ElasticSearch_仿京东搜索

Elasticsearch 2020-11-24

仿京东搜索

目录

本博客内容根据狂神说整理

https://www.bilibili.com/video/BV17a4y1x7zq

1. 爬虫

首先明确数据从哪里来

  • 数据库中获取
  • 消息队列中获取
  • 爬虫
  • ......

爬取数据 : 获取请求返回的页面信息,筛选出屋面想要的信息就可以了!

导入依赖 JSoup,解析网页 ==> 爬电影,音乐,用tika

<!-- https://mvnrepository.com/artifact/org.jsoup/jsoup -->
<dependency>
    <groupId>org.jsoup</groupId>
    <artifactId>jsoup</artifactId>
    <version>1.13.1</version>
</dependency>

1. 测试使用爬虫

package com.wang.wangesjd.utils;

import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;

import java.io.IOException;
import java.net.URL;

public class HtmlParseUtil {
    public static void main(String[] args) throws IOException {
        //获取请求 https://search.jd.com/Search?keyword=java
        //前提: 需要联网,而且不能获取到AJAX!
        String url = "https://search.jd.com/Search?keyword=java";

        //设置超时时间 30S
        int timeOut = 30000;

        //解析网页 ==> Document就是浏览器的Document对象
        Document document = Jsoup.parse(new URL(url),timeOut);
        //所有你在JS中可以使用的方法,这里都能用!
        Element element = document.getElementById("J_goodsList");
//        System.out.println(element.html());
        //获取所有的li元素
        Elements elements = element.getElementsByTag("li");
        //获取元素中的内容,这里的el就是每一个li标签了
        for (Element el : elements) {
            //关于这种图片特别多的网站,所有的图片都是延迟加载的!
            //JD 放在了这个class data-lazy-img
            String img = el.getElementsByTag("img").eq(0).attr("data-lazy-img");
            String price = el.getElementsByClass("p-price").eq(0).text();
            String title = el.getElementsByClass("p-name").eq(0).text();

            System.out.println("===================================================");
            System.out.println(img);
            System.out.println(price);
            System.out.println(title);
        }

    }
}
  • 注意
    • JD 貌似图片使用了反爬虫技术,要获取的属性名和我们在前端调试时看到的不一样...

2. 提取工具类

package com.wang.wangesjd.utils;

import com.wang.wangesjd.pojo.Content;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;

import java.io.IOException;
import java.net.URL;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;

public class HtmlParseUtil {
    public static void main(String[] args) throws IOException {
        //URL会将符号转义!
//        HtmlParseUtil.parseJD("C%2B%2B").forEach(System.out::println);
        //查询中文需要URL转码
//        HtmlParseUtil.parseJD("心理学").forEach(System.out::println);
        HtmlParseUtil.parseJD("C++").forEach(System.out::println);
    }

    public static List<Content> parseJD(String keywords) throws IOException {
        //URL会对符号和汉字转码
        //要先转码再拼接,否则URL无法解析 (因为会将url中的符号也一起转码,无法识别)
        String urlKeywords = URLEncoder.encode(keywords,"UTF-8");

        //获取请求 https://search.jd.com/Search?keyword=java
        //前提: 需要联网,而且不能获取到AJAX!
        String url ="https://search.jd.com/Search?keyword=" + urlKeywords + "&enc=utf-8";



        //设置超时时间 30S
        int timeOut = 30000;

        //解析网页 ==> Document就是浏览器的Document对象
        Document document = Jsoup.parse(new URL(url),这里都能用!
        Element element = document.getElementById("J_goodsList");
        //获取所有的li元素
        Elements elements = element.getElementsByTag("li");

        List<Content> goodsList = new ArrayList<>();
        //获取元素中的内容,所有的图片都是延迟加载的!
            //JD 放在了这个class data-lazy-img
            String img = el.getElementsByTag("img").eq(0).attr("data-lazy-img");
            String price = el.getElementsByClass("p-price").eq(0).text();
            String title = el.getElementsByClass("p-name").eq(0).text();

            Content content = new Content();
            content.setImg(img)
                    .setPrice(price)
                    .setTitle(title);
            goodsList.add(content);
        }
        return goodsList;
    }
}
  • 注意
    • URL解析时会转义符号和中文,因此如果我们想传递中文或者符号的关键字,需要先转义
    • 不能将拼接后的url转义,这样会导致URL中正常的符号也被转义,导致无法识别,正确的做法是先将被拼接的转义,再拼接即可

3. 编写实体类和业务层

1. 实体类

package com.wang.wangesjd.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.experimental.Accessors;

@Data
@AllArgsConstructor
@NoArgsConstructor
@Accessors(chain = true)
public class Content {
    private String img;
    private String price;
    private String title;
}

