/*
* Copyright 2010 Harald Wellmann
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.ops4j.pax.exam.sample6.service;
import java.io.Serializable;
import java.util.List;
import javax.ejb.Stateless;
import javax.ejb.TransactionAttribute;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.TypedQuery;
import org.ops4j.pax.exam.sample6.model.Author;
import org.ops4j.pax.exam.sample6.model.Book;
/**
* NOTE: By the EJB 3.1 specification, all public business methods are transactional by default,
* with a REQUIRED transaction type, so the <code>@TransactionAttribute</code> annotations on the
* methods of this class are redundant.
* <p>
* However, by adding these annotations, we can use this class both in a Java EE 6 and in a Spring
* 3.0.x container. Of course, the preferred solution would be if Spring supported the
* <code>@Stateless</code> and other EJB annotations <a
* href="https://jira.springframework.org/browse/SPR-3858">out-of-the-box</a>.
*
* @author hwellmann
*
*/
@Stateless
public class LibraryService implements Serializable {
private static final long serialVersionUID = 1L;
@PersistenceContext
private EntityManager em;
@TransactionAttribute
public void fillLibrary() {
if (getNumBooks() != 0) {
return;
}
Author mann = createAuthor("Thomas", "Mann");
Author steinbeck = createAuthor("John", "Steinbeck");
createBook("Buddenbrooks", mann);
createBook("East of Eden", steinbeck);
}
@TransactionAttribute
public List<Book> findBooks() {
String jpql = "select b from Book b";
TypedQuery<Book> query = em.createQuery(jpql, Book.class);
List<Book> books = query.getResultList();
return books;
}
@TransactionAttribute
public List<Book> findBooksByAuthor(String lastName) {
String jpql = "select b from Book b where b.author.lastName = :lastName";
TypedQuery<Book> query = em.createQuery(jpql, Book.class);
query.setParameter("lastName", lastName);
List<Book> books = query.getResultList();
return books;
}
@TransactionAttribute
public List<Book> findBooksByTitle(String title) {
String jpql = "select b from Book b where b.title = :title";
TypedQuery<Book> query = em.createQuery(jpql, Book.class);
query.setParameter("title", title);
List<Book> books = query.getResultList();
return books;
}
@TransactionAttribute
public Author createAuthor(String firstName, String lastName) {
Author author = new Author();
author.setFirstName(firstName);
author.setLastName(lastName);
em.persist(author);
return author;
}
@TransactionAttribute
public Book createBook(String title, Author author) {
Book book = new Book();
book.setTitle(title);
book.setAuthor(author);
author.getBooks().add(book);
em.persist(book);
return book;
}
@TransactionAttribute
public long getNumBooks() {
String jpql = "select count(b) from Book b";
Long numBooks = (Long) em.createQuery(jpql).getSingleResult();
return numBooks;
}
@TransactionAttribute
public long getNumAuthors() {
String jpql = "select count(a) from Author a";
Long numAuthors = (Long) em.createQuery(jpql).getSingleResult();
return numAuthors;
}
}