mybatis框架——实战练习——第一个spring boot + mybatis项目——在第一个项目的基础上查询某个记录

POJO类不变

 

 

 

 

 

mybatis映射文件：

<?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.test.mapper.UserMapper">
    <select id="findAll" resultType="com.test.entity.MyUser">
        select * from users
    </select>
    <select id="getUser" resultType="com.test.entity.MyUser" parameterType="int">
        select * from users where id = #{id}
    </select>
</mapper>

　　

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

UserMapper

 

package com.test.mapper;


import com.test.entity.MyUser;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;

import java.util.List;

@Mapper
public interface UserMapper {
    public List<MyUser> findAll();

    @Select("select * from users limit 10")
    public List<MyUser> findShi();


    public MyUser getUser( int id );
}

　　

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

服务接口：

UserService

 

 

package com.test.service;


import com.test.entity.MyUser;

import java.util.List;

public interface UserService
{
    List<MyUser> findAll();

    List<MyUser> findShi();

    MyUser getUserForId(int id);
}

　　

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

实现服务接口：

UserServiceImpl

 

package com.test.service.impl;


import com.test.entity.MyUser;
import com.test.mapper.UserMapper;
import com.test.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class UserServiceImpl implements UserService
{
    @Autowired
    UserMapper userMapper;
    @Override
    public List<MyUser> findAll()
    {
        return userMapper.findAll();
    }

    @Override
    public List<MyUser> findShi()
    {
        return userMapper.findShi();
    }

    @Override
    public MyUser getUserForId(int id)
    {
       MyUser user =   userMapper.getUser(id);

       return user;
    }

}

　　

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

控制层：

 

package com.test.controller;

import com.test.entity.MyUser;
import com.test.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class StartMainController
{
    @Autowired
    private UserService userService;


    @GetMapping(value = "/1")
    public List<MyUser> home1()
    {
        // 查询所有网站
        List<MyUser> users = userService.findAll();
        for (MyUser user : users)
        {
            System.out.println(user.getId()+"  "+user.getName()+"  "+user.getName());
        }
        return users;
    }

    @GetMapping(value = "/2")
    public List<MyUser> home2()
    {
        // 查询所有网站
        List<MyUser> users = userService.findShi();
        for (MyUser user : users)
        {
            System.out.println(user.getId()+"  "+user.getName()+"  "+user.getName());
            System.out.println("         ");
        }

        return users;
    }

    @GetMapping(value = "/3")
    public String home3()
    {
        int id = 2;

        MyUser userxy = userService.getUserForId(id);

        return userxy.getId()+"  "+userxy.getName()+"   "+userxy.getAge();
    }


}

　　

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

http://localhost:8080/3