java - Play Framework : could not bind from form

Question

我正在开发一个 play 2.2.3 应用程序，但在将表单绑定(bind)到我的模型类时遇到一些问题。这是我的模型类:

package models;

import java.util.Date;

import javax.persistence.Access;
import javax.persistence.AccessType;
import javax.persistence.Entity;
import javax.persistence.Id;

@Entity
@Access(AccessType.FIELD)
public class User {
    @Id
    private int id;
    private String firstname;
    private String lastname;
    private Date birthdate;
    private String gender;
    private String username;
    private String password;

    // some getter and setters...

}

我的表格:

@(form: Form[User])

@helper.form(action = routes.Application.register) {
                <fieldset>
                    <legend>Persönliche Daten</legend>
                    @helper.inputText(form("firstname"),'_label -> "Vorname:")
                    @helper.inputText(form("lastname"),'_label -> "Nachname:")
                    @helper.inputDate(form("birthdate"),'_label -> "Geburtstag:")
                    @helper.inputRadioGroup(form("gender"),options = Seq(("male"->"Männlich"),("female"->"Weiblich")),'_label -> "Geschlecht:")
                </fieldset>
                <fieldset>
                    <legend>Login Daten</legend>
                    @helper.inputText(form("username"),'_label -> "Benutzername*:")
                    @helper.inputText(form("password"),'_label -> "Passwort*:")
                    <input id="registersubmit" type="submit" value="Registrieren" accesskey="s"/>
                    <p id="requiredhint">Mit "*" gekennzeichnete Felder sind Pflichtfelder</p>
                </fieldset>
            }

以及我的操作方法:

@Transactional
    public static Result register() {
        Form<User> form = Form.form(User.class).bindFromRequest();
        if (form.hasErrors()) {
            return badRequest("/registration");
        } else {
            User user = form.get();
            //JPA.em().persist(user);
            System.out.println("User "+user.getUsername()+" successfully saved!");
            return redirect("/index");
        }
    }

这些字段位于表单中，但随后它们不会绑定(bind)到用户，并且 user.getUsername() 会打印 null。可能是什么问题？

Answer 1

好像还好。您可以将字段设置为公共(public)字段并删除 getter 和 setter 吗？只是为了检查它们是否有问题或将完整的 User 类放入示例中。