AsyncTask Callback Example

gistfile1.java

public class Act extends Activity {
	OnTaskCompleted otc = new OnTaskCompleted() {
		@Override
		public void onTaskCompleted(String result) {
			Log.d("onTaskCompleted", result);
		}
	};
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		Async a = new Async(otc);
		a.execute();
	}
}

gistfile2.java

public interface OnTaskCompleted {
	void onTaskCompleted(String result);
}

gistfile3.java

public class Async extends AsyncTask<String, Void, String> {
	private OnTaskCompleted listener;
	private String result;
	public Async(OnTaskCompleted listener) {
		this.listener = listener;//
	}
	@Override
	protected String doInBackground(String... arg0) {
		//do thread work
		return result;
	}
	protected void onProgressUpdate(Integer... progress) {

	}
	@Override
	protected void onPostExecute(String result) {
		try {
			listener.onTaskCompleted(result);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}