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How to process GCM notifications, launching activity per alert without erasing other alerts

I guess it is hard to explain just by reading the title of this question. I am coding an app that gets ambient factors alerts (temperature, etc) sent by a known server to GCM, and then GCM sends it back to the phone. The whole GCM works well. The problem is when notifications arrive. It is thought to send notifications to the phone when an alert happens (a trigger). Then clicking on the alert launches the activity to display the alert. That is OK, but if there is 2 or more alerts on waiting to be clicked, it will only process one, ignoring the rest ("mensaje"). This is how my notification inside a class that extends extends GcmListenerService looks like.
public static void showAlerts(Context context, String mensaje)
{
Intent notificationIntent = new Intent(context.getApplicationContext(), MainActivity.class);
notificationIntent.putExtra("mensaje", mensaje);
notificationIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP
| Intent.FLAG_ACTIVITY_SINGLE_TOP);
Random r = new Random();
PendingIntent pendingIntent = PendingIntent.getActivity(context, r.nextInt(),
notificationIntent, 0);
NotificationManager notificationManager = (NotificationManager) context
.getSystemService(Context.NOTIFICATION_SERVICE);
Notification notification = new NotificationCompat.Builder(context)
.setContentTitle(context.getString(R.string.app_name))
.setContentText("Nueva alerta recibida")
.setSmallIcon(R.drawable.termometrorojo)
.setNumber(UtilidadesGCM.num_notificaciones++)
.setOnlyAlertOnce(true)
.setContentIntent(pendingIntent)
.setWhen(System.currentTimeMillis())
.setDefaults(Notification.DEFAULT_SOUND | Notification.DEFAULT_VIBRATE)
.setDefaults(Notification.DEFAULT_LIGHTS)
.setAutoCancel(true).build();
notificationManager.notify(0, notification);
}
Then in MainActivity, I have the code to process this, and open the activity to display the alert
private final BroadcastReceiver mHandleMessageReceiver = new BroadcastReceiver()
{
#Override
public void onReceive(Context context, Intent intent)
{
String nuevaAlerta = intent.getExtras().getString("mensaje");
procesaAlerta(nuevaAlerta);
//mDisplay.append(nuevaAlerta + "\n");
}
};
public void procesaAlerta (String alerta)
{
Intent intent = new Intent(this, Alertas.class);
intent.putExtra("mensaje" , alerta);
startActivity(intent);
}
The Alertas class will parse the message fine and display it in its activity, but will only do that once. If there are more than 2 alerts stacked to be read, it only process one. If there is one, it works ok. Sorry if I odn't explain better, but it hard not showing all the code.
Thanks!

Try with writing this line
notificationManager.notify( new Random().nextInt(), notification);
instead of
notificationManager.notify(0, notification);
Your notification id is every time same so your last notification only work. Every new notification id is replaced by id 0. So i use random id instead of fixed id 0. I think above code will work for you

generating notification when time matches, even without running application - ANDROID

In my android application, I want to generate a notification when current time matches with the time that I have retrieved from my database. And the notification should be generated even if the application is not running. For this I have done something like this, but this is not working (no notification is being generated).
I am new to android, and I have seen many examples and tutorials for solving this issue, but they did not helped. So please give Answer that what should I do for getting the desired result?
In MainActivity.java I am doing this:
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
/*here I am retrieving time from database*/
String time_from_database = "20:00:00";
if(Calendar.getInstance()==time_from_database) {
AlarmManager alarmMgr = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(MainActivity.this, NotGen.class);
PendingIntent alarmIntent = PendingIntent.getBroadcast(MainActivity.this, 0, intent, 0);
alarmMgr.set(AlarmManager.RTC, Calendar.getInstance(), alarmIntent);
}
}
}
this is code of NotGen.java class:
public class NotGen extends BroadcastReceiver {
public NotificationCompat.Builder mBuilder;
#Override
public void onReceive(Context context, Intent intent) {
PendingIntent pIntent = PendingIntent.getActivity(context,0,intent,0);
NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(context);
mBuilder.setTicker("Ticker Title");
mBuilder.setSmallIcon(R.drawable.my_img);
mBuilder.setContentTitle("Notification Alert, Click Me!");
mBuilder.setContentText("Hi, This is Android Notification Detail!");
mBuilder.setContentIntent(pIntent).getNotification();
mBuilder.setAutoCancel(true);
mBuilder.getNotification().flags |= Notification.FLAG_AUTO_CANCEL;
Uri alarmSound = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
mBuilder.setSound(alarmSound);
NotificationManager mNotificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
mNotificationManager.notify(0,mBuilder.build());
}
}

Calendar.getInstance()==time_from_database will never work.
First, getInstance() is going to create a new instance, and == is object identity equality.
Second, time_from_database is a String ("20:00:00"). A Calendar instance will never equal that, if for no other reason than a Calendar is a combination of date and time.

