AtomicReference中的第二个新对象！= class.this

Question

I'm reading some android service code which handles gps coordinates and sets AtomicReference with new Object for 1 time :

public class SingleLocationUpdateService extends ServicePart {
 private final AtomicReference<GPSUpdater> currentUpdater = new AtomicReference<>();
 @Override
protected boolean onStart() {
    lastSaverModeOn = mService.getSettings().getRootSettings().isSaverModeOn();
    if (mService.getSettings().getRootSettings().isStopMileageInWorkOn()) {
        if (lastSaverModeOn) {
            return false;
        }
    }

    singleUpdateSeconds = mService.getSettings().getRootSettings().getGpsRareUpdateSeconds();
    ***currentUpdater.set(new GPSUpdater());***
    mService.getExecutor().schedule(currentUpdater.get(), 10, TimeUnit.SECONDS);
    return true;
}

Then sheduler executes this:

private class GPSUpdater implements Runnable, LocationListener {

 @Override
    public void run() {
        if (!isCurrentRunning()) {
            return;
        }
        Log.d(TAG, "Requesting single location update");
        final LocationManager lm = (LocationManager) mService.getSystemService(Context.LOCATION_SERVICE);
        try {
            lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this, Looper.getMainLooper());
        } catch (Throwable t) {
            Log.e(TAG, "Failed to request single location update", t);
        }
        reschedule();
    }

    private boolean isCurrentRunning() {
        return isStarted() && currentUpdater.get() == GPSUpdater.this;
    }

    private void reschedule() {
        final LocationManager lm = (LocationManager) mService.getSystemService(Context.LOCATION_SERVICE);
        lm.removeUpdates(this);

        final GPSUpdater next = new GPSUpdater();

        if (isStarted() && currentUpdater.compareAndSet(GPSUpdater.this, next)) {
            Log.d(TAG, "Rescheduling single location updater");
            mService.getExecutor().schedule(next, 10, TimeUnit.SECONDS);
        }
    }

In debugger if I run currentUpdater.compareAndSet(GPSUpdater.this, next) for 1 time it returns true, so means new GPSUpdater(which was set in onStart()) == GPSUpdater.this. Then AtomicReference is set to next. But next is also new GPSUpdater. But if u eveluate currentUpdater.compareAndSet(GPSUpdater.this, next) 2 time, it will return false. So for 2 time new GPSUpdater != GPSUpdater.this. How can it be explained correctly? If I create 2 new object references - only the first one will be equal to its class reference? Why? Thx in advance.

Answer 1

You are creating two different objects of the Class GPSUpdater by calling for each of them new GPSUpdater() . Therefore if you want to compare two objects you should better use the equals() method. And if you wrote the GPSUpdate Class by yourself you may need to overwrite the equals() method to produce appropriate results. By this I mean that equals should return true if you define two objects to be equal. If you use the == Operator to check if two objects are the same only there reference is checked not the real "content" of the objects