Question

I’m porting some of my Windows Phone 7 apps to Android. When we call services in the WP7 world, the calls are async. We call the service and there is a delegate _completed event that triggers when when the result is returned. Meanwhile we go on about our way.

The java android code pasted below is how I am calling an HTTP service on my cloud server. I developed this code by going through Android tutorials teaching how to call a service in the android world. Apparently, service calls here are synchronus so the instruction starting with InputStream in… doesn’t get executed until the result is returned.

Is this how it is supposed to work for Android? If the service does not respond, there is a wait of a couple minutes and then a timeout exception takes place. That’s no good. Everything will hang.

What is the reccommended way to call services in android?
Thanks, Gary

    public void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    HttpURLConnection urlConnection = null;

        try 
        {
            URL url = new URL("http://www.deanblakely.com/REST/api/products");
            urlConnection = (HttpURLConnection) url.openConnection();
            InputStream in = new BufferedInputStream(urlConnection.getInputStream());     
            String myString = readStream(in);
            String otherString = myString;
            otherString = otherString + " ";
        } 
        catch (MalformedURLException e) 
        {
            e.printStackTrace();
        } 
        catch (IOException e) 
        {   
            e.printStackTrace();
        }  

        finally 
        {     
            urlConnection.disconnect();   
        } 
}       

Answer 1

Is this how it is supposed to work for Android?

Yes. Do HTTP operations in a background thread, such as the one supplied by an AsyncTask.

If the service does not respond, there is a wait of a couple minutes and then a timeout exception takes place. That’s no good. Everything will hang.

You can set a socket timeout to be something shorter than “a couple minutes”. For example, you can call setReadTimeout() on your HttpURLConnection to specify a timeout period in milliseconds.