当索引是变量时，Struts2访问列表的特定索引 [英] Struts2 Access specific index of list when index is a variable

问题描述

当索引是变量时，我在访问列表的特定元素时遇到一些麻烦.

I'm having some trouble accessing a specific element of a list when the index is a variable.

当索引只是一个数字时，我完全不会显示要查找的内容.

When the index is just a number, I have no issues at all displaying what I'm looking for.

<s:property value="#session.userList[1].email" />

效果很好，并显示在UserList的该元素中找到的电子邮件

That works perfectly, and displays the email found in that element of UserList

但是，当我将索引更改为变量时，我很难找到编写ognl语句的正确方法.我尝试了所有可以想到的％#组合，但都没有运气.

However, when I change the index to be a variable, I'm having difficulties finding the proper way to write the ognl statement. I've tried every combination of %# I can think of with no luck.

<s:set var="userIndex" >${param.index}</s:set>
<s:property value="#session.userList[#userIndex].email" />

我应该如何精确格式化ognl语句?

How exactly should I format my ognl statement?

推荐答案

您应在此示例中设置其格式:

You should format it like in this example:

<s:set var="userIndex" value="%{@java.lang.Integer@valueOf(#parameters.index)}" />
<s:property value="%{#session.userList[#userIndex].email}" />

如果您正在使用struts标记，最好使用OGNL代替EL来求值表达式.强制OGNL评估整个表达而不是一部分.

If you are working with the struts tags better use OGNL for evaluate expressions instead of EL. Force OGNL to evaluate whole expression not a part.

需要将变量的值转换为整数类型.用于名称的字符串类型.

Needed to convert to integer type the value of the variable. String types used for names.

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