Elastic search : Impossible to get buckets result

Question

I'm counting per day the number of install by apkId.

LocalDate today = LocalDate.now();                  
LocalDate beginningDate = today.minusDays(intervalle);

BoolQueryBuilder query = QueryBuilders.boolQuery();
query.must(QueryBuilders.rangeQuery("date") 
        .gte(convertToDateViaInstant(beginningDate))  
        .lte(convertToDateViaInstant(today)));
query.must(QueryBuilders.matchQuery("apkId", apkId));
query.must(QueryBuilders.matchQuery("event", Event.INSTALL));

Iterable<ApkHistory> list = apkHistoryRepo.search(query);

AggregationBuilder aggregation = AggregationBuilders
        .dateHistogram("nb_install_per_day")
        .field("date")
        .dateHistogramInterval(DateHistogramInterval.DAY);


SearchRequest searchRequest = new SearchRequest("apkhistory"); 
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
searchSourceBuilder.query(query).aggregation(aggregation);
searchRequest.source(searchSourceBuilder); 

try {
    SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
    
    Aggregation agg = searchResponse.getAggregations().get("nb_install_per_day");
    
    
    System.out.println("test");
} catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}

The search response return a correct json in which i can see the result i'm looking for.

{
   "took":70,
   "timed_out":false,
   "_shards":{
      "total":5,
      "successful":5,
      "skipped":0,
      "failed":0
   },
   "hits":{
      "total":34,
      "max_score":2.0042462,
      "hits":[
         {
            "_index":"apkhistory",
            "_type":"apkhistory",
            "_id":"mQw_OnYBj8D21YQgTRHA",
            "_score":2.0042462,
            "_source":{
               "appUserId":"rsty-45ts-8978HU9",
               "apkId":1,
               "event":"INSTALL",
               "date":1605481200000
            }
         },
         {
            "_index":"apkhistory",
            "_type":"apkhistory",
            "_id":"-wwPOnYBj8D21YQgdA9Q",
            "_score":2.0042462,
            "_source":{
               "appUserId":"id-test-app-user95",
               "apkId":1,
               "event":"INSTALL",
               "date":1605654000000
            }
         }...
         }
      ]
   },
   "aggregations":{
      "date_histogram#per_day_count":{
         "buckets":[
            {
               "key_as_string":"2020-11-07T00:00:00.000Z",
               "key":1604707200000,
               "doc_count":2
            },
            {
               "key_as_string":"2020-11-08T00:00:00.000Z",
               "key":1604793600000,
               "doc_count":2
            }...
         ]
      }

} }

When I tried to get the buckets, it is impossible. I don't have the method getBuckets() in Aggregation. When I tried Terms terms = searchResponse.getAggregations().get("nb_install_per_day"), I got an exception, cannot convert Aggregations to Terms

Please, how could I do to get this buckets values ? I use Spring 2.2.4and spring data elastic search 3.2.4.RELEASE.

Thanks

Here the content of my variable. In agg I have no method to get buckets ArrayList...I tried many ways without success. Please help.

Answer 1

LocalDate today = LocalDate.now();
LocalDate beginningDate = today.minusDays(intervalle);

    BoolQueryBuilder query = QueryBuilders.boolQuery();
    query.must(QueryBuilders.rangeQuery("date") 
            .gte(beginningDate)  
            .lte(today));
    query.must(QueryBuilders.matchQuery("apkId", apkId));
    query.must(QueryBuilders.matchQuery("event", Event.INSTALL));

    Iterable<ApkHistory> list = apkHistoryRepo.search(query);

    AggregationBuilder aggregation = AggregationBuilders
            .dateHistogram("nb_install_per_day")
            .field("date")
            .dateHistogramInterval(DateHistogramInterval.DAY);


    SearchRequest searchRequest = new SearchRequest("apkhistory"); 
    SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
    searchSourceBuilder.query(query).aggregation(aggregation);
    searchRequest.source(searchSourceBuilder); 

    try {
        SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);

        ParsedDateHistogram dateGroupBy = searchResponse.getAggregations().get("nb_install_per_day");

        for(org.elasticsearch.search.aggregations.bucket.histogram.Histogram.Bucket b : dateGroupBy.getBuckets()) {
            
            System.out.println(b.getKeyAsString() + " "+b.getDocCount());
            
        }
        System.out.println("test");
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }