springboot-整合mybatis

1 新建一个sprigboot项目

项目创建过程中,导入以下三个包

2 导入mybatis所需要的依赖

pom.xml

</dependency>
<!--mybatis-spring-boot-starter-->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.2.2</version>
</dependency>

3 配置数据库连接信息

application.properties

spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.url=jdbc:mysql://localhost:3306/mybatis?useSSL=false&useUnicode=true&characterEncoding=utf-8
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

4 启动测试类,查看控制台

数据库连接连接成功

5 导入lombok依赖

pom.xml

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

6 创建实体类

新建pojo包,并在包下编写一个User类

User.java

package com.lv.pojo;
 
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
 
@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
    private int id;
    private String name;
    private String pwd;
}

7 编写实体类对应的接口

新建mapper包,并在包下编写一个UserMapper接口

UserMapper.java

package com.lv.mapper;
 
import com.lv.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);
}

8 编写UserMapper接口对应的Mapper映射文件

在resources目录下新建一个mybatis文件夹,在mybatis文件夹下创建一个mapper文件夹.在mapper文件夹下编写一个UserMapper.xml

src/main/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.lv.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>

9 在配置文件中添加mybatis的配置

application.properties

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

10 编写控制器

新建controller包,并在包下编写一个UserController

UserController.java

package com.lv.controller;
 
import com.lv.mapper.UserMapper;
import com.lv.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();
        return userList;
    }
    @GetMapping("/queryUserById")
    public User queryUserById(){
        User user = userMapper.queryUserById(1);
        return user;
    }
    @GetMapping("/addUser")
    public String addUser(){
        userMapper.addUser(new User(4,"嘿嘿","000000"));
        return "addUser-ok";
    }
    @GetMapping("/updateUser")
    public String updateUser(){
        userMapper.updateUser(new User(4,"哈哈","888888"));
        return "updateUser-ok";
    }
    @GetMapping("/deleteUser")
    public String deleteUser(){
        userMapper.deleteUser(4);
        return "deleteUser-ok";
    }
}

11 启动项目,进行测试

查看User表

访问queryUserList请求

访问queryUserById请求

访问addUser

刷新并查看User表

访问updateUser请求

刷新并查看User表

访问deleteUser请求

刷新并查看User表