springboot的事务管理的一个完整demo

事务注解@Transactional 可以标注到mapper的dao接口上，或者service的接口上。两者均可。

首先建立一个springboot的项目,

 引入pom，需要注意的是，tomcat包，aop包，druid数据源包，jdbc包，mybatis包，servlet，jsp，jstl包

<!-- 手动添加 -->
        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-jasper</artifactId>
            <scope>provided</scope>
        </dependency>
        
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-aop</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.2.4</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
            <!-- <version>2.4.2</version> -->
        </dependency>
        <!--/mybatis-spring-boot-starter -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.4</version>
        </dependency>
        <!--servlet依赖的jar包 -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <scope>provided</scope>
        </dependency>
        <!--jsp依赖的jar包 -->
        <!-- https://mvnrepository.com/artifact/javax.servlet.jsp/javax.servlet.jsp-api -->
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>javax.servlet.jsp-api</artifactId>
            <version>2.3.1</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            
        </dependency>

书写application.yml

注意配置，配置了jsp后缀后，就可以找到默认index.jsp主页了。

mapper的包含，需要配置目录，否则不会加载mapp.xml 文件。另外还要在启动文件上，标注@MapperScan(basePackages = {"cn.taotao.dao"})，指明mapper找的哪个接口文件。

spring:
  mvc:
    view:
      suffix: .jsp
#上面这行配置后，就可以把index.jsp 作为默认首页了。
   #  prefix: /views/
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    druid:
      driver-class-name: com.mysql.cj.jdbc.Driver
      url: jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=Asia/Shanghai
      username: root
      password: 123456
      initial-size: 1
      min-idle: 1
      max-active: 50
      max-wait: 15000
      enable: true
      test-on-borrow: true
      test-on-return: true
      test-while-idle: true
      
mybatis:
  mapper-locations:
   - classpath:mapper/*Mapper.xml              #这个需要指出，否则不会加载mapper.xml文件，或者把生成的文件，写入到和类同级别的目录中（不建议）。
 
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

编写UserService接口文件，这个接口可以标注@Transactional

package cn.taotao.service;

import java.util.List;

import org.springframework.transaction.annotation.Transactional;

import cn.taotao.bean.User;

public interface UserService {
    
    int deleteByPrimaryKey(Integer id);

    int insert(User record);

    int insertSelective(User record);

    User selectByPrimaryKey(Integer id);

    int updateByPrimaryKeySelective(User record);

    int updateByPrimaryKey(User record);

    List<User> queryAll();
}

编写UserServiceImpl文件，需要标注@Service

package cn.taotao.service.impl;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import cn.taotao.bean.User;
import cn.taotao.dao.UserMapper;
import cn.taotao.service.UserService;

@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserMapper userMapper;
    
    @Override
    public int deleteByPrimaryKey(Integer id) {
        // TODO Auto-generated method stub
        return this.userMapper.deleteByPrimaryKey(id);
    }

    @Override
    public int insert(User record) {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public int insertSelective(User record) {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public User selectByPrimaryKey(Integer id) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public int updateByPrimaryKeySelective(User record) {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public int updateByPrimaryKey(User record) {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public List<User> queryAll() {
        // TODO Auto-generated method stub
        return this.userMapper.queryAll();
        //return null;
    }

}

另外，在UserMapper接口文件，也可以标注@Transactional

package cn.taotao.dao;

import java.util.List;

import org.springframework.transaction.annotation.Transactional;

import cn.taotao.bean.User;

@Transactional
public interface UserMapper {
    int deleteByPrimaryKey(Integer id);

    int insert(User record);

    int insertSelective(User record);

    User selectByPrimaryKey(Integer id);

    int updateByPrimaryKeySelective(User record);

    int updateByPrimaryKey(User record);
    
    List<User> queryAll();
}

编写controller文件

package cn.taotao.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.ModelAndView;

import cn.taotao.bean.User;
import cn.taotao.service.UserService;
import cn.taotao.service.impl.UserServiceImpl;

@Controller
public class IndexController {

    @Autowired
    private UserServiceImpl userService;
    
    @RequestMapping(value= {"/","/index"})
    public ModelAndView getIndex() {
        ModelAndView mv = new ModelAndView("index");
        List<User> queryAll = userService.queryAll();
    //    User selectByPrimaryKey = this.userService.selectByPrimaryKey(1);
        mv.addObject("users", queryAll);
        return mv;
    }
}

建立  src/main/webapp目录，这个目录不会自动创建，需要手工创建

建立index.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>    
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
index.jsp 

<a href="/addUser">添加用户</a>
<a href="/updateUser">修改用户</a>
<a href="/deleteUser">delete</a>
<hr/>
<c:forEach var="u" items="${users }">
<li>un:${u.username}</li>
<li>pw:${u.password }</li>
<li>addr:${u.address }</li>
<li><fmt:formatDate value="${u.birthday }" pattern="yyyy-MM-dd"/></li>
<li>dept: ${u.dept }</li>
<hr/>
</c:forEach>


</body>
</html>