Recently I was creating some JSP pages using JBoss Portal when I got an error: org.apache.jasper.JasperException: The absolute uri: http://java.sun.com/jsp/jstl/core cannot be resolved in either web.xml or the jar files deployed with this application I followed the advice from the JBoss page referenced above to resolve the issue. Basically I need to add a jsp-config tag to web.xml then add the c.tld file and jar files to my war deployment. I found the jar files in a spring-portlet-example project that I had downloaded from springframework.org.