Question

I’m using the following code to grab images from the web. It uses Gridview and depending on position, picks a URL from an array. It works but the loading of images is often hit or miss. Almost every time I start the app, a different number of images load.

It also has issues when changing from portrait to landscape view, 5 out of 10 images may be displayed then I’ll turn the device and usually lose all the images. Sometimes a few do show up though.

Any ideas on making this more robust?

try {
                    URLConnection conn = aURL.openConnection();
                    conn.connect();
                    InputStream is = conn.getInputStream();
                    BufferedInputStream bis = new BufferedInputStream(is);
                    Bitmap bm = BitmapFactory.decodeStream(bis);
                    bis.close();
                    return bm;
            } catch (IOException e) {
                    Log.d("DEBUGTAG", "error...");
            }
            return null;

Answer 1

One thing I read is that there’s a known bug with decoding Bitmaps from an InputStream, and the suggested fix from Google was to use a FlushedInputStream (example in below URL):

http://android-developers.blogspot.com/2010/07/multithreading-for-performance.html

Also, I’d put the download code into an AsyncTask. Here’s what I currently use for mine:

public static Bitmap loadImageFromUri(URI uri)
    {   
        URL url;
        try {
            url = uri.toURL(); 
        } catch (MalformedURLException e) {
            Log.v("URL Exception", "MalformedURLException");
            return null;
        }

        try
        {           
            HttpURLConnection connection = (HttpURLConnection)url.openConnection();
            connection.setDoInput(true);
            connection.connect();
            InputStream input = connection.getInputStream();
            return BitmapFactory.decodeStream(new FlushedInputStream(input));
        }
        catch (IOException e)
        {
            e.printStackTrace();
            return null;
        }
    }

I just pass in a URI due to the way I’ve got the rest of my code set up, you could pass in a URL instead and skip the first part. This will keep the download from tying up your UI thread.