springboot+mybatis+pageHelper

标签：main   ntp   utf-8   mapper   inf   适用于   数据库表   字段   ima   

1.概念：PageHelper 是一款好用的开源免费的 Mybatis 第三方物理分页插件，可以支持多个数据库，应用mybatis

2.引入依赖：

<!-- 这个pagehelper好像适用于spring，对springboot不适用，给个提醒-->
<!--<dependency>-->
    <!--<groupId>com.github.pagehelper</groupId>-->
    <!--<artifactId>pagehelper</artifactId>-->
    <!--<version>5.0.3</version>-->
<!--</dependency>-->

<!--分页插件-->
<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>pagehelper-spring-boot-starter</artifactId>
    <version>1.2.3</version>
</dependency>

3.application.yml

server:
  port: 8088

spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/mybatis?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf-8&useSSL=false&allowMultiQueries=true
    username: root
    password: zhang

mybatis:
  mapper-locations: classpath:mapper/*.xml
  type-aliases-package: com.yiyezhiqiu.jwt.jwt.domain
  configuration:
    map-underscore-to-camel-case: true

logging:
  level:
    com:
      yiyezhiqiu:
        jwt:
          jwt:
           dao: debug

4.数据库表：

5.domain层

　　5.1.Goods实体类

package com.yiyezhiqiu.jwt.jwt.domain;

import lombok.Data;

import java.math.BigDecimal;

@Data
public class Goods {

    private int id;

    private  String goodsType;

    private BigDecimal goodsPrice;

    private Double     goodsWeight;

    private String goodsShape;
}

　　5.2 分页传入参数实体类
　　

package com.yiyezhiqiu.jwt.jwt.domain;

import lombok.Data;

/**
 * 分页实体类
 */

@Data
public class PageHelpParam {

    /**
     * 当前页
     */
    private String currentPageParam ;

    /**
     * 当前页条数
     */
    private String pageSizeParam;

    /**
     * 模糊查询参数fuzzy
     */
    private String fuzzy;

    /**
     * 模糊查询参数 nextFuzzy
     */

    private String nextFuzzy;
}

6.service层
　　6.1 接口：IGoodsService
　　

package com.yiyezhiqiu.jwt.jwt.service;


import com.yiyezhiqiu.jwt.jwt.domain.PageHelpParam;

import java.util.List;
import java.util.Map;

public interface IGoodsService {

    public Map findPageHelp(PageHelpParam pageHelpParam);

}

　　6.2.实现类:GoodsServiceImpl

package com.yiyezhiqiu.jwt.jwt.service.impl;

import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.yiyezhiqiu.jwt.jwt.dao.GoodsDao;
import com.yiyezhiqiu.jwt.jwt.domain.Goods;
import com.yiyezhiqiu.jwt.jwt.domain.PageHelpParam;
import com.yiyezhiqiu.jwt.jwt.service.IGoodsService;
import com.yiyezhiqiu.jwt.jwt.service.IUsersService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.util.CollectionUtils;
import org.springframework.util.StringUtils;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * 实现分页
 */
@Service
@Slf4j
public class GoodsServiceImpl implements IGoodsService {


    @Autowired
    IGoodsService goodsService;
    @Autowired
    GoodsDao goodsDao;
    @Override
    public Map findPageHelp(PageHelpParam pageHelpParam) {
        String currentPageParam = pageHelpParam.getCurrentPageParam();
        String pageSizeParam   =  pageHelpParam.getPageSizeParam();
        log.info("currentPageParam:"+currentPageParam);
        log.info("pageSizeParam:"+pageSizeParam);
        int currenPage = 1;
        int pageSize = 10;
        if(StringUtils.isEmpty(currentPageParam)){
         currenPage = 1;
        }else{
            currenPage = Integer.parseInt(currentPageParam);
        }
        if(StringUtils.isEmpty(pageSizeParam)){
            pageSize = 10;
        }else{
            pageSize = Integer.parseInt(pageSizeParam);

