App端文章搜索

文章搜索：用户在app端输入关键字，搜索文章。

一、ElastcSearch环境搭建

（1）拉取ElasticSearch镜像

　　docker pull elasticsearch:7.4.0

（2）创建ElasticSearch容器

docker run -id --name elasticsearch -d --restart=always -p 9200:9200 -p 9300:9300 -v /usr/share/elasticsearch/plugins:/usr/share/elasticsearch/plugins -e "discovery.type=single-node" elasticsearch:7.4.0

 

（3）配置中文分词器 ik

　　把资料中的elasticsearch-analysis-ik-7.4.0.zip上传到服务器上,放到对应目录（plugins）

（4）使用postman测试

向192.168.200.130:9200/_analyze发送post方法

请求体用json传输参数

{

    "analyzer":"ik_max_word",

    "text":"学习java"

}

 

二、需求说明
（1）用户输入关键字可搜索文章列表

（2）关键字高亮展示

（4）文章列表展示与home展示一样，当用户点击某一篇文章，可查看文章详情

为了加快检索的效率，在查询的时候不会直接从数据库中查询文章，需要在elasticsearch中进行高速检索。

搜索结果页面展示什么内容：标题 布局 封面图片 发布时间 作者名称 文章id 作者id 静态url

哪些需要索引和分词：标题 内容

 

使用postman添加映射和查询

1.PUT请求添加映射: http://192.168.200.130:9200/app_info_article

{
    "mappings":{
        "properties":{
            "id":{
                "type":"long"
        },
        "publishTime":{
                "type":"date"
        },
        "layout":{
                "type":"integer"
        },
        "images":{
                "type":"keyword",
        "index": false
        },
        "staticUrl":{
                "type":"keyword",
        "index": false
        },
        "authorId": {
                "type": "long"
        },
        "authorName": {
                "type": "text"},
        "title":{
                "type":"text",
        "analyzer":"ik_smart"
        },
        "content":{
                "type":"text",
        "analyzer":"ik_smart"
            }
        }
    }
}

 

2.其他操作

GET请求查询映射：http://192.168.200.130:9200/app_info_article

DELETE请求删除索引及映射：http://192.168.200.130:9200/app_info_article

GET请求查询所有文档：http://192.168.200.130:9200/app_info_article/_search

 

三、数据初始化到索引库

注：当postman查询不到时，使用docker logs -f elasticsearch跟踪es日志，提示"flood stage disk watermark [95%] exceeded"，得知磁盘使用率超出阈值，es索引模式变为只读，无法写入数据，会造成数据同步失败。

package com.heima.es;

import com.alibaba.fastjson.JSON;
import com.heima.es.mapper.ApArticleMapper;
import com.heima.es.pojo.SearchArticleVo;
import org.elasticsearch.action.bulk.BulkRequest;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.xcontent.XContentType;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import java.util.List;

@SpringBootTest
@RunWith(SpringRunner.class)
public class ApArticleTest {

    @Autowired
    private ApArticleMapper apArticleMapper;

    @Autowired
    private RestHighLevelClient restHighLevelClient;
    /**
     * 注意：数据量的导入，如果数据量过大，需要分页导入
     * @throws Exception
     */
    @Test
    public void init() throws Exception {

        //1、查询所有符合条件的文章数据
        List<SearchArticleVo> searchArticleVos = apArticleMapper.loadArticleList();

        //2、批量导入到es索引库
        BulkRequest bulkRequest = new BulkRequest("app_info_article"); //索引库名称

        for (SearchArticleVo searchArticleVo : searchArticleVos) {
            IndexRequest indexRequest = new IndexRequest().id(searchArticleVo.getId().toString())
                    .source(JSON.toJSONString(searchArticleVo), XContentType.JSON);
            //批量添加数据
            bulkRequest.add(indexRequest);
        }
        restHighLevelClient.bulk(bulkRequest, RequestOptions.DEFAULT);
    }

}

 

四、app端文章搜索

创建搜索微服务heiama-leadnews-search

package com.heima.search.service.impl;

import com.alibaba.fastjson.JSON;
import com.heima.model.common.dtos.ResponseResult;
import com.heima.model.common.enums.AppHttpCodeEnum;
import com.heima.model.search.dtos.UserSearchDto;
import com.heima.search.service.ArticleSearchService;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
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.index.query.*;
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.elasticsearch.search.sort.SortOrder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import javax.naming.directory.SearchResult;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

@Service
@Slf4j
public class ArticleSearchServiceImpl implements ArticleSearchService {

    @Autowired
    private RestHighLevelClient restHighLevelClient;
    /**
     * es文章分页检索
     *
     * @param dto
     * @return
     */
    @Override
    public ResponseResult search(UserSearchDto dto) throws IOException {
        //1.检查参数
        if(dto == null || StringUtils.isBlank(dto.getSearchWords())){
            return ResponseResult.errorResult(AppHttpCodeEnum.PARAM_INVALID);
        }

        //2.设置查询条件
        SearchRequest searchRequest = new SearchRequest("app_info_article");
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();

        //布尔查询
        BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();

        //关键字的分词之后查询
        QueryStringQueryBuilder queryStringQueryBuilder = QueryBuilders.queryStringQuery(dto.getSearchWords()).field("title").field("content").defaultOperator(Operator.OR);
        boolQueryBuilder.must(queryStringQueryBuilder);

        //查询小于mindate的数据
        RangeQueryBuilder rangeQueryBuilder = QueryBuilders.rangeQuery("publishTime").lt(dto.getMinBehotTime().getTime());
        boolQueryBuilder.filter(rangeQueryBuilder);

        //分页查询
        searchSourceBuilder.from(0);
        searchSourceBuilder.size(dto.getPageSize());

        //按照发布时间倒序查询
        searchSourceBuilder.sort("publishTime", SortOrder.DESC);

        //设置高亮  title
        HighlightBuilder highlightBuilder = new HighlightBuilder();
        highlightBuilder.field("title");
        highlightBuilder.preTags("<font style='color: red; font-size: inherit;'>");
        highlightBuilder.postTags("</font>");
        searchSourceBuilder.highlighter(highlightBuilder);


        searchSourceBuilder.query(boolQueryBuilder);
        searchRequest.source(searchSourceBuilder);
        SearchResponse searchResponse = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);


        //3.结果封装返回

        List<Map> list = new ArrayList<>();

        SearchHit[] hits = searchResponse.getHits().getHits();
        for (SearchHit hit : hits) {
            String json = hit.getSourceAsString();
            Map map = JSON.parseObject(json, Map.class);
            //处理高亮
            if(hit.getHighlightFields() != null && hit.getHighlightFields().size() > 0){
                Text[] titles = hit.getHighlightFields().get("title").getFragments();
                String title = StringUtils.join(titles);
                //高亮标题
                map.put("h_title",title);
            }else {
                //原始标题
                map.put("h_title",map.get("title"));
            }
            list.add(map);
        }

        return ResponseResult.okResult(list);
    }
}