Question

我想知道是否有更新现有@ModelAttribute的方法。如果可能的话，不保留会话中的值我们说我有一个豆子：

class TravelDetails{
    private String origin;
    private String destination;
    private String travelerName;
    private String travelerAge;
        // Getters & Seters
}

这是我的控制人员：

@Controller
class TravelerController{

@RequestMapping(value="/searchDetails", method=RequestMethod.GET)
public ModelAndView getSearchDetails(@RequestParam("origin") String origin,
        @RequestParam("destination") String destination,ModelMap modelMap){
    TravelDetails travelDetails = new TravelDetails();
    travelDetails.setOrigin(origin);
    travelDetails.setDestination(destination);
    modelMap.addAttribute("travelDetails",travelDetails);
    return new ModelAndView("get_traveler_details");
    }

@RequestMapping(value="/addTravelerDetails", method=RequestMethod.POST)
public ModelAndView addTravelerDetails(
    @ModelAttribute("travelDetails") TravelDetails travelDetails,
           ModelMap modelMap){
    System.out.println(travelDetails.getOrigin);
    System.out.println(travelDetails.getDestination);
    System.out.println(travelDetails.getTravelerName);
    System.out.println(travelDetails.getTravelerAge);
    return new ModelAndView("get_traveler_details");
    }
   }

在第二个控制器方法中获得的帖子表格只包含旅行者姓名和年龄，而需要从第一个控制器中设置的模型属性中检索原点和目的地。我不想在Post表单中明确设置隐藏字段。
我们假设我的HTML为：

<form:form modelAttribute="travelDetails" action="/addTravelerDetails" method="POST">
    <form:input type="text" path="travelerName"/>
    <form:input type="text" path="travelerAge"/>
</form:form>

注意：我在StackOverflow的文本区域编写代码而不是在某些IDE上编写代码，因此如果代码中存在一些错误的拼写或语法错误，请忽略。

Answer 1

您可以在类级别使用@SessionAttributes注释

@Controller
@SessionAttributes("travelDetailsPersist")
class TravelerController{

    @RequestMapping(value="/searchDetails", method=RequestMethod.GET)
    public ModelAndView getSearchDetails(@RequestParam("origin") String origin, @RequestParam("destination") String destination,ModelMap modelMap){
        TravelDetails travelDetails = new TravelDetails();
        travelDetails.setOrigin(origin);
        travelDetails.setDestination(destination);
        modelMap.addAttribute("travelDetails",travelDetails);
        modelMap.addAttribute("travelDetailsPersist",travelDetails);
        return new ModelAndView("get_traveler_details");
    }

    @RequestMapping(value="/addTravelerDetails", method=RequestMethod.POST)
    public ModelAndView addTravelerDetails(@ModelAttribute("travelDetailsPersist") TravelDetails travelDetailsPersist, @ModelAttribute("travelDetails") TravelDetails travelDetails, ModelMap modelMap){
        System.out.println(travelDetailsPersist.getOrigin);
        System.out.println(travelDetailsPersist.getDestination);
        System.out.println(travelDetails.getTravelerName);
        System.out.println(travelDetails.getTravelerAge);
        return new ModelAndView("get_traveler_details");
    }  
}

使用现有值更新@ModelAttribute

1 个答案: