android RecyclerView LayoutManager 分页加载判断

mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {

            @Override
            public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
                super.onScrollStateChanged(recyclerView, newState);
                int lastPosition = -1;

                if(newState == RecyclerView.SCROLL_STATE_IDLE) {
                    RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
                    if(layoutManager instanceof GridLayoutManager){
                        lastPosition = ((GridLayoutManager) layoutManager).findLastVisibleItemPosition();
                    }else if(layoutManager instanceof LinearLayoutManager){
                        lastPosition = ((LinearLayoutManager) layoutManager).findLastVisibleItemPosition();
                    }else if(layoutManager instanceof StaggeredGridLayoutManager){
                        int[] lastPositions = new int[((StaggeredGridLayoutManager) layoutManager).getSpanCount()];
                        ((StaggeredGridLayoutManager) layoutManager).findLastVisibleItemPositions(lastPositions);
                        lastPosition = findMax(lastPositions);
                    }
                    if(lastPosition >= recyclerView.getLayoutManager().getItemCount() - 1){
                        getData();
                    }
                }
            }

            @Override
            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                super.onScrolled(recyclerView, dx, dy);

            }
        });