分类列表查询

1 需求分析

以关键字作为查询条件，查询结果中包含的商品分类，在页面中显示出来

2 实现思路

（1）商品分类列表的显示使用聚合查询

（2）使用过滤查询

3 代码实现

修改SearchServiceImpl的search方法，在第一段代码（封装查询请求）的末尾处添加以下代码：

package com.changgou.service;import org.apache.commons.lang.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.BoolQueryBuilder;
import org.elasticsearch.index.query.MatchQueryBuilder;import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.aggregations.Aggregation;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.Aggregations;
import org.elasticsearch.search.aggregations.bucket.terms.Terms;
import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
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 java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;/*** @author ：lijunxuan* @date ：Created in 2019/7/17  19:00* @description ：* @version: 1.0*/
@Service
public class SearchServiceImpl implements SearchService {@Autowiredprivate RestHighLevelClient restHighLevelClient;//设置每页查询条数据public final static Integer PAGE_SIZE = 4;@Overridepublic Map search(Map<String, String> paramMap) throws Exception {Map<String,Object> resultMap=new HashMap<>();/*** 1.获取查询参数*///查询关键字String keywords = paramMap.get("keywords");//当前页数String pageNo = paramMap.get("pageNo");//按照什么域进行排序String sort = paramMap.get("sort");//排序方式是升序还是降序String sortOrder = paramMap.get("sortOrder");/*** 2.获取查询需要的对象*///创建查询对象，指定索引库名称，_indexSearchRequest searchRequest = new SearchRequest("sku");//指定查询索引库中的类型searchRequest.types("doc");//创建查询构造对象SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();//创建布尔查询（组合查询对象）BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();/*** 3.设置根据关键字查询（关键字需要中文分词）*/MatchQueryBuilder nameQueryBuilder = QueryBuilders.matchQuery("name", keywords);//根据名称查询条件放入组合查询对象中boolQueryBuilder.must(nameQueryBuilder);/*** 4. 设置高亮查询*/HighlightBuilder highlightBuilder = new HighlightBuilder();//设置在哪个域中高亮显示highlightBuilder.field("name");//设置高亮前缀highlightBuilder.preTags("<em style=\"color:red\">");//设置高亮后缀highlightBuilder.postTags("</em>");searchSourceBuilder.highlighter(highlightBuilder);/*** 5. 设置分页查询*/if (StringUtils.isEmpty(pageNo)) {paramMap.put("pageNo", "1");resultMap.put("pageNo", "1");}Integer pageNoTemp = Integer.parseInt(pageNo);if (pageNoTemp < 1) {paramMap.put("pageNo", "1");resultMap.put("pageNo", "1");pageNoTemp = 1;}//从第几条开始查询Integer start = (pageNoTemp - 1) * PAGE_SIZE;//从第几条开始查询searchSourceBuilder.from(start);//每页查询多少条数据searchSourceBuilder.size(PAGE_SIZE);/*** 6. 设置排序查询*/if (!StringUtils.isEmpty(sort)) {//升序if ("ASC".equals(sortOrder)) {searchSourceBuilder.sort(sort, SortOrder.ASC);}//降序if ("DESC".equals(sortOrder)) {searchSourceBuilder.sort(sort, SortOrder.DESC);}}/*** 7. 设置根据分类聚合查询* 其实就是按照分类名称分组查询, 目的是找到根据当前的关键字, 查询出对应的分类, 并且要去除掉重复的分类* tems中传入的是聚合组的名称, 可以随意起名, 但是不要重复*/TermsAggregationBuilder termsAggregationBuilder = AggregationBuilders.terms("categoryGroup").field("categoryName");searchSourceBuilder.aggregation(termsAggregationBuilder);/*** 12.查询并返回的结果*///将组合查询条件放入查询构造对象中searchSourceBuilder.query(boolQueryBuilder);//将组合查询条件放入查询请求中searchRequest.source(searchSourceBuilder);SearchResponse searchResponse = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);/*** 13. 获取查询到的结果集, 封装后返回*/SearchHits searchHits = searchResponse.getHits();//获取查询到的总条数long totalHits = searchHits.getTotalHits();resultMap.put("total",totalHits);//获取查询结果集SearchHit[] hits = searchHits.getHits();List rows = new ArrayList<>();if (hits!=null){for (SearchHit hit : hits) {//获取普通的查询出来的一条数据(不带高亮名称)Map<String, Object> sourceAsMap = hit.getSourceAsMap();//获取高亮结果Map<String, HighlightField> highlightFields = hit.getHighlightFields();if (highlightFields != null) {HighlightField highlightField = highlightFields.get("name");Text[] fragments = highlightField.fragments();if (fragments != null && fragments.length > 0) {//将高亮名称放入查询出来的数据中, 覆盖原来不带高亮的名称sourceAsMap.put("name", fragments[0].toString());}}rows.add(sourceAsMap);}}resultMap.put("rows",rows);/*** 14. 获取根据分类聚合查询结果*/Aggregations aggregations = searchResponse.getAggregations();//将聚合结果转换成MapMap<String, Aggregation> asMap = aggregations.getAsMap();//根据分组名称获取聚合的具体结果Terms terms =  (Terms)asMap.get("categoryGroup");//获取分组后集合中的具体内容List<? extends Terms.Bucket> buckets = terms.getBuckets();List<String> categoryList = new ArrayList<>();if (buckets != null) {for (Terms.Bucket bucket : buckets) {categoryList.add(bucket.getKeyAsString());}}resultMap.put("categoryList", categoryList);return resultMap;}
}