Delay service action until network connection is available

Question

In my app, I would like to offer an action, which shall be executed in background regularly. So I use the AlarmManager, which starts an IntentService.

The tricky part is, that this background action needs Internet connection. So I tried using a WakeLock which didn't seem to enforce a connection, when the device was locked.

Then I thought about registering a BroadcastReceiver to listen for "android.net.conn.CONNECTIVITY_CHANGE" when the service starts and immediately unregistering it, as soon as the desired broadcast is received.

My code looks something like this:

public class BackgroundService extends IntentService {
    private static final IntentFilter filter =
        new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION);
    private static NetworkStateChangedReceiver receiver =
        new NetworkStateChangedReceiver();

    protected void onHandleIntent(Intent intent) {
        registerReceiver(receiver, filter);
    }
}

My question is now: Will this receiver be destroyed, as soon as the service stops (as it has nothing to do, as long as no connection is available)? And therefore, how can I realize a service, that delays it's work until a network connection is availalbe?

Thanks.

Answer 1

Will this receiver be destroyed, as soon as the service stops (as it has nothing to do, as long as no connection is available)?

Yes. It will live for a few microseconds.

And therefore, how can I realize a service, that delays it's work until a network connection is availalbe?

Use ConnectivityManager and getActiveNetworkInfo(), see if there's a connection, and if not, just exit onHandleIntent() and wait for the next alarm.

Or, register your CONNECTIVITY_ACTION receiver in the manifest and use it to schedule and cancel your alarms, so the alarms are only active while there's a connection.

There are various other strategies, but those two should give you a starting point.