Transform 问题！晕！高分求援....

Question

public static void main(String[] args) {
    try {
      TransformerFactory transformerFactory =
                        TransformerFactory.newInstance();
       StreamSource source = new StreamSource("d:\\xmlt\\Pay.xml");
       StringWriter sw = new StringWriter();
       StreamResult result = new StreamResult(sw);
       String styleName = "d:\\xmlt\\Pay.xsl";
       Transformer transformer = null;
       StreamSource style = new StreamSource(styleName);
       transformer =  transformerFactory.newTransformer(style);
       transformer.transform(source,result);
       String s = sw.toString();
       System.out.println(s);
    } catch (Exception e) {
              e.printStackTrace();
    }
  }