How to change the filename in @include file?

Question

I want to do a checking before deciding to include which file,
for example,
<%
if(isValid){
%>
<%@ include file="abc.jsp" %>
<%
else{ %>
<%@ include file="def.jsp" %>
<% } %>but the code above doesnt work in my JSPs
any idea how to solve this?
thanks
Desmond

Answer 1

Am i clear?? pls correct me if i am wrong..You are wrong.
The include directive is being used here, which is a compile time include, not a runtime include. Both includes will be performed before the resulting servlet is compiled.
If they have a conflict between them (either by not nesting them in their own { scope } or using <%! declarations %>) then the generated servlet will fail to compile.
So if you had the following:
abc.jsp:
Hello from ABC!
<% String myVar = "ABC"; %>def.jsp:
Hello from DEF!
<%  String myVar = "DEF";  %>And the page as mentioned in the original post, you would end up with a Servlet something like this:
if (isValid){
   out.println("Hello from ABC!");
    String myVar = "ABC";
else{
   out.println("Hello from DEF!");
  String myVar = "DEF";
}This example would compile because of the presence of the braces.
However removing the braces or using a <%! declaration %> would probably screw things up with a compile error.
The %Include directive is like a copy/paste into a JSP before you compile it.
The <jsp:include> is evaluated at runtime and copies in the result of executing the page.
The difference is quite subtle, but very important.
Cheers,
evnafets