Problems running Apache FOP: org.apache.fop.fo.FOTreeBuilder fatalError

Dear all,

I am trying to use Apache FOP to create PDF from URLs, but something
is going wrong.

I am using JTidy to convert a URL to XHTML, and then FOP to transform
this XHTML to PDF.

I am using a xslt file that I have downloaded here to transform xhtml
to FO format: http://www.antennahouse.com/XSLsample/XSLsample.htm
and http://www-128.ibm.com/developerworks/library/x-xslfo2app/

I am wondering if anyone have a working example of FOP to generate
PDFs from HTML that could be shared here.

My code is bellow:

    public static void main(String[] args) {
        PDFMaker pdf = new PDFMaker();
        pdf.setPdfPath("teste.pdf");
        pdf.setUrl("http://validator.w3.org/");
        pdf.setXmlPath("test.xml");
        pdf.setXsltPath("xhtml2fo-ms.xsl");
        pdf.convert2PDF();
    }

    public void convert2PDF() {
        try {
            // Setup directories
            File baseDir = new File("e:/pdf-temp/");
            File outDir = new File(baseDir, "out");
            outDir.mkdirs();

            // Setup input and output files
            File xmlfile = this.convert2Xhtml(baseDir,
this.getXmlPath()); //input xml using JTidy
            File xsltfile = new File(baseDir, this.getXsltPath()); //
xslt style sheet
            File pdffile = new File(outDir, this.getPdfPath()); //
output pdf

            // configure fopFactory as desired
            FopFactory fopFactory = FopFactory.newInstance();

            // configure foUserAgent as desired
            FOUserAgent foUserAgent = fopFactory.newFOUserAgent();

            // Setup output
            OutputStream out = new java.io.FileOutputStream(pdffile);
            out = new java.io.BufferedOutputStream(out);

            try {
                // Construct fop with desired output format
                Fop fop = fopFactory.newFop(MimeConstants.MIME_PDF,
foUserAgent, out);

                // Setup XSLT
                TransformerFactory factory =
TransformerFactory.newInstance();
                Transformer transformer = factory.newTransformer(new
StreamSource(xsltfile));

                // Setup input for XSLT transformation
                Source src = new StreamSource(xmlfile);

                // Resulting SAX events (the generated FO) must be
piped through to FOP
                Result res = new SAXResult(fop.getDefaultHandler());

                //set transformer parameters
                transformer.setParameter("title-text","PDFTester");
                transformer.setParameter("docid-text","JK130759");
                transformer.setParameter("version-text","V0.0");
                transformer.setParameter("status-text","Onbekend");
                transformer.setParameter("authorizor-text","Jacques
Kors");
                transformer.setParameter("date-text",(new
SimpleDateFormat("dd/MM/yyyy")).format(new Date()));
                transformer.setParameter("copytype-text","Test
kopie");

                // Start XSLT transformation and FOP processing
                transformer.transform(src, res);
            } finally {
                out.close();
            }
        } catch (Exception e) {
            e.printStackTrace(System.err);
            System.exit(-1);
        }
    }