Ricevo solo una notifica e se arriva un'altra notifica, sostituisce la precedente ed ecco il mio codice
private static void generateNotification(Context context, String message,
String key) {
int icon = R.drawable.ic_launcher;
long when = System.currentTimeMillis();
NotificationManager notificationManager = (NotificationManager) context
.getSystemService(Context.NOTIFICATION_SERVICE);
Notification notification = new Notification(icon, message, when);
String title = context.getString(R.string.app_name);
Intent notificationIntent = new Intent(context,
FragmentOpenActivity.class);
notificationIntent.putExtra(key, key);
// set intent so it does not start a new activity
notificationIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP
| Intent.FLAG_ACTIVITY_SINGLE_TOP);
PendingIntent intent = PendingIntent.getActivity(context, 0,
notificationIntent, 0);
notification.setLatestEventInfo(context, title, message, intent);
notification.flags |= Notification.FLAG_AUTO_CANCEL;
notification.defaults |= Notification.DEFAULT_SOUND;
// notification.sound = Uri.parse("android.resource://" +
// context.getPackageName() + "your_sound_file_name.mp3");
notification.defaults |= Notification.DEFAULT_VIBRATE;
notificationManager.notify(0, notification);
}