You should create an IntentService. Send an intent to the service to start it. Send back an intent with the result using a LocalBroadcastManager (from the support library). The IntentService stops itself when it completes, unlike regular Services.
If the user rotates the device while the AsyncTask is executing the result will be lost since the AsyncTask thread is associated with the activity that was destroyed by the rotation. You can find an example here on StackOverflow of how to circumvent this problem, but it's much more code and more complex than writing an IntentService. Since the IntentService is on its own thread, it doesn't get lost when the activity is destroyed.
public class MyIntentService extends IntentService {
public static final String SERVICE_NAME ="whatever";
public MyIntentService() {
super("MyIntentService");
}
@Override
protected void onHandleIntent(Intent intent) {
//Get input from the intent, do your http stuff here,
// create a new intent to send back
LocalBroadcastManager.getInstance(this).sendBroadcast(intentToSendBack);
}
}
Check out the IntentService docs: Intent Service is about 1/3 down the page
Use a LocalBroadcastManager in your activity to listen for the returning intents. You just hook it up in the OnResume event handler and unhook it in the OnPause handler. So after your original activity is destroyed on the rotation, the new one will start listening. The magic of LocalBroadcastManager queues up the intent for that small period of time between the destruction of the first activity and the creation of the second.
@Override
protected void onResume() {
super.onResume();
IntentFilter filter = new IntentFilter(MyIntentService.SERVICE_NAME);
LocalBroadcastManager.getInstance(this).registerReceiver(onNotice, filter);
}
@Override
protected void onPause() {
super.onPause();
LocalBroadcastManager.getInstance(this).unregisterReceiver(onNotice);
}
private BroadcastReceiver onNotice = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
//Do your UI stuff here....
}
}
There is more detail on LocalBroadcastManager in the docs. There are some other good side effects of LocalBroadcastManager. Intents sent this way do not leave the application scope, so other apps can't snoop on data you pass around, and your activity processes the result without being forced into the foreground.
Don't forget to register the service in your AndroidManifest.xml.
