entity

package com.ge.mp.entity;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import java.io.Serializable;
import java.time.LocalDateTime;
import lombok.Getter;
import lombok.Setter;


@Getter
@Setter
  @TableName("sys_user")
public class User implements Serializable {

    private static final long serialVersionUID = 1L;

      /**
     * id
     */
        @TableId(value = "id", type = IdType.AUTO)
      private Integer id;

      /**
     * 用户名
     */
      private String username;

    private String password;

      /**
     * 昵称
     */
      private String nickname;

    private String email;

    private String phone;

      /**
     * 地址
     */
      private String address;

      /**
     * 创建时间
     */
      private LocalDateTime creatTime;


}

mapper

package com.ge.mp.mapper;

import com.ge.mp.entity.User;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.apache.ibatis.annotations.Mapper;

/**
 * <p>
 *  Mapper 接口
 * </p>
 * @since 2022-03-26
 */
@Mapper
public interface UserMapper extends BaseMapper<User> {

}

mapper.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.ge.mp.mapper.UserMapper">

</mapper>

service

package com.ge.mp.service;

import com.ge.mp.entity.User;
import com.baomidou.mybatisplus.extension.service.IService;

/**
 * <p>
 *  服务类
 * </p>
 *
 * @since 2022-03-26
 */
public interface IUserService extends IService<User> {

}

serviceImpl

package com.ge.mp.service.impl;

import com.ge.mp.entity.User;
import com.ge.mp.mapper.UserMapper;
import com.ge.mp.service.IUserService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.springframework.stereotype.Service;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @since 2022-03-26
 */
@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements IUserService {

}

controller

package com.ge.mp.controller;

import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import org.springframework.web.bind.annotation.*;
import javax.annotation.Resource;
import java.util.List;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;

import com.ge.mp.service.IUserService;
import com.ge.mp.entity.User;

import org.springframework.web.bind.annotation.RestController;

/**
 * <p>
 *  前端控制器
 * </p>
 *
 * @since 2022-03-26
 */
@RestController
@RequestMapping("/user")
public class UserController {

@Resource
private IUserService userService;

// 新增或者更新
@PostMapping
public boolean save(@RequestBody User user) {
        return userService.saveOrUpdate(user);
        }

@DeleteMapping("/{id}")
public Boolean delete(@PathVariable Integer id) {
        return userService.removeById(id);
        }

@PostMapping("/del/batch")
public boolean deleteBatch(@RequestBody List<Integer> ids) {
        return userService.removeByIds(ids);
        }

@GetMapping
public List<User> findAll() {
        return userService.list();
        }

@GetMapping("/{id}")
public User findOne(@PathVariable Integer id) {
        return userService.getById(id);
        }

@GetMapping("/page")
public Page<User> findPage(@RequestParam Integer pageNum,
                                @RequestParam Integer pageSize) {
        QueryWrapper<User> queryWrapper = new QueryWrapper<>();
        queryWrapper.orderByDesc("id");
        return userService.page(new Page<>(pageNum, pageSize), queryWrapper);
        }



}

properties

server.port=9000

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/qing?serverTimezone=GMT%2b8
spring.datasource.username=root
spring.datasource.password=123456

mybatis-plus.mapper-locations= classpath:mapper/*.xml  #扫描所有mybatis的xml文件
mybatis-plus.configuration.log-impl=org.apache.ibatis.logging.stdout.StdOutImpl