Question

我有一个我在请求中放入的Contact对象，该对象在中被修改然后获取修改后的对象。我希望返回的对象与您发送的对象相同，保留不在表单中的属性的值。

class Contact{

     private String name;          // this attributes will be modified
     private String lastName;

     private Long id;
     private Date created;        // this atributes will not be modified

     // getters and setters ....

}


    @RequestMapping(value = "/{id}/edit", method = RequestMethod.GET)
    public String updateContact(@PathVariable("id") Long id, Model model) {

         Contact c = contactDao.get(id);
         model.addAttribute("contact", c);

         return "contact/form";

    }



     @RequestMapping(value = "/{id}/edit", method = RequestMethod.POST)
     public String update(@PathVariable("id") Long id, @Valid @ModelAttribute Contact contact, BindingResult result, Model model) {

        // The contact I get here I want to keep the original attributes of the
       // object sent, and have the changes in the fields shown on the form. is that possible?

        return "redirect:/contact";
  }


   <form:form action="${pageContext.servletContext.contextPath}/tags/create"            commandName="contact">

              <form:input path="name"/>
              <form:errors path="name" cssClass="formError"/>
              <form:input path="lastName"/>

   </form:form>

我不想使用隐藏字段来维护不会改变的属性的值

Answer 1

如果您只想在表单中处理某些字段，请创建一个新类 - 仅包含它们的ContactDTO，然后手动（或通过反射）将它们复制到原始Contact对象（你从DB加载id）

Answer 2

我通过将联系对象声明为会话中的对象

来找到问题的解决方案

@Controller
@RequestMapping("/contact")  
@SessionAttributes("contact")
public class ContactController {

....
....


    @RequestMapping(value = "/{id}/edit", method = RequestMethod.GET)
    public String updateContact(@PathVariable("id") Long id, Model model) {

        Contact c = contactDao.get(id);
        model.addAttribute("contact", c);
        return "contact/form";

    }


    @RequestMapping(value = "/{id}/edit", method = RequestMethod.POST)
    public String update(@PathVariable("id") Long id, @Valid @ModelAttribute Contact contact, BindingResult result, Model model) {

        contactDao.update(contact);

        return "redirect:/contact";
    }
}

Answer 3

你的持久性框架是什么？是JPA还是Hibernate？如果是，请使用 @Column（updatable = false）

注释该字段

数据绑定Spring

3 个答案: