Android HorizontalLitview refresh is not working

Question

In my adapter class i have return a refresh custom method

public void refreshList(ArrayList<VehicleVo> list) {
    LogUtil.d("in Adaper class" + list.size());

    sRoutlist.clear();
    sRoutlist.addAll(list);

    LogUtil.d("sRoutlist" + sRoutlist.size());

    notifyDataSetChanged();
}

In this method my sRoutlist always return null, but LogUtil.d("in Adaper class" + list.size()); in this log i can see actual size of my arraylist. dont know what mistake i have done. even its very silly question not able to find the proper solution kindly correct me