springboot整合mybatis写查询接口

1. 创建springboot新项目

勾选mybatis

2. 配置application.yml

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/momo?characterEncoding=utf-8&serverTimezone=UTC
    username: root
    password: root
    driver-class-name: com.mysql.cj.jdbc.Driver
mybatis:
  mapper-locations: classpath:mapper/*Mapper.xml
server:
  port: 8000

准备mysql数据

image.png

3. 创建Img实体

package com.unik.entity;

public class Img {
    private Integer id;
    private String name;
    private String url;

    public Img(){

    }
    public Integer getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getUrl() {
        return url;
    }

    public void setUrl(String url) {
        this.url = url;
    }

    @Override
    public String toString() {
        return "Img{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", url='" + url + '\'' +
                '}';
    }
}

4. 创建ImgMapper

package com.unik.mapper;

import com.unik.entity.Img;
import org.springframework.stereotype.Repository;

import java.util.List;
@Repository
public interface ImgMapper {
    List<Img> findAll();
}

5. 创建ImgMapper.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.unik.mapper.ImgMapper">

    <select id="findAll" resultType="com.unik.entity.Img">
        select * from bian
    </select>
</mapper>

6. 创建ImgService

package com.unik.service;

import com.unik.entity.Img;
import com.unik.mapper.ImgMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service

public class ImgService {
    @Autowired
    private ImgMapper imgMapper;
    public List<Img> findAll(){
        return imgMapper.findAll();
    }

}

7. 创建ImgController

package com.unik.controller;

import com.unik.entity.Img;
import com.unik.service.ImgService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class ImgController {
    @Autowired
    private ImgService imgService;
    @RequestMapping(value = "/img")
    public List<Img> listImg(){
        return imgService.findAll();
    }
}

8. 入口文件进行mapper扫描

package com.unik;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@MapperScan("com.unik.mapper")
@SpringBootApplication
public class LinkageApplication {

    public static void main(String[] args) {
        SpringApplication.run(LinkageApplication.class, args);
    }

}

启动项目,访问localhost:8000/img

image.png