Lost Session JSP-Vaadin

Hello,

In my Vaadinapp i have a JSP embeded


final Embedded browser = new Embedded("", new ExternalResource("../firmaCliente.jsp"));

In the submit of this JSP


				<input type="hidden" name="emisor" value="" />
				<input type="hidden" name="sujeto" value="" />
				<input type="hidden" name="numSerie" value="" />
				<input type="hidden" name="fechaInicioValidez" value="" />
				<input type="hidden" name="fechaFinValidez" value="" />
				<input type="hidden" name="firma" value="" />
				<input type="hidden" name="valorBoolean" value="" />

in my appVaadin :


@Override
	public boolean handleRequest(VaadinSession session, VaadinRequest request,
			VaadinResponse response) throws IOException {
		if ("/controllerReceived".equals(request.getPathInfo())) {			
			//UI.setCurrent(VaadinSession.getCurrent().getUIById(0));
			cert = new Certificado();
			cert.setEmisor(request.getParameter("emisor"));
			cert.setSujeto(request.getParameter("sujeto"));
			cert.setNumSerie(request.getParameter("numSerie"));
			cert.setFechaInicioValidez(Format.convertToDate(request.getParameter("fechaInicioValidez")));
			cert.setFechaFinValidez(Format.convertToDate(request.getParameter("fechaFinValidez")));			
			cert.setFirma(request.getParameter("firma"));
			cert.setValorBoolean(request.getParameter("valorBoolean"));
						
			response.setContentType("text/html");
            response.getWriter().append(cert.toHtmlResponse());

			VaadinSession.getCurrent().setAttribute("CERTIFICADO", cert);
			
			
			return true;
		}
		return false;
	}

And the object cert has the values but the problem is that finish the method handleRequest i have other session and the object cert is NULL and


cert = (Certificado) VaadinSession.getCurrent().getAttribute("CERTIFICADO");

is null.

How can i do get object cert ?