Question

A small part of my application checks if files exist on the user’s device. The list of files is potentially quite long – apparently long enough to cause ANR’s with a few users. A thousand files is by no means impossible.

The code is quite simple:

new File(fileUrl).exists()

I’m currently doing it on the main thread, as I need the operations to be blocking. I could do it using an AsyncTask class and then continue the rest of the work once it’s done, but I’m wondering if that’s a valid cause?

All the work is being done in a background Service, if that changes anything. I’m also potentially going to experience orientation changes, and that might be annoying with AsyncTask. Would a Handler be better?

So, to sum things up: Should I do use an AsyncTask for a potentially long-running operation in a background Service, where orientation changes may occur?

Answer 1

Firstly, a Service isn’t affected by orientation change – it’s only the currently running Activity class which is destroyed / recreated.

Secondly, an AsyncTask isn’t of much advantage in a Service as it’s designed to be able to interact with the UI. It would give the advantage of doing work on a separate thread but the rest of the methods would basically be redundant.

I’d recommend using an IntentService which manages its own worker thread to do work. See the IntentService documentation