android 的ListView中，如何判断其内容已滚动到最顶部、底部

listView.setOnScrollListener(new OnScrollListener() {
            @Override
            public void onScrollStateChanged(AbsListView view, int scrollState) {
            }

            @Override
            public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
                if(firstVisibleItem==0){
                    Log.e("log", "滑到顶部");
                }
                if(visibleItemCount+firstVisibleItem==totalItemCount){
                    Log.e("log", "滑到底部");
                }
            }
        });