SparseBooleanArray.size() is null in base adapter

[skyshine999]

i am using drag-sort -listview in base adapter when i using drop listener i am getting exception

@OverRide
public void drop(int from, int to)
{

        if (from != to)
        {
            GetPlaylistValueVO item = _getPlaylistData.get(from);
            _getPlaylistData.remove(item);
            _getPlaylistData.add(to,item);
            _listView.moveCheckState(from,to);
            _getPlaylistAdapter.notifyDataSetChanged();
        }
    }

exception
java.lang.NullPointerException: Attempt to invoke virtual method 'int android.util.SparseBooleanArray.size()' on a null object reference
at com.jio.media.mobile.apps.jiobeats.views.DragSortListView.moveCheckState(DragSortListView.java:2921)
at com.jio.media.mobile.apps.jiobeats.playlist.CreatePlaylistFragment$2.drop(CreatePlaylistFragment.java:158)
at com.jio.media.mobile.apps.jiobeats.views.DragSortListView.dropFloatView(DragSortListView.java:1620)
at com.jio.media.mobile.apps.jiobeats.views.DragSortListView.access$1200(DragSortListView.java:35)
at com.jio.media.mobile.apps.jiobeats.views.DragSortListView$DropAnimator.onStop(DragSortListView.java:1365)
at com.jio.media.mobile.apps.jiobeats.views.DragSortListView$SmoothAnimator.run(DragSortListView.java:1233)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)