[JAVA] Hibernate, configurazione base

[Gil Mour]

stack

java.lang.NoClassDefFoundError: org/apache/commons/logging/LogFactory
	at org.hibernate.cfg.Configuration.(Configuration.java:110)
	at prova.HibernateHelper.(HibernateHelper.java:14)
	at prova.Prova.doGet(Prova.java:15)

codice completo della servlet

public void doGet (HttpServletRequest request, HttpServletResponse response)
	{
		System.out.println("ciao");
		
		Session session = HibernateHelper.currentSession();
		Transaction tx = session.beginTransaction();
		
		Cat c = new Cat();
		c.setNome("Birba");
		
		session.save(c);
		tx.commit();
		
		HibernateHelper.closeSession();

	}

codice completo di hibernate helper

package prova;

import org.hibernate.*;
import org.hibernate.cfg.*;

public class HibernateHelper {
	
    private static final SessionFactory sessionFactory;
	
	static
	{
        try 
        {
            sessionFactory = new Configuration().configure().buildSessionFactory();
        } catch (Exception ex) {
        	ex.printStackTrace();
            throw new ExceptionInInitializerError(ex);
        }
    }
    
    public static final ThreadLocal session = new ThreadLocal();

    public static Session currentSession() 
    {
        Session s = (Session) session.get();
        
        if (s == null) 
        {
            s = sessionFactory.openSession();
            session.set(s);
        }
        return s;
    }

    public static void closeSession() 
    {
        Session s = (Session) session.get();
        if (s != null)
            s.close();
        session.set(null);
    }


	
}