Which is the best method to excecute a task repeatedly in android ? (Eg :- Refreshing scores, Update Ui)

Question

In android there are some options for refresh handling such as Timer, TimerTask, ScheduledExecutorService, AlarmManager & Handler. Which is the best method to do this.

Did anyone checks the resource utilization of above mentioned methods?. I am listing the implementation of above mentioned methods here.

Using Handler for executing a task repeatedly

final Handler handler = new Handler();
handler.postDelayed(new Runnable() {

    public void run() {
        new MyScheduledTask.execute(param);
    }

}, TimeInterval);

Using Timer for executing a task repeatedly

timer = new Timer();

timer.scheduleAtFixedRate(new TimerTask() {

    synchronized public void run() {
        new MyScheduledTask.execute(param);
        }

}}, 10000, 10000);

Using ScheduledExecutorService for excuting a task repeatedly

ScheduledExecutorService scheduler =
Executors.newSingleThreadScheduledExecutor();
scheduler.scheduleAtFixedRate
  (new Runnable() {
     public void run() {
        new MyScheduledTask.execute(param);
     }
  }, 0, 10, TimeInterval);

Using Timer with TimerTask for executing a task repeatedly

Timer timer = new Timer();
timer.schedule(new UpdateTimeTask(),1, TimeInterval);
class UpdateTimeTask extends TimerTask {

    public void run() 
       {        
        new MyScheduledTask.execute(param);
       }
}

AlarmManager for executing scheduled task

public void setupTask(){

    // check task is scheduled or not
    boolean alarmUp = (PendingIntent.getBroadcast(this, 0, 
            new Intent("YourPackageHere.AlarmReceiver"), 
            PendingIntent.FLAG_NO_CREATE) != null);

    if (  !alarmUp) {
        Intent intent = new Intent("YourPackageHere.AlarmReceiver");
        intent.putExtra("activate", true);
        PendingIntent pendingIntent =
                    PendingIntent.getBroadcast(this, 0, 
                  intent, PendingIntent.FLAG_UPDATE_CURRENT);

        Calendar calendar = Calendar.getInstance();
        calendar.setTimeInMillis(System.currentTimeMillis());
        calendar.set(Calendar.HOUR_OF_DAY, 0);   
        calendar.set(Calendar.MINUTE, 1);
        calendar.set(Calendar.SECOND, 0);

        AlarmManager alarmManager =
                    (AlarmManager)
                    this.getSystemService(this.ALARM_SERVICE);
        alarmManager.setRepeating(AlarmManager.RTC_WAKEUP,
                    calendar.getTimeInMillis(), AlarmManager.INTERVAL_DAY,
                    pendingIntent);

        calendar = Calendar.getInstance();
        calendar.setTimeInMillis(System.currentTimeMillis());
        calendar.set(Calendar.HOUR_OF_DAY, 7);   
        calendar.set(Calendar.MINUTE, 0);

        alarmManager = (AlarmManager)
                    this.getSystemService(this.ALARM_SERVICE);
        PendingIntent pendingIntent2 =
                    PendingIntent.getBroadcast(this, 1, 
                intent, PendingIntent.FLAG_UPDATE_CURRENT);
        alarmManager.setRepeating(AlarmManager.RTC_WAKEUP,
                    calendar.getTimeInMillis(),
                    AlarmManager.INTERVAL_DAY, pendingIntent2);         

    }

}

AlarmManager class

public class AlarmReceiver extends BroadcastReceiver { 

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

    if (intent.hasExtra("activate")) {

        new MyScheduledTask.execute(param);
    }

}
}

Manifest

<receiver android:name="YourPackageHere.AlarmReceiver"></receiver>

Answer 1

For being continuously online you'll need an android Service running above a thread. You can use any of the above methods you stated with a service.

BUT as you are making a chat application you'll have to hit the server continuously for every 2-3 seconds, which I think is not good for the user(in terms of internet data that your app will use).

The best recommended protocol to use for a chat application is XMPP(Jabber). It defines all the rules that a normal chat application should have and is very easy to implement. It is a push notification type server which will automatically push a notification to the client whenever a new message has arrived or a new friend is added.(Even Gtalk uses this protocol)

There is a good open source server that provides the XMPP integration named Openfire, which I would recommend.

The same company also provides a library for client side integration named Smack which you can easily implement in your application to use the simple chat functionality.