Apache HTTPAsyncClient closes connection before response - https

Question

I am sending a GET request to an API using the Apache AsyncHTTPClient version 4.1.4 (latest). I can't seem to get a response from the server.
This is my request log.
Jun 04, 2020 3:40:01 PM org.apache.http.impl.nio.client.MainClientExec generateRequest
FINE: [exchange: 2] Connection route established
Jun 04, 2020 3:40:01 PM org.apache.http.impl.nio.client.MainClientExec generateRequest
FINE: [exchange: 2] Attempt 1 to execute request
Jun 04, 2020 3:40:01 PM org.apache.http.impl.nio.client.MainClientExec generateRequest
FINE: [exchange: 2] Proxy auth state: UNCHALLENGED
Jun 04, 2020 3:40:01 PM org.apache.http.headers onRequestSubmitted
FINE: http-outgoing-1 >> GET /v1/contact?id=24 HTTP/1.1
Jun 04, 2020 3:40:01 PM org.apache.http.headers onRequestSubmitted
FINE: http-outgoing-1 >> Authorization: Bearer <token_removed>
Jun 04, 2020 3:40:01 PM org.apache.http.headers onRequestSubmitted
FINE: http-outgoing-1 >> Host: api.trial.ezyvet.com
Jun 04, 2020 3:40:01 PM org.apache.http.headers onRequestSubmitted
FINE: http-outgoing-1 >> Connection: Keep-Alive
Jun 04, 2020 3:40:01 PM org.apache.http.headers onRequestSubmitted
FINE: http-outgoing-1 >> User-Agent: Apache-HttpAsyncClient/4.1.4 (Java/11.0.6)
Jun 04, 2020 3:40:01 PM org.apache.http.impl.nio.conn.ManagedNHttpClientConnectionImpl setEvent
FINE: http-outgoing-1 192.168.1.2:52932<->52.27.52.37:443[ACTIVE][rw:][ACTIVE][rw][NEED_UNWRAP][0][0][437]: Event set [w]
Jun 04, 2020 3:40:01 PM org.apache.http.impl.nio.client.MainClientExec requestCompleted
FINE: [exchange: 2] Request completed
[INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 14.622 s
When I send the same request using Postman, I get a successful response.
This is my code to handle the connection.
public void connect(HttpUriRequest request, FutureCallback<HttpResponse> callback) {
SSLContextBuilder sslContextBuilder = new SSLContextBuilder();
try {
sslContextBuilder.loadTrustMaterial(null, new TrustSelfSignedStrategy());
try (CloseableHttpAsyncClient client = HttpAsyncClients.custom()
.setSSLContext(sslContextBuilder.build())
.setSSLHostnameVerifier(NoopHostnameVerifier.INSTANCE)
.build()) {
client.start();
client.execute(request, callback).get();
}
} catch (Exception e) {
Logger.getGlobal().severe("Couldn't execute the request using the AsyncClient.");
}
}
My debugger won't get triggered in any of the callback's methods (completed, failed, cancelled). Apparently the connection gets terminated for some reason.
Can someone explain what is happening here?
Thanks

Answer 1

I managed to solve this issue by changing the code to include a CountDownLatch instead of using client.execute(request, callback).get().
I passed down the latch to where the HttpResponse is read by JSON deserializer and count it down after everything completes.
This answer helped a lot.
https://stackoverflow.com/a/49359725/6663366