An aggregation summarizes your data as metrics, statistics, or other analytics. Aggregations help you answer questions like:
Elasticsearch organizes aggregations into three categories:
Use the query parameter to limit the documents on which an aggregation runs.
By default, searches containing an aggregation return both search hits and aggregation results. To return only aggregation results, set size to 0
SearchRequest searchRequest = new SearchRequest(index.toLowerCase());
searchRequest.allowPartialSearchResults(true);
searchRequest.indicesOptions(IndicesOptions.lenientExpandOpen());
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
searchSourceBuilder.from(0);
searchSourceBuilder.size(0);
searchSourceBuilder.timeout(new TimeValue(60, TimeUnit.SECONDS));
// @formatter:off
searchSourceBuilder.aggregation(
AggregationBuilders
.terms("propertyTypeKeys")
.field("PropertyTypeKey").size(20)
.order(BucketOrder.key(true)));
// @formatter:on
searchRequest.source(searchSourceBuilder);
log.info("sending search request to elastic...");
Map<String, Long> results = new HashMap<>();
try {
SearchResponse searchResponse = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);
log.info("search got response from elastic!");
if (searchResponse.getAggregations() != null) {
Terms propertyTypeKeys = searchResponse.getAggregations().get("propertyTypeKeys");
for (Terms.Bucket bucket : propertyTypeKeys.getBuckets()) {
log.info("keyAsString={}, docCount={}", bucket.getKeyAsString(), bucket.getDocCount());
results.put(bucket.getKeyAsString(), bucket.getDocCount());
}
} else {
log.info("no aggregations!");
}
log.info("sending reponse to client! ,size={}", searchResponse.getHits().getHits().length);
} catch (IOException e) {
e.printStackTrace();
} catch (ElasticsearchException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
You can specify multiple aggregations in the same request.
SearchRequest searchRequest = new SearchRequest(index.toLowerCase());
searchRequest.allowPartialSearchResults(true);
searchRequest.indicesOptions(IndicesOptions.lenientExpandOpen());
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
searchSourceBuilder.from(0);
// set size to 0 to only return aggregations
searchSourceBuilder.size(0);
searchSourceBuilder.timeout(new TimeValue(60, TimeUnit.SECONDS));
// @formatter:off
searchSourceBuilder.aggregation(
AggregationBuilders
.terms("propertyTypeKeys")
.field("PropertyTypeKey").size(20)
.order(BucketOrder.key(true)));
searchSourceBuilder.aggregation(
AggregationBuilders
.terms("propertySubTypeKeys")
.field("PropertySubTypeKey").size(100)
.order(BucketOrder.key(true)));
// @formatter:on
searchRequest.source(searchSourceBuilder);
log.info("sending search request to elastic...");
Map<String, Long> results = new HashMap<>();
try {
SearchResponse searchResponse = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);
log.info("search got response from elastic!");
if (searchResponse.getHits() != null && searchResponse.getHits().getHits() != null) {
for (SearchHit hit : searchResponse.getHits().getHits()) {
log.info("source={}", hit.getSourceAsString());
}
}
log.info("retreiving aggregations...");
if (searchResponse.getAggregations() != null) {
Terms propertyTypeKeys = searchResponse.getAggregations().get("propertyTypeKeys");
for (Terms.Bucket bucket : propertyTypeKeys.getBuckets()) {
log.info("keyAsString={}, docCount={}", bucket.getKeyAsString(), bucket.getDocCount());
results.put(bucket.getKeyAsString(), bucket.getDocCount());
}
Terms propertySubTypeKeys = searchResponse.getAggregations().get("propertySubTypeKeys");
for (Terms.Bucket bucket : propertySubTypeKeys.getBuckets()) {
log.info("keyAsString={}, docCount={}", bucket.getKeyAsString(), bucket.getDocCount());
results.put(bucket.getKeyAsString(), bucket.getDocCount());
}
} else {
log.info("no aggregations!");
}
log.info("sending reponse to client! ,size={}", searchResponse.getHits().getHits().length);
} catch (IOException e) {
log.error("Property search elastic search error. IOException, msg={}", e.getLocalizedMessage());
e.printStackTrace();
} catch (ElasticsearchException e) {
log.error("Property search elastic search error. ElasticsearchStatusException, msg={},{},{}",
e.getDetailedMessage(), e.getLocalizedMessage(), e.getResourceId());
e.printStackTrace();
} catch (Exception e) {
log.error("Property search elastic search error. Exception, msg={},{}", e.getMessage(),
e.getLocalizedMessage());
e.printStackTrace();
}