从内部类获取 Arraylist

Question

我正在寻求帮助，以便我可以在另一个班级获得ArrayList<String>。正如您在下面的代码中看到的那样，我有内部和外部类。两者都按预期工作，并且我都能够使用 php 脚本从我的在线数据库中插入值和获取详细信息（为了代码清晰，我已经注释掉了这些详细信息，因为它占用了大量空间）。

public class ServerRequests {

ProgressDialog progressDialog;
public static final int CONNECTION_TIMEOUT = 15000;
public static final String SERVER_ADDRESS = "// my url domain";

public ArrayList<String> list1 = new ArrayList<>();


public ServerRequests(Context context)
{
    progressDialog = new ProgressDialog(context);
    progressDialog.setCancelable(false);
    progressDialog.setTitle("Processing");
    progressDialog.setMessage("Please wait..");

}


public void storeDataInBackground(MultiChallenge multiChallenge)
{
    progressDialog.show();
    new StoreDataAsyncTask(multiChallenge).execute();

}

public class StoreDataAsyncTask extends AsyncTask<Void , Void , Void>
{
    MultiChallenge multiChallenge;


    public StoreDataAsyncTask(MultiChallenge multiChallenge)
    {
        this.multiChallenge = multiChallenge;

    }

    @Override
    protected Void doInBackground(Void... voids) {
        // where I insert values...

    @Override
    protected void onPostExecute(Void aVoid) {
        progressDialog.dismiss();
        super.onPostExecute(aVoid);
        Log.d("ServerRequests", "Post execute");
    }

}

public ArrayList<String> fetchDataInBackground() {
    progressDialog.show();
    new FetchDataAsyncTask().execute();

    return list1;
}

public class FetchDataAsyncTask extends AsyncTask<Void, Void, ArrayList<String>>
{
    public FetchDataAsyncTask()
    {

    }

    String text = "";

    @Override
    protected ArrayList<String> doInBackground(Void... params) {

         InputStream is1;

        HttpParams httpRequestParams = new BasicHttpParams();
        HttpConnectionParams.setConnectionTimeout(httpRequestParams, CONNECTION_TIMEOUT);
        HttpConnectionParams.setSoTimeout(httpRequestParams, CONNECTION_TIMEOUT);

        HttpClient client = new DefaultHttpClient(httpRequestParams);
        HttpPost post = new HttpPost(// my url domain+ "// php script");

        try {

            HttpResponse httpResponse = client.execute(post);
            is1 = httpResponse.getEntity().getContent();

            BufferedReader reader;

            reader = new BufferedReader(new InputStreamReader(is1, "iso-8859-1"), 8);
            String line = null;
            while ((line = reader.readLine()) != null) {
                text += line + "\n";
            }
            is1.close();


            JSONArray data = new JSONArray(text);

            for (int i = 0; i < data.length(); i++) {
                Log.d("GetNames", data.getString(i));
                JSONObject jsonData = data.getJSONObject(i);
                list1.add( // I successfully add details to list1 here, I have commented it out for code clarity);

            }

            for (int iterate = 0; iterate < list1.size(); iterate++) {
                Log.d("list1", list1.get(iterate));
            }


        } catch (IOException e) {
            e.printStackTrace();
        } catch (JSONException e) {
            e.printStackTrace();
        }

        // catch (JSONException e) {e.printStackTrace();}

        return list1;

    }


    @Override
    protected void onPostExecute(ArrayList<String> myList) {
        progressDialog.dismiss();
        super.onPostExecute(myList);

    }
}

}

现在我已成功添加到 list1（我可以告诉它添加了值，因为带有 int 迭代的 for 循环），我现在需要将它发送到另一个类，我将把项目放在 @ 987654324@。这是我在类中的代码，我想在其中显示从ServerRequests 获得的ArrayList 的详细信息：

ServerRequests serverRequests = new ServerRequests(DisplayInfo.this);

            ArrayList<String> myList = new ArrayList<>();
            myList = serverRequests.fetchDataInBackground();

            for (int iterate = 0; iterate < myList.size(); iterate++) {
                Log.d("Display", myList.get(iterate));

然而，上面的 for 循环从未被调用，这表明myList 从未被提供list1 设法在FetchDataAsync 类的doInBackground 方法中获取的详细信息。

请注意，在提出这个问题之前，我确实花了几个小时尝试从 SO 得出的各种想法和答案。提前感谢大家的帮助。

Answer 1

在 onPostExecute 方法中调用调用类中的一个函数

@Override
protected void onPostExecute(ArrayList<String> myList) {
    progressDialog.dismiss();
    super.onPostExecute(myList);
    MainActivity.sendStrings(myList);

}

在调用函数中实现一个方法：

public static void sendStrings(ArrayList<String> strings)
{
  //Add for loop here
}

或者，您也可以使用接口。在 onPostExecute 中调用接口并在调用类中实现接口