Hopefully this would help.
public HttpClient getBasicAuthDefaultHttpClient() {
CredentialsProvider provider = new BasicCredentialsProvider();
UsernamePasswordCredentials creds = new UsernamePasswordCredentials(user,
password);
provider.setCredentials(AuthScope.ANY, creds);
//Fix to avoid HTTP 504 ERROR (GATEWAY TIME OUT ERROR)
RequestConfig.Builder requestBuilder = RequestConfig.custom();
requestBuilder.setConnectTimeout(30 * 1000);
requestBuilder.setConnectionRequestTimeout(30 * 1000);
HttpClientBuilder builder = HttpClientBuilder.create();
builder.setDefaultRequestConfig(requestBuilder.build());
builder.setDefaultCredentialsProvider(provider).build();
return builder.build();
}