Hi, guys. Thank you for building such wonderful tools. 
While I was coding with the guidance of the [SubmitAsyncSearchRequest document](https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-high-asyncsearch-asyncsearch-submit.html), I didn't know what to do in order to wait for the response from the current thread in the context as below.
@Async
@CrossOrigin
@GetMapping(path="/my/path/{docId}")
public @ResponseBody ResponseEntity<Result> getAsyncResult(
@PathVariable Integer docId
) {
ClientConfiguration clientConfiguration = ClientConfiguration.builder().connectedTo("localhost:9200").build();
RestHighLevelClient client = RestClients.create(clientConfiguration).rest();
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
SearchSourceBuilder searchSource = searchSourceBuilder.query(QueryBuilders.matchQuery("_id", docId));
String[] indices = new String[] {"my_index"};
SubmitAsyncSearchRequest request
= new SubmitAsyncSearchRequest(searchSource, indices);
request.setWaitForCompletionTimeout(TimeValue.timeValueSeconds(1));
request.setKeepAlive(TimeValue.timeValueDays(365));
request.setKeepOnCompletion(true);
AsyncSearchClient asyncClient = client.asyncSearch();
Result result = new Result();
ActionListener<AsyncSearchResponse> actionListner
= new ActionListener<AsyncSearchResponse>() {
@Override
public void onResponse(AsyncSearchResponse response) {
if (response.isPartial() == true) {
logger.info("The response is PARTIAL!");
} else {
logger.info("The response is COMPLETE!");
}
SearchResponse searchResponse = response.getSearchResponse();
if (searchResponse != null) {
SearchHit[] searchHits = searchResponse.getHits().getHits();
int numHits = searchHits.length;
logger.info("******* No. hits: " + numHits);
if (numHits > 0) {
for (int i=0; i<numHits; i++) {
logger.info("[" + i + "] : " + searchHits[i].getId());
String jsonString = searchHits[i].getSourceAsString();
logger.info(">>> The raw string: " + jsonString);
// SOME BUSINESS LOGIC filling `result`.
} // END: for (~)
logger.info("******* ABOVE: Hit IDs");
} // END: if (numHits > 0)
} // END: if (searchResponse != null)
} // END: public void onResponse(AsyncSearchResponse response)
@Override
public void onFailure(Exception e) {
String expMsg = e.getMessage();
logger.error("Async Request Failed for error: " + expMsg);
} // END: public void onFailure(Exception e)
}; // END: new ActionListener<AsyncSearchResponse>(){}
Cancellable cancellable = asyncClient.submitAsync(request, RequestOptions.DEFAULT, actionListner);
// cancellable.cancel();
// TODO: Wait for request to be done. If the onResponse() finishes, then continue to below.
ResponseEntity<Result> result0 = null;
result0 = (result.filled() == true) ? new ResponseEntity<Result>(minute, HttpStatus.OK)
: new ResponseEntity<Result>(HttpStatus.INTERNAL_SERVER_ERROR);
logger.info("BEFORE RETURNING");
return result0;
}
According to those log messages, always BEFORE RETURNING appears before the ones in onResponse().
But, I want the current thread(?) to wait until onResponse() is done.
What am I supposed to do?
Thank you for reading my question and answering in advance! 