java 会话过期时 spring 3 mvc SessionAttributes 中的默认对象
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Default objects in spring 3 mvc SessionAttributes when session expired
提问by Art79
I think im confused a bit about session annotation in spring mvc.
我想我对 spring mvc 中的会话注释有点困惑。
I have code like this (2 steps form sample, step 1 user data, step 2 address)
我有这样的代码（2 步表单示例，第 1 步用户数据，第 2 步地址）
@SessionAttributes({"user", "address"})
public class UserFormController {
@RequestMapping(method = RequestMethod.GET)
public ModelAndView show( ModelAndView mv ){
mv.addObject( new User() );
mv.addObject( new Address() );
mv.setViewName("user_add_page");
return mv;
}
@RequestMapping(method = RequestMethod.POST)
public String processForm( User user, BindingResult result ){
new UserValidator().validate(user, result);
if( result.hasErrors() ){
return "user_add_page";
}else{
return "redirect:/user_form/user_add_address";
}
// .........
}
Now if i submit page after my session expires i get error
现在，如果我在会话过期后提交页面，则会出现错误
org.springframework.web.HttpSessionRequiredException: Session attribute 'user' required - not found in session
org.springframework.web.HttpSessionRequiredException：需要会话属性“用户”-在会话中找不到
How do i handle it? i would like to have 2 options
我该如何处理？我想有 2 个选择
- i create empty objects if missing in session and accept submit
- i forward back to user form with some message
- 如果在会话中丢失，我会创建空对象并接受提交
- 我用一些消息转发回用户表单
Im still in early stage of learning Spring so sorry if its something very obvious, i just cant see it.
我还处于学习 Spring 的早期阶段，很抱歉，如果它的某些东西非常明显，我只是看不到它。
ps. is that even the good way to solve this kind of form in spring mvc or would you recomment different approach?
附：这是在spring mvc中解决这种形式的好方法还是你会推荐不同的方法？
采纳答案by axtavt
1.i create empty objects if missing in session and accept submit
1.如果会话中丢失，我创建空对象并接受提交
Use @ModelAttribute("user")-annotated method to provide the default value
使用@ModelAttribute("user")-annotated 方法提供默认值
2.i forward back to user form with some message
2.我用一些消息转发回用户表单
Use @ExceptionHandler(HttpSessionRequiredException.class)-annotated method
使用带@ExceptionHandler(HttpSessionRequiredException.class)注释的方法
回答by andrew0007
Try to check here:
尝试在这里检查：
http://forum.springsource.org/showthread.php?t=63001&highlight=HttpSessionRequiredException
http://forum.springsource.org/showthread.php?t=63001&highlight=HttpSessionRequiredException
@Controller
@RequestMapping(value="/simple_form")
@SessionAttributes("command")
public class ChangeLoginController {
@ModelAttribute("command")
public MyCommand createCommand() {
return new MyCommand();
}
@RequestMapping(method = RequestMethod.GET)
public String get() {
return "form_view";
}
@RequestMapping(method = RequestMethod.POST)
public String post(@ModelAttribute("command") MyCommand command) {
doSomething(command); // execute business logic
return "form_view";
}
}
回答by matt b
According to the Spring 3.0 reference manual, it looks like @SessionAttributes is meant to be used on a type that you want to be stored transparently in the session, such as a "Command" or a form-backing object. I don't think you would want to store a Controller in session.
根据Spring 3.0 参考手册，看起来 @SessionAttributes 旨在用于您希望在会话中透明存储的类型，例如“命令”或表单支持对象。我认为您不想在会话中存储控制器。
