java.lang.ClassNotFoundException for my generic DAO

I create a generic DataAccessObject and try to save a data in my database

HibernateDAO.java

/*
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 * and open the template in the editor.
 */

package br.salesianos.dao;

import br.salesianos.db.CriadorDeSessao;
import java.io.Serializable;
import java.util.List;
import javax.faces.bean.ManagedBean;

import org.hibernate.Session;

public class HibernateDAO<T> {

private Class<T> classe;

public HibernateDAO(Class<T> classe) {
		super();
		this.classe = classe;
	}

public void atualizar(T bean) {
		Session session = CriadorDeSessao.getSession();
		session.beginTransaction();
		session.update(bean);
		session.getTransaction().commit();
	}

public void excluir(T bean) {
		Session session = CriadorDeSessao.getSession();
		session.beginTransaction();
		session.delete(bean);
		session.getTransaction().commit();
	}

public T getBean(Serializable codigo) {
		Session session = CriadorDeSessao.getSession();
		session.beginTransaction();
		T bean = (T)session.get(classe, codigo);
		session.getTransaction().commit();
		return bean;
	}

public List<T> getBeans() {
		Session session = CriadorDeSessao.getSession();
		session.beginTransaction();
		List<T> beans = (List<T>)session.createCriteria(classe).list();
		session.getTransaction().commit();
		return beans;
	}

public void salvar(T bean) {
		Session session = CriadorDeSessao.getSession();
		session.beginTransaction();
		session.save(bean);
		session.getTransaction().commit();
	}

}

I use JSF and Hibernate in my application.

This code works perfect when i call him inside netbeans like a desktop app

but when i try to use him inside a JSF app, he give me a error

this is the ManagedBean that i use to save data through xhtml file

GravaCidade.java

package br.salesianos.db;

import br.salesianos.dao.HibernateDAO;
import br.salesianos.modelo.Cidade;
import br.salesianos.modelo.Estado;

import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import javax.faces.bean.ManagedBean;
import org.hibernate.*;

@ManagedBean
public class GravaCidade
{
    private int est_id;
    private String cid_nome;
    private List<Estado> estados;

public String gravar()
    {

HibernateDAO<Cidade> cidadeDAO = new HibernateDAO<Cidade>(Cidade.class);

Estado obj_estado = new Estado();
        obj_estado.setEst_id(1);

Cidade obj_cidade = new Cidade();
        obj_cidade.setCid_nom("ffffddd");
        obj_cidade.setEstado(obj_estado);

cidadeDAO.salvar(obj_cidade);
        return "sucesso";
    }

/**
     * @return the est_id
     */
    public int getEst_id() {
        return est_id;
    }

/**
     * @param est_id the est_id to set
     */
    public void setEst_id(int est_id) {
        this.est_id = est_id;
    }

/**
     * @return the cid_nome
     */
    public String getCid_nome() {
        return cid_nome;
    }

/**
     * @param cid_nome the cid_nome to set
     */
    public void setCid_nome(String cid_nome) {
        this.cid_nome = cid_nome;
    }
}

why this don't work in JSF app?

cadastro_cidade.xhtml

So your error message is "java.lang.NoClassDefFoundError: br/salesianos/dao/HibernateDAO"
It works for your stand-alone application, but not for your web application.

Have you added this class into the classpath for your web application?
Classpath for a web application means the WEB-INF/classes folder and jar files in the WEB-INF/lib folder.

I think the only thing you are missing is to tell NetBeans that your web application wants to use this code.
I don't know much about Netbeans, but presume you already have a "web" project that runs a web server through netbeans? Or are you deploying externally somewhere?