Async Task with JSON Api request

RestApi.java

 private class RestApi extends AsyncTask<String, Void, JSONObject> {
    @Override
    protected JSONObject doInBackground(String... params) {
        return this.GET(params[0]);
    }

    @Override
    protected void onPostExecute(JSONObject jsonObject) {
        super.onPostExecute(jsonObject);
        this.onReceived(jsonObject);
    }

    protected abstract void onReceived(JSONObject json);
 }