1. 添加依赖

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </dependency>

2. 添加数据库连接信息

在application.yml中添加数据量的连接信息

spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC
    username: root
    password: root

3. 实体类Bean

package com.siyi.pojo;

import java.util.Date;

public class User {

    private Long id;

    private String username;

    private String sex;

    private Date birthday;

    public Long getId() {
        return id;
    }

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

    public String getUserName() {
        return username;
    }

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

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public Date getBirthday() {
        return birthday;
    }

    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }

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

4. 编写Mapper

package com.siyi.mapper;

import com.siyi.pojo.User;
import org.apache.ibatis.annotations.Mapper;

import java.util.List;

@Mapper
public interface UserMapper {
    public List<User> queryUserList();
}

注意：@Mapper标记该类是一个mybatis的mapper接口，可以被spring boot自动扫描到spring上下文中

5. 配置Mapper映射文件

在src\main\resources\mapper路径下加入UserMapper.xml配置文件

<?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.siyi.mapper.UserMapper">
    <select id="queryUserList" resultType="user">
      select * from user
    </select>
</mapper>

6. 在application.yml中添加mybatis的信息

spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC
    username: root
    password: root
    
#spring集成Mybatis环境
mybatis:
  #pojo别名扫描包
  type-aliases-package: com.siyi.pojo
  #加载Mybatis映射文件
  mapper-locations: classpath:mapper/*Mapper.xml

7. 编写Controller

package com.siyi.controller;

import com.siyi.mapper.UserMapper;
import com.siyi.pojo.User;
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.ResponseBody;

import java.util.List;

@Controller
public class UserController {
    
    @Autowired
    private UserMapper userMapper;
    
    @RequestMapping("/queryUser")
    @ResponseBody
    public List<User> queryUser(){
        List<User> users = userMapper.queryUserList();
        return users;
    }
}

8. 测试