Sankar Ganesh’s Technical Planet: Notification in Android Using AlarmManager, BoradCastReceiver & Services

Our aim is to show notification message to user in a specific time.

Say For example , I have planned to show Notification Message to user at 2 pm on 25 September 2012, even though the user did not visited my app.

   You can download the complete code from My Github
    https://github.com/sankarganesh/NotificationDemo

          Step 1:

Create a Calendar Object and set the date and time in which we want to show the Notification message to the user. As per our example , we have to set 2012-Sep-06 14:25:00

The Calendar takes the Value for month of January as 0 , the value of Sep should be 8 not 9.

                         Calendar Calendar_Object = Calendar.getInstance();
                         Calendar_Object.set(Calendar.MONTH, 8);
                         Calendar_Object.set(Calendar.YEAR, 2012);
                         Calendar_Object.set(Calendar.DAY_OF_MONTH, 6);

                         Calendar_Object.set(Calendar.HOUR_OF_DAY, 14);
                         Calendar_Object.set(Calendar.MINUTE, 25);
                         Calendar_Object.set(Calendar.SECOND, 0);

Step 2:

We need to create an alarm which help us to invoke the BroadCastReceiver on our specified time.

// MyView is my current Activity, and AlarmReceiver is the BoradCastReceiver

                             Intent myIntent = new Intent(MyView.this, AlarmReceiver.class);

                            PendingIntent pendingIntent = PendingIntent.getBroadcast(
                            MyView.this, 0, myIntent, 0);

                           AlarmManager alarmManager = (AlarmManager)                              getSystemService(ALARM_SERVICE);

The following sets the Alarm in the specific time by getting the long value of the alarm date time which is in calendar object by calling the getTimeInMillis(). Since Alarm supports only long value , we're using this method.

alarmManager.set(AlarmManager.RTC, Calendar_Object.getTimeInMillis(),
pendingIntent);

Step 3:

We need to create a BroadCastReceiver which invoked when our alarm is triggered.

import android.content.BroadcastReceiver;
                            import android.content.Context;
                            import android.content.Intent;

                            public class AlarmReceiver extends BroadcastReceiver {

         @Override
   public void onReceive(Context context, Intent intent) {

// When our Alaram time is triggered , this method will be excuted (onReceive)

                                 // We're invoking a service in this method which shows Notification to the User
            Intent myIntent = new Intent(context, NotificationService.class);
          context.startService(myIntent);
                                }

                          }

Step 4:

We need to Create a Service which will show Notification to the User.

                           import android.app.Notification;
                           import android.app.NotificationManager;
                           import android.app.PendingIntent;
                           import android.app.Service;
                           import android.content.Intent;
                           import android.os.IBinder;

                           public class NotificationService extends Service {

   private NotificationManager mManager;

                               @Override
                                public IBinder onBind(Intent arg0) {
       // TODO Auto-generated method stub
                                 return null;
   }

                               @Override
   public void onCreate() {
         super.onCreate();
   }

   @Override
   public void onStart(Intent intent, int startId) {
               super.onStart(intent, startId);

                              // Getting Notification Service
              mManager = (NotificationManager) this.getApplicationContext()
                         .getSystemService(                                                         this.getApplicationContext().NOTIFICATION_SERVICE);

When the user taps the notification we have to show the Home Screen of our App, this job can be done with the help of the following Intent.

                                Intent intent1 = new Intent(this.getApplicationContext(),
            MyView.class);

       Notification notification = new Notification(R.drawable.icon,
            "See My App something for you", System.currentTimeMillis());

       intent1.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP
                                | Intent.FLAG_ACTIVITY_CLEAR_TOP);

                               PendingIntent pendingNotificationIntent = PendingIntent.getActivity(
               this.getApplicationContext(), 0, intent1,
                               PendingIntent.FLAG_UPDATE_CURRENT);

notification.flags |= Notification.FLAG_AUTO_CANCEL;

notification.setLatestEventInfo(this.getApplicationContext(), "SANBOOK",
"See My App something for you", pendingNotificationIntent);

                              mManager.notify(0, notification);
    }

    @Override
    public void onDestroy() {
        // TODO Auto-generated method stub
        Logger.error("Alam Services Destroyed");
        super.onDestroy();
    }

}

Step 5:

Don't forget to register your Broadcast Receiver as well as Services and your Activity in Manifest File.

Also Don't forget to add the permission <uses-permission android:name="android.permission.WAKE_LOCK" />

Step 6:

Here's the output in Tablet Devices and Mobile

Tablet Device: