Quick and ugly support for transactional tasks using vraptor-tasks and Hibernate.

TransactionalTask.java

package ...;

import br.com.caelum.vraptor.tasks.Task;
import javax.inject.Inject;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @author Jardel Weyrich
 */
public abstract class TransactionalTask implements Task {
	
	private static final Logger log = LoggerFactory.getLogger(TransactionalTask.class);
	
	@Inject protected SessionFactory sessionFactory;
	protected Session session;
	
	@Override
	public void execute() {
		final boolean canContinue = beforeExecute();
		if (!canContinue)
			return;
		try {
			session.beginTransaction();
			doWork();
			session.flush();
			session.getTransaction().commit();
		} catch (HibernateException e) {
			session.getTransaction().rollback();
			throw e; // or display error message
		}
		afterExecute();
	}
	
	protected boolean beforeExecute() {
		this.session = this.sessionFactory.openSession();
		if (this.session == null) {
			log.error("Could not get an instance of {0}", Session.class.getCanonicalName());
			return false; // FIXME: Should throw an exception and abort execution?
		}
		return true;
	}
	
	protected void afterExecute() {
		if (this.session != null && this.session.isOpen())
			this.session.close();
	}
	
	public abstract void doWork();
	
}

This is really awesome.
In any post I could find something so usefull to Vraptor-Task as it!