How to return a class to a onPostExecute?

Question

Update, please see below.

How do I return my class LocationData and my ArrayList listOfObjects to the onPostExecute()? I want to use it in my UI and right now it is in the background in an AsyncTask. Also I want to add markers with:

mMap.addMarker(new MarkerOptions()
    .position(new LatLng(lati, longi))
    .title(name));

so that I can add each new location to the map after each loop.

Do I place the above in the onPostExecute after returning the LocationData class?

    try {

        String apples = endpoint.listContactInfo().execute().toString();

        JSONObject jObject = new JSONObject(apples);

        JSONArray jsonArr = jObject.getJSONArray("items");

        for (int i = 0; i < jsonArr.length(); i++) {
            JSONObject jsonObj1 = jsonArr.getJSONObject(i);

            // Storing each json item in variable
            String id = jsonObj1.getString(TAG_ID);
            String nameFirst1 = jsonObj1.getString(TAG_FIRSTNAME);
            String nameLast1 = jsonObj1.getString(TAG_LASTNAME);
            String emailAddress1 = jsonObj1.getString(TAG_EMAIL);
            String streetAddress1 = jsonObj1.getString(TAG_ADDRESS);
            String phone1 = jsonObj1.getString(TAG_PHONE);

            // test to see if made it to string
            Log.d("YOUR_TAG", "First Name: " + nameFirst1 + " Last Name: "
                    + nameLast1);

            address = coder.getFromLocationName(streetAddress1, 5);

            Address location1 = address.get(0);

            // SET LAT LNG VALUES FOR MARKER POINT

            lati = location1.getLatitude();
            longi = location1.getLongitude();

            Log.d("Location", "Location:" + lati + " " + longi);

            class LocationData {
                private double lat;
                private double longitude;
                private String name;

                public LocationData(double lat, double longitude,
                        String name) {
                    this.lat = lat;
                    this.longitude = longitude;
                    this.name = name;
                }

                public void setLat(double lat) {
                    this.lat = lat;
                }

                public void setLongitude(double longitude) {
                    this.longitude = longitude;
                }

                public double getLat() {
                    return lat;
                }

                public double getLongitude() {
                    return longitude;
                }

                public void setName(String name) {
                    this.name = name;
                }

                public String getName() {
                    return name;
                }

            }

            ArrayList listOfObjects = new ArrayList();

            listOfObjects.add(new LocationData(lati, longi, nameFirst1));

        }

    } catch (IOException e) {
        e.printStackTrace();
    } catch (JSONException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    return (long) 0;

}

// WHAT DO I PUT HERE TO RETURN LocationData Class here
// ADD MARKER TO MAP UI
protected void onPostExecute() {

    // mMap.addMarker(new MarkerOptions()
    // .position(new LatLng(lati, longi))
    // .title("Hello world"));

This may seem elementary but I've created this method: public ArrayList getLocationData() {

                                 ArrayList listOfObjects = new ArrayList();

                                 listOfObjects.add(new LocationData(lati, longi, nameFirst1));

                                 return listOfObjects;
                             }

within my LocationData class. I then placed LocationData.getLocationData(); with the onPostExecute and I get the LocationData can't be resolved. The code together looks like this at the moment:

 try {

    String apples = endpoint.listContactInfo().execute().toString();

    JSONObject jObject = new JSONObject(apples);

    JSONArray jsonArr = jObject.getJSONArray("items");

     for(int i =0 ; i getLocationData() {

                                 ArrayList listOfObjects = new ArrayList();

                                 listOfObjects.add(new LocationData(lati, longi, nameFirst1));

                                 return listOfObjects;
                             }

                             }

     }

    } catch (IOException e) {
    e.printStackTrace();
  } catch (JSONException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}
      return (long) 0;


    }
    //WHAT DO I PUT HERE TO RETURN LocationData Class here
         // ADD MARKER TO MAP UI
    protected void onPostExecute(Long result ) {

                  //CANT BE RESOLVED
        LocationData.getLocationData();

        //mMap.addMarker(new MarkerOptions()
        //.position(new LatLng(lati, longi))
        // .title("Hello world"));

Here are my changes based upon @Sustain recommendations. I seem to not be getting any map markers now. Anyone see anything?

