account fromAccount = accountDao.findById(fromUser).get();
       fromAccount.setBalance(fromAccount.getBalance()-account);
       accountDao.save(fromAccount);

       Account toAccount = accountDao.findById(toUser).get();
       toAccount.setBalance(toAccount.getBalance()+account);
       accountDao.save(toAccount);
   }
}

7，AccountController ，使用RestController注解，注入service接口。删除book相关的代码，以防有影响。

使用try{...}catch(Exception e){...}来判断是否执行成功，如果成功返回OK，如果失败返回NO

package com.cruise.controller;

import javax.annotation.Resource;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.cruise.service.AccountService;

@RestController
@RequestMapping("/account")
public class AccountController {

   @Resource
   private AccountService accountService;

   @RequestMapping("/transfer")
   public String transferAccount(){
       try{
           accountService.transferAccounts(1, 2, 200);
           return "OK";
       }catch(Exception e){
           return "NO";
       }
   }
}

8，测试，

10._SpringBoot事物管理

9，在service中设置异常代码，测试，

10，在service实现类上添加事物注解，测试，注意导哪个包

第10讲. SpringBoot事物管理

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