1、引入依赖（mybatis和lombok）

<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.1</version>
</dependency>

<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
</dependency>

2、创建User实体类

注：此处使用lombok

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@NoArgsConstructor
@AllArgsConstructor
public class User {
    private int id;
    private String name;
}

3、创建UserMapper接口

import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;
import java.util.List;
@Mapper
@Repository
public interface UserMapper {
    List<User> queryUserList();
    User queryUserById(int id);
    int addUser(User user);
    int updateUser(User user);
    int deleteUser(int id);
}

4、创建UserMapper.xml文件

注：此文件位置 resources/mybatis/mapper/UserMapper.xml

<?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.demo.UserMapper">
    <select id="queryUserList" resultType="User">
        select * from user
    </select>

    <select id="queryUserById" resultType="User">
        select * from user where id = #{id}
    </select>

    <insert id="addUser" parameterType="User">
        insert into user (name) values (#{name})
    </insert>

    <update id="updateUser" parameterType="User">
        update user set name = #{name} where id = #{id}
    </update>

    <delete id="deleteUser" parameterType="int">
        delete from user where id = #{id}
    </delete>
</mapper>

5、application.yml配置

注：最后三行（此处classpath后面的路径默认是resources开始，若带 / 则代表从根目录开始）

mybatis:
  type-aliases-package: com.example.demo
  mapper-locations: classpath:mybatis/mapper*.xml

spring:
  datasource:
    username: root123
    password: root123
    url: jdbc:mysql://localhost:3306/jianshu
    driver-class-name: com.mysql.jdbc.Driver

mybatis:
  type-aliases-package: com.example.demo
  mapper-locations: classpath:*.xml

6、创建UserController

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class UserController {

    @Autowired
    private UserMapper userMapper;

    @GetMapping("/mybatis/queryUserList")
    public List<User> queryUserList(){
        List<User> userList = userMapper.queryUserList();
        return userList;
    }

    @GetMapping("/mybatis/adduser")
    public int addUser(){
        return userMapper.addUser(new User(1,"a"));
    }

    @GetMapping("/mybatis/queryUserById/{id}")
    public User queryUserById(@PathVariable("id") int id){
        return userMapper.queryUserById(id);
    }

    @GetMapping("/mybatis/updateUser")
    public int updateUser(){
        return userMapper.updateUser(new User(2, "abcdef"));
    }

    @GetMapping("/mybatis/deleteUser/{id}")
    public int deleteUser(@PathVariable("id") int id){
        return userMapper.deleteUser(id);
    }
}

7、访问相应接口

http://localhost:8080/mybatis/queryUserList
http://localhost:8080/mybatis/queryUserById/1
http://localhost:8080/mybatis/addUser
http://localhost:8080/mybatis/updateUser
http://localhost:8080/mybatis/deleteUser/1

​