Elasticsearch如何在aggs下获取过滤器的doc_count值？

问题描述

在使用Elasticsearch的聚合查询时遇到了一些问题。这是我使用的DSL语句

    {
      "size": 0,"aggs": {
        "terms_vlid_year":{
          "terms": {
            "field": "valid_year","size": 5,"order": {
              "_key": "asc"
            }
          }
        },"filteRSS":{
          "filter": {
            "range": {
              "valid_year": {
                "gte": 6
              }
            }
          }
        }
      }
    }

这是合计结果

    "aggregations" : {
    "terms_vlid_year" : {
      "doc_count_error_upper_bound" : 0,"sum_other_doc_count" : 13918850,"buckets" : [
        {
          "key" : 1,"doc_count" : 1632006
        },{
          "key" : 2,"doc_count" : 3588976
        },{
          "key" : 3,"doc_count" : 3710637
        },{
          "key" : 4,"doc_count" : 2948910
        },{
          "key" : 5,"doc_count" : 2672394
        }
      ]
    },"filters" : {
      "doc_count" : 13918850
    }
  }

现在我想使用Java获取过滤器的doc_count。以下是我的Java代码，但是无法通过filterResult.getDocCount（）获得过滤器对象的doc_count值。如何解决这个问题？

    SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
    TermsAggregationBuilder termsAggregationBuilder = AggregationBuilders.terms("terms_vlid_year");
    FilteraggregationBuilder filter = AggregationBuilders.filter("filters",QueryBuilders.rangeQuery("valid_year").gte(6));
    termsAggregationBuilder.field("valid_year");
    termsAggregationBuilder.size(5);
    termsAggregationBuilder.order(Bucketorder.key(true));
    sourceBuilder.aggregation(termsAggregationBuilder.subAggregation(filter));
    searchRequest.source(sourceBuilder);
    ReturnValue returnValue = new ReturnValue();
    LinkedList<Object> list = new LinkedList<>();
    try {
        SearchResponse searchResponse = client.search(searchRequest,RequestOptions.DEFAULT);
        Terms terms = searchResponse.getAggregations().get("terms_vlid_year");
        List<? extends Terms.Bucket> buckets = terms.getBuckets();

        Filter filterResult = searchResponse.getAggregations().get("filters");
        long docCount1 = filterResult.getDocCount();
        System.out.println("docCount1 = " + docCount1);

        for (Terms.Bucket bucket : buckets) {
            String keyAsstring = bucket.getKeyAsstring();
            long docCount = bucket.getDocCount();
            returnValue.setFieldName(keyAsstring);
            returnValue.setDocValue(docCount);
            System.out.println(returnValue.toString());
        }
    }

解决方法

现在问题已解决。FilterAggregation无法使用嵌套在termAggregation中的subAggregation，它们属于同一级别。应该通过这种方式来获得所需的结果：

sourceBuilder.aggregation(termsAggregationBuilder); 
FilterAggregationBuilder filter = AggregationBuilders.filter("filters",QueryBuilders.rangeQuery("valid_year").gte(6)); 
sourceBuilder.aggregation(filter);