Normal class to AsyncTask

Question

I have made a normal class and an AsyncTask and I want to make this code:

private void addNewQuake (Quake _quake) {
    //Add the new quake to our list of earthquakes
    earthquakes.add(_quake);

    //Notify the array adapter of a change
    aa.notifyDataSetChanged();
}

So I can add it to AsyncTask? Or do I need to do in a other way?

I have made a app that shows new earthquakes. And addNewQuake wil add a new to the list. — user3238333, Jan 27 '14 at 20:42
If you want you can see all code here: http://stackoverflow.com/questions/21389779/android-os-networkonmainthreadexception-manifest/21389847?noredirect=1#comment32261426_21389847 I have added all code on refreshEarthquake to the Async and: ListView earthquakeListView; ArrayAdapter aa; ArrayList earthquakes = new ArrayList(); This is the first time I use Async — user3238333, Jan 27 '14 at 20:44

score 0 · Answer 1 · answered Jan 27 '14 at 22:47

0

@Override
protected void onCreate(Bundle savedInstanceState) {

   // your other code

   new DataLoadAsync().execute(); //start to get data
}


public class DataLoadAsync extends AsyncTask{

   private Quake quake;

   @Override
   protected void doInBackground(){
      // handle network data in here and put the result to quake in here.
      refreshEarthquakes();
   }

   @Override
   protected void onPostExecute(){
      // use the result
      addNewQuake(quake);
   }
}

syntax is not complete, I just wanted to show you, you need to put your network data load method in doInBackground to get data, then you can use it in onPostExecute()

answered Jan 27 '14 at 22:47

Orhan Obut

8,756
5
32
42

The emulator is just white now. Nothing comes up, is it because of the internet? – user3238333 Jan 28 '14 at 20:05
Also I need to remove the @Override is that why I got the problems? I had to do it – user3238333 Jan 29 '14 at 18:43
you are not using AsyncTask correctly, check this out http://stackoverflow.com/questions/9671546/asynctask-android-example?rq=1 – Orhan Obut Jan 29 '14 at 19:44
Can you give me a example with my code. I dont understand it. Also should I make a new file or use the main? – user3238333 Jan 29 '14 at 19:56

score 0 · Answer 2 · answered Jan 29 '14 at 19:27

Here is my new code:

public class Earthquake extends Activity {

ListView earthquakeListView;
ArrayAdapter<Quake> aa;

ArrayList<Quake> earthquakes = new ArrayList<Quake>();

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

    earthquakeListView = (ListView) this
            .findViewById(R.id.earthquakeListView);

    int layoutID = android.R.layout.simple_list_item_1;
    aa = new ArrayAdapter<Quake>(this, layoutID, earthquakes);
    earthquakeListView.setAdapter(aa);

    new DataLoadAsync().execute();
}   

public class DataLoadAsync extends AsyncTask<Object, Object, Object>{

       private Quake quake;

       protected void doInBackground(){
          // handle network data in here and put the result to quake in here.
          refreshEarthquakes();
       }

       protected void onPostExecute(){
          // use the result
          addNewQuake(quake);
       }

    @Override
    protected Object doInBackground(Object... arg0) {
        // TODO Auto-generated method stub
        return null;
    }
    }

     void refreshEarthquakes() {
        //get the XML
        URL url;
        try {
            String quakeFeed = getString(R.string.quake_feed);
            url = new URL(quakeFeed);

            URLConnection connection;
            connection = url.openConnection();

            HttpURLConnection httpConnection = (HttpURLConnection)connection;
            int responseCode = httpConnection.getResponseCode();

            if (responseCode == HttpURLConnection.HTTP_OK) {
                InputStream in = httpConnection.getInputStream();

                DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
                DocumentBuilder db = dbf.newDocumentBuilder();

                //Parse the earthquake feed
                Document dom = db.parse(in);
                Element docEle = dom.getDocumentElement();

                //Clear the old earthquakes
                earthquakes.clear();

                //Get a list of each earthquake entry
                NodeList nl = docEle.getElementsByTagName("entry");
                if (nl != null && nl.getLength() > 0) {
                    for (int i = 0 ; i < nl.getLength(); i++) {
                        Element entry = (Element)nl.item(i);
                        Element title = (Element)entry.getElementsByTagName("title").item(0);
                        Element g = (Element)entry.getElementsByTagName("georss:point").item(0);
                        Element when = (Element)entry.getElementsByTagName("updated").item(0);
                        Element link = (Element)entry.getElementsByTagName("link").item(0);

                        String details = title.getFirstChild().getNodeValue();
                        String hostname = "http://earthquake.usgs.gov";
                        String linkString = hostname + link.getAttribute("href");

                        String point = g.getFirstChild().getNodeValue();
                        String dt = when.getFirstChild().getNodeValue();
                        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'hh:mm:ss'Z'");
                        Date qdate = new GregorianCalendar(0,0,0).getTime();
                        try {
                            qdate = sdf.parse(dt);
                        } catch (ParseException e) {
                            e.printStackTrace();
                        }

                        String[] location = point.split(" ");
                        Location l = new Location("dummyGPS");
                        l.setLatitude(Double.parseDouble(location[0]));
                        l.setLongitude(Double.parseDouble(location[1]));

                        String magnitudeString = details.split(" ")[1];
                        int end = magnitudeString.length()-1;
                        double magnitude = Double.parseDouble(magnitudeString.substring(0, end));

                        details = details.split(",")[1].trim();

                        Quake quake = new Quake(qdate, details, l, magnitude, linkString);
                    }
                }
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ParserConfigurationException e) {
            e.printStackTrace();
        } catch (SAXException e) {
            e.printStackTrace();
        }
        finally {
        } 
    }

private void addNewQuake (Quake _quake) {
    //Add the new quake to our list of earthquakes
    earthquakes.add(_quake);

    //Notify the array adapter of a change
    aa.notifyDataSetChanged();
}
}

Normal class to AsyncTask

2 Answers2