@Override
public void onUpdateReceived(Update update) {
 if (update.hasMessage()) {
  long chat_id = update.getMessage().getChatId();

  List < PhotoSize > photos = update.getMessage().getPhoto();

  String f_id = photos.stream()
   .sorted(Comparator.comparing(PhotoSize::getFileSize).reversed())
   .findFirst()
   .orElse(null).getFileId();
  SendPhoto msg = new SendPhoto()
   .setChatId(chat_id)
   .setPhoto(f_id);
  try {
   sendPhoto(msg);
  } catch (TelegramApiException e) {
   e.printStackTrace();
  }
 }
}