Variables in jsp pages with "included" pages

In JSP there are two ways of including other jsp pages.

<%@include file="include.jsp"%>

and

<jsp:include page="include.jsp" />

If you use the former, then any variable declared on the parent JSP will be in scope in the include.jsp (of course Eclipse will not see this as you surmised) as it is effectively copied in by the compiler.

If you use the second approach, the inclusion is done at runtime and the include page has its own scope.

Ditto for imports. Although it is safe to redundantly import them in the include page.

If I'm using the former I prefer to suffix them with .jspf to signify a JSP fragment. I can than turn off some of Eclipses warning in the fragment files. But in general I try to avoid using that method and prefer the second approach.

More information can be found in the docs here: Include directive and JSP include.

Use the following, if you want to use variable within the path of the page to be included:

<% pageContext.include("/cities/" + (String) request.getAttribute("country_code") + ".jsp"); %>

From an object-orientated point of view, i would recommend not relying on the scope of the variable in parent.jsp being included in the child.jsp. This is because when i include a fragment in a jsp i tend to want to reuse that fragment in many different places. For example if i have a child.jsp i may want to use it in parent1.jsp as well as parent2.jsp. In the case it is better not to variable inheritence.

When you create a variable, you should set the scope to session, otherwise, the included page will not see it. Example :

<logic:iterate id="supportTmp" name="publicites" indexId="indexLots" scope="session">                                    
    <c:set var="support" value="${supportTmp}" scope="session"/>
    <c:choose>
    <c:when test="${publiciteMoniteur == true}">
    <jsp:include page="/jsp/bodies/suiviEnvoiPubliciteMoniteurLigne.jsp" />
    </c:when>
    <c:otherwise>
        <jsp:include page="/jsp/bodies/suiviEnvoiPubliciteDefautLigne.jsp" />
    </c:otherwise>
</c:choose>
</logic:iterate>