cannot Resolve Symbol 'AsyncResult'

Question

here is my code for downloading information from a google sheet to my app. my android studio cant seem to find this class. what can i do about this problem? i'm lost. thanks. i took this code from this tutorial: http://www.telerik.com/blogs/google-spreadsheet-as-data-source-android

package yrapps.szone;
import android.os.AsyncTask;

import org.json.JSONException;
import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class DownloadWebpageTask extends AsyncTask<String, Void, String> {
    AsyncResult callback;

    public DownloadWebpageTask(AsyncResult  callback) {
        this.callback = callback;
    }

    @Override
    protected String doInBackground(String... urls) {

        // params comes from the execute() call: params[0] is the url.
        try {
            return downloadUrl(urls[0]);
        } catch (IOException e) {
            return "Unable to download the requested page.";
        }
    }

    // onPostExecute displays the results of the AsyncTask.
    @Override
    protected void onPostExecute(String result) {
        // remove the unnecessary parts from the response and construct a JSON
        int start = result.indexOf("{", result.indexOf("{") + 1);
        int end = result.lastIndexOf("}");
        String jsonResponse = result.substring(start, end);
        try {
            JSONObject table = new JSONObject(jsonResponse);
            callback.onResult(table);
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }

    private String downloadUrl(String urlString) throws IOException {
        InputStream is = null;

        try {
            URL url = new URL(urlString);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setReadTimeout(10000 /* milliseconds */);
            conn.setConnectTimeout(15000 /* milliseconds */);
            conn.setRequestMethod("GET");
            conn.setDoInput(true);
            // Starts the query
            conn.connect();
            int responseCode = conn.getResponseCode();
            is = conn.getInputStream();

            String contentAsString = convertStreamToString(is);
            return contentAsString;
        } finally {
            if (is != null) {
                is.close();
            }
        }
    }

    private String convertStreamToString(InputStream is) {
        BufferedReader reader = new BufferedReader(new InputStreamReader(is));
        StringBuilder sb = new StringBuilder();

        String line = null;
        try {
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return sb.toString();
    }
}

Answer 1

You cannot resolve the symbol because you have not included the class for AsyncResult on your imports. AsyncResult is not standard Android code. If you go to the GitHub repo that is mentioned in your link, I see that it is a custom class that is part of the same package as DownloadWebpageTask. That is why he gets it for free. But you will need to create AsyncResult yourself.

Here is his source: https://github.com/telerik/Android-samples/blob/master/Blogs/Json-Reader/app/src/main/java/com/example/progress/json_reader/AsyncResult.java