Interface generation

Hi,
   We've been trying to generate the interfaces by a program, and can't get it working, the test code goes as follows:

         org.netbeans.api.mdr.MDRepository repository = 
              new org.netbeans.mdr.NBMDRepositoryImpl();
        RefPackage ref = repository.createExtent("ElXML");
        JMIMapper mapper = JMIMapper.getDefault();
        JMIStreamFactory streamFactory = new FileStreamFactory(new File("c:/javaout"));
        org.netbeans.api.mdr.XMIReader x= org.netbeans.api.mdr.XMIReader.getDefault();
        Collection c = x.read("d:/facultad/pgrad/xml.xml", ref);
        Object[] arr =c.toArray();
        RefBaseObject baseObject = (RefBaseObject)arr[0];
        mapper.generate (streamFactory, baseObject);

We get plenty of exceptions. Does someone know what are we doing wrong?
Maybe the problem is how to start a repository...
Any pointer would help us us lot.

Many thanks,
Máximo Gurméndez, Iang Yim
CWM Repository Project (http://www.fing.edu.uy/~pgsdrcwm)