private void createAlert(AcInputChannel channel) {
   AcReceivedFileAlert alert = _access.newReceivedFileAlert();
   alert.setInputChannelId(channel.getId());
   alert.setCreateUtcTs(_now);
   alert.setExpirationUtcTs(getAlertExpiration());
   _access.getReceivedFileAlertDb().insert(alert);
 }
 private void expireOldAlerts() {
   _access.getReceivedFileAlertDb().deleteOldAlerts();
 }
 private boolean noActiveAlertFor(AcInputChannel channel) {
   AcReceivedFileAlertDb db = _access.getReceivedFileAlertDb();
   JwList<AcReceivedFileAlert> v = db.getAllByInputChannelId(channel.getId());
   if (activeAlerts(v)) return false;
   return true;
 }