CODEWITHSUNDEEP
androidmultithreadingasynchronousdownload
Ahmed Aeon Axan
Ahmed Aeon Axan

Reputation: 2139

Separate downloader class (separate thread) accessed by different activities

Intro : I have 3 activities, DashBoard, Feed and Events. DashBoard is the launched when the application launches. From there the user can goto Feed or Events.

Problem : I want to initiate a download (in a separate thread, of course) when the DashBoard launches. From there the user can goto Feed or Events, and the download would be in progress or already finished. The activities Feed or Event (which ever appropriate at the instance) should be notified that the download is finished and the data is available. What is the best way to accomplish this?

My current code : I have a downloader class DownloadHandler which gets initiated by the DashBoard activity. This class downloads on a separate thread. The class keeps track of a boolean called completed. It is instantiated to false and when the download completes it is changed to true.

Currently My classes Feed or Events will poll the variable completed every 100ms or so in a separate thread so it doesn't block the UI thread. and when the completed variable becomes true it calls a function in that specific class which then queries the DataHandler class for the downloaded data.

This does work, but I feel like my logic is a bit messy and there must be a better way to do it. Because I am using two separate threads, one for downloading, one for polling the completed variable. Is there a better way to do this?

I have read on AsyncTask and different callbacks, but the problem is I cannot specify a callback in a specific class. Because when the download completes the current activity might be DashBoard, Events or Feeds. There is no guarantee which activity will be in front when the download finishes.

Upvotes: 0

Views: 302

Answers (1)

Fabian Knapp
Fabian Knapp

Reputation: 1382

i would fire up a broadcast in my download thread (seting up an intentfilter for that) and registerreceiver in Feeds and Events (dont forget to unregister them in onStop() ). I use this solution often for this purpose - its easy and makes a good job.

BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
        public void onReceive(Context context, Intent intent) {
            // TODO Auto-generated method stub
        }
};

you should solve the rest on your own :) isnt that hard. There are many tuts for that or buy a standard book to get in android.

Upvotes: 1

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