Create a SpringBoot instance using mybatis-plus

Create a SpringBoot framework

Configure maven /pom file

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <!--        mybatis-plus-->
    <dependency>
        <groupId>com.baomidou</groupId>
        <artifactId>mybatis-plus-boot-starter</artifactId>
        <version>3.4.3</version>
    </dependency>
    <!--        druid-->
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid-spring-boot-starter</artifactId>
        <version>1.2.6</version>
    </dependency>
    <!--        lombok-->
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
    </dependency>
    <!--        mysql-->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
    </dependency>
    <!--        测试-->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
        <exclusions>
            <exclusion>
                <groupId>org.junit.vintage</groupId>
                <artifactId>junit-vintage-engine</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
</dependencies>

Create application.yml configuration file

# 应用名称
server:
  port: 80
spring:
  datasource:
    druid:
      driver-class-name: com.mysql.cj.jdbc.Driver
      url: jdbc:mysql://localhost:3306/oiosp?serverTimezone=UTC
      username: root
      password: 123456
mybatis-plus:
  global-config:
    db-config:
      id-type: auto
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

Create database mapping class domaim.Book

package com.spark.domain;

import lombok.Data;

//这里直接用了 lombok 直接生成 getter setter toString  等方法。上面pom文件中已经导入对应坐标
@Data
public class Book {
    
    
    private Integer id;
    private String name;
}

Create a data layer interface

package com.spark.Dao;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.spark.domain.Book;
import org.apache.ibatis.annotations.Mapper;


@Mapper
//直接继承mybatis-plus的 BaseMapper<Book> 方法  泛型中放入映射类。 它帮助我们做了很多常用的方法
public interface BookDao extends BaseMapper<Book> {
    
    

}

Take a look at which methods BaseMapper helps us define

Create Service interface BookService

package com.spark.Service;

import com.baomidou.mybatisplus.extension.service.IService;
import com.spark.domain.Book;

//这里直接继承 mybatis-plus的  IService<Book>
public interface BookService extends IService<Book> {
    
    

}

Take a look at what methods IService helps us define

Create Service interface implementation class BookServiceImpl

package com.spark.Service.Impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.spark.Dao.BookDao;
import com.spark.Service.BookService;
import com.spark.domain.Book;
import org.springframework.stereotype.Service;

@Service
// 继承mybatis-plus的  ServiceImpl 再实现 刚才定义的BookService接口
public class BookServiceImpl extends ServiceImpl<BookDao, Book> implements BookService {
    
    

}

Create control layer Controller/BookController

package com.spark.Controller;
import com.spark.Service.BookService;
import com.spark.domain.Book;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
@RequestMapping("/books")
public class BookController {
    
    

    @Autowired
    private BookService bookService;

    //获取表中全部数据 并返回
    @GetMapping
    List<Book> getAll(){
    
    
        return bookService.list();
    }
}

run the test

instance directory