Best way to load a notification image?

What is the best way to load a notification image?

Here's my current way: As you can see the image loads synchronously and thus the notification can be delayed. This is a bad way.

public Bitmap getBitmapFromURL(String strURL) {
    try {
        URL url = new URL(strURL);
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.setDoInput(true);
        connection.connect();
        InputStream input = connection.getInputStream();
        Bitmap myBitmap = BitmapFactory.decodeStream(input);
        return myBitmap;
    } catch (IOException e) {
        e.printStackTrace();
        return null;
    }
}

Bitmap bitmap = getBitmapFromURL("https://graph.facebook.com/YOUR_USER_ID/picture?type=large");

// CONSTRUCT THE NOTIFICATION DETAILS
builder.setAutoCancel(true);
builder.setSmallIcon(R.drawable.ic_launcher);
builder.setContentTitle("Some Title");
builder.setContentText("Some Content Text");
builder.setLargeIcon(bitmap);
builder.setContentIntent(pendingIntent);

I really need an answer to continue working on my project.