Download multiple files simultaneously in Android apps


I'm writing an application for Android which let users browse a list of files and download them. For every download, I created a thread and I download the file with an HttpURLConnection instance (by reading from the connection in a while loop).

This method works fine with one active download. But when user starts more than one, download performance degrades dramatically. Most of the time, these parallel downloads consume all the bandwidth and the users is unable to browse files (which uses another HttpUrlConnection to load the files list).

Any suggestions on refining the download system? Thanks.

P.S.: The method that popular browsers such as Google Chrome and Firefox do seems good. Anyone knows how they work?

Alas, i don't know of a way to throttle certain connections. However, a practical approach would be to implement a queue of downloads to control the number of simultaneous downloads. In your case, you would probably want to only let 1 thing download at a time. This can be implemented a few different ways.

Here's a way to do it with Handlers and a Looper:

Edit 1: See mice's comment. It may be smarter to have a max of 2 threads downloading at a time.