SpringBoot09：整合MyBatis

整合MyBatis

官方文档：http://mybatis.org/spring-boot-starter/mybatis-spring-boot-autoconfigure/

Maven仓库地址：https://mvnrepository.com/artifact/org.mybatis.spring.boot/mybatis-spring-boot-starter/2.1.1

注意：版本不同，会导致程序错误

整合测试

1、导入 MyBatis 所需要的依赖

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

2、配置数据库连接信息

spring:
  datasource:
    username: root
    password: 123456
    #?serverTimezone=UTC解决时区的报错
    url: jdbc:mysql://localhost:3306/mybatis?serverTimezone=GMT%2B8&useUnicode=true&characterEncoding=utf-8
    driver-class-name: com.mysql.cj.jdbc.Driver

# 整合mybatis
mybatis:
  type-aliases-package: com.zhu.pojo
  mapper-locations: classpath:mybatis/mapper/*.xml

3、测试数据库是否连接成功！

4、创建实体类，导入 Lombok！

package com.zhu.pojo;

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

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

}

5、创建mapper目录以及对应的 Mapper 接口

UserMapper.java

package com.zhu.mapper;

import com.zhu.pojo.User;
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
@Mapper
@Repository
public interface UserMapper {

    List<User> queryUserList();

    User queryUserById(int id);

    int addUser(User user);

    int updateUser(User user);

    int deleteUser(int id);
}

6、对应的Mapper映射文件

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.zhu.mapper.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 (id,name,pwd) values (#{id},#{name},#{pwd})
    </insert>

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

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

</mapper>

7、编写UserController 进行测试！

package com.zhu.controller;

import com.zhu.mapper.UserMapper;
import com.zhu.pojo.User;
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 UserController {

    @Autowired
    private UserMapper userMapper;

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

        for (User user : userList) {

            System.out.println(user);
        }
        return userList;
    }
}