SpringBoot整合MyBatis

1、连接数据库
2、创建pojo包，并创建与数据库对应实体类

package com.li.pojo;

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

@Data
@AllArgsConstructor
@NoArgsConstructor
public class admin {
  private Integer adminid;
  private String username;
  private String pwd;
  private String name;
}

3、创建Mapper包，并创建实体类对应接口

package com.li.mapper;

import com.li.pojo.admin;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

import java.util.List;

//这个注解表示了这是一个mybatis的mapper类：Dao,还可以在SpringbootMybatisApplication中配置@MapperScan("com.li.mapper")扫描包
@Mapper
@Repository
public interface adminMapper {
    List<admin> queryAdminList();

    admin queryById(int id);

    int addAdmin(admin admin);

    int updateAdmin(admin admin);

    int deleteAdmin(int id);
}

3、在resources下创建mybatis——>mapper,创建adminMapper.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.li.mapper.adminMapper">
<!--    <cache/>开启缓存-->
<!-- resultType="admin"需要去设置别名在application.properties   -->
    <select id="queryAdminList" resultType="admin">
    select * from admin
  </select>
    <select id="queryById" resultType="admin">
        select * from admin where adminid=#{adminid}
    </select>
    <insert id="addAdmin" parameterType="admin">
        insert into admin (adminid,username,pwd,name) values (#{adminid},#{username},#{pwd},#{name})
    </insert>
    <update id="updateAdmin" parameterType="admin">
        update admin set username=#{username},pwd=#{pwd},name=#{name} where adminid=#{adminid}
    </update>
    <delete id="deleteAdmin" parameterType="int">
        delete from admin where adminid=#{adminid}
    </delete>
</mapper>

4、application.properties

spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.url=jdbc:mysql://localhost:3306/test?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
#整合mybatis
mybatis.type-aliases-package=com.li.pojo
mybatis.mapper-locations=classpath:mybatis/mybatis/*.xml

5、创建Service层
6、创建Controller层

package com.li.controller;

import com.li.mapper.adminMapper;
import com.li.pojo.admin;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class AdminController {
    @Autowired
    private adminMapper adminMapper;
    @GetMapping("/aaa")
    public List<admin> queryAdminList(){
        List<admin> adminList=adminMapper.queryAdminList();
        for (admin a:adminList) {
            System.out.println(a);
        }
        return adminList;
    }
}