RecyclerViewでリストの先頭or末尾検知をシンプルに実装する

recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
    @Override
    public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
        super.onScrollStateChanged(recyclerView, newState);
    }

    @Override
    public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
        super.onScrolled(recyclerView, dx, dy);
        if (!recyclerView.canScrollVertically(-1)) {
           /*リストの先頭に来た時の処理*/
         }

        if (!recyclerView.canScrollVertically(1)) {
           /*リストの末尾に来た時の処理*/
        }
    }
);

/**
  * Check if this view can be scrolled vertically in a certain direction.
  *
  * @param direction Negative to check scrolling up, positive to check scrolling down.
  * @return true if this view can be scrolled in the specified direction, false otherwise.
  */
public boolean canScrollVertically(int direction) {
     final int offset = computeVerticalScrollOffset();
     final int range = computeVerticalScrollRange() - computeVerticalScrollExtent();
     if (range == 0) return false;
     if (direction < 0) {
         return offset > 0;
     } else {
         return offset < range - 1;
     }
 }

if (!recyclerView.canScrollVertically(-1)) {
   swipeRefreshLayout.setEnabled(true);
} else if (swipeRefreshLayout.isEnabled()) {
   swipeRefreshLayout.setEnabled(false);
}

@Override
public void onBindViewHolder(BindingHolder holder, int position) {
    if (position == getItemCount() - 1) {
       /*リストの末尾に来た時の処理*/

       handler.post(() -> {/*要素の変更をする場合*/})); 
    }
}