Does c_rt:import act like include directive or tag

Question

The include directive <%@ include ... will not recompile when the included file changes. The tag <jsp:inlcude will always re-fetch the included file so new content is picked up immediately.
How do c:import and c_rt:import behave?
Can someone point me to a good description of the difference between c and c_rt libraries. The short one or two sentence descriptions I've seen don't really say much.
Thanks,
-- Frank

Answer 1

How do c:import and c_rt:import behave?The JSTL <c:import> tag acts like the <jsp:include> tag - it is evaluated at page runtime.
It uses either a RequestDispatcher.forward (for local resources on the same application server) or the java.net classes to open a URL connection for remote resources.
Can someone point me to a good description of the difference
between c and c_rt libraries. The short one or two sentence
descriptions I've seen don't really say much.The "c_rt" library is only included for historical reasons. If you are using JSTL and EL expressions, you should not be using the "c_rt" library.
There is only one functional difference between the two, and it only applies to JSP1.2 containers (eg Tomcat 4).
The "c" tags work only with el expressions: ${expr},
The "c_rt" tags work only on standard runtime expressions ie <%= expr %>
In a JSP2.0 containers (eg Tomcat 5), el expressions ARE runtime expressions, and you can use ${expr} or <%= expr %> interchangably with the JSTL1.1 "c" taglib.
You should only be using the c_rt library if
- you have a JSP1.2 container
- you want to use <%= expr %> with one of the JSTL tags.
Cheers,
evnafets