2. 业务层

这里有个小坑 ==> SpringBoot接管类,如果是静态方法,使用自动装载无法使用静态方法

package com.wang.wangesjd.service;

import com.alibaba.fastjson.JSON;
import com.wang.wangesjd.pojo.Content;
import com.wang.wangesjd.utils.HtmlParseUtil;
import org.elasticsearch.action.bulk.BulkRequest;
import org.elasticsearch.action.bulk.BulkResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.text.Text;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.common.xcontent.XContentType;
import org.elasticsearch.index.query.MatchQueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.index.query.TermQueryBuilder;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightField;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Service;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

@Service
public class ContentService {

    @Autowired
    @Qualifier("restHighLevelClient")
    private RestHighLevelClient rest;

    @Autowired
    private HtmlParseUtil htmlParseUtil;


    //解析数据,放入ES索引中
    public Boolean parseContent(String keywords) throws IOException {
        List<Content> contents = htmlParseUtil.parseJD(keywords);
        //把查询的数据放入ES中
        BulkRequest bulkRequest = new BulkRequest();
        bulkRequest.timeout(TimeValue.timeValueMinutes(2L));

        for (int i = 0; i < contents.size(); i++) {
            bulkRequest.add(new IndexRequest("jd_goods")
                    .source(JSON.toJSONString(contents.get(i)),XContentType.JSON));
        }

        BulkResponse bulk = rest.bulk(bulkRequest,RequestOptions.DEFAULT);
        return !bulk.hasFailures();
    }

    //获取这些数据(从ES索引中),实现搜索功能
//    public List<Map<String,Object>> searchPage(String keyword,int pageNo,int pageSize) throws IOException {
//        if (pageNo <= 1) {
//            pageNo = 1;
//        }
//        //条件搜索
//        SearchRequest searchRequest = new SearchRequest("jd_goods");
//        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
//        //精准匹配
//        MatchQueryBuilder matchQueryBuilder = QueryBuilders.matchQuery("title",keyword);
//        sourceBuilder.query(matchQueryBuilder)
//                .timeout(TimeValue.timeValueMinutes(1L));
//        //分页
//        sourceBuilder.from(pageNo)
//                .size(pageSize);
//        //执行搜索
//        searchRequest.source(sourceBuilder);
//        SearchResponse searchResponse = rest.search(searchRequest,RequestOptions.DEFAULT);
//        //解析结果
//        List<Map<String,Object>> list = new ArrayList<>();
//        for (SearchHit documentFields : searchResponse.getHits()) {
//            list.add(documentFields.getSourceAsMap());
//        }
//        return list;
//    }

    //实现搜索高亮
    public List<Map<String,int pageSize) throws IOException {
        if (pageNo <= 1) {
            pageNo = 1;
        }
        //条件搜索
        SearchRequest searchRequest = new SearchRequest("jd_goods");
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        //精准匹配
        MatchQueryBuilder matchQueryBuilder = QueryBuilders.matchQuery("title",keyword);
        sourceBuilder.query(matchQueryBuilder)
                .timeout(TimeValue.timeValueMinutes(1L));
        //高亮
        HighlightBuilder highlightBuilder = new HighlightBuilder();
        //定义要高亮的标签和样式
        highlightBuilder.field("title")
                .preTags("<span style='color:red'>")
                .postTags("</span>")
                .requireFieldMatch(false);          //是否需要高亮多个字段
        sourceBuilder.highlighter(highlightBuilder);
        //分页
        sourceBuilder.from(pageNo)
                .size(pageSize);
        //执行搜索
        searchRequest.source(sourceBuilder);
        SearchResponse searchResponse = rest.search(searchRequest,RequestOptions.DEFAULT);
        //解析结果
        List<Map<String,Object>> list = new ArrayList<>();
        for (SearchHit documentFields : searchResponse.getHits()) {

            //解析高亮的字段
            Map<String,HighlightField> highlightFields = documentFields.getHighlightFields();
            HighlightField title = highlightFields.get("title");
            Map<String,Object> sourceAsMap = documentFields.getSourceAsMap();  //这里是原来的结果(不含高亮)

            if(title != null) {
                Text[] fragments = title.fragments();
                String highlightTitle = "";
                for (Text text : fragments) {
                    highlightTitle += text;
                }
                //将高亮字段替换没有高亮的字段
                sourceAsMap.put("title",highlightTitle);
            }

            list.add(sourceAsMap);

        }
        return list;
    }


}

4. 页面跳转

package com.wang.wangesjd.controller;

import com.wang.wangesjd.service.ContentService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

import java.io.IOException;
import java.util.List;
import java.util.Map;

@RestController
public class ContentController {

    @Autowired
    private ContentService contentService;

    @GetMapping("/parse/{keyword}")
    public Boolean parse(@PathVariable String keyword) throws IOException {
        return contentService.parseContent(keyword);
    }

