如何在EL中评估scriptlet变量? [英] How to evaluate a scriptlet variable in EL?

问题描述

我想知道是否在<c:if>语句中使用了JSP.

I was wondering if there was anyway of using JSP in <c:if> statement.

例如

<c:if test="${ param.variable1 == 'Add' <% JSP variable clause %>}">

所以我也想检查我的JSP变量.

So I want my JSP variable to checked against as well.

有什么建议吗?我无知地试着仅仅坚持该子句，显然那是行不通的.

Any suggestions? I have tried ignorantly just sticking in the clause, obviously it did not work.

谢谢

推荐答案

所以您想在EL中评估 scriptlet 变量?将其存储为请求属性.

So you want to evaluate a scriptlet variable in EL? Store it as a request attribute.

<%
    String var = "some";
    request.setAttribute("var", var);
%>

<c:if test="${param.variable1 == 'Add' && var == 'some'}">

但是，这没有任何意义.您应该避免 脚本并使用JSTL/EL准备此变量.因此，如果您使功能要求更加明确，例如如何使用JSTL/EL做到这一点(插入 scriptlet 代码片段?")，那么我们将能够提出正确的方法.

However, this makes no sense. You should avoid scriptlets altogether and use JSTL/EL to prepare this variable. So if you make the functional requirement more clear, e.g. "How do I do this (insert scriptlet code snippet) using JSTL/EL?", then we'll be able to suggest the right approach.

例如，您可以使用<c:set>在EL作用域中设置变量.

For example, you could use <c:set> to set a variable in EL scope.

<c:set var="var" value="some" scope="request" />

另请参见:

• 我们的EL Wiki页面
• <％= foo％>之间的差异和$ {foo}
• 直接在脚本<％XY％>中使用EL $ {XY} ;
• 什么是隐式对象?是什么意思?

See also:

• Our EL wiki page
• Difference between <%= foo %> and ${ foo }
• Use EL ${XY} directly in scriptlet <% XY %>
• What are implicit objects? What does it mean?

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