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Editorial Team
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Asked: 2026-06-01T08:48:23+00:00

I just wanted to demonstrate why we should not be using JSTL tags to

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I just wanted to demonstrate why we should not be using JSTL tags to a colleague but I got lost not sure why is every thing getting rendered.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<ui:composition
    xmlns="http://www.w3.org/1999/xhtml"
    xmlns:ui="http://java.sun.com/jsf/facelets"
    xmlns:h="http://java.sun.com/jsf/html"
    xmlns:f="http://java.sun.com/jsf/core"
    xmlns:c="http://java.sun.com/jstl/core">    
     <h:outputLabel>#{dummyBean.pageBuild}</h:outputLabel>
     <h:outputLabel>#{dummyBean.pageRerendered}</h:outputLabel>     
     <h:outputLabel>#{dummyBean.pageBuild and !dummyBean.pageRerendered}</h:outputLabel>
     <h:outputLabel>#{dummyBean.pageBuild and dummyBean.pageRerendered}</h:outputLabel>
        <c:if test="#{dummyBean.pageBuild and !dummyBean.pageRerendered}">
             <h:outputLabel value="Section 1"></h:outputLabel>
        </c:if>

        <c:if test="#{dummyBean.pageBuild and dummyBean.pageRerendered}">
            <h:outputLabel value="Section 2"></h:outputLabel>
        </c:if>

</ui:composition>

Results are 

true
false
true
false 
Section 1 
Section 2

I would have thought they would be

true
false
true
false 
Section 1
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1 Answer

  1. Editorial Team
    <c:if test="true">
     <h:outputLabel value="Section 1.1"></h:outputLabel>
</c:if>

<c:if test="false">
    <h:outputLabel value="Section 2.2"></h:outputLabel>
</c:if>

    The test="true" and test="false" will always evaluate as boolean true, simply because it are valid and non-null String values.

    You likely meant to use test="#{true}" and test="#{false}" instead.

    <c:if test="#{true}">
     <h:outputLabel value="Section 1.1" />
</c:if>

<c:if test="#{false}">
    <h:outputLabel value="Section 2.2" />
</c:if>

    Another problem is that the XML namespace for JSTL tags is wrong, you’re using the one of Facelets 1.x while you’re using JSF 2.x. It should be

    xmlns:c="http://java.sun.com/jsp/jstl/core"

    As to using JSTL in JSF, check this answer: JSTL in JSF2 Facelets… makes sense?

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