    @GetMapping("/search/{keyword}/{pageNo}/{pageSize}")
    public List<Map<String,Object>> search(@PathVariable("keyword") String keyword,@PathVariable("pageNo") int pageNo,@PathVariable("pageSize") int pageSize) throws IOException {
        return contentService.searchPage(keyword,pageNo,pageSize);
    }
}

使用RestFul风格

5. 前端

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">

<head>
    <meta charset="utf-8"/>
    <title>ES仿京东实战</title>
    <link rel="stylesheet" th:href="@{/css/style.css}"/>
    <script src="https://unpkg.com/axios/dist/axios.min.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>

<body class="pg">
<div class="page" id="app">
    <div id="mallPage" class=" mallist tmall- page-not-market ">

        <!-- 头部搜索 -->
        <div id="header" class=" header-list-app">
            <div class="headerLayout">
                <div class="headerCon ">
                    <!-- Logo-->
                    <h1 id="mallLogo">
                        <img th:src="@{/images/jdlogo.png}" alt="">
                    </h1>

                    <div class="header-extra">

                        <!--搜索-->
                        <div id="mallSearch" class="mall-search">
                            <form name="searchTop" class="mallSearch-form clearfix">
                                <fieldset>
                                    <legend>天猫搜索</legend>
                                    <div class="mallSearch-input clearfix">
                                        <div class="s-combobox" id="s-combobox-685">
                                            <div class="s-combobox-input-wrap">
                                                <input v-model="keyword" type="text" autocomplete="off" value="dd"
                                                       id="mq"
                                                       class="s-combobox-input" aria-haspopup="true">
                                            </div>
                                        </div>
                                        <button type="submit" @click.prevent="searchKey" id="searchbtn">搜索</button>
                                    </div>
                                </fieldset>
                            </form>
                            <ul class="relKeyTop">
                                <li><a>狂神说Java</a></li>
                                <li><a>狂神说前端</a></li>
                                <li><a>狂神说Linux</a></li>
                                <li><a>狂神说大数据</a></li>
                                <li><a>狂神聊理财</a></li>
                            </ul>
                        </div>
                    </div>
                </div>
            </div>
        </div>

        <!-- 商品详情页面 -->
        <div id="content">
            <div class="main">
                <!-- 品牌分类 -->
                <form class="navAttrsForm">
                    <div class="attrs j_NavAttrs" style="display:block">
                        <div class="brandAttr j_nav_brand">
                            <div class="j_Brand attr">
                                <div class="attrKey">
                                    品牌
                                </div>
                                <div class="attrValues">
                                    <ul class="av-collapse row-2">
                                        <li><a href="#"> 狂神说 </a></li>
                                        <li><a href="#"> Java </a></li>
                                    </ul>
                                </div>
                            </div>
                        </div>
                    </div>
                </form>

                <!-- 排序规则 -->
                <div class="filter clearfix">
                    <a class="fSort fSort-cur">综合<i class="f-ico-arrow-d"></i></a>
                    <a class="fSort">人气<i class="f-ico-arrow-d"></i></a>
                    <a class="fSort">新品<i class="f-ico-arrow-d"></i></a>
                    <a class="fSort">销量<i class="f-ico-arrow-d"></i></a>
                    <a class="fSort">价格<i class="f-ico-triangle-mt"></i><i class="f-ico-triangle-mb"></i></a>
                </div>

                <!-- 商品详情 -->
                <div class="view grid-nosku">

                    <div class="product" v-for="result in results">
                        <div class="product-iWrap">
                            <!--商品封面-->
                            <div class="productImg-wrap">
                                <a class="productImg">
                                    <img :src="result.img">
                                </a>
                            </div>
                            <!--价格-->
                            <p class="productPrice">
                                <em><b>¥</b>{{result.price}}</em>
                            </p>
                            <!--标题,我们传递的是一个html-->
                            <p class="productTitle">
                                <a v-html="result.title"></a>
                            </p>
                            <!-- 店铺名 -->
                            <div class="productShop">
                                <span>店铺： 狂神说Java </span>
                            </div>
                            <!-- 成交信息 -->
                            <p class="productStatus">
                                <span>月成交<em>999笔</em></span>
                                <span>评价 <a>3</a></span>
                            </p>
                        </div>
                    </div>
                </div>
            </div>
        </div>
    </div>
</div>

<!--前端使用Vue,实现前后端分离-->
<script>
    new Vue({
        el: '#app',data: {
            keyword: '',//搜索的关键字
            results: []      //搜索的结果
        },methods: {
            searchKey() {
                let keyword = this.keyword;
                console.log(keyword);
                //对接后端的接口
                axios.get('search/' + keyword + "/0/10").then(response => {
                    console.log(response.data);
                    this.results = response.data;    //绑定数据
                })
            }
        }
    })
</script>

</body>
</html>
  • 注意
    • 由于后端高亮传回来的是一个html,我们需要解析,不能单纯的双向绑定,因此用 v-html

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