        }

        //分页条件查询参数
        PageHelper.startPage(currenPage,pageSize);//页数和每页大小

        /**
         * 获得要分页的集合，
         *    1.这里获得集合，如果你要给参数到数据库，比如模糊查询，就可以在PageHelpParam中添加相关字段（在实现了分页后，做了下模糊查询）
         *   2.这里是返回某个表的实体类，当然你也可以用一个vo类，也就是不同表字段返回在一个vo类中使用
         */
        String fuzzy = pageHelpParam.getFuzzy();
        String nextFuzzy = pageHelpParam.getNextFuzzy();
        Map<String,Object>  mapParam = new HashMap<>();
        if(null != fuzzy && fuzzy  != ""){
            mapParam.put("fuzzy",fuzzy);
        }

        if(null != nextFuzzy && fuzzy != ""){
            mapParam.put("nextFuzzy",nextFuzzy);
        }

        List<Goods> goodsList = goodsDao.findAll(mapParam);


        //这里可以看下PageInfo为啥会和PageHelper有关系，因为startPage会返回page，PageInfo中使用page，这就是联系，可以去看源码
        PageInfo<Goods> pageInfo = new PageInfo<Goods>(goodsList);

        List<Goods> goods = new ArrayList<>();
        if(!CollectionUtils.isEmpty(goodsList)){
            for(Goods good:pageInfo.getList()){
                goods.add(good);
            }
        }

        Map<String,Object>  map = new HashMap<>();
        map.put("total",pageInfo.getTotal());
        map.put("currentPage",pageInfo.getPageNum());
        map.put("pageSize", pageInfo.getPageSize());

        Map<String ,Object> maps = new HashMap<>();
        maps.put("pageInfo",map);
        maps.put("goods",goods);

        return maps;
    }
}

 7.controller

package com.yiyezhiqiu.jwt.jwt.controller;

import com.github.pagehelper.PageHelper;
import com.yiyezhiqiu.jwt.jwt.annotation.OtherPermit;
import com.yiyezhiqiu.jwt.jwt.domain.PageHelpParam;
import com.yiyezhiqiu.jwt.jwt.service.IGoodsService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import java.util.Map;

@RestController
@RequestMapping("/goods")
public class GoodsController {

    @Autowired
    IGoodsService goodsService;

    @RequestMapping(value = "/findGoods",method = RequestMethod.GET)
    public Map   findGoodsPageHelper(PageHelpParam pageHelpParam){

        Map<String,Object> map = goodsService.findPageHelp(pageHelpParam);

        return map;
    }

}


8.GoodsMapping.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.yiyezhiqiu.jwt.jwt.dao.GoodsDao">

<!--这里
    IFNULL（A,B） 意思是如果A不为空，则为A，否则为B
    CONCAT(多个IFNULL)实现一个框就可以分别对多个字段进行模糊查询
-->
    <select id="findAll"  resultType="com.yiyezhiqiu.jwt.jwt.domain.Goods">
        select * from goods
        <where>
            <if test= "fuzzy != null">
                IFNULL(goods_type ," ") like  "%"#{fuzzy}"%"
            </if>
            <if test="nextFuzzy != null">
            and CONCAT(IFNULL(goods_price," "),IFNULL(goods_shape," ")) like  "%"#{nextFuzzy}"%"
            </if>

        </where>
    </select>
    
</mapper>

9.postman测试：
 9.1：
　　　　当只为分页时，不模糊筛选

 　　　　9.2：

　　　　　　　　当为输入goods_type单个参数筛选时

 　　　　9.3 :

　　　　　　当可以是goods_weight 或者goods_shape筛选时

github地址：https://github.com/yiyeluowuchen/springboot-jwt-token.git

springboot+mybatis+pageHelper

标签：main   ntp   utf-8   mapper   inf   适用于   数据库表   字段   ima   

原文地址：https://www.cnblogs.com/yiyezhiqiuwuchen/p/11994467.html