Attachment problems

[BTInternet]

I am trying to create a soap message with attachments and running into a
problem I cannot figure out.  Below is a fragment of code used to add an
attachment to a SOAP message.  It throws a nullPointer Exception in the
createAttachmentPart method.  Any ideas?

        URL report = new File(filePath).toURL();
        DataHandler dataHandler = new DataHandler(report);
        System.out.println(dataHandler.getContentType());
// Exception thrown at this point               
        AttachmentPart attachment =
message.createAttachmentPart(dataHandler);
        System.out.println(attachment.getContentType());
        attachment.setContentId("report_id");
        message.addAttachmentPart(attachment);

Thanks

Martin