filtering of android listview using CursorAdapter not working

Question

I have created a list view in android and I want to add edit text above the list and when the user enter text the list will be filtered according to user input.listview in fragmentcode like below:

public class FindPeopleFragment extends BaseFragment implements LoaderCallbacks<Cursor> {

    public FindPeopleFragment() {
    }

    private TextView advancedSearchOption;
    private TextView saerchButton;
    private EndlessListView listUsers;
    private EditText searchWord;
    private EditText searchFirstName;
    private EditText searchLastName;
    private EditText searchEmail;
    private EditText searchCountry;
    private EditText searchState;
    private int offset = 0;
    private final int limit = 30;
    private boolean mHaveMoreDataToLoad = true;
    private VROAccountManager manager;
    private ArrayList<VROUser> postsList = new ArrayList<>();
    private View advanced;
    private Cursor FriendsCursor;
    private Cursor FriendsCursorTemp;

    // Cursor  c;
    private TextView description;
    long friend_name;
    FriendsListCursorAdapter FRIEND_ADAPTER;
    DatabaseHelper dh;
    FriendinfoService friendinfoService;
String searchValue;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        title = "My Friends";
//      setSelection(0);

    }

    private View rootView;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        friendinfoService = new FriendinfoService();
        if (rootView != null) {

            ((ViewGroup) rootView.getParent()).removeView(rootView);
            return rootView;
        }

        rootView = inflater.inflate(R.layout.fragment_find_people, null);
        getLoaderManager().initLoader(1, null, this);
      //  progressBar = rootView.findViewById(R.id.progressBar);
        saerchButton = (TextView) rootView.findViewById(R.id.button_search);
        listUsers = (EndlessListView) rootView.findViewById(R.id.user_list);
        searchWord = (EditText) rootView
                .findViewById(R.id.editText_search_word);
        searchFirstName = (EditText) rootView
                .findViewById(R.id.editText_search_first_name);
        searchLastName = (EditText) rootView
                .findViewById(R.id.editText_search_last_name);
        searchEmail = (EditText) rootView
                .findViewById(R.id.editText_search_email);
        searchCountry = (EditText) rootView
                .findViewById(R.id.editText_search_country);
        searchState = (EditText) rootView
                .findViewById(R.id.editText_search_state);
        advancedSearchOption = (TextView) rootView
                .findViewById(R.id.advancedSearch);
        advancedSearchOption.setVisibility(View.GONE);
        manager = new VROAccountManager(getActivity());
        advanced = rootView.findViewById(R.id.layout_advanced_search);
        description = (TextView) rootView.findViewById(R.id.description);
        dh=new DatabaseHelper(getActivity());
        description
                .setText("You are friends with the following users. To find new friends or to view friends request sent or received use the menu on right");
        searchWord.addTextChangedListener(new TextWatcher() {

            @Override
            public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) {

                FindPeopleFragment.this.FRIEND_ADAPTER.getFilter().filter(cs);
            }

            @Override
            public void beforeTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) {
            }

            @Override
            public void afterTextChanged(Editable arg0) {
            }
        });


        listUsers.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                                    int position, long id) {
                Cursor mycursor = (Cursor) listUsers.getItemAtPosition(position);
                VROUser user = VROUser.parse(mycursor);
                Intent intent = new Intent(getActivity(), ProfileViewActivity.class);
                intent.putExtra("userId", user.getUserID());
                getActivity().startActivity(intent);

            }
        });
        return rootView;
    }


    @Override
    public Loader<Cursor> onCreateLoader(int id, Bundle args) {

        CursorLoader cursorLoader=null;
 if(id==1) {
      cursorLoader = new CursorLoader(getActivity(),
             FriendinfoTable.CONTENT_URI, null, null, null, null);
 }


    @Override
    public void onLoadFinished(Loader<Cursor> loader, Cursor data) {


      System.out.println("Value returningnnnnnnnnnnnnnnnnnnnnnnnnnnn   " + data.getCount());

            FriendsCursor = data;

            if (FRIEND_ADAPTER == null) {
                FRIEND_ADAPTER = new FriendsListCursorAdapter(getActivity(),
                        FriendsCursor, true);
                listUsers.setAdapter(FRIEND_ADAPTER);
                FRIEND_ADAPTER = null;

            } else {

                FRIEND_ADAPTER.swapCursor(FriendsCursor);



            }


  }





    @Override
    public void onLoaderReset(Loader<Cursor> loader) {



    }
}

and CursorAdapter is coded as

public class FriendsListCursorAdapter extends CursorAdapter implements Filterable {
    private Cursor cursor;
    final VROPreferenceManager preferenceManager = new VROPreferenceManager();
    Context con;
    String cString;
   List<String> arrayListNames;
    public FriendsListCursorAdapter(Context context, Cursor c, boolean b) {
          super(context,c,true);
        cursor = c;
        con=context;
    }

    public void addItems(Cursor newItems) {
        if (0 == newItems.getCount()) {
            return;
        }


        notifyDataSetChanged();
    }

    public int getCount() {
        // TODO Auto-generated method stub
        return cursor.getCount();
    }






    @Override
    public View newView(Context context, Cursor cursor, ViewGroup viewGroup) {
        LayoutInflater inflater = LayoutInflater.from(context);
        View view = inflater.inflate(R.layout.vro_contact_view, null);
        bindView(view, context, cursor);
        return view;
    }

    @Override
    public void bindView(View view, Context context, Cursor cursor) {

        TextView txtID = (TextView) view.findViewById(R.id.text_fname_lname);
        txtID.setText(cursor.getString(cursor.getColumnIndex("first_name")));

        TextView txtCode = (TextView) view.findViewById(R.id.text_email);
        txtCode.setText(cursor.getString(cursor.getColumnIndex("email")));
        ImageView profilePic = (ImageView) view.findViewById(R.id.user_image);


         VROUser pic = VROUser.parse(cursor);

        ImageLoader.getInstance().displayImage(
                preferenceManager.getResourceSertver()
                        + pic.getProfilePICURL(), profilePic,
                Consts.UIL_USER_AVATAR_DISPLAY_OPTIONS);


    }
    @Override
    public Filter getFilter() {

        Filter filter = new Filter() {


            @Override
            protected FilterResults performFiltering(CharSequence charSequence) {
                FilterResults results = new FilterResults();
                ArrayList<String> FilteredArrayNames = new ArrayList<String>();

                // perform your search here using the searchConstraint String.

                cString = charSequence.toString().toLowerCase();
                for (int i = 0; i < cursor.getCount(); i++) {
                    String dataNames = cursor.getString(i);
                    if (dataNames.toLowerCase().startsWith(cString.toString()))  {
                        FilteredArrayNames.add(dataNames);
                    }
                }

                results.count = FilteredArrayNames.size();
                results.values = FilteredArrayNames;
            //    Log.e("VALUES", results.values.toString());

                return results;

            }

            @Override
            protected void publishResults(CharSequence charSequence, FilterResults filterResults) {
                arrayListNames = (List<String>) filterResults.values;
                notifyDataSetChanged();
            }
        };
        return filter;
    }

}

but i got an error like java.lang.NullPointerException: Attempt to invoke virtual method 'android.widget.Filter vro.nagainfo.vromain.ui.adaptors.FriendsListCursorAdapter.getFilter()' on a null object reference at line

 FindPeopleFragment.this.FRIEND_ADAPTER.getFilter().filter(cs);

please help me to find the solution.