DocumentService.java

/**
 * This file is part of jpa-cert application.
 *
 * Jpa-cert is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * Jpa-cert is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with jpa-cert; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
package net.kaczmarzyk.jpacert.service.locking;

import javax.ejb.LocalBean;
import javax.ejb.Stateless;
import javax.ejb.TransactionAttribute;
import javax.ejb.TransactionAttributeType;
import javax.persistence.EntityManager;
import javax.persistence.LockModeType;
import javax.persistence.PersistenceContext;

import net.kaczmarzyk.jpacert.domain.locking.Document;


@Stateless
@LocalBean
@TransactionAttribute(TransactionAttributeType.REQUIRES_NEW)
public class DocumentService {

	@PersistenceContext
	private EntityManager em;
	
	
	public Document newDoc(String content) {
		Document doc = new Document(content);
		em.persist(doc);
		return doc;
	}
	
	public void append(Long id, String text) {
		Document doc = em.find(Document.class, id);
		doc.append(text);
	}
	
	public void deleteAll() {
		em.createQuery("delete from Document").executeUpdate();
	}

	public Document readWithForceIncrement(Long id) {
		return em.find(Document.class, id, LockModeType.OPTIMISTIC_FORCE_INCREMENT);
	}
}