Download files in queue in Android

Question

How do I download multiple files in a queue one by one! I'm using this as a sample code, since. I would be passing the URLs to download in Strings from my local DB dynamically.

Please let me know how to do that. I want the download to start as soon as the application launches. Kindly help me out! Android Dev Type: Newbie Purpose of Download Queue: To download multiple files from the server after in-app billing gets successful!

P.S.: I already referenced this question. But I'm not sure if that would solve my issue!

Answer 1

A good way of queuing up requests to be handled asynchronously, one at a time, is with an IntentService. If you have an IntentService which reads URLs from the supplied Intent, then all you have to do is create an Intent for each file you want to download, and send each Intent to the service,

Here is a good tutorial.

EDIT: I see you've already referred to a similar question, where the answer recommends IntentService. So, maybe you should use an IntentService. :)

Answer 2

From API 11 up, a good approach is to use a FixedThreadPool with async tasks. Do once:

ExecutorService threadPoolExecutor = Executors.newFixedThreadPool(3);

Where 3 is the number of downloads you want to run at the same time. It will queueu the task if there are already 3 downloads running, and automatically handle the task later. Launch your async tasks with:

yourAsynTask.executeOnExecutor(threadPoolExecutor, params);

Params is probably the url you wish to connect to. You can read it out in the onPostExecute of your asynctask, and connect to the server using a HttpURLConnection.

Make sure you call down this on shutdown:

threadPoolExecutor.shutdown()

Answer 3

What's the best way to implement a download queue in Android?

Use an IntentService. It supplies the queue and the background thread for you, so all you have to do is put your download logic in onHandleIntent(). See here for a sample project demonstrating this.