Java applications can be written that react to events from an SVG document. The binding is specified in the URL. IMHO the challenge is to access the manifest file to get the name of the class that implements the interface for the binding.
This should be possible to autogenerate as part of our JavaScript (and soon Obj-C) binding autogeneration code. It should be possible to write a perl module (WebCore/bindings/scripts/CodeGeneratorJava.pm) which knew how to write out the proper java & cpp files to make this happen. I think this could be quite cool.
WebKit really has nothing to do with Java. Closing as invalid.