[Java知识库]网络通信第六周--

IDEA实现Mybatis

1.代码编写

创建spring项目，选择如下图依赖

在项目中的resources文件夹下，删除原有的application.properties文件
新建
application.yml

spring:
  profiles:
    active: dev

application-dev.yml

server:
  port: 8080

spring:
  datasource:
    username: root
    password: 1206
    url: jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC
    driver-class-name: com.mysql.cj.jdbc.Driver

mybatis:
  mapper-locations: classpath:mapping/*Mapper.xml
  type-aliases-package: com.example.mybatiswork.entity
#showSql
logging:
  level:
    com:
      example:
        mapper : debug

接着新建mapping文件夹，新建一个xml文件

<?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.example.mybatiswork.mapper.UserMapper">

    <resultMap id="BaseResultMap" type="com.example.mybatiswork.entity.User">
        <result column="id" jdbcType="INTEGER" property="id" />
        <result column="userName" jdbcType="VARCHAR" property="userName" />
        <result column="passWord" jdbcType="VARCHAR" property="passWord" />
        <result column="realName" jdbcType="VARCHAR" property="realName" />
    </resultMap>

    <select id="Sel" resultType="com.example。mybatiswork.entity.User">
        select * from user where id = #{id}
    </select>

</mapper>

接着在主文件夹下新建controller、mapper、entity、service包
UserController.java

package com.example.demo.controller;



import com.example.mybatiswork.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;



@RestController
@RequestMapping("/testBoot")
public class UserController {

    @Autowired
    private UserService userService;

    @RequestMapping("getUser/{id}")
    public String GetUser(@PathVariable int id){
        return userService.Sel(id).toString();
    }
}

entity包的User.java

package com.example.demo.entity;


public class User {
    private Integer id;
    private String userName;
    private String passWord;
    private String realName;

    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 String getPassWord() {
        return passWord;
    }

    public void setPassWord(String passWord) {
        this.passWord = passWord;
    }

    public String getRealName() {
        return realName;
    }

    public void setRealName(String realName) {
        this.realName = realName;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", userName='" + userName + '\'' +
                ", passWord='" + passWord + '\'' +
                ", realName='" + realName + '\'' +
                '}';
    }
}

UserService.java

package com.example.demo.service;


import com.example.mybatiswork.entity.User;
import com.example.mybatiswork.mapper.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;


@Service
public class UserService {
    @Autowired
    UserMapper userMapper;
    public User Sel(int id){
        return userMapper.Sel(id);
    }
}

UserMapper.java

package com.example.demo.mapper;


import com.example.mybatiswork.entity.User;
import org.apache.ibatis.annotations.Mapper;


@Mapper
public interface UserMapper {

    User Sel(int id);
}

MybatisworkApplication

package com.example.demo;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@MapperScan("com.example.mybatiswork.mapper")
@SpringBootApplication
public class MybatisworkApplication {

    public static void main(String[] args) {
        SpringApplication.run(MybatisworkApplication.class, args);
    }

}