You can achieved it using Service. Service will running in background all the time even your application is not running.
1) Create service and register it into Manifest file.
2) Start it on application start.
3) Into service you can generating your notification when current time will matched with database time.
For service example you can see below links
http://javatechig.com/android/android-service-example
http://www.tutorialspoint.com/android/android_services.htm

Transaction to a specific fragment if we receive a push notification while app is running

Is it possible not launch new activity if we receive a push notification while the app is running?
My activity works with fragments and I want to do transition to a determinate fragment when the notification is received. My activity have data that I need to show the fragments. The problem is that when I receive the push notification while the app is running the method onDestroy is called and here I clear the data and then the app crash because the data are null. How can I do to not create new activity when the app receive a push notification while is running? In case the app is running I want that if you click the notification do a transition fragment, not create again the activity.
Thanks in advance.

First of all, I think that you mean "notification" to be a "message", but not android.app.Notification class.
And second, I don't think it's a best practise to raise new GUI when receiving a message, which would interrupt the user interaction. For details, please refer to: http://developer.android.com/training/notify-user/index.html and http://developer.android.com/design/patterns/notifications.html.
At last, if you really wanna do what you stated in your thread, I wonder why the data used to generate the show-data fragment is held in the activity. Try holding the data in an android.app.IntentService object, and then generate transfer the data to new activity, and then use android.app.Fragment.setArguments method to transfer the data from activity to fragment.

I think that this code will help you. This which you need is PendingIntent, it make transaction to desired activity.
/**
* Issues a notification to inform the user that server has sent a message.
*/
private static void generateNotification(Context context, String title,
String message) {
//get the default notification sound URI
Uri uriNotificationSound = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
//make intent to the application. if the application is opened just maximize it.
Intent homeIntent = new Intent(context, 'your desired activity');
homeIntent.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
PendingIntent contentIntent = PendingIntent.getActivity(context, 0,
homeIntent, 0);
NotificationCompat.Builder mBuilder =
new NotificationCompat.Builder(context)
.setSmallIcon(R.drawable.ic_launcher)
.setContentTitle("eCommCongress")
.setContentText(message)
.setLights(Color.GREEN, 1500, 1500)
.setSound(uriNotificationSound)
.setAutoCancel(true)
.setContentIntent(contentIntent);
NotificationManager mNotificationManager =
(NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
// mId allows you to update the notification later on.
mNotificationManager.notify(counter, mBuilder.build());
counter++;
}

It is perfectly possible and I do such a thing in one of my apps. First, you need to declare your activity as android:launchMode="singleTop",
Then, when you build you must configure your pending intent not to fire a new instance of your activity:
mNotificationManager = (NotificationManager)
this.getSystemService(Context.NOTIFICATION_SERVICE);
Intent intent = new Intent("YOUR ACTION HERE");
intent.setClassName(this, MainActivity.class.getName());
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
PendingIntent resultPendingIntent = PendingIntent.getActivity(getApplicationContext(), 0, intent, PendingIntent.FLAG_CANCEL_CURRENT);
NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(this);
mBuilder.setContentIntent(resultPendingIntent);
Notification notification = mBuilder.build();
notification.defaults |= Notification.DEFAULT_VIBRATE | Notification.DEFAULT_LIGHTS;
notification.flags |= Notification.FLAG_SHOW_LIGHTS | Notification.FLAG_AUTO_CANCEL;
mNotificationManager.notify(idNotificacion,notification);
Now all you have to do is to override your onNewIntent inside your Activity and do whatever you want with your fragment:
#Override
protected void onNewIntent(Intent intent) {
MiLog.i(getApplicationContext(),"IntentShit","new intent received");
MiLog.i(getApplicationContext(),"IntentShit","Action: "+intent.getAction());
if(intent.getAction()!=null && intent.getAction().equals("YOUR ACTION HERE"){
//DO your stuff here
}
}
You should also take a look at this page for more info:
http://www.intridea.com/blog/2011/6/16/android-understanding-activity-launchmode

