Dynamic include in a custom tag, called from a jsp

Question

Hello, I would like to be able to dynamically include other jsp's from within a custom tag that I create. is this possible?
in a jsp page i would just write <%@ include file="file.jsp" %> and all would be ok... but if i do an out.println( "<%@ include file=\"file.jsp\" %>" ); inside a custom tag bean then it doesn't work. it just prints out the command to the page as plain text.
I do understand why this is happening, but can anyone offer me a way around this problem?
Thanks in advance,
Randy

Answer 1

That's actually the same result as you get with a normal include - The method I suggested is a dynamic include similar to the <jsp:include> tag, not the <%@ include %> tag.
When you use a dynamic include, the included page is compiled and 'invoked' as serarately, and the result is what gets included, not the actual source. To get the behaviour you want would require an include directive (the <%@ include %> tag) which I don't think has an equivalence you can use inside a custom tag.
What you can do is pass attributes from the tag class like this:
pageContext.setAttribute(<name>, <object>, pageContext.REQUEST_SCOPE);
and then remove them after the include using pageContext.removeAttribute.
I'm not certain, but this implies that if you declare your variables with a <jsp:usebean> tag with request scope, instead of normal Java variable declarations, you should be able to use them in the page included by the custom tag.
*** in the jsp ***
<jsp:useBean id="myVar" scope="request" class="java.lang.String" />
<% myVar = "Something"; %>
// Now call the tag which uses the pageContext.include() mehtod.
*** end ***
*** in the include ***
<jsp:useBean id="myVar" scope="request" class="java.lang.String" />
<%= myVar + " something else" %>
*** end ***
Let me know if it works.