JoinQuery.java

// initializing the CriteriaBuilder and CriteriaQuery object
CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
CriteriaQuery<Book> criteriaQuery = criteriaBuilder.createQuery(Book.class);

Root<Book> root = criteriaQuery.from(Book.class);
// defining the JOIN clauses
Join<Book, Author> author = root.join("authors");
Join<Book, Genre> genre = root.join("genres");

// specifying the WHERE conditions
criteriaQuery.where(
    criteriaBuilder.equal(author.get("id"), 3),
    criteriaBuilder.equal(genre.get("id"), 5)
);

// retrieving the list of books
List<Book> books = entityManager
                                .createQuery(criteriaQuery)
                                .getResultList();