为什么我收到此错误为什么类型为User的方法getId（）未定义

Question

我正在使用java ee创建社交网络应用程序，并使用此错误在im堆栈中创建该方法getId（）对于类型User未定义。这是我的用户模型

public class User {
    private int id;
    private String name;
    private String surname;
    private String email;
    private String password;
    private String avatar;
}

我在此类user.getId（）中遇到此错误

protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
     HttpSession session = req.getSession();
     String acceptId = req.getParameter("acceptId");
     User user = (User) session.getAttribute("user");

     friendRequestManager.acceptUserById(user.getId(), Integer.parseInt(acceptId));
     req.getRequestDispatcher("/user/userHome").forward(req, resp);
 } 
 ```