Using JSTL "dynamic" parameter name

JSTL Code:

<c:forEach var = "currentUser" items = "${users}">
    <c:out value = "${currentUser.userName}" /></p>
    <c:if test = "${!empty param.${currentUser.id}}">
        <p>Details</p>
    </c:if>
</c:forEach>

I have a list of user objects and i display all of their names. If one wants to see the details of any user a request is sent t开发者_JAVA技巧o a servlet which will return a Attribute with the name id and a DetailUser Object

Servlet:

req.setAttribute(currentUSer.getId, userDetails);

The problem is that, now if have to use the value of "id" in the if test not as a parameter, but a parameter name instead. I've tried that EL in EL expression but I am really sure that it isn't allowed. Any other suggestions?

It seems to me that you're making it more complex than it could be.I would simply do

req.setAttribute("userDetails", userDetails);

and, in the JSP, test if the current user's ID is the same as the one being detailed:

<c:if test="${userDetails.id == currentUser.id}">
    <p>Details</p>
</c:if>

BTW, param.foo returns the value of a request parameter, not the value of a request attribute. You could do what you wanted by using

<c:if test = "${!empty requestScope[currentUser.id]}">

The [] notation instead of the . operator is the way to pass a dynamic name rather than a static one.