public class FinderActivity extends Activity implements LocationListener  {


GoogleMap mMap;
Location myLocation;
EditText length;
String lengthString;
LocationManager locationmanager;
double lati;
double longi;
String nameFirst1;
//Spinner s;

   List address;
   Geocoder coder = new Geocoder(this);
private static final String TAG_ID = "id";
private static final String TAG_FIRSTNAME = "nameFirst";
private static final String TAG_LASTNAME = "nameLast";
private static final String TAG_EMAIL = "emailAddress";
private static final String TAG_ADDRESS = "streetAddress";
private static final String TAG_STATE = "state";

private static final String TAG_PHONE = "phone";
JSONArray contacts = null;


private static class LocationData {
     private double lat;
     private double longitude;
     private String name;

     public LocationData(double lat, double longitude, String name) {
         this.lat = lat;
         this.longitude = longitude;
         this.name = name;
     }

     public void setLat(double lat) {
         this.lat = lat;
     }

     public void setLongitude(double longitude) {
         this.longitude = longitude;
     }

     public double getLat() {
         return lat;
     }

     public double getLongitude() {
         return longitude;
     }

     public void setName(String name) {
           this.name = name;
        }

     public String getName() {
         return name;

        }

     }

@SuppressLint("NewApi")
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.maps);
    mMap = ((MapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();
    if (mMap!= null) {

        mMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);


        mMap.setMyLocationEnabled(true);
        mMap.animateCamera(CameraUpdateFactory.zoomBy(17));

        }

    LocationManager locationmanager = (LocationManager) getSystemService(LOCATION_SERVICE);
    Criteria cr = new Criteria();
    String provider = locationmanager.getBestProvider(cr, true);

    Location location = locationmanager.getLastKnownLocation(provider);

    locationmanager.requestLocationUpdates(provider, 20, 0, (LocationListener) this);

    mMap.moveCamera(CameraUpdateFactory.newLatLng((new LatLng(location.getLatitude(), location.getLongitude()))));


    new EndpointsTask().execute(getApplicationContext());

}

public class EndpointsTask extends AsyncTask {

    private List locationList = new ArrayList();

    public Long doInBackground(Context... contexts) {

      Contactinfoendpoint.Builder endpointBuilder = new Contactinfoendpoint.Builder(
          AndroidHttp.newCompatibleTransport(),
          new JacksonFactory(),
          new HttpRequestInitializer() {
          public void initialize(HttpRequest httpRequest) { }
          });
  Contactinfoendpoint endpoint = CloudEndpointUtils.updateBuilder(
  endpointBuilder).build();

  try {

    String apples = endpoint.listContactInfo().execute().toString();

    JSONObject jObject = new JSONObject(apples);

    JSONArray jsonArr = jObject.getJSONArray("items");

     for(int i =0 ; i

Sustain · Accepted Answer

The class LocationData is defined inside an unreachable scope. Instead, define it in it's own .java file like so:

class LocationData {
    // final Fields
    // Constructor
    // Getters
}

or as a private static class of your outermost class if you don't use it anywhere else.

Then for your subclass of AsyncTask you could have something like:

private class AsyncJsonTask extends AsyncTask
{
    private List locationList = new ArrayList();
    // ...
    protected void doInBackground(Param) {
        // ...
        for (int i = 0; i < jsonArr.length(); i++) {
            // Do your stuff with JSon Objects
            // ...
            // Instanciate a new LocationData and pass it as progress:
            LocationData data = new LocationData(latitude, longitude, name);
            locationList.add(data);
            publishProgress(data);
        }
    }

    protected void onProgressUpdate(LocationData data) {
        // Add Marker on Map using data. This is called by
        // publishProgress(LocationData) on the UI Thread.
        mMap.addMarker(/* marker */);
    }

    protected void onPostExecute() {
        // Assign outer class member field the value of the builded list
        // for future reference.
        mLocationList = locationList;
    }
}

This way, you can publish each marker individually on the map before fetching the next one.

As a side note, you should investigate the meaning of static methods and fields; your call to LocationData.getLocationData() would not be valid.

How to return a class to a onPostExecute?

Answers (2)

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