Spring boot3 集成Mybatis-Plus

      <!--web开发需要 为了写测试接口特加入了-->

    
 		<dependency>
    
 			<groupId>org.springframework.boot</groupId>
    
 			<artifactId>spring-boot-starter-web</artifactId>
    
 		</dependency>
    
 		
    
 		<!--mybatis-plus starter-->
    
 		<dependency>
    
 			<groupId>com.baomidou</groupId>
    
 			<artifactId>mybatis-plus-boot-starter</artifactId>
    
 			<version>3.5.5</version>
    
 		</dependency>
    
 	 
    
 		<!--mysql 连接驱动-->
    
 		<dependency>
    
 			<groupId>com.mysql</groupId>
    
 			<artifactId>mysql-connector-j</artifactId>
    
 			<scope>runtime</scope>
    
 		</dependency>
    
    
    
    

 spring:

    
   datasource:
    
     # 数据库连接驱动
    
     driver-class-name: com.mysql.cj.jdbc.Driver
    
     # 数据库连接地址
    
     url: jdbc:
    
     # 数据库连接用户名
    
     username: root
    
     # 数据库连接密码
    
     password:XXX
    
 mybatis-plus:
    
   configuration:
    
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
    
    
    
    

 package com.ld.druid.pojo;

    
  
    
  
    
 import com.baomidou.mybatisplus.annotation.TableField;
    
 import com.baomidou.mybatisplus.annotation.TableName;
    
  //数据库表名称
    
 @TableName(value = "contract_company_info")
    
 public class SubCompany implements Serializable { 
    
      
    
 	private static final long serialVersionUID = 1L;
    
  
    
 	private Integer id;
    
  
    
     private String companyType;
    
  
    
     private String companyName;
    
  
    
     private String companyNameSub; 
    
  
    
     private String idNoUrl2;
    
     //数据库表不存在的字段
    
     @TableField(exist = false)
    
     private String showIdNoUrl1;
    
     @TableField(exist = false) 	 
    
 	private String reason; 
    
    //getter setter
    
 }
    
    
    
    

 package com.ld.druid.dao;

    
  
    
 import org.apache.ibatis.annotations.Mapper;
    
 import org.apache.ibatis.annotations.Param;
    
  
    
 import com.baomidou.mybatisplus.core.mapper.BaseMapper;
    
 import com.baomidou.mybatisplus.core.metadata.IPage;
    
 import com.ld.druid.pojo.SubCompany;
    
  
    
 public interface SubCompanyDao extends BaseMapper<SubCompany>{
    
    
    
 }
    
    
    
    

 package com.ld.druid.service;

    
  
    
 import com.baomidou.mybatisplus.core.metadata.IPage;
    
 import com.ld.druid.pojo.SubCompany;
    
  
    
 public interface ISubCompanyService { 
    
     SubCompany findById(Integer id);
    
     
    
 }
    
    
    
    

 package com.ld.druid.service.impl;

    
  
    
 import org.springframework.beans.factory.annotation.Autowired;
    
 import org.springframework.stereotype.Service;
    
 import com.ld.druid.dao.SubCompanyDao;
    
 import com.ld.druid.pojo.SubCompany;
    
 import com.ld.druid.service.ISubCompanyService;
    
 @Service("subCompanyService")
    
 public class SubCompanyServiceImpl implements ISubCompanyService {
    
     @Autowired
    
 	private SubCompanyDao subCompanyDao;
    
  
    
  
    
 	@Override
    
 	public SubCompany findById(Integer id) {
    
 		//dao中并没有设计该接口，其实是调用了BaseMapper的接口
    
 		//BaseMapper封装了常用的CRUD操作，直接调用就节省了代码开发
    
  		return subCompanyDao.selectById(id);
    
 	}
    
 }
    
    
    
    

 package com.ld.druid.controller;

    
  
    
 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 com.ld.druid.service.ISubCompanyService;
    
  
    
 @RestController
    
 @RequestMapping("/plus")
    
 public class MyBatisPlusController {
    
 	@Autowired
    
 	private ISubCompanyService subCompanyService;	
    
  
    
 	@GetMapping(value = "/findById")
    
 	public Object findById(){
    
 		return subCompanyService.findById(2);
    
 	} 
    
 }
    
    
    
    

 package com.ld.druid;

    
  
    
 import org.mybatis.spring.annotation.MapperScan;
    
 import org.springframework.boot.SpringApplication;
    
 import org.springframework.boot.autoconfigure.SpringBootApplication;
    
  
    
 @SpringBootApplication
    
 @MapperScan("com.ld.druid.dao") // 替换为你的Mapper接口所在包的路径 非MyBatis官方starter 所以需要配置包扫描 如果不加该注解则要在每个mapper接口添加@Mapper注解
    
  
    
 public class SpringDruidDemoApplication {
    
  
    
 	public static void main(String[] args) {
    
 		SpringApplication.run(SpringDruidDemoApplication.class, args);
    
 	}
    
  
    
 }