As Sun Microsystems' legal battles for control of Java persist, the groundwork is being laid to open the multiplatform programming language and run-time environment to more heterogeneous configurations.
The Object Management Group (OMG) last week finalised modifications of its Internet Inter-ORB Protocol (IIOP) communications protocol -- the glue binding distributed objects conforming to the OMG's CORBA (Common Object Request Broker Architecture) specification -- to fully support Java.
Sun's JavaSoft division initially resisted supporting IIOP, leaving its own Java Remote Method Protocol (JRMP) as the sole transport for the Java Remote Method Invocation (RMI) programming interfaces. Responding to pressure from developers to open RMI beyond Java, Sun in 1997 said it would work with the OMG to integrate IIOP and RMI.
At its Salt Lake City technical meeting, the OMG last week completed its revision of IIOP to support objects-by-value, enabling it to act as a transport protocol for RMI. In the Java programming model, methods pass arguments by value.
"RMI over standard IIOP is now a snap," concluded Richard Soley, OMG chairman and CEO.
Yet it may not be seamless. According to one JavaSoft representative, IIOP support will come as an extension to the Java Development Kit (JDK) 1.2 -- due this summer -- instead of an integral part of the kit.
"RMI in theory could run over anything; it could run over DCOM [Distributed Component Object Model], as long as DCOM provided the support for all capabilities RMI needs, [namely pass-by-value instead of pass-by-reference]," noted Anne Thomas, editor in chief of The Patricia Seybold Group Distributed Computing Monitor, in Boston. "By extending IIOP to support pass-by-value, it means there will be complete integration and probably the JRMP will go away."
James Gosling, Java author and Sun executive, agreed RMI over IIOP would prove to be popular.
"It turned out that Java developers really liked RMI because of some of its higher-level functions, while the platform people really liked IIOP for its underlying transport," Gosling said.
Also at last week's OMG meeting, the group advanced its vertical industry standards work, and gave final approval to the OMG bridging specification for Microsoft's Component Object Model.
In March, the group will vote on a revised submission for adding asynchronous messaging support as part of the upcoming CORBA 3 update, OMG's bid for a standard for message-oriented middleware.
Also, Gosling said Sun will demonstrate the JDK 1.2 HotSpot compiler at JavaOne in March.