数据聚合

聚合的种类

DSL实现Bucket聚合

 如图所示，设置了10个桶，那么就显示了数量最多的前10个桶，品牌含有7天酒店的有30家，

品牌含有如家的也有30家。

修改排序规则

 

 限定聚合范围

 DSL实现Metrics聚合

如下案例要求对不同的品牌进行统计，所以要进行分组。

 如图所示，要对桶的平均评分做排序，要使用不同桶的平均评分

 

RestClient实现聚合

请求组装 

    @Testvoid testAggregation() throws IOException {//1.准备RequestSearchRequest request = new SearchRequest("hotel");//2.准备DSl//2.1设置sizerequest.source().size(0);//2.2聚合request.source().aggregation(AggregationBuilders.terms("brandAgg").field("brand").size(10));//3.发出请求SearchResponse response = client.search(request, RequestOptions.DEFAULT);//4.解析结果System.out.println(response);}

 

结果解析

    @Testvoid testAggregation() throws IOException {//1.准备RequestSearchRequest request = new SearchRequest("hotel");//2.准备DSl//2.1设置sizerequest.source().size(0);//2.2聚合request.source().aggregation(AggregationBuilders.terms("brandAgg").field("brand").size(10));//3.发出请求SearchResponse response = client.search(request, RequestOptions.DEFAULT);//4.解析结果Aggregations aggregations = response.getAggregations();//4.1根据聚合名称获取聚合结果Terms brandTerms = aggregations.get("brandAgg");//4.2获取bucketsList<? extends Terms.Bucket> buckets = brandTerms.getBuckets();//4.3遍历for (Terms.Bucket bucket : buckets) {//4.4获取keyString key = bucket.getKeyAsString();System.out.println(key);}}

 

多条件聚合

在Service中 

将公共代码抽取出来，提高复用性

    @Overridepublic Map<String, List<String>> filters() {try {//1.准备RequestSearchRequest request = new SearchRequest("hotel");//2.准备DSl//2.1设置sizerequest.source().size(0);//2.2聚合buildAggregation(request);//3.发出请求SearchResponse response = client.search(request, RequestOptions.DEFAULT);//4.解析结果Map<String, List<String>>result=new HashMap<>();Aggregations aggregations = response.getAggregations();//5.1根据品牌名称获取品牌结果List<String> brandList = getAggByName(aggregations,"brandAgg");result.put("品牌",brandList);//5.2根据品牌名称获取品牌结果List<String> cityList = getAggByName(aggregations,"cityAgg");result.put("城市",cityList);//5.3根据品牌名称获取品牌结果List<String> starList = getAggByName(aggregations,"starAgg");result.put("星级",starList);return result;} catch (IOException e) {throw new RuntimeException(e);}}private static List<String> getAggByName(Aggregations aggregations,String aggName) {//4.1根据聚合名称获取聚合结果Terms brandTerms = aggregations.get(aggName);//4.2获取bucketsList<? extends Terms.Bucket> buckets = brandTerms.getBuckets();//4.3遍历List<String>brandList=new ArrayList<>();for (Terms.Bucket bucket : buckets) {//4.4获取keyString key = bucket.getKeyAsString();brandList.add(key);}return brandList;}

 

在一个测试类中

@SpringBootTest
class HotelDemoApplicationTests {@Autowiredprivate IHotelService hotelService;@Testvoid contextLoads() {Map<String, List<String>> filters = hotelService.filters();System.out.println(filters);}}

 运行得到

带过滤条件的聚合

在查询的时候要在查询结果上做聚合，不应该直接将所有数据的聚合结果返回。

所以就是加上query参数。

Controller中 

传递的参数和正常参数一模一样 

@PostMapping("filters")public Map<String, List<String>> getFilters(@RequestBody RequestParams Params){return hotelService.filters(Params);}

Service中

添加传递参数，并且新设置了2.3query，使用搜索时同款的query设置方法

 @Overridepublic Map<String, List<String>> filters(RequestParams Params) {try {//1.准备RequestSearchRequest request = new SearchRequest("hotel");//2.准备DSl//2.1设置sizerequest.source().size(0);//2.2聚合buildAggregation(request);//2.3querybuildBasicQuery(Params, request);//3.发出请求SearchResponse response = client.search(request, RequestOptions.DEFAULT);//4.解析结果Map<String, List<String>>result=new HashMap<>();Aggregations aggregations = response.getAggregations();//5.1根据品牌名称获取品牌结果List<String> brandList = getAggByName(aggregations,"brandAgg");result.put("品牌",brandList);//5.2根据品牌名称获取品牌结果List<String> cityList = getAggByName(aggregations,"cityAgg");result.put("城市",cityList);//5.3根据品牌名称获取品牌结果List<String> starList = getAggByName(aggregations,"starAgg");result.put("星级",starList);return result;} catch (IOException e) {throw new RuntimeException(e);}}

结果测试

根据搜索框和过滤条件成功过滤