Android,AsyncTask中的实用程序类和松散耦合请指教

这就是我的工作,我从StackOverflow中了解到:

假设我们正在从服务器数据库下载类别

首先,创建一个接口

public interface OnCategoriesDownloadedListener {
    public void onCategoriesDownloadSuccess(ArrayList<String> categories);
    public void onCategoriesDownloadFailure(String reason);
}

然后,在等待下载这些类别的活动中,我实现了这个接口:

public class MyActivity extends Activity implements  OnCategoriesDownloadedListener {

    @Override
    onCategoriesDownloadSuccess(ArrayList<String> categories) {
        //get the categories and do whatever my soul desire
    }

    @Override
    onCategoriesDownloadFailure(String reason) {
       //get the reason and come up with appropriate failure excuse
    }

}

在我的asynctask类中,我执行以下操作

public class GetCategoriesFromServerAsync extends AsyncTask<String, String, ArrayList<String>> {


private OnCategoriesDownloadedListener listener;
private ArrayList<String> categoryNamesArray;
private String reason;

public GetCategoriesFromServerAsync(OnCategoriesDownloadedListener listener) {
    this.listener = listener;
            //usually I pass more data here, for example when Im registering a user in the server database, Im using the constructor to pass their data.
}

@Override
protected ArrayList<String> doInBackground(String... args) {
    int success;

    try {
        //JSON stuff

            return categoryNames;

        } else if (success == 2) {
            reason = "failure";
            return null;
        } else {
            reason = "Connection error";
            return null;
        }
    } catch (JSONException e) {
        e.printStackTrace();
        reason = "Connection error";
        return null;
    }
}

@Override
protected void onPostExecute(Object[] categoryNamesAndLogos) {

    if (listener != null) {
        if (categoryNames!=null) {
            listener.onCategoriesDownloadSuccess(categoryNames);
        } else if (reason.contentEquals(TAG_FAILURE)) {
            listener.onCategoriesDownloadFailure(reason);
        } else if (reason.contentEquals(TAG_CONNECTION_ERROR)) {
            listener.onCategoriesDownloadFailure(reason);
        }

    }
    super.onPostExecute(categoryNames);
}

}

从实现侦听器的活动开始,我使用其构造函数启动asynctask:

new GetCategoriesFromDatabase(this).execute();

因此注意到该活动正在实施听众并正在等待结果.

在asynctask postExecute中我只处理结果,将它们发送到等待它们的活动并在onCategoriesDownloadSuccess方法中处理它们

如果要显示Loader,可以在启动活动的asynctask的同时将其显示在onSuccess和onFailure方法中.此时我在AsyncTask的onPreExecute和onPostExecute中执行此操作,但我需要花一些时间或建议并考虑哪种方法更好.

不确定这是否是最佳做法,因为它是我所知道的唯一一个,但它肯定对我有用.