@Override protected LegacyApplication createApplication() { VaadinServlet servlet = VaadinServlet.getCurrent(); if (servlet instanceof LegacyVaadinServlet) { LegacyVaadinServlet legacyServlet = (LegacyVaadinServlet) servlet; HttpServletRequest request = VaadinServletService .getCurrentServletRequest(); try { if (legacyServlet.shouldCreateApplication(request)) { return legacyServlet.getNewApplication(request); } } catch (ServletException e) { throw new RuntimeException(e); } } return null; } };