public class HeaderItem implements StickyHeaderModel {

    public final String title;

    /**
     * 状态保存示例，如果header存在一些交互性行为，在onBindViewHolder里面需要绑定悬浮header的状态
     */
    public int color = 0xff777777;

    public HeaderItem(String title) {
        this.title = title;
    }
}

public class Item {

    public final String title;
    public final String message;

    public Item(String title, String message) {
        this.title = title;
        this.message = message;
    }
}

public final class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.BaseViewHolder> implements AdapterDataProvider {

    private final List<Object> dataList = new ArrayList<>();

    @Override
    public BaseViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        if (viewType == 0) {
            return new ItemViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.item_view, parent, false));
        } else {
            return new HeaderViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.header_view, parent, false));
        }
    }

    @Override
    public void onBindViewHolder(final BaseViewHolder holder, final int position) {
        
    }

    @Override
    public int getItemCount() {
        return dataList.size();
    }

    @Override
    public int getItemViewType(int position) {
        return dataList.get(position) instanceof Item ? 0 : 1;
    }

    @Override
    public List<?> getAdapterData() {
        return dataList;
    }

    private static final class ItemViewHolder extends BaseViewHolder {

        TextView titleTextView;
        TextView messageTextView;

        ItemViewHolder(View itemView) {
            super(itemView);

            titleTextView = itemView.findViewById(R.id.tv_title);
            messageTextView = itemView.findViewById(R.id.tv_message);
        }
    }

    private static final class HeaderViewHolder extends BaseViewHolder {

        TextView titleTextView;
        TextView button;

        HeaderViewHolder(View itemView) {
            super(itemView);

            titleTextView = itemView.findViewById(R.id.tv_title);
            button = itemView.findViewById(R.id.button);
        }
    }

    static class BaseViewHolder extends RecyclerView.ViewHolder {

        BaseViewHolder(View itemView) {
            super(itemView);
        }
    }
}

RecyclerView recyclerView = findViewById(R.id.recycler_view);
recyclerView.setLayoutManager(new StickyLinearLayoutManager(this, adapter)); // StickyLinearLayoutManager 替代 LinearLayoutManager

RecyclerAdapter adapter = new RecyclerAdapter();
adapter.setDataList(genDataList(0));
recyclerView.setAdapter(adapter);

stickyLinearLayoutManager.setStickyHeaderListener(new StickyLinearLayoutManager.StickyHeaderListener() {
    @Override
    public void headerAttached(View headerView, int adapterPosition) {
        Log.d("StickyHeaderRecyclerView", "Header Attached : " + adapterPosition);
    }

    @Override
    public void headerDetached(View headerView, int adapterPosition) {
        Log.d("StickyHeaderRecyclerView", "Header Detached : " + adapterPosition);
    }
});

layoutManager.elevateHeaders(true); // default value : 5dp

// or
layoutManager.elevateHeaders(dpValue);