vertx:create Socketio (server) - java

vertx:createSocketio

            int port = 9090;
            HttpServer server = vertx.createHttpServer();
            SocketIOServer io = new DefaultSocketIOServer(vertx, server);

            io.sockets().onConnection(new Handler<SocketIOSocket>() {
                public void handle(final SocketIOSocket socket) {
                    socket.on("timer", new Handler<JsonObject>() {
                        public void handle(JsonObject event) {
                            socket.emit("timer", event);
                        }
                    });
                }
            });

            System.out.println("server is running on http://localshot:" + port);
            server.listen(port);