public void finishExchange(boolean refresh, String errmsg) {
    errMessage = errmsg;
    if (status != ExchangeState.COMPLETED) {
      status = ExchangeState.FAILED;
      forceToStop = true;
    }

    if (request != null) request.release();
    if (response != null) response.release();

    if (refresh) {
      notifyExchangeFinished();
    }
  }
 public void setCompleted() {
   status = ExchangeState.COMPLETED;
   notifyExchangeFinished();
 }