Question

String transportVehicle = "";
    String firstname = request.getParameter("fname");
    String lastname = request.getParameter("lname");
    String email = request.getParameter("email");
    String password = request.getParameter("password");
    String number = request.getParameter("phone");
    int phone = Integer.parseInt(number);
    String gender = request.getParameter("gender");
    String[] vehicle = request.getParameterValues("vehicle");
    String country = request.getParameter("country");
    String city = request.getParameter("city");
    List<String> errors = new ArrayList<String>();
    User user = new User();
    user.setFname(firstname);
    user.setLname(lastname);
    user.setEmail(email);
    user.setPassword(password);
    user.setPhone_no(phone);
    user.setGender(gender);
    for (int i = 0; i < vehicle.length; i++) {
        transportVehicle += vehicle[i] + "";
    }
    user.setVehicles(transportVehicle);
    user.setCountry(country);
    user.setCity(city);

    Map<String, String> message = new HashMap<String, String>();
    request.setAttribute("message", message);

    if (firstname.equals("") || firstname == null || firstname.trim().isEmpty()) {
        message.put("fname", "enter the firstname");
    }
    if (lastname.equals("") || lastname == null || lastname.trim().isEmpty()) {
        message.put("lname", "enter the lastname");
    }
    if (email.equals("") || email == null || email.trim().isEmpty()) {
        message.put("email", "enter the email");
    }
    if (password.equals("") || password == null || password.trim().isEmpty()) {
        message.put("password", "enter the password");
    }
    if (number.equals("") || number == null || number.trim().isEmpty()) {
        message.put("phone", "enter the number");
    }
    if (country.equals("") || country == null || country.trim().isEmpty()) {
        message.put("country", "enter the country");
    }
    if (city.equals("") || city == null || city.trim().isEmpty()) {
        message.put("city", "enter the city");
    }
    if (!message.isEmpty()) {
        request.getRequestDispatcher("index.html").forward(request, response);
    } else {;

如何将列表发送到jsp页面并在显示页面显示错误我应该怎么做。请帮助我吗？任何帮助都会很好吗？在这段代码中，我创建了一个用于错误的map类。我应该如何把我的错误放在jsp页面中。我应该这样做。非常感谢。

Answer 1

你已经达到了想要做的一切。该地图位于int result = query.FirstOrDefault();，可用：

int result = (from p in aspdb.RouteLinqs
                           orderby p.RouteId descending
                           select p.Id).FirstOrDefault();

您只需迭代地图并显示消息即可。你在这里有一个例子：How to loop through a HashMap in JSP?。

使用jsp你必须做这样的事情：

request.setAttribute("message", message);

使用自定义CSS jstl来设置邮件样式。

我在那个地方做一个servlet项目我想在java中使用map进行服务器端验证？请举个例子？

1 个答案: