@Override
public void contextInitialized(ServletContextEvent event) {
ServletContext context = event.getServletContext();
socketManager = new DefaultSocketManager();
socketIOServlet = new BaseSocketIOServlet(socketManager);
ServletRegistration.Dynamic registration = context.addServlet("socket.io", socketIOServlet);
registration.addMapping("/socket.io/*");
registration.setAsyncSupported(true);
registration.setLoadOnStartup(1);