Jini

In short, Jini is an open architecture to create scalable, evolvable, and flexible, network-centric services that are highly adaptive to change.

Sun provides a couple of Jini service implementations:

• Fiddler (lookup discovery service)
• Mahalo (transaction manager service)
• Mercury (event mailbox service)
• Norm (lease renewal service)
• Outrigger (JavaSpaces service)
• Phoenix (RMI activation system daemon; supports Jini ERI)
• Reggie (lookup service)

How does it work. Like with RPC (be it EJB, CORBA, or something else), services are located by querying a directory. Then methods of the service are called up by using the technology employed. Jini goes one step further: when using a Jini service, the code to "talk" to the client gets downloaded as well. The client simply calls method on the service proxy, and does not have to know how the actual communication works. This provides complete network and protocol transparency. Jini offers Jeri (or JERI) for remote invocation.

Homepage: http://www.jini.org/, http://java.sun.com/developer/products/jini/index.jsp

Book tip: Jini in a Nutshell