@Override
public Book save(Book book) {
bookDao.add(book);
deleteBookFromCategories(book.getId());
if (book.getCategory() != null && categoryDao.get(book.getCategory()) != null) {
Category category = categoryDao.get(book.getCategory());
HashSet<String> booksSet = category.getBooks();
if (booksSet == null) booksSet = new HashSet<String>();
booksSet.add(book.getId());
category.setBooks(booksSet);
categoryDao.add(category);
}
bookDao.add(book);
return get(book.getId());
}
