logout

/**
     * Efetua logout do sistema.
     * @return
     */
    public String logout() {
        log.info( String.format("Efetuado logout do usuario: %s ", this.getUsuarioLogado().getEmail() ));
        ExternalContext ec = FacesContext.getCurrentInstance().getExternalContext();
        HttpServletRequest req = (HttpServletRequest) ec.getRequest();
        HttpSession session = req.getSession(false);
        try {
            log.info(String.format("Contexto: ", req.getContextPath() ));
            req.logout();
            session.invalidate();
            usuarioLogado = null;
            ec.redirect("/");
        } catch (ServletException ex) {
            log.error( String.format("Erro de Servlet ao efetuar logout. [%s]", ex.getMessage()) );
        } catch (IOException ex) {
            log.error( String.format("Erro de I/O ao efetuar logout. [%s]", ex.getMessage()) );
        } catch (Exception ex){
            log.error( String.format("Erro desconhecido ao efetuar logout. [%s]", ex.getMessage()) );
        }
        return null;
    }