@Override @Transactional public List<AuthorEntity> getBookAuthors(int id) throws NoSuchEntityException { BookEntity book = bookDao.getNotNull(id); List<AuthorEntity> list = Lists.newArrayList(); if (book.getBookToAuthor() != null) { for (BookAuthorEntity b2a : book.getBookToAuthor()) list.add(b2a.getAuthor()); } return list; }