public RoundTripDemo() 
{

}

 public static  void main(String[] args) 
{
        run(new RoundTripDemo(), args);
}

 protected  void outputDocument(Document document,
    Writer out) 
{
        try {
            TransformerFactory factory = TransformerFactory.newInstance();
            Transformer transformer = factory.newTransformer();
            StreamResult result = new StreamResult(out);
            DocumentSource source = new DocumentSource(document);
            transformer.transform(source, result);
        } catch (Exception ex) {
            ex.printStackTrace();
        }
}

 protected Document parseDocument(Reader in) 
{
        try {
            TransformerFactory factory = TransformerFactory.newInstance();
            Transformer transformer = factory.newTransformer();
            DocumentResult result = new DocumentResult();
            StreamSource source = new StreamSource(in);
            transformer.transform(source, result);
            return result.getDocument();
        } catch (Exception ex) {
            ex.printStackTrace();
            return null;
        }
}

 protected  void process(Document document) throws Exception 
{
        System.out.println("about to output: " + document);
        StringWriter out = new StringWriter();
        outputDocument(document, out);
        Document doc2 = parseDocument(new StringReader(out.toString()));
        System.out.println("parsed back again: " + doc2);
        System.out.println("Writing it out...");
        XMLWriter writer = new XMLWriter(System.out);
        writer.write(doc2);
}

Outputs the document to a buffer, parse it back again then output it