Estúdio Android Carregar URL da imagem na visualização de lista

class ImageDownloaderTask extends AsyncTask<String, Void, Bitmap> {

    private final WeakReference<ImageView> imageViewReference;

    public ImageDownloaderTask(ImageView imageView) {
        imageViewReference = new WeakReference<ImageView>(imageView);
    }

    @Override
    protected Bitmap doInBackground(String... params) {
        return downloadBitmap(params[0]);
    }

    @Override
    protected void onPostExecute(Bitmap bitmap) {
        if (isCancelled()) {
            bitmap = null;
        }

        if (imageViewReference != null) {
            ImageView imageView = imageViewReference.get();
            if (imageView != null) {
                if (bitmap != null) {
                    imageView.setImageBitmap(bitmap);
                } else {
                    Drawable placeholder = null;
                    imageView.setImageDrawable(placeholder);
                }
            }
        }
    }

    private Bitmap downloadBitmap(String url) {
        HttpURLConnection urlConnection = null;
        try {
            URL uri = new URL(url);
            urlConnection = (HttpURLConnection) uri.openConnection();

            final int responseCode = urlConnection.getResponseCode();
            if (responseCode != HttpURLConnection.HTTP_OK) {
                return null;
            }

            InputStream inputStream = urlConnection.getInputStream();
            if (inputStream != null) {
                Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
                return bitmap;
            }
        } catch (Exception e) {
            urlConnection.disconnect();
            Log.w("ImageDownloader", "Errore durante il download da " + url);
        } finally {
            if (urlConnection != null) {
                urlConnection.disconnect();
            }
        }
        return null;
    }
}

new ImageDownloaderTask(holder.imageView).execute(urlPhoto);