Question

I am developing an Android app which needs to poll a specific webpage in time intervals. I’ve got it to the point where it does indeed poll the page on a specific interval, and that interval is specified in a SharedPreference which can be changed by the user in the settings page of the app. But complications arise when network connectivity is flaky.

For example, how do I ensure that the Service “wakes up” the network adapter and gives it ample time to connect before polling the page, in the case that the phone was sleeping to save power? This polling action can happen as little as once every 24 hours, so I don’t want to miss one action just because the network was out (but turned on a few seconds, minutes, or even hours later).

Or there are times when the web service doesn’t respond, or DNS doesn’t respond, or what have you, and for any reason it doesn’t get a response even though the phone is technically connected. What sort of rule do I put in place to make this retry later, so that I’m not retrying repeatedly when the user specifically turned off their internet but I’m retrying soon enough that if it was just a hiccup, the data can be received soon after the first try?

Are there any examples for this type of situation? What is the logic to best handle this?

Answer 1

Listen for CONNECTIVITY_ACTION

This looks like good sample code. Here is a snippet:

        IntentFilter filter = new IntentFilter();
        filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
        context.registerReceiver(mReceiver, filter);

Check out this other question about How can we get notified if the phone has got internet access?