Checking variable existance using JSTL

[reena]

How can I check a variable's existance using JSTL? I am expecting an attribute in my session and if that attribute exist I need to display a block of code. How can I do that?

[albinjoseph]

You can use <c:if> for that purpose.

Code:

<c:if test='${not empty variableName}'>
    <c:out value="${variable}" />
</c:if>

Where variable is your variable name. If you have a variable named var in your session and if you want to check whether that variable existence or not use the following code.

Code:

<c:if test='${not empty sessionScope.var}'>
    <c:out value="${variable}" />
</c:if>

[reena]

I need something like a if else . If the variable exist display some content else some other content. Please give me the code for that.

[albinjoseph]

Here you go.

Code:

<c:choose>
    <c:when test="${not empty sessionScope.var}">
        Variable exist.
    </c:when>
    <c:otherwise>
        Variable does not exist.
    </c:otherwise>
</c:choose>

[reena]

Thank you.