关于servlet网页404的问题

Question

问题遇到的现象和发生背景

问题相关代码，请勿粘贴截图

运行结果及报错内容

网页跳转404

服务器报错第13行创建对象出现问题

  protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String username = req.getParameter("username");
        String password = req.getParameter("password");
        String code = req.getParameter("code");
        String email = req.getParameter("email");

        if ("abcde".equalsIgnoreCase(code)){
            if (service.existsUsername(username)){
                System.out.printf("用户名已存在");
                req.getRequestDispatcher("/pages/user/regist.html").forward(req,resp);
           }else {
                req.getRequestDispatcher("/pages/user/regist_success.html").forward(req,resp);
            }
        }else {
            System.out.printf("验证码不正确");
            req.getRequestDispatcher("/pages/user/regist.html").forward(req,resp);
        }
    }

这是UserServiceImpl类，是UserService接口的实现类

public class UserServiceImpl extends UserDaoImpl implements UserService {
    @Override
    public void RegistUser(User user) {
       saveUser(user);

    }

    @Override
    public User login(User user) {
    return UserDaoByUsernamePassword(user.getUsername(),user.getPassword());
    }

    @Override
    public boolean existsUsername(String username) {
        User user = UserDaoByUsername(username);
        if (user==null){
            return false;
        }else {
            return true;
        }
    }
}

我的解答思路和尝试过的方法

尝试过把有关这个对象的代码注释掉servlet可以正常运行

我想要达到的结果

Answer 1

请求路径有问题吗