[Jetty-support] Trying to use EL to set attribute of custom tag

[Richard D. <rd...@ma...>]

I'm trying to use EL to set the value of an attribute for a custom tag  
in a JSP page deployed to Jetty under JBoss. When I tried it under  
JBoss 3.2.3 with Jetty (not sure what version of Jetty, jar files have  
a date of Dec. 17, 2003), an exception was thrown:
javax.servlet.ServletException: javax.servlet.jsp.JspException: For  
input string: "${param.id}"
         at  
org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageCont 
extImpl.java:821)
         at  
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContex 
tImpl.java:758)
I thought it was about time I updated JBoss and Jetty anyway and I  
thought it might make the problem go away, so I downloaded and  
installed JBoss 4.0.1 and Jetty 5.1.4rc0 for JBoss 4.0.1 and deployed  
there and tried it again. I'm using J2SDK 1.4.2 (on a PowerBook using  
Mac OS X) and J2EE 1.3. It made no difference. (The copied exception  
from above was generated by this later version.) When I invoke the page  
I get the same exception. The tld for the custom tag declares  
rtexprvalue=true for the attribute in question.
Can anyone tell me what part of this puzzle I'm not considering?
Thanks.

Rich