Thanks for this.
I have since solved the problem with a tool from the IBM Alphaworks site called Bridge2Java. It seems to work very well, and is easy to use.
After trying for some time to get an answer to this problem from the web, I found Bridge2Java in an excellent Wrox book called "Professional J2EE EAI" - which included a reference to the Jacob project that you mention.
Make sure you check out the license for that. As I remember it has an unusual license.