We assume that the Devtest agents is installed correctly and you are able to virtualize a Java call without errors. 

Do we support Java Agent for EJB or Java calls. when routing traffic to Live backend?  

All supported DevTest environments. 

Any mode that sends virtualized Java service to a Live system is not supported and will not work.  When you virtualize a Java call, it mimics the returned messages and not the fully developed objects that is preventing a call to the live service.