You can use this class to realize a simple sectioned grid RecyclerView.Adapter without changing your code.

The RecyclerView has to use a GridLayoutManager.

This is a porting of the class SimpleSectionedListAdapter provided by Google

If you are looking for a sectioned list RecyclerView.Adapter you can take a look here

Example:

         //Your RecyclerView
        mRecyclerView = (RecyclerView) getActivity().findViewById(R.id.list);
        mRecyclerView.setHasFixedSize(true);
        mRecyclerView.setLayoutManager(new GridLayoutManager(getActivity(),4));

        //Your RecyclerView.Adapter
        mAdapter = new SimpleAdapter(getActivity());

        //This is the code to provide a sectioned grid
        List<SectionedGridRecyclerViewAdapter.Section> sections =
                new ArrayList<SectionedGridRecyclerViewAdapter.Section>();

        //Sections
        sections.add(new SectionedGridRecyclerViewAdapter.Section(0,"Section 1"));
        sections.add(new SectionedGridRecyclerViewAdapter.Section(5,"Section 2"));
        sections.add(new SectionedGridRecyclerViewAdapter.Section(12,"Section 3"));
        sections.add(new SectionedGridRecyclerViewAdapter.Section(14,"Section 4"));
        sections.add(new SectionedGridRecyclerViewAdapter.Section(20,"Section 5"));

        //Add your adapter to the sectionAdapter
        SectionedGridRecyclerViewAdapter.Section[] dummy = new SectionedGridRecyclerViewAdapter.Section[sections.size()];
        SectionedGridRecyclerViewAdapter mSectionedAdapter = new
                SectionedGridRecyclerViewAdapter(getActivity(),R.layout.section,R.id.section_text,mRecyclerView,mAdapter);
        mSectionedAdapter.setSections(sections.toArray(dummy));

        //Apply this adapter to the RecyclerView
        mRecyclerView.setAdapter(mSectionedAdapter);

You can customize the section layout, changing the layout section.xml and changing the code in the SectionedGridRecyclerViewAdapter.SectionViewHolder class and SectionedGridRecyclerViewAdapter#onBindViewHolder method.