EDIT

    @Override

    public boolean login(URI uri, String context, String userName, String password) {

        UsernamePasswordAuthenticationToken token = new UsernamePasswordAuthenticationToken(userName, password);

        AuthenticationManager authenticationManager = (AuthenticationManager) CdmSpringContextHelper.getCurrent().getBean("authenticationManager");

        Authentication authentication = authenticationManager.authenticate(token);

        if(authentication != null && authentication.isAuthenticated()) {

            SecurityContextHolder.getContext().setAuthentication(authentication);

            CdmVaadinAuthentication cvAuthentication = (CdmVaadinAuthentication) VaadinSession.getCurrent().getAttribute(CdmVaadinAuthentication.KEY);

            CdmVaadinSessionUtilities.setCurrentAttribute(CdmVaadinAuthentication.KEY, cvAuthentication);

            return true;

        }

        return false;

    }