We currently use jboss-3.2.0 / tomcat-4.1.24 and I need to cache POJOs & Stateless Beans. Since this is an old version of JBoss that can't work with TreeCacheAop, is there a way to use TreeCache with POJOs?
TreeCache is typically used as a plain cache system. That is, it stores directly the object references and has HashMap like Api.
? no need to implement Serializable interface for the POJOs
To use old version JBoss with TreeCacheAop is more tricky because of JBoss Aop support. See the wiki page of JBoss Aop for more details.
If you want to cache your own Pojo with TreeCache (has to be Serializable), I think you should be able to do it without problem in 3.2.0.
If you have any luck, please feel free to update JBoss Cache wiki with your finds.