package com.mzh.library.dao; import com.mzh.library.entity.Book; import com.mzh.library.entity.BookCategory; import com.mzh.library.entity.BookSearchCriteria; import java.util.List; import java.util.Optional; public interface BookDao { List findAllCategories(); List search(BookSearchCriteria criteria); Optional findById(long id); Optional findByIdentifier(String identifier); long create(Book book); boolean update(Book book); boolean delete(long id); }