Folks, I needed to write this for something I am working on and thought there might be a wider audience for it. Tomcat 8 supports standard compliant Websockets, which provide convenient asynchronous full-duplex server to client data transport. The framework I am offering builds on top of that a feature rich remote method invocation paradigm. Please check it out.
https://github.com/iurisman/FERMI Apache 2.0 license. Happy coding. Igor.