@Path("/") @Produces("application/json")
public class BookResource {
    private static final RESULTS_PER_PAGE = 20;

    @GET @Path("books/{titlePattern}/{page:\\d+}")
    public List<Book> findBooks(String titlePattern, int page) {
        var books = sessionFactory.fromTransaction(session -> {
            return entityManager.createQuery("from Book where title like ?1 order by title", Book.class)
                    .setParameter(1, titlePattern)
                    .setPage(Page.page(RESULTS_PER_PAGE, page))
                    .getResultList();
        });
        return books.isEmpty() ? Response.status(404).build() : books;
    }

}