InformationWeek

un Microsystems originally intended Jini as a network technology to connect devices ranging from storage arrays to televisions. "Sun saw Jini as a way for devices to talk with each other," says Keith Edwards, author of Core Jini (Prentice Hall, 1999) and a senior researcher at Xerox PARC in Palo Alto, Calif. "Maybe that will happen eventually, but a lot has to happen first." For instance, all those devices will need a Java Virtual Machine, which is unlikely anytime soon.

But Jini's immediate potential may lie in Web services. With Jini, clients join the network by registering their presence with the look-up service. The clients can then inquire about available services on the network and download those services for a limited time as specified by the lease. When a service joins the network, it similarly registers itself and leaves behind a Java object that enables clients to use the service. By comparison, in a conventional network every participant has to be identified and configured in advance.

IT might find Jini ideal for distributing Java-based software services across the network and to provide client access to those services. "Jini offers a way to build enterprise systems where software components move from machine to machine," Edwards says. A Web service would be built using Enterprise JavaBeans and Jini class libraries. The services would automatically have the properties of Jini built in, such as failover, built-in redundancy, and self-healing.

LightFlow Inc. of Chicago adopted Jini in its call-center services. The Jini services it built include customer queuing, search, and document management. When a customer-service rep logs on to the Web site, the customer-service application finds and loads the appropriate Jini services. Jini provides fault tolerance, which is critical to a call-center operation, says Elliot Weissbluth, CEO of LightFlow.

If a particular service isn't available, another copy starts up. "We can even build services that monitor each other," he says. "If we're not careful, we could actually build a system of services with Jini that we could never turn off." Are you listening, HAL?