How to do _cat/indices/<index_name_with_reg_ex> with JAVA API? - elasticsearch

Question

I have some indexes with name test-1-in, test-2-in, test-3-in. I want to do _cat/indices/test-*-in from JAVA API. How to do this?
I tried using the IndexAdminClient but no luck.

Answer 1

Given an ElasticSearch Client object:
client.admin().indices()
.getIndex(new GetIndexRequest().indices("regex-*"))
.actionGet().getIndices();

Answer 2

In addition to Mario's answer, use the following to retrieve the indices with the Elasticsearch 6.4.0 high level REST client:
GetIndexRequest request = new GetIndexRequest().indices("*");
GetIndexResponse response = client.indices().get(request, RequestOptions.DEFAULT);
String[] indices = response.getIndices();

Answer 3

I have a solution:
final ClusterStateRequest clusterStateRequest = new ClusterStateRequest();
clusterStateRequest.clear().metaData(true);
final IndicesOptions strictExpandIndicesOptions = IndicesOptions.strictExpand();
clusterStateRequest.indicesOptions(strictExpandIndicesOptions);
ClusterStateResponse clusterStateResponse = client.admin().cluster().state(clusterStateRequest).get();
clusterStateResponse.getState().getMetadata().getIndices()
This will give all indexes. After that the reg ex matching has to be done manually. This is what is done for _cat implementation in elasticsearch source code.

Answer 4

In case you want to cat indices with ?v option:
IndicesStatsRequestBuilder indicesStatsRequestBuilder = new
IndicesStatsRequestBuilder(client, IndicesStatsAction.INSTANCE);
IndicesStatsResponse response = indicesStatsRequestBuilder.execute().actionGet();
for (Map.Entry<String, IndexStats> m : response.getIndices().entrySet()) {
System.out.println(m);
}
Each of the entries contains document count, storage usage, etc. You can run this for all or filtering some index.
PD: Tested with 5.6.0 version