@WebServlet(name = "WebhookBot", urlPatterns = {"/pagebot"})
public class WebhookBot extends HttpServlet {

    static ExecutorService service = Executors.newCachedThreadPool();


 @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
.....
                case "update_id":

                    service.submit(() -> {
                        Update_id(obj);
                    });
                    break;
.....
}
}

public static synchronized void DFL_set_IP(){.....}