快速搭建mybatis-plus项目

项目初始化

• 

• 

• pom.xml补全mybatis-plus的依赖（mybatis-plus-boot-starter）

  <dependency>
      <groupId>com.baomidou</groupId>
      <artifactId>mybatis-plus-boot-starter</artifactId>
      <version>3.5.1</version>
  </dependency>

• 默认插件spring-boot-maven-plugin的skip属性改为false，否则打包的jar包无法运行

• 修改resources下的application.yaml (当前mysql版本5.7)

  server:
    port: 8080
  
  spring:
    datasource:
      url: jdbc:mysql://localhost:3306/demo
      username: root
      password: 123456
      driver-class-name: com.mysql.cj.jdbc.Driver

mybatis-plus集成

• 项目结构

  

  • 实体类

    package com.example.demo1.entity;
    
    
    import com.baomidou.mybatisplus.annotation.IdType;
    import com.baomidou.mybatisplus.annotation.TableId;
    import com.baomidou.mybatisplus.annotation.TableName;
    import lombok.Data;
    
    @Data
    @TableName("user")
    public class User {
    
        @TableId(type = IdType.AUTO)
        private Long id;
    
        private String username;
        private String password;
    }

  • mapper接口

    package com.example.demo1.mapper;
    
    
    import com.baomidou.mybatisplus.core.mapper.BaseMapper;
    import com.example.demo1.entity.User;
    import org.springframework.stereotype.Repository;
    
    @Repository
    public interface UserMapper extends BaseMapper<User> {
    }

  • 数据库（id字段自增）

    

  • service接口

    package com.example.demo1.service;
    
    import com.baomidou.mybatisplus.extension.service.IService;
    import com.example.demo1.entity.User;
    
    public interface UserService extends IService<User> {
    }

  • service实现类

    package com.example.demo1.service.impl;
    
    import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
    import com.example.demo1.entity.User;
    import com.example.demo1.mapper.UserMapper;
    import com.example.demo1.service.UserService;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    
    
    @Service
    public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService {
    
        @Autowired
        private UserMapper userMapper;
    }

  • 控制器

    package com.example.demo1.controller;
    
    
    import com.example.demo1.entity.User;
    import com.example.demo1.service.UserService;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.*;
    
    import java.util.List;
    
    @RestController
    @RequestMapping("/user")
    public class UserController {
    
        @Autowired
        private UserService userService;
    
        @GetMapping
        public List<User> findAll() {
            return userService.list();
        }
    
        @GetMapping("/{id}")
        public User findById(@PathVariable Long id) {
            return userService.getById(id);
        }
    
        @PostMapping
        public boolean save(@RequestBody User user) {
            return userService.save(user);
        }
    
        @PutMapping
        public boolean update(@RequestBody User user) {
            return userService.updateById(user);
        }
    
        @DeleteMapping("/{id}")
        public boolean delete(@PathVariable Long id) {
            return userService.removeById(id);
        }
    }

  • 启动类Application下添加MapperScan

    package com.example.demo1;
    
    import org.mybatis.spring.annotation.MapperScan;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    
    @SpringBootApplication
    @MapperScan("com.example.demo1.mapper")
    public class Demo1Application {
    
        public static void main(String[] args) {
            SpringApplication.run(Demo1Application.class, args);
        }
    }

  • 运行测试

    http://127.0.0.1:8080/user/
    http://127.0.0.1:8080/user/1
    ...