Mybatis-Plus在SpringBoot下的使用

说明

项目使用Mybatis作为持久化框架时，我们可以使用一些别人再次封装的一些插件来提高开发效率，使用较多的如通用mapper，PageHelper等，这次介绍一个更好用的插件Mybatis-Plus，感觉这个比较像通用mapper+PageHelper，并且分页方面还可以选出总条数。

Mybatis-plus官网->https://baomidou.gitee.io/mybatis-plus-doc/#/

快速开始

首先给出项目结构

1 初始化和配置

首先更新pom.xml

        
            com.baomidou
            mybatis-plus-boot-starter
            3.1.2
        

2 配置application.yml

server:
  port: 8082
mybatis-plus:
  mapper-locations: classpath:mapper/*.xml
  global-config:
    # 关闭MP3.0自带的banner
    banner: false
    db-config:
      # 默认数据库表下划线命名
      table-underline: true

3 编写application.java 添加分页配置

package cn.yunlingfly.springbootmybatisplus;

import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;

@SpringBootApplication
@MapperScan("cn.yunlingfly.springbootmybatisplus.infra.mapper")
public class SpringbootMybatisPlusApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringbootMybatisPlusApplication.class, args);
    }

    /**
     * mybatis-plus分页插件
     */
    @Bean
    public PaginationInterceptor paginationInterceptor() {
        return new PaginationInterceptor();
    }

}

4 编写Mapper

package cn.yunlingfly.springbootmybatisplus.infra.mapper;

import cn.yunlingfly.springbootmybatisplus.api.dto.TestDTO;
import cn.yunlingfly.springbootmybatisplus.domain.entity.TestEntity;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import org.apache.ibatis.annotations.Param;
import org.springframework.stereotype.Component;

@Component
public interface ITestMapper extends BaseMapper {
    IPage getPageByName(IPage page, @Param("name") String name);
}

5 编写Service接口

package cn.yunlingfly.springbootmybatisplus.api.service;

import cn.yunlingfly.springbootmybatisplus.api.dto.TestDTO;
import cn.yunlingfly.springbootmybatisplus.domain.entity.TestEntity;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.baomidou.mybatisplus.extension.service.IService;

public interface ITestService extends IService {
    IPage getPageByName(Page page, String name);
}

6 编写Service实现类

package cn.yunlingfly.springbootmybatisplus.api.service.impl;

import cn.yunlingfly.springbootmybatisplus.api.dto.TestDTO;
import cn.yunlingfly.springbootmybatisplus.api.service.ITestService;
import cn.yunlingfly.springbootmybatisplus.domain.entity.TestEntity;
import cn.yunlingfly.springbootmybatisplus.infra.mapper.ITestMapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class TestServiceImpl extends ServiceImpl implements ITestService {
    @Autowired
    private ITestMapper testMapper;

    public IPage getPageByName(Page page, String name) {
        return testMapper.getPageByName(page, name);
    }
}

7 编写Controller

package cn.yunlingfly.springbootmybatisplus.api.controller;

import cn.yunlingfly.springbootmybatisplus.api.dto.Result;
import cn.yunlingfly.springbootmybatisplus.api.dto.TestDTO;
import cn.yunlingfly.springbootmybatisplus.api.service.ITestService;
import cn.yunlingfly.springbootmybatisplus.domain.entity.TestEntity;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

@RestController
public class TestController {
    @Autowired
    private ITestService testService;

    @RequestMapping(value = "/getOne/{id}", method = RequestMethod.GET)
    public Result getOne(@PathVariable String id) {
        Result result = new Result<>();
        TestEntity aa = testService.getById(id);
        if (aa == null) {
            result.error500("未找到对应实体");
        } else {
            result.setResult(aa);
            result.setSuccess(true);
        }
        return result;
    }

    @RequestMapping(value = "/list/{pageNum}/{pageSize}", method = RequestMethod.GET)
    public Result> queryPageList(@PathVariable Integer pageNum, @PathVariable Integer pageSize) {
        Result> result = new Result<>();
        // IPage的convert()方法做包装
        IPage pageList = testService.getPageByName(new Page(pageNum, pageSize), "aa");

        result.setSuccess(true);
        result.setResult(pageList);
        return result;
    }
}

测试

访问http://localhost:8082/list/1/1，查看返回值，可以看到total-总数，current-当前页码，pages-总页数，records-结果集

{
	"success": true,
	"message": "操作成功！",
	"code": 0,
	"result": {
		"records": [{
			"id": "3"
		}],
		"total": 3,
		"size": 1,
		"current": 1,
		"orders": [],
		"searchCount": true,
		"pages": 3
	},
	"timestamp": 1567136573151
}

最后放上笔者的该项目github仓库地址，有需要的可以当测试：https://github.com/Yunlingfly/springboot-mybatis-plus