How can I use JSP to generate content pages with a non-JSP extension?

Question

I'm developing a web application to be deployed on the latest Glassfish server.

To make the application compatible with different context roots (like "/apps/myapp/"), I need the CSS files in it to be generated dynamically.

The problem is that the these pages aren't treated like JSP files so I can't use <%= contextRoot %>. I know I could use a JSP file with a Content-Type header to mimic a CSS file, but I would prefer to have a CSS extension on it.

Is it possible to have Glassfish treat a non-JSP file as a JSP file?

Answer 1

This is simple, I've done it before, works great.

Simply take the extension you want to map, and map it to the JSP servlet.

JSPs are processed by a servlet, like anything else. Nothing really special about them.

So, for Glassfish, this servlet happens to be named "jsp". I don't know whether that is portable (i.e. the name), but it likely runs in Glassfish and Tomcat, and probably anyplace that uses the Jasper JSP compiler.

In Glassfish, it's defined in $glassfish_domain_dir/config/default-web.xml.

So, add this to your web.xml

<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">    
  <servlet-mapping>
    <servlet-name>jsp</servlet-name>
    <url-pattern>*.css</url-pattern>
  </servlet-mapping>
</web-app>

The nice thing that this will pretty much work for straight up CSS files if there's no markup in them, or with custom ones that you add markup too.