spring mvc3中的addFlashAttribute方法

记得在spring mvc2中，当保存POJO到数据库后,要返回成功页面，如果这个时候要带点信息，

则要这样：

Java代码:

//第三个参数（UserModel user）默认为绑定对象
@RequestMapping(value = "/user/save", method = RequestMethod.POST)
public ModelAndView saveUser(HttpServletRequest request, HttpServletResponse response,UserModel user) throws Exception {
ModelAndView mv = new ModelAndView("/user/save/result");//默认为forward模式
// ModelAndView mv = new ModelAndView("redirect:/user/save/result");//redirect模式
mv.addObject("message","保存用户成功！");
return mv;
}

而在spring mvc 3.1后，可以这样

Java代码:

@RequestMapping(value = "/user/save", method = RequestMethod.POST)
public ModelAndView saveUser(UserModel user, RedirectAttributes redirectAttributes) throws Exception {
redirectAttributes.addFlashAttribute("message", "保存用户成功！");//使用addFlashAttribute,参数不会出现在url地址栏中
return "redirect:/user/save/result";
}

来个稍微完整点的例子，首先是一个表单，在其中填入一些信息：

Java代码:

<form:form id="myform" action="saveUserDetails.action" method="POST" commandName="user">
<form:input type="text" name="firstName" path="firstName"/>
<form:input type="text" name="lastName" path="lastName"/>
<form:input type="text" name="email" path="email"/>
<input type="submit" value="submit">
</form:form>

则在controller中，可以这样：

Java代码:

@RequestMapping(value="/saveUserDetails.action", method=RequestMethod.POST)
public String greetingsAction(@Validated User user,RedirectAttributes redirectAttributes){
someUserdetailsService.save(user);
redirectAttributes.addFlashAttribute("firstName", user.getFirstName());
redirectAttributes.addFlashAttribute("lastName", user.getLastName())
return "redirect:success.html";
}
success.html:
<div>
<h1>Hello ${firstName} ${lastName}. Your details stored in our database.</h1>
</div><br>

但如果F5的时候，会发现参数丢失，因为flash scope其实只支持redirect的，所以可以判断下：

Java代码:

@RequestMapping(value="/success.html", method=RequestMethod.GET)
public String successView(HttpServletRequest request){
Map<String,?> map = RequestContextUtils.getInputFlashMap(request);
if (map!=null)
return "success";
else return "redirect:someOtherView"; //給出其他提示信息
原文地址：http://www.software8.co/wzjs/java/2943.html

posted on 2013-02-19 14:42 飞猪一号阅读(9442) 评论(3) 编辑收藏

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