Example 6.46 TransformerHelper
class TransformHelper {

  public void transform(ServletRequest request, 
      ServletResponse response, Reader xmlReader, 
      InputStream xslStream) {

    try  {
      // SAXParserFactory
      SAXParserFactory parserFactory = SAXParserFactory.newInstance();
      SAXParser parser = parserFactory.newSAXParser();
      Source xmlSource = new StreamSource(xmlReader);
      Source xslSource = new StreamSource(xslStream);
      Result outputTarget = new StreamResult(response.getWriter());

      Transformer transformer = TransformerFactory.newInstance().
          newTransformer(xslSource);

      transformer.transform(xmlSource, outputTarget);
    } catch(Exception e) {
      // Handle Exception
    }
  }
}