spring-data-elasticsearch/src/main/asciidoc/reference/elasticsearch-misc.adoc

[[elasticsearch.misc]]
= Miscellaneous Elasticsearch Operation Support

This chapter covers additional support for Elasticsearch operations that cannot be directly accessed via the repository interface. It is recommended to add those operations as custom implementation as described in <<repositories.custom-implementations>> .

[[elasticsearch.misc.filter]]
== Filter Builder

Filter Builder improves query speed.

====
[source,java]
----
private ElasticsearchOperations operations;

IndexCoordinates index = IndexCoordinates.of("sample-index");

SearchQuery searchQuery = new NativeSearchQueryBuilder()
  .withQuery(matchAllQuery())
  .withFilter(boolFilter().must(termFilter("id", documentId)))
  .build();
  
Page<SampleEntity> sampleEntities = operations.searchForPage(searchQuery, SampleEntity.class, index);
----
====

[[elasticsearch.scroll]]
== Using Scroll For Big Result Set

Elasticsearch has a scroll API for getting big result set in chunks. `ElasticsearchOperations` has startScroll and continueScroll methods that can be used as below.

.Using startScroll and continueScroll
====
[source,java]
----
IndexCoordinates index = IndexCoordinates.of("sample-index");

SearchQuery searchQuery = new NativeSearchQueryBuilder()
  .withQuery(matchAllQuery())
  .withIndices(INDEX_NAME)
  .withTypes(TYPE_NAME)
  .withFields("message")
  .withPageable(PageRequest.of(0, 10))
  .build();

ScrolledPage<SampleEntity> scroll = operations.startScroll(1000, searchQuery, SampleEntity.class, index);

String scrollId = scroll.getScrollId();
List<SampleEntity> sampleEntities = new ArrayList<>();
while (scroll.hasContent()) {
  sampleEntities.addAll(scroll.getContent());
  scrollId = scroll.getScrollId();
  scroll = operations.continueScroll(scrollId, 1000, SampleEntity.class);
}
operations.clearScroll(scrollId);
----
====

`ElasticsearchOperations` additionally has the stream method which wraps the scan and scroll operations into a CloseableIterator.

.Using stream
====
[source,java]
----
IndexCoordinates index = IndexCoordinates.of("sample-index");

SearchQuery searchQuery = new NativeSearchQueryBuilder()
  .withQuery(matchAllQuery())
  .withIndices(INDEX_NAME)
  .withTypes(TYPE_NAME)
  .withFields("message")
  .withPageable(PageRequest.of(0, 10))
  .build();

CloseableIterator<SampleEntity> stream = elasticsearchTemplate.stream(searchQuery, SampleEntity.class, index);

List<SampleEntity> sampleEntities = new ArrayList<>();
while (stream.hasNext()) {
  sampleEntities.add(stream.next());
}
----
====

[[elasticsearch.misc.sorts]]
== Sort options

In addition to the default sort options described <<repositories.paging-and-sorting>> Spring Data Elasticsearch has a `GeoDistanceOrder` class which can be used to have the result of a search operation ordered by geographical distance.

If the class to be retrieved has a `GeoPoint` property named _location_, the following `Sort` would sort the results by distance to the given point:

[source,java]
----
Sort.by(new GeoDistanceOrder("location", new GeoPoint(48.137154, 11.5761247)))
----