Question

Given the image url, I need to download it and display in an ImageView.
Everything works fine, except the situation when the images are quite large, and an OutOfMemoryException is thrown.

Hopefully, Android documentation provides a solution to this problem: http://developer.android.com/training/displaying-bitmaps/load-bitmap.html

I tried to adapt that snipped of code to accept an InputStream, instead of a Resource.
However, it seems I am missing something there, because the image is not displayed, no exception, but I see in the LogCat this: SkImageDecoder::Factory returned null

Here is how I decode the image and scale it down (based on Android documentation):

public static Bitmap decodeBitmapFromInputStream(InputStream inputStream,
            int reqWidth, int reqHeight) {
        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeStream(inputStream, null, options);

        options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);

        options.inJustDecodeBounds = false;
        return BitmapFactory.decodeStream(inputStream, null, options);
    }

    public static int calculateInSampleSize(BitmapFactory.Options options,
            int reqWidth, int reqHeight) {
        final int height = options.outHeight;
        final int width = options.outWidth;
        int inSampleSize = 1;

        if (height > reqHeight || width > reqWidth) {
            if (width > height) {
                inSampleSize = Math.round((float) height / (float) reqHeight);
            } else {
                inSampleSize = Math.round((float) width / (float) reqWidth);
            }
        }
        return inSampleSize;
    }

Now, in my bitmap downloader method, I call it like this:

inputStream=entity.getContent();
return decodeBitmapFromInputStream(inputStream, 320, 480);

Here’s the full method, just in case:

static Bitmap downloadBitmap(String url){
        AndroidHttpClient client=AndroidHttpClient.newInstance("Android");
        HttpGet getRequest=new HttpGet(url);

        try{
            HttpResponse response=client.execute(getRequest);
            int statusCode=response.getStatusLine().getStatusCode();

            if(statusCode!=HttpStatus.SC_OK){
                Log.d("GREC", "Error "+statusCode+" while retrieving bitmap from "+url);
                return null;
            }

            HttpEntity entity=response.getEntity();
            if(entity!=null){
                InputStream inputStream=null;
                try{
                    inputStream=entity.getContent();
                    return decodeBitmapFromInputStream(inputStream, 320, 480);
                }catch (Exception e) {
                    Log.d("GREC", "Exception occured in BitmapDownloader");
                    e.printStackTrace();
                }
                finally{
                    if(inputStream!=null){
                        inputStream.close();
                    }
                    entity.consumeContent();
                }
            }
        }catch (Exception e) {
            getRequest.abort();
            Log.d("GREC", "Error while retriving bitmap from "+url+", "+e.toString());
        }finally{
            if(client!=null){
                client.close();
            }
        }
        return null;
    }

Answer 1

The problem was that once you’ve used an InputStream from a HttpUrlConnection, you can’t rewind and use the same InputStream again. Therefore you have to create a new InputStream for the actual sampling of the image. Otherwise we have to abort the http request.
see decodeStream returns null