重定向后 Flash 范围内的对象不可用 [英] Object in Flash scope is not available after redirect

问题描述

我对在 jsf 2 中使用 flash 范围有误解.我想在我的操作过程中将一个对象放入 flash map，并在下一页中显示该对象.这是我的操作(由 h:commandLink 调用):

I have a misunderstanding with the use of flash scope in jsf 2. I want to put an object in flash map during my action and show this object in the next page. Here is my action (call by h:commandLink):

public String showDetail(PersonneDTO personne) {
    MessageFlashBean message = new MessageFlashBean();
    message.addMessage("test");
    FacesContext.getCurrentInstance().getExternalContext().getFlash()
        .put("test", message);
    return "showDetail";
}

这只是一个测试，但我要使用的真实对象更复杂.

It's just a test, but the real object I want to use is more complex.

这是使用 flash 的第二页:

Here is the second page with the flash use:

<ui:fragment rendered="#{flash.test != null and flash.test.hasMessage()}" >
    <ui:repeat var="message" value="#{flash.test.messages}">
        #{message}
    </ui:repeat>
</ui:fragment>

这是导航(这是我的问题:)):

Here is the navigation (and here is my problem :) ):

<navigation-rule>
    <from-view-id>/index.xhtml</from-view-id>
    <navigation-case>
        <from-outcome>showDetail</from-outcome>
        <to-view-id>/private/showDetail.xhtml</to-view-id>
    </navigation-case>
</navigation-rule>

在这种情况下，闪光灯可以正常工作并且显示我的消息.

In this case, the flash scope works fine and my message appears.

但是如果我在导航案例中添加重定向，我在闪图上的对象就消失了.

But if I add a redirect in the navigation case, my object in the flash map has disappeared.

我不明白为什么我不能在导航规则中使用重定向(我认为这是 flash 范围的目标).

I don't understand why I can't use redirect in the navigation rule (I believed it was the goal of flash scope).

可能是我的代码有问题.

May be something is wrong in my code.

有人可以帮助我吗?

谢谢

推荐答案

Mojarra 对 JSF2 Flash 范围的实现 有很多问题.大多数问题都在每个新的 Mojarra 版本中得到解决.目前，使用最新的 Mojarra 版本，即 2.1.6，据我所知，仍然只有一个主要的未解决问题:它不会如果您重定向到不同的基本路径，则不起作用.另请参阅 issue 1751 中长时间讨论中的(当前)最后一条评论.

The Mojarra's implementation of the JSF2 Flash scope had a lot of problems. Most of them were resolved with every new Mojarra release. Currently, with the latest Mojarra version, the 2.1.6, there's as far as I know still only one major open problem: it won't work if you redirect to a different base path. See also the (currently) last comment in the long discussion in issue 1751.

现在，您基本上有以下选择:

Right now, you have basically the following options:

1. 当您需要重定向到不同的基本路径时，请忘记使用 Flash.改用请求参数或尝试使用自定义 cookie 模拟 Flash 范围.

1. Forget using Flash when you need to redirect to a different base path. Use a request parameter instead or try to simulate the flash scope with a custom cookie.

如果可能，请重新组织文件夹结构，以便在需要 Flash 范围继续存在时无需重定向到不同的基本路径.

If possible, reorganize the folder structure so that you don't need to redirect to a different base path when you need the flash scope to survive.

尝试 MyFaces 而不是 Mojarra.也许它在闪光范围方面做得更好.

Try MyFaces instead of Mojarra. Maybe it does it better with regard to flash scope.

<小时>

更新:根据issue 2136，Flash scope最后一个未解决的问题在即将推出的 Mojarra 2.1.14 中解决了在不同路径上重定向后不可用的问题.因此，在此版本中，所有 Flash 范围相关问题已发现并已打开应该解决并关闭.

---

Update: as per issue 2136, the last open problem of Flash scope not being available after a redirect on a different path is solved in the shortly upcoming Mojarra 2.1.14. So with this version, all Flash scope related problems discovered and open so far should be solved and closed.

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