NPE getCount in Adapter when trying to get user al

Question

I am trying to get the users albums using the FB SDK. I have managed to log-in successfully and am able to retrieve the users profile picture and acquire an access token.

I am following this answer here and am trying to get it to work, but I am running into an issue where I get java.lang.NullPointerException in the adapter class on at com.myapp.myapp.PhotosAdapter.getCount(PhotosAdapter.java:37)

Here's the full set-up as to what I have:

Where am I going wrong? thanks

FBGRID activity:

public class FBGRID extends Activity {

private String URL;

// STORE THE PAGING URL
private String pagingURL;

// FLAG FOR CURRENT PAGE
int current_page = 1;

// BOOLEAN TO CHECK IF NEW FEEDS ARE LOADING
Boolean loadingMore = true;

Boolean stopLoadingData = false;

GridView grid;

ArrayList<getPhotos> arrPhotos;

PhotosAdapter adapter;


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

    grid = (GridView) findViewById(R.id.gridView1);

    grid.setOnScrollListener(new OnScrollListener() {

        @Override
        public void onScrollStateChanged(AbsListView view, int scrollState) {

        }

        @Override
        public void onScroll(AbsListView view, int firstVisibleItem,
                int visibleItemCount, int totalItemCount) {
            int lastInScreen = firstVisibleItem + visibleItemCount;
            if ((lastInScreen == totalItemCount) && !(loadingMore)) {

                if (stopLoadingData == false) {
                    // FETCH THE NEXT BATCH OF FEEDS
                    new loadMorePhotos().execute();
                }

            }
        }
    });

    new getPhotosData().execute();

}

private class getPhotosData extends AsyncTask<Void, Void, Void> {

    @Override
    protected Void doInBackground(Void... arg0) {

        // CHANGE THE LOADING MORE STATUS TO PREVENT DUPLICATE CALLS FOR
        // MORE DATA WHILE LOADING A BATCH
        loadingMore = true;

        Session s = Session.getActiveSession();

        // SET THE INITIAL URL TO GET THE FIRST LOT OF ALBUMS
        URL = "https://graph.facebook.com/" + "me/albums"
                + "/photos&access_token=" + s.getAccessToken()
                + "?limit=10";

        try {

            HttpClient hc = new DefaultHttpClient();
            HttpGet get = new HttpGet(URL);
            HttpResponse rp = hc.execute(get);

            if (rp.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                String queryAlbums = EntityUtils.toString(rp.getEntity());

                JSONObject JOTemp = new JSONObject(queryAlbums);

                JSONArray JAPhotos = JOTemp.getJSONArray("data");

                // IN MY CODE, I GET THE NEXT PAGE LINK HERE

                getPhotos photos;

                for (int i = 0; i < JAPhotos.length(); i++) {
                    JSONObject JOPhotos = JAPhotos.getJSONObject(i);
                    // Log.e("INDIVIDUAL ALBUMS", JOPhotos.toString());

                    if (JOPhotos.has("link")) {

                        photos = new getPhotos();

                        // GET THE ALBUM ID
                        if (JOPhotos.has("id")) {
                            photos.setPhotoID(JOPhotos.getString("id"));
                        } else {
                            photos.setPhotoID(null);
                        }

                        // GET THE ALBUM NAME
                        if (JOPhotos.has("name")) {
                            photos.setPhotoName(JOPhotos.getString("name"));
                        } else {
                            photos.setPhotoName(null);
                        }

                        // GET THE ALBUM COVER PHOTO
                        if (JOPhotos.has("picture")) {
                            photos.setPhotoPicture(JOPhotos
                                    .getString("picture"));
                        } else {
                            photos.setPhotoPicture(null);
                        }

                        // GET THE PHOTO'S SOURCE
                        if (JOPhotos.has("source")) {
                            photos.setPhotoSource(JOPhotos
                                    .getString("source"));
                        } else {
                            photos.setPhotoSource(null);
                        }

                        arrPhotos.add(photos);
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }

    @Override
    protected void onPostExecute(Void result) {

        grid.setAdapter(new PhotosAdapter(FBGRID.this, arrPhotos));

        loadingMore = false;
    }

}

private class loadMorePhotos extends AsyncTask<Void, Void, Void> {

    @Override
    protected Void doInBackground(Void... arg0) {

        // SET LOADING MORE "TRUE"
        loadingMore = true;

        // INCREMENT CURRENT PAGE
        current_page += 1;

        // Next page request
        URL = pagingURL;

        try {

            HttpClient hc = new DefaultHttpClient();
            HttpGet get = new HttpGet(URL);
            HttpResponse rp = hc.execute(get);

            if (rp.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                String queryAlbums = EntityUtils.toString(rp.getEntity());
                // Log.e("PAGED RESULT", queryAlbums);

                JSONObject JOTemp = new JSONObject(queryAlbums);

                JSONArray JAPhotos = JOTemp.getJSONArray("data");

                // IN MY CODE, I GET THE NEXT PAGE LINK HERE

                getPhotos photos;

                for (int i = 0; i < JAPhotos.length(); i++) {
                    JSONObject JOPhotos = JAPhotos.getJSONObject(i);
                    // Log.e("INDIVIDUAL ALBUMS", JOPhotos.toString());

                    if (JOPhotos.has("link")) {

                        photos = new getPhotos();

                        // GET THE ALBUM ID
                        if (JOPhotos.has("id")) {
                            photos.setPhotoID(JOPhotos.getString("id"));
                        } else {
                            photos.setPhotoID(null);
                        }

                        // GET THE ALBUM NAME
                        if (JOPhotos.has("name")) {
                            photos.setPhotoName(JOPhotos.getString("name"));
                        } else {
                            photos.setPhotoName(null);
                        }

                        // GET THE ALBUM COVER PHOTO
                        if (JOPhotos.has("picture")) {
                            photos.setPhotoPicture(JOPhotos
                                    .getString("picture"));
                        } else {
                            photos.setPhotoPicture(null);
                        }

                        // GET THE ALBUM'S PHOTO COUNT
                        if (JOPhotos.has("source")) {
                            photos.setPhotoSource(JOPhotos
                                    .getString("source"));
                        } else {
                            photos.setPhotoSource(null);
                        }

                        arrPhotos.add(photos);
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }

    @Override
    protected void onPostExecute(Void result) {

        // get listview current position - used to maintain scroll position
        int currentPosition = grid.getFirstVisiblePosition();

        // APPEND NEW DATA TO THE ARRAYLIST AND SET THE ADAPTER TO THE
        // LISTVIEW
        adapter = new PhotosAdapter(FBGRID.this, arrPhotos);
        grid.setAdapter(adapter);

        // Setting new scroll position
        grid.setSelection(currentPosition + 1);

        // SET LOADINGMORE "FALSE" AFTER ADDING NEW FEEDS TO THE EXISTING
        // LIST
        loadingMore = false;
    }

}

public class getPhotos {

    String PhotoID;

    String PhotoName;

    String PhotoPicture;

    String PhotoSource;

    // SET THE PHOTO ID
    public void setPhotoID(String PhotoID) {
        this.PhotoID = PhotoID;
    }

    // GET THE PHOTO ID
    public String getPhotoID() {
        return PhotoID;
    }

    // SET THE PHOTO NAME
    public void setPhotoName(String PhotoName) {
        this.PhotoName = PhotoName;
    }

    // GET THE PHOTO NAME
    public String getPhotoName() {
        return PhotoName;
    }

    // SET THE PHOTO PICTURE
    public void setPhotoPicture(String PhotoPicture) {
        this.PhotoPicture = PhotoPicture;
    }

    // GET THE PHOTO PICTURE
    public String getPhotoPicture() {
        return PhotoPicture;
    }

    // SET THE PHOTO SOURCE
    public void setPhotoSource(String PhotoSource) {
        this.PhotoSource = PhotoSource;
    }

    // GET THE PHOTO SOURCE
    public String getPhotoSource() {
        return PhotoSource;
    }
}

}

and for the Adapter class(it uses an image loading library):

final class PhotosAdapter extends BaseAdapter {

private Activity activity;

ArrayList<getPhotos> arrayPhotos;

private static LayoutInflater inflater = null;
ImageLoader imageLoader;

public PhotosAdapter(Activity a, ArrayList<getPhotos> arrPhotos) {

    activity = a;

    arrayPhotos = arrPhotos;

    inflater = (LayoutInflater) activity
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    imageLoader = new ImageLoader(activity.getApplicationContext());
}

public int getCount() {
    return arrayPhotos.size();
}

public Object getItem(int position) {
    return arrayPhotos.get(position);
}

public long getItemId(int position) {
    return position;
}

public View getView(final int position, View convertView, ViewGroup parent) {

    ViewHolder holder;

    View vi = convertView;
    if (convertView == null) {
        vi = inflater.inflate(R.layout.photos_item, null);

        holder = new ViewHolder();

        holder.imgPhoto = (ImageView) vi.findViewById(R.id.grid_item_image);

        vi.setTag(holder);
    } else {
        holder = (ViewHolder) vi.getTag();
    }

    if (arrayPhotos.get(position).getPhotoPicture() != null) {
        imageLoader.DisplayImage(arrayPhotos.get(position)
                .getPhotoPicture(), holder.imgPhoto);
    }
    return vi;
}

static class ViewHolder {
    ImageView imgPhoto;

}
}

Here's logcat:

    FATAL EXCEPTION: main
java.lang.NullPointerException
at com.myapp.myapp.PhotosAdapter.getCount(PhotosAdapter.java:37)
at android.widget.GridView.setAdapter(GridView.java:186)
at com.myapp.myapp.FBGRID$getPhotosData.onPostExecute(FBGRID.java:173)
at com.myapp.myapp.FBGRID$getPhotosData.onPostExecute(FBGRID.java:1)
at android.os.AsyncTask.finish(AsyncTask.java:631)
at android.os.AsyncTask.access$600(AsyncTask.java:177)
at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:213)
at android.app.ActivityThread.main(ActivityThread.java:5225)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:741)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557)
at dalvik.system.NativeStart.main(Native Method)