Android JSON Live updates

I can't figure out how to get live updates in android from a json api that updates every 2-3 seconds. I've managed to download the JSON code and then create some arrays and log them, but I the values from the json api change every 2-3 seconds and I have no idea how to redownload the JSON. Thanks in advance for your help!

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    DownloadTask task = new DownloadTask();

    String result = null;
    try{
        result = task.execute("thelinkIuse").get();
    } catch (InterruptedException | ExecutionException e) {
        e.printStackTrace();
    }

}


public class DownloadTask extends AsyncTask<String, Void, String>{


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

        String result = "";
        URL url;
        HttpURLConnection urlConnection = null;


        while (true) {
            try {
                url = new URL(urls[0]);
                urlConnection = (HttpURLConnection) url.openConnection();
                InputStream in = urlConnection.getInputStream();
                InputStreamReader reader = new InputStreamReader(in);
                int data = reader.read();
                while (data != -1) {
                    char current = (char) data;
                    result += current;
                    data = reader.read();
                }
                return result;
            } catch (IOException e) {
                e.printStackTrace();
                return "Failed";
            }
        }
    }


    @Override
    protected void onPostExecute(String result) {
        super.onPostExecute(result);


        try {
            JSONArray arr = new JSONArray(result);

            for (int i = 0; i < arr.length(); i++) {

                JSONObject jsonPart = arr.getJSONObject(i);
                symbols.add(jsonPart.getString("symbol"));
                bids.add(jsonPart.getString("bid"));
                asks.add(jsonPart.getString("ask"));


            }

            Log.i("Symbols", String.valueOf(symbols));
            Log.i("Bids", String.valueOf(bids));
            Log.i("Asks", String.valueOf(asks));


        } catch (JSONException e) {
            e.printStackTrace();
            Log.i("failed", "failed");
        }


    }



}

 Timer timer = new Timer();
        timer.scheduleAtFixedRate(new TimerTask() {
            @Override
            public void run() {
                try{
                    result =new DownloadTask().execute("thelinkIuse").get();
                } catch (InterruptedException | ExecutionException e) {
                    e.printStackTrace();
                }
            }
        },0,5000);

This will call the asynctask every 5 seconds, thus fetching the updated JSON string