Question

I have this application that needs to run a service (background) that beeps periodically.
The phone needs to beep the entire day for 5 seconds every one minute (used a handler in the service). I have implemented this service which does this perfectly, but when the phone goes into deep sleep mode, the execution stops of this handler stops. Using this answer from the question in SO, I managed to use wake locks and it works fine. But when I explicitly put the phone in deep sleep mode, the handler stops executing. Where do I place the wakelock in the service. Code snippet below.

public class PlaySound extends Service{
PowerManager.WakeLock wl ;
    PowerManager pm;
private SoundManager mSoundManager;
    boolean wakeUpFlag = false;

@Override
    public void onCreate(){
        super.onCreate();
        mSoundManager = new SoundManager();
        mSoundManager.initSounds(getBaseContext());
        mSoundManager.addSound(1, R.raw.sound);
    }
@Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        startservice();
        return START_STICKY;
    }
private void startservice() {
        System.out.println("Started the service");
        timer.scheduleAtFixedRate( new TimerTask() {
            public void run() {
                toastHandler.sendEmptyMessage(0);
            }
        }, 0, 60000);
    }
private final Handler toastHandler = new Handler()
    {
        @Override
        public void handleMessage(Message msg)
        {
            result =start();

                System.out.println("result"+result);
                close();
        }
    };

protected void close() {
        try {
            if(wakeUpFlag){
                wl.release();
                System.out.println("Released the wakelock");
            }

            if(!pm.isScreenOn()){
                System.out.println("Screen is off - back to sleep");
                pm.goToSleep(1000);
            }
            else{
                System.out.println("Screen is on - no need to sleep");
            }
            bs.close();
            writer.close();
            System.out.println("Closed socket and writer");
            System.out.println("Size of file:"+f.length()/1024);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
public void start(){
        try{
            wakeUpFlag = false;
            pm = (PowerManager)getSystemService(Context.POWER_SERVICE);


            if(!pm.isScreenOn()) {
                wakeUpFlag  = true;
                wl = pm.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK | PowerManager.ON_AFTER_RELEASE,"CollectData");
                System.out.println("Screen off - wake lock acquired");
                wl.acquire();
            }
            else{
                System.out.println("Screen on - no need of wake lock");
            }



        }
        catch(Exception e){
            e.printStackTrace();
        }
mSoundManager.playSound(1);
}

Answer 1

Follow the pattern Mark Murphy provides with the WakefulIntentService. I would suggest picking up his books, not only for the detailed explanation of this class and example he includes in one of them, but for the other wealth of information you’ll find in them.

I just recently implemented this pattern for my main app and this class works like a charm.