code: @Override
      public void service(HttpServletRequest req, HttpServletResponse res) 
          throws ServletException, IOException
      {
      	String sourceFileName = req.getParameter("source");
      	String styleSheetFileName = req.getParameter("stylesheet");
      	FileReader sourceFileReader = new FileReader(sourceFileName);
      	FileReader stylesheetFileReader = new FileReader(styleSheetFileName);
      	
      	ServletOutputStream outStream = res.getOutputStream();
      	
          try {
              StreamSource source = new StreamSource(sourceFileReader);
  
              Result result = new StreamResult(outStream);
  
              TransformerFactory tFact = TransformerFactory.newInstance();
              StreamSource streamTransformer = new StreamSource(stylesheetFileReader);
              
              Transformer transformer = tFact.newTransformer(streamTransformer);
  
              transformer.transform(source, result);
          } catch (TransformerConfigurationException ex)    {
              ex.printStackTrace();
          } catch (TransformerException ex) {
              ex.printStackTrace();
          }                    
      	
      	super.service(req, res);
      }
docs: process an HTML get or post.
  @exception ServletException From inherited class.
  @exception IOException From inherited class.