How to associate a service with a fragment

Question

I try to bind the service to the fragment in the same way as I did successfully in action, but when I try to call a method in the service, I get a NullPointerException - obviously because the service is null. Now there are some problems with service binding in onStart or am I just doing it wrong?

@Override public void onStart() { super.onStart(); Intent intent = new Intent(getActivity(), LiteTrickService.class); getActivity().registerReceiver(receiver, new IntentFilter(LiteTrickService.BROADCAST_ACTION)); getActivity().registerReceiver(receiver, new IntentFilter(LiteTrickService.BROADCAST_FAIL)); getActivity().bindService(intent, mConnection, Context.BIND_AUTO_CREATE); } @Override public void onStop() { super.onStop(); getActivity().unbindService(mConnection); getActivity().unregisterReceiver(receiver); mBound = false; } 

Edit: Sorry. I thought that it was my mistake that I did not ask this question. mConnection is a ServiceConnection and looks like this:

 private ServiceConnection mConnection = new ServiceConnection() { @Override public void onServiceConnected(ComponentName className, IBinder service) { // We've bound to LocalService, cast the IBinder and get LocalService instance LocalBinder binder = (LocalBinder) service; mService = binder.getService(); mBound = true; } @Override public void onServiceDisconnected(ComponentName arg0) { mBound = false; } }; 

Stacktrace:

 01-03 15:21:22.355: E/AndroidRuntime(12360): FATAL EXCEPTION: main 01-03 15:21:22.355: E/AndroidRuntime(12360): java.lang.NullPointerException 01-03 15:21:22.355: E/AndroidRuntime(12360): at lite.hattrick.players.PlayerRankingFragment.onOptionsItemSelected(PlayerRankingFragment.java:205) 

And this will be the exact place where the exception is thrown: case POPULATE_ID:

  if (hasData) { return false; } if(!mBound) getActivity().bindService(new Intent(getActivity().getApplicationContext(), LiteTrickService.class), mConnection, Context.BIND_AUTO_CREATE); mService.refreshPlayers(); // Null Pointer Exception as mService is null pBar.setVisibility(View.VISIBLE); return true; 

Answer 1

I solved the problem. Turns out I forgot to provide a service declaration in my manifest with its correct package name.

changing

 <service android:name=".LiteTrickService" /> 

to

 <service android:name="lite.hattrick.services.LiteTrickService" /> 

I solved the problem and the service is now connecting as expected.

Answer 2

Your NullPointerException is in the mService variable. When you call bindService() , the Activity binds to Service in its own thread. This means that your code will continue to work while the service is required. This causes your mService variable mService remain null .

What you can do is move the code that should run after the Service bound to the onServiceConnected() method of your mConnection . This ensures that the mService variable points to your service and is not equal to zero.