Struts 2 Action标签，检索属性 [英] Struts 2 Action tags, retrieving properties

问题描述

如果我有一个典型的设置，其中一个动作转发到JSP，我会请求我的属性如下：

If I had a typical setup with an action that forwards to the JSP I would request my properties like so:

< s： property value =myVariable/>

其中myVariable是动作中的变量。

where myVariable is a variable in the action.

我想在另一页中使用这样的动作标签：

I want to use action tags like this in another page:

<s:action name="actionName" executeResult="false"> 
    <s:param name="switch">true</s:param>
</s:action>

使用时如何访问 myVariable 动作标签如上？我尝试了< s：property value =myVariable/> 但它不起作用。

How do I access myVariable when using an action tag like above? I tried <s:property value="myVariable" /> but it doesn't work.

推荐答案

当你写< s：property value =myVariable/> 时，Struts会查找属性 myVariable 在其价值堆栈中。当前操作在ValueStack中，这就是典型设置的原因。现在，在

When you write <s:property value="myVariable" />, Struts looks for the property myVariable in its "Value Stack". The current action is in the ValueStack, and that's why the typical setup works. Now, in the case of

<s:action name="actionName" executeResult="false"> 
    <s:param name="switch">true</s:param>
</s:action>
<s:property value="myVariable" />

执行最后一行 actionName 动作已经执行，当前动作不是主动（外部）动作。如果你想访问内部动作的属性，你有几个选择，其中两个显示在 docs ：

when the last line is executed the actionName action has already executed, the current action is not that but the main ("outer") one . If you want to acces properties of your "inner" action, you have several alternatives, two of them are shown in the docs:

添加 var 属性以便执行（内部）操作被分配给变量并使用＃syntax 引用它：

Either add the var attribute so that the executed (inner) action is assigned to a variable and reference it with the # syntax:

<s:action name="actionName" var="innerAction" executeResult="false">
   <s:param name="switch">true</s:param>
</s:action>
<s:property value="#innerAction.myVariable" />

或者，在您的操作方法中，将您的属性值显式添加到某个范围（例如：attribute）

Or, in your action method, add your property value explicitly to some scope ( eg: attribute)

// in your inner action: 
ServletActionContext.getRequest().setAttribute("myVariable", "blah blah");

<s:property value="#attr.myVariable" />

免责声明：我没有测试过这个

Disclaimer: I've not tested this

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