创建springboot

用到的工具

• IDEA
• mysql
• HeidiSQL

首先创建文件

创建如下文件夹

有一些删掉

代码部分

UserController

package com.example.springbootdemo.controller;


import com.example.springbootdemo.mapper.UserMapper;
import com.example.springbootdemo.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;
    }
    @GetMapping(value = "test")
    public String test(){
        return "测试接口!!!!";
    }
    //添加一个用户
    @GetMapping("/addUser")
    public String addUser(){
        userMapper.addUser(new User(3,"小王","345"));
        return "addUser-ok";
    }
    //修改一个用户
    @GetMapping("/updateUser")
    public String updateUser(){
        userMapper.updateUser(new User(3,"小张","567"));
        return "updateUser-ok";
    }
    //删除一个用户
    @GetMapping("/deleteUser")
    public String deleteUser(){
//        userMapper.updateUser(new User(3,"小张","567"));
        userMapper.deleteUser(3);
        return "updateUser-ok";
    }
}

UserMapper

package com.example.springbootdemo.mapper;

import com.example.springbootdemo.pojo.User;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

import java.util.List;
//表示这个注解是mybatis的mapper类
@Mapper
@Repository
public interface UserMapper {
    List<User> queryUserList();
    User queryUserById(int id);
  
    int addUser(User user);//增加user
    int updateUser(User user);//更改user
    int deleteUser(int id);//删除user
}

User

package com.example.springbootdemo.pojo;

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

@Data
@NoArgsConstructor
@AllArgsConstructor
public class User {
    private int id;          //根据数据库修改
    private String name;
    private String pwd;
}

SperingbootdemoApplication

不用改

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.springbootdemo.mapper.UserMapper">
    <select id="queryUserList" resultType="com.example.springbootdemo.pojo.User">
        select * from user
    </select>

    <select id="queryUserById" resultType="com.example.springbootdemo.pojo.User">
        select * from user where id = #{id}
    </select>
    <insert id="addUser" parameterType="com.example.springbootdemo.pojo.User">
        insert into user(id,name,pwd) values(#{id},#{name},#{pwd})
    </insert>//根据你数据库适当修改这里的参数

    <update id="updateUser" parameterType="java.lang.Integer">
        update  user set name = #{name},pwd={pwd} where id = #{id}
    </update>

    <delete id="deleteUser" parameterType="java.lang.Integer">
        delete from user where id = #{id}
    </delete>

</mapper>

application.properties

spring.datasource.username=root //数据库账号
spring.datasource.password=1234 //数据库密码
spring.datasource.url=jdbc:mysql://localhost:3306/springbootdemodb?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
server.port=8082 //你选择的端口有时候被占用改一下就行
#??mybatis
mybatis.type-aliases-package=com.example.springbootdemo.pojo
mybatis.mapper-locations=classpath:mybatis/mapper/*.xml

注意spring.datasource.url=jdbc:mysql://localhost:3306/springbootdemodb（这里是你的数据库名称）?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.6.1</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.zya</groupId>
    <artifactId>springboot-mybais_01</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springboot-mybais_01</name>
    <description>springboot-mybais_01</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.2.0</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

最后贴一下数据库

运行

运行SpringbootdemoApplication

在网页打开

localhost://8082/test

测试是否连接成功

localhost://8082/addUser

添加用户，添加的用户为你在UserController中设定的

改删类似，不在赘述。