Can not initiate activity from GCMIntentService.class

I have a GCMIntentService class, in which i get some messages returned from my server. I want to be able to start a certain activity when a certain message arrives at my app. For example if in my onMessage() method (onMethod() is the method, and the first place, in the app, that receives the messages from the server) arrives the string = "tomatoe", i want to start a specific activity. The way i know right now to start an activity, is this:
Intent resactivity = new Intent(getApplicationContext(), ResponseActivity.class);
resactivity.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(resactivity);
The problem is that GCMIntentService, is not a class that extends activity, and i believe that i can't use this code for this purpose. Is there some way to initiate an activity from a class that is not an activity, by creating an intent inside that class?

The problem is that GCMIntentService, is not a class that extends activity, and i believe that i can't use this code for this purpose.
GCMIntentService inherits from Context, which is where startActivity() is defined.
Bear in mind, though, that your users may attack you with pitchforks or machine guns for popping up activities at random points in time, perhaps in the middle of something else that they are doing. Please make this behavior configurable, or else make very very certain that your users will appreciate these interruptions.

I post the method I usually use to start an activity when a notification arrives in my apps. Take a look to all the configurations and remove those you are not interested in:
#Override
protected void onMessage(Context context, Intent intent) {
String app_name = context.getString(R.string.app_name);
String message = intent.getStringExtra("payload");
String ns = Context.NOTIFICATION_SERVICE;
NotificationManager notificationManager = (NotificationManager) context.getSystemService(ns);
int icono = R.drawable.ic_stat_notify;
long time = System.currentTimeMillis();
Notification notification = new Notification(icono, app_name, time);
notification.defaults |= Notification.DEFAULT_SOUND;
Intent notificationIntent = new Intent(context, ResponseActivity.class);
PendingIntent pendingIntent = PendingIntent.getActivity(context, -1, notificationIntent, PendingIntent.FLAG_UPDATE_CURRENT);
notification.when = System.currentTimeMillis();
notification.flags |= Notification.FLAG_AUTO_CANCEL;
notification.setLatestEventInfo(context, app_name, message, pendingIntent);
notificationManager.notify(0, notification);
}

You should be able to do it as such:
getApplication().startActivity(resactivity);

Android Notification PendingIntent problem

I have a alarm manager which is calling an activity class named ScheduleAlert.
public class ScheduleAlert extends ActivityGroup {
private String notificationAlart, editEventid;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
...........
..........
// ************* Notification ************//
NotificationManager mNotificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
final Notification notifyDetails = new Notification(R.drawable.icon, "Myapp", nextAlarmTime);
Context context = getApplicationContext();
CharSequence contentTitle = "Myapp";
CharSequence contentText = notificationAlart;
Intent notifyIntent = new Intent(context, MyApp.class);
PendingIntent pendingIntent = PendingIntent.getActivity(ScheduleAlert.this, 0, notifyIntent,android.content.Intent.FLAG_ACTIVITY_CLEAR_TOP);
notifyDetails.setLatestEventInfo(context, contentTitle, contentText,pendingIntent);
notifyDetails.flags = Notification.FLAG_FOREGROUND_SERVICE | Notification.FLAG_AUTO_CANCEL;
notifyDetails.defaults |= Notification.DEFAULT_SOUND | Notification.DEFAULT_VIBRATE;
mNotificationManager.notify((int) editEventid, notifyDetails);
// ************* Notification ************//
this.finish();
}
public void onDestroy(){
super.onDestroy();
}
}
I want that the indent of MyApp activity should fire when I tap on the notification massage. At the time of notification I want just sound and vibration. But now the I am getting the sound and vibration, and also the MyApp activity is fired, which I do not want actually. What is problem in my code?

There are lots and lots of strange things with this code:
I have no idea why you are extending ActivityGroup for this code
Do not use getApplicationContext() in most circumstances, such as this one
Since this is an ActivityGroup (for whatever reason) and not a Service, it is misleading to the OS and the user to have FLAG_FOREGROUND_SERVICE
FLAG_FOREGROUND_SERVICE and FLAG_AUTO_CANCEL make little sense in combination
However, I would not expect any of this to cause MyApp to automatically start. In fact, AFAIK, there is no circumstance in which a Notification will automatically invoke its PendingIntent without the user tapping on it. I suspect that your real problem lies elsewhere.