70 lines
2.3 KiB
Plaintext
70 lines
2.3 KiB
Plaintext
[[java-aggs-bucket-datehistogram]]
|
|
==== Date Histogram Aggregation
|
|
|
|
Here is how you can use
|
|
{ref}/search-aggregations-bucket-datehistogram-aggregation.html[Date Histogram Aggregation]
|
|
with Java API.
|
|
|
|
|
|
===== Prepare aggregation request
|
|
|
|
Here is an example on how to create the aggregation request:
|
|
|
|
[source,java]
|
|
--------------------------------------------------
|
|
AggregationBuilder aggregation =
|
|
AggregationBuilders
|
|
.dateHistogram("agg")
|
|
.field("dateOfBirth")
|
|
.interval(DateHistogramInterval.YEAR);
|
|
--------------------------------------------------
|
|
|
|
Or if you want to set an interval of 10 days:
|
|
|
|
[source,java]
|
|
--------------------------------------------------
|
|
AggregationBuilder aggregation =
|
|
AggregationBuilders
|
|
.dateHistogram("agg")
|
|
.field("dateOfBirth")
|
|
.interval(DateHistogramInterval.days(10));
|
|
--------------------------------------------------
|
|
|
|
|
|
===== Use aggregation response
|
|
|
|
Import Aggregation definition classes:
|
|
|
|
[source,java]
|
|
--------------------------------------------------
|
|
import org.elasticsearch.search.aggregations.bucket.histogram.Histogram;
|
|
--------------------------------------------------
|
|
|
|
[source,java]
|
|
--------------------------------------------------
|
|
// sr is here your SearchResponse object
|
|
Histogram agg = sr.getAggregations().get("agg");
|
|
|
|
// For each entry
|
|
for (Histogram.Bucket entry : agg.getBuckets()) {
|
|
DateTime keyAsDate = (DateTime) entry.getKey(); // Key
|
|
String key = entry.getKeyAsString(); // Key as String
|
|
long docCount = entry.getDocCount(); // Doc count
|
|
|
|
logger.info("key [{}], date [{}], doc_count [{}]", key, keyAsDate.getYear(), docCount);
|
|
}
|
|
--------------------------------------------------
|
|
|
|
This will basically produce for the first example:
|
|
|
|
[source,text]
|
|
--------------------------------------------------
|
|
key [1942-01-01T00:00:00.000Z], date [1942], doc_count [1]
|
|
key [1945-01-01T00:00:00.000Z], date [1945], doc_count [1]
|
|
key [1946-01-01T00:00:00.000Z], date [1946], doc_count [1]
|
|
...
|
|
key [2005-01-01T00:00:00.000Z], date [2005], doc_count [1]
|
|
key [2007-01-01T00:00:00.000Z], date [2007], doc_count [2]
|
|
key [2008-01-01T00:00:00.000Z], date [2008], doc_count [3]
|
|
--------------------------------------------------
|