GNU Classpath - org.omg.CORBA

This package provides the support of CORBA; see overview of the implemented functionality.

CORBA a system that applications use to work over networks. CORBA messages are binary, not text oriented. They practically cary no "data wrapping" information like XML <opening> </closing> tags. Hence CORBA objects easier exchange large amounts of binary data. CORBA can work in such data-intensive application areas as telecommunications or radio broadcasting. Java programs connect to CORBA objects without care about what platform they run on, where they exist in the network, or what language they were written in. The remote CORBA objects appear to the programmer as the ordinary Java objects and can be passed as parameters in both remote or local method invocations.

The CORBA processing unit is divided into {@link org.omg.CORBA.Object} that is exposed to the client and the servant ({@link org.omg.PortableServer.Servant} where the method, invoked on object, is finally delegated. It can be multiple objects per servant or multiple servants per object. The servant for particular object or even particular call can be dynamically chosen at run time using {@link org.omg.PortableServer.ServantManager}.

All stages of both local and remote invocations on CORBA objects can be monitored and modified using {@link org.omg.PortableInterceptor.Interceptor}. The interceptors can add an extra data to the CORBA message (these data can be later accessed by other interceptor on remote side).

#### Overview of the currently implemented CORBA functionality

The CORBA implementation in the Classpath project is now a working prototype.

- This prototype is interoperable with Sun's implementation v 1.4, transferring object references, primitive types, narrow and wide strings, arrays, structures and trees between these two platforms.
- The prototype provides interoperable support for the Abstract interface and Value types. Those appear in 1.3, being a feature of CORBA 2.3.
- The remote exceptions are also transferred and handled as expected.
- The support for parsing stringified object references (IORs), both Big and Little Endian encoded, is implemented.
- The redirection commands works, LOCATION_FORWARD_PERM changing the target address until the application is restarted and LOCATION_FORWARD redirecting for the current session only.
- Both Little and Big Endian encoded messages are accepted. The encoding of the sent messages is the same as used in the stringified IOR reference of that object or Big Endian, if no such data available.
- You can use both request-oriented (based on {@link org.omg.CORBA.Request} and stream-oriented (based on {@link org.omg.CORBA.portable.ObjectImpl} invocation models. The current release includes the working examples, demonstrating the client-server communication using both methods.
- These examples also show, how to use the Classpath naming service.
- The IDL compiler is not yet written (and not even started), but as a side effect of the required compatibility, the implementation seems accepting the output of the Sun's idlj.
- The Portable Object Adapter is already released. For details on POA, see the {@link org.omg.PortableServer} package.
- We provide the implementation of the {@link org.omg.DynamicAny} package. ORB returns the working DynAnyFactory that produces working DynAny's as defined in OMG specification.
- The Portable Interceptor is also complete. See {@link org.omg.PortableInterceptor} package for details how to register and use CORBA interceptors.
- All GNU Classpath classes in omg.org namespace are newly written using the OMG .pdf document (Version 3.0.3, formal/04-03-12).

@author Audrius Meskauskas, Lithuania (AudriusA@Bioinformatics.org)