scroller.setOnScrollChangeListener(new NestedScrollView.OnScrollChangeListener() {
        @Override
        public void onScrollChange(NestedScrollView v, int scrollX, int scrollY, int oldScrollX, int oldScrollY) {if (scrollY == (v.getChildAt(0).getMeasuredHeight() - v.getMeasuredHeight())) {
               //到底了
            }
       }
    });