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: 8088spring: 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: zhangmybatis: mapper-locations: classpath:mapper/*.xml type-aliases-package: com.yiyezhiqiu.jwt.jwt.domain configuration: map-underscore-to-camel-case: truelogging: level: com: yiyezhiqiu: jwt: jwt: dao: debug4.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;@Datapublic 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 */@Datapublic 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@Slf4jpublic 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
来源：https://www.cnblogs.com/yiyezhiqiuwuchen/p/11994467.html