HibernateFilter em app JSF

package br.com.cienci.nfe.dao;

import java.util.List;
import org.hibernate.Session;

public class Dao<T> {

	private Session session;
	private final Class classe;
	
	public Dao(Session session, Class classe){
		this.session = session;
		this.classe = classe;
	}
	
	public void adiciona(T u){
		this.session.save(u);
	}

	public void remove(T u){
		this.session.delete(u);
	}
	
	public void atualiza(T u){
		this.session.merge(u);
	}
	
	public List<T> listaTudo(){
		return this.session.createCriteria(this.classe).list();
	}

	public T procura(Long id){
		return (T) session.load(this.classe, id);
	}
	
	protected Session getSession(){
		return session;
	}
}

package br.com.cienci.nfe.dao;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.AnnotationConfiguration;
import org.hibernate.cfg.Configuration;

public class HibernateUtil {

    private static SessionFactory factory;
   
    static {
        Configuration conf = new AnnotationConfiguration();
        conf.configure();
        factory = conf.buildSessionFactory();
    }
 
    public static Session getSession() {
        return factory.openSession();
    }
}

package br.com.cienci.nfe.dao;

import br.com.cienci.nfe.modelo.Login;
import br.com.cienci.nfe.modelo.Role;
import org.hibernate.Session;
import org.hibernate.Transaction;

public class DaoFactory {

    private Session session;
    private Transaction transaction;
    
    public DaoFactory() {
        this.session = HibernateUtil.getSession();
    }
  
    public void beginTransaction() {
        this.transaction = this.session.beginTransaction();
    }
   
    public void commit() {
        this.transaction.commit();
        this.transaction = null;
    }
   
    public boolean hasTransaction() {
        return this.transaction != null;
    }
   
    public void rollback() {
        this.transaction.rollback();
        this.transaction = null;
    }

    public void close() {
        this.session.close();
    }    
    
    public Dao<Login> getLoginDao(){
        return new Dao<Login>(this.session, Login.class);
    }
    
    public Dao<Role> getRoleDao(){
        return new Dao<Role>(this.session, Role.class);
    }    
    
    protected Session getSession() {
        return session;
    }
}

public class UsuarioBean {

    private DaoFactory daoFactory;

    public UsuarioBean() {
        this.daoFactory = new DaoFactory();        
    }

    public String removerUsuario() {

        try {
            this.daoFactory.beginTransaction();
            this.daoFactory.getLoginDao().remove(this.getLoginFromList());
            this.daoFactory.commit();
        } catch (HibernateException ex) {
            this.daoFactory.rollback();
            System.err.println(ex.getMessage());
      }
       return "sucesso";
    }
       
}