Sun Dreams of Jini for Web Services
Claims dynamic network architecture not just for devices, suitable for discovery, delivery
By Edward J. Correia
March 1, 2002 —
(Page 1 of 3)
Since 1999, Sun Microsystems Inc. has been telling the market that Jini, its dynamic network communications architecture, was designed mainly for devices. Now the company is repositioning the technology, saying that it's also a suitable framework for developing and publishing software services.
"What was picked up on the launch was a very device-centric message. That was half the story," said Franc Romano, Sun's group marketing manager for Jini, who is now offering Jini as an implementation solution for what the company calls Services on Demand, a concept that encompasses all service delivery over a network, including Web services.
"For instance, a printer is a device that provides printer services," he said. Romano went on to claim that Jini's lookup service is a more feature-rich method of facilitating Web service discovery than UDDI. "They are different ways of providing similar functionality; both serve directory functions."
Unlike UDDI, asserted Romano, Jini is dynamic, and can discover and deliver additional information about the devices or services it finds. "Jini provides logic code that encapsulates instructions on how to work with that device or service. And Jini is the only technology that can pass objects over the network; UDDI can only accommodate character strings," and not device drivers or executables.
Chris Kurt, group program manager of UDDI and Web services at Microsoft Corp. who sits on the board of UDDI.org, argued that comparing UDDI to Jini is "like comparing apples and oranges. It would be a pretty big challenge for us to line UDDI up with Jini; the points of the technologies are so different. What [UDDI] passes back and forth is a set of SOAP XML requests. I guess technically they are strings. But inside, there is information about the services and protocols that UDDI stores or provides references to."
Those references could be used to point to drivers, and the drivers could then be downloaded, according to Tom Glover, program manager for Web services and standards at IBM Corp. who's also with UDDI.org. "It may be possible to use Jini to mimic UDDI to allow someone to discover and access Web services, in the same way it may be possible to use UDDI to discover and get access to system devices. That doesn't mean they are good at doing each other's jobs." Glover said that early in UDDI's life, there were comparisons drawn between Jini and UDDI. "People said, 'Maybe UDDI is a better Jini,' but our answer was that it's not. Jini and UDDI are designed to do fundamentally different jobs, so the data structures and mechanisms in the two are very different."