How to return Object from inside Volley Request with AsyncTask

Question

So I've been making an android app, and at this point I am trying to send a GET request to retrieve a list of Poll data

{"authorID":"1","pollID":"1","status":"3","createdDate":"2019-11-10 13:06:32","patientID":"1","urgency":"3"}

After I retrieve the data I want to store it in an ArrayList of polls inside my pollsList.java class where I will display a listView of these polls.

While trying to do this I have found trouble setting the ArrayList and appending the retrieved poll values to it. I have come to understand that all volley requests are asynchronous and therefore I am not able to explicitly set them from inside the request code. With this finding I have now looked to create an AsyncTask implementation but I am still struggling to understand how data is passed in AsyncTest implementations.

Here is the code for the pollsList.java Activity

public class PollsList extends AppCompatActivity {



public PollsListAdapter adapter;
ArrayList<Poll> polls = new ArrayList<>();

public void onCreate(Bundle icicle) {
    super.onCreate(icicle);
    setContentView(R.layout.activity_polls);
    ListView listView = (ListView)findViewById(R.id.list);
    polls = new ArrayList<Poll>();

    MyAsyncTask task = new MyAsyncTask(PollsList.this);
    task.execute();

}

}

Below is the code for MyAsyncTask.java

public class MyAsyncTask extends AsyncTask<Void, Integer, Poll> {
static Context context;
public AsyncResponse delegate = null;
static ArrayList<Poll> polls = new ArrayList<>();

public MyAsyncTask(Context context){
    this.context = context;
}

public interface AsyncResponse {
    void processFinish(String output);
}



public MyAsyncTask(AsyncResponse delegate){
    this.delegate = delegate;
}


@Override
protected Poll doInBackground(Void... voids) {
    String url = "https://votingappapi.000webhostapp.com/VotingAppCrudAPI/Polls.php";
//        Poll poll; if I initialize this poll object it must be final meaning it can't be modified

    JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(
            Request.Method.GET,
            url,
            null,
            new Response.Listener<JSONArray>() {
                @Override
                public void onResponse(JSONArray response) {
                    // Process the JSON
                    if (response.length() == 0) {
                        Toast.makeText(MyAsyncTask.context, "No Polls, Sorry", Toast.LENGTH_SHORT).show();
                    } else {
                        try {
                            JSONObject id = (JSONObject) response.get(1);
                            ArrayList<Poll> polls = new ArrayList();
//                                Poll poll;
                            for (int i = 0; i < response.length(); i++) {
                                JSONObject row = (JSONObject) response.get(i);
                                Poll poll = new Poll();
                                poll.authorID = row.getInt("authorID");
                                poll.urgency = row.getInt("urgency");
                                poll.patientID = row.getInt("patientID");
                                poll.status = row.getInt("status");
                                poll.pollID = row.getInt("pollID");
                                poll.createdDate = row.getString("createdDate");
                                polls.add(poll);

//                                    cant return here
                            }
//                                can't return inside inner void class
//                                    return poll;


                      } catch (JSONException e) {
                            e.printStackTrace();
                            Toast.makeText(context, "JsonException: " + e.getMessage(), Toast.LENGTH_LONG).show();
                        }
                    }
                }
            },
            new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                    // Do something when error occurred
                    Log.d("TAG", "erorororor: " + error.getMessage());
                }
            }
    );
}

@Override
protected void onPostExecute(Poll poll) {
    Log.d("TAG", "New Poll " + poll + " created: " + poll.createdDate);
}

protected void onProgressUpdate(){
}

}

In the doInBackground method I am not sure how to return a poll. I would also like to ask which function handles the returned data from doInBackground once it is returned?

When I send the request for the list of polls should I return the poll of each iteration to pass on? Or should I wait for all Polls to be added to an arrayList before returning an arrayList instead?

Any help or guidance would be greatly appreciated!

The `AsyncTask` is not helping you because volley is already doing the background work for you. In your code, the `doInBackground` launches a volley request (which will be executed in a background thread automatically) and returns immediately with nothing accomplished other than launching a request. The `onResponse` executes on the UI thread. — , Nov 19 '19 at 02:52
if you are using volley than it does not need to use Async task because internally volley itself uses it so you need not worry about network calls asynchronicity, you can find here, how you can use volley https://stackoverflow.com/questions/24873718/how-do-i-make-a-volley-jsonobject-request-with-a-custom-object-as-a-parameter — PJain, Nov 19 '19 at 02:55

How to return Object from inside Volley Request with AsyncTask

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