Android: Calling AsyncTask.execute() Crashes The App

I have an activity where I load an image from the given URI. The android training article suggested that it should be done in background so that it does not block the UI. I followe

Solution 1:

Instead of passing ImaageView reference to Async class standard practice try to define custom interface for load bitmap

public interface ImageBitampLoadListener {
    public void onBitampLoad(Bitmap bitmap);
}

Pass custom interface reference Async :

private ImageBitmapLoadListener listener;

public ImageLoaderTask(ImageBitmapLoadListener listener) {
    this.listener = listener;
}

Set call back from Async :

@Override
protected void onPostExecute(Bitmap bitmap) {
   super.onPostExecute(bitmap);
   if(listener!=null){
      listener.onBitampLoad(bitmap);
   }
}

Set custom listener to Async and get Bitamp :

ImageLoaderTask task = new ImageLoaderTask(new ImageBitmapLoadListener() {
    @Override
    public void onBitampLoad(Bitmap bitmap) {
         imageView.setImageBitmap(bitmap);
    }
});
task.execute(uri);

Solution 2:

I solved the issue by overriding onProgressUpdate() method of the AsyncTask. Now my ImageLoader code looks like

@Override
protected void onProgressUpdate(Void... values) {
    try {
        if (imageViewReference != null && bitmap != null) {
            final ImageView imageView = imageViewReference.get();
            if (imageView != null) {
                imageView.setImageBitmap(bitmap);
            }
        }
    } catch (Throwable t) {
        Utils.showErrorDialog(ChatWindow.getInstance(), t);
    }
}

@Override
protected void onPostExecute(Bitmap bitmap) {
    this.bitmap = bitmap;
    onProgressUpdate();
}