Android AsyncTask vs. Threads for a specific case

Question

I am working on an application that Looks similar to the Google Play App (swipe view with gridviews inside the fragments, in addition data in the gridview [image + text] is retrieved from a remote server).

My problem is with background tasks. I can’t decide what to use for retrieval of data from the internet. Mainly I am trying to decide whether to use AsyncTask or manual threading. Of course it would be easier to implement AsyncTask, but after some research I noticed that many people find it limiting.

In my particular case, I want to download data from the internet as Json Objects, parse them and display the data in the gridview. The gridview would have up to 30 items, each item contains a thumbnail and 3 textviews. In Android documentation, they say that AsyncTask is suitable for short operations (few seconds at most). Would filling up to 30 items be considered as a short operation? I want the data to be fetched concurrently. Also I want to support Android phones from API 8 and above. I read that for different APIs AsyncTask behaves differently (serially or concurrently)

My question is: Is it appropriate to use AsyncTask for my app? Or do I have to do everything manually? Is ThreadPoolExecutor a 3rd way to do this? Is it easier than manual threading?

Any advice would be appreciated, I can't move forward in the implementation without deciding on this issue.

Thanks in Advance!

Answer 1

My understanding is that the comment about using AsyncTasks only for short operations is aimed more at not expecting the same views to be available when a long operation finishes. For example, if a user leaves the app and comes back or the current activity goes away for some reason. Typical ways around this would be to use a Service and start up a plain old Thread there, then send some message telling the current Activity to refresh when the operation is done.

The download and processing of your data is likely to be the longest operation. So I'd use that as a basis for whether this is short or long. If you don't care about persisting data at all and don't mind restarting downloads if a user leaves and comes back, you can just use an AsyncTask with very little thought.

If you are using a GridView, you should only ever be populating enough views to for just over the number displayed on the screen at one time.

I'd say that AsyncTask is fine in your situation assuming it's a few kilobytes of data and not megabytes or hundreds of kilobytes. Megs of data, I'd say move to a Service with a Thread. Hundreds of k, is a toss up.

Also, take a look into Loaders... if you want to see an alternative that is better for this kind of loading.

Answer 2

When attending DroidCon in London last year, a presentation brought to my attention why using AsyncTasks for loading data from the network is unreliable.

This presentation was about the RoboSpice library.

The site also has a very nice infographic explaining why exactly AsyncTasks are unreliable and what RoboSpice does to amend these problems.

Disclaimer: I am in no way affiliated with RoboSpice, nor have I ever tried it. I was just impressed and convinced by their presentation that it's a tool worth trying.

Answer 3

Friend, I am working in a project exactly as you need, and to support API 8 and above you should use Asynctask to download anything or you will get a crash for API 15 and above, because it won't even let you run your app without AsyncTask even for short operations.

So as I almost did everything that you need and it is working very well for API 9 above, you should use Asynctask, I´ve implemented SherlockActionbar, EndlessAdapter and ViewPager all with AsyncTask, so go on, if you need more help just ask again later.