Not a question but an observation (others might find helpful when searching)
When you want to store a value in the attributes of a HttpSession Tomcat requires it to be serializable. Seems it is a result of the cluster support Tomcat offers. I tried to stuff a HashMap into an attribute and was kicked with an "not serializable" error. Packing the HashMap into a wrapper object with "implements serializable" did the trick.
I think everyone who uses Sessions has run into this at some time or other. What I find interesting is that HashMap does implement Serializable. This sounds like a bug to me. [ November 22, 2005: Message edited by: Ulf Dittmer ]