ImageFetcherActivity.java

public class ImageFetcherActivity extends AppCompactActivity {
    class WorkerThread extends Thread {
        void fetchImage(String url) {
            // network logic to create and execute request
            handler.post(new Runnable() {
                @Override
                public void run() {
                    imageView.setImageBitmap(image);
                }
            });
        }
    }
    
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        // prepare the view, maybe setContentView, etc
        new WorkerThread().fetchImage(imageUrl);
    }
}