androidtimernstimer

How to run a method every X seconds


I'm developing an Android 2.3.3 application and I need to run a method every X seconds.

In iOS, I have NSTimer, but in Android I don't know what to use.

Someone have recommend me Handler; another recommend me AlarmManager but I don't know which method fits better with NSTimer.

This is the code I want to implement in Android:

timer2 = [
    NSTimer scheduledTimerWithTimeInterval:(1.0f/20.0f)
    target:self
    selector:@selector(loopTask)
    userInfo:nil
    repeats:YES
];

timer1 = [
    NSTimer scheduledTimerWithTimeInterval:(1.0f/4.0f)
    target:self
    selector:@selector(isFree)
    userInfo:nil
    repeats:YES
];

I need something what works like NSTimer.

What do you recommend me?


Solution

  • The solution you will use really depends on how long you need to wait between each execution of your function.

    If you are waiting for longer than 10 minutes, I would suggest using AlarmManager.

    // Some time when you want to run
    Date when = new Date(System.currentTimeMillis());
    
    try {
        Intent someIntent = new Intent(someContext, MyReceiver.class); // intent to be launched
    
        // Note: this could be getActivity if you want to launch an activity
        PendingIntent pendingIntent = PendingIntent.getBroadcast(
            context,
            0, // id (optional)
            someIntent, // intent to launch
            PendingIntent.FLAG_CANCEL_CURRENT // PendingIntent flag
        );
    
        AlarmManager alarms = (AlarmManager) context.getSystemService(
            Context.ALARM_SERVICE
        );
    
        alarms.setRepeating(
            AlarmManager.RTC_WAKEUP,
            when.getTime(),
            AlarmManager.INTERVAL_FIFTEEN_MINUTES,
            pendingIntent
        );
    } catch(Exception e) {
        e.printStackTrace();
    }
    

    Once you have broadcasted the above Intent, you can receive your Intent by implementing a BroadcastReceiver. Note that this will need to be registered either in your application manifest or via the context.registerReceiver(receiver, intentFilter); method. For more information on BroadcastReceiver's please refer to the official documentation..

    public class MyReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent)
        {
            System.out.println("MyReceiver: here!") // Do your work here
        }
    }
    

    If you are waiting for shorter than 10 minutes then I would suggest using a Handler.

    final Handler handler = new Handler();
    final int delay = 1000; // 1000 milliseconds == 1 second
    
    handler.postDelayed(new Runnable() {
        public void run() {
            System.out.println("myHandler: here!"); // Do your work here
            handler.postDelayed(this, delay);
        }
    }, delay);