Abstract
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 Section 1.3, “Custom implementations for Spring Data repositories” .
Filter Builder improves query speed.
Example 3.1.
private ElasticsearchTemplate elasticsearchTemplate;
SearchQuery searchQuery = new NativeSearchQueryBuilder()
.withQuery(matchAllQuery())
.withFilter(boolFilter().must(termFilter("id", documentId)))
.build();
Page<SampleEntity> sampleEntities =
elasticsearchTemplate.queryForPage(searchQuery,SampleEntity.class);
Elasticsearch has scan and scroll feature for getting big result set
in chunks.
ElasticsearchTemplate
has scan and scroll methods that can be used as below.
Example 3.2. Using Scan and Scroll
SearchQuery searchQuery = new NativeSearchQueryBuilder()
.withQuery(matchAllQuery())
.withIndices("test-index")
.withTypes("test-type")
.withPageable(new PageRequest(0,1))
.build();
String scrollId = elasticsearchTemplate.scan(searchQuery,1000,false);
List<SampleEntity> sampleEntities = new ArrayList<SampleEntity>();
boolean hasRecords = true;
while (hasRecords){
Page<SampleEntity> page = elasticsearchTemplate.scroll(scrollId, 5000L , new ResultsMapper<SampleEntity>()
{
@Override
public Page<SampleEntity> mapResults(SearchResponse response) {
List<SampleEntity> chunk = new ArrayList<SampleEntity>();
for(SearchHit searchHit : response.getHits()){
if(response.getHits().getHits().length <= 0) {
return null;
}
SampleEntity user = new SampleEntity();
user.setId(searchHit.getId());
user.setMessage((String)searchHit.getSource().get("message"));
chunk.add(user);
}
return new PageImpl<SampleEntity>(chunk);
}
});
if(page != null) {
sampleEntities.addAll(page.getContent());
hasRecords = page.hasNextPage();
}
else{
hasRecords = false;
}
}
}