Pool de Conexões [RESOLVIDO]

public class ConexaoDb {

    private static SessionFactory sessionFactory = null;
    private static Session sessao;

    private static void construirSeNecessario() {

        try {
            if (sessionFactory == null) {
                //Configuration configuration = new Configuration();
                Configuration configuration = new AnnotationConfiguration();
                configuration.configure("/br/com/geosapiens/igeolog/modelo/util/hibernate.cfg.xml");
                sessionFactory = configuration.buildSessionFactory();
                sessao = sessionFactory.openSession();
                //System.out.println("Factory criada");
            }
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }

    public static Session openSession() {
        construirSeNecessario();
        try {
            //return sessionFactory.getCurrentSession();
            return sessao;
        } catch (Exception Ex) {
            System.err.println(Ex.getMessage());
            //return sessionFactory.openSession();
            return null;
        }
    }

    public static void close(Session session) {
        if (session != null) {
            try {
                session.close();
            } catch (HibernateException ex) {
                System.err.println("Impossível fechar sessão: " + ex.getMessage());
            }
        }
    }

    public static SessionFactory getFactory() {
        construirSeNecessario();
        return sessionFactory;
    }
}