I was involved with writing a Java front-end to Forte back-end bridge. At that point no one on the project understood soap so we used the CORBA connection. It worked fine.
Through that experience we found that you could only communicate scaler attributes. (Makes sense, how would objects be known to two differnt languages?) So we ended up having to include in our custom framework in both languages objects that were identical and limit what could be sent over the bridge. We used CORBA for the pipeline, but used a custom XML structure as the message.
It was a long development process as we worked out moving data between the two languages. But we made it.
The official channel would be to contact your local Sun sales representative and buy a license for Sun ONE Integration Server EAI 3.2.x which is powered buy UDS 5.2.x but it may be hard to get and costs at least for the pro version: development environment US$15000 + US$5000 per developer, runtime $40000 per CPU per platform (Win/Sun) double it for the enterprise version.
The unofficial would be to find someone that bought the license and give it to you free of charge.