Handle Empty or Null Cases

protected Event doInBackground(String... urls){
	if (urls.length < 1 || urls[0] == null){
		return null;
	}

	Event result = Utils.fetchEarthquakeData(urls[0]);
	return result;
}

protected void onPostExecute(Event result){
	if (result == null){
		return;
	}
	updateUi(result);
}

private class EarthquakeAsyncTask extends AsyncTask {

	protected Event doInBackground(String... urls){
		if (urls.length < 1 || urls[0] == null){
			return null;
		}

		Event result = Utils.fetchEarthquakeData(urls[0]);
		return result;
	}

	protected void onPostExecute(Event result){
		if (result == null){
			return;
		}

		updateUi(result);
	}

}