code: @Override
      public ValidationMessage[] validate(String prefix, String uri, PageData page) {
          try {
              MyContentHandler handler = new MyContentHandler();
              parser.parse(page, handler);
              return handler.reportResults();
          } catch (ParserConfigurationException e) {
              return vmFromString(e.toString());
          } catch (SAXException e) {
              return vmFromString(e.toString());
          } catch (IOException e) {
              return vmFromString(e.toString());
          }
      }
docs: Validates a single JSP page.
  
  @param prefix the namespace prefix specified by the page for the
  custom tag library being validated.
  @param uri    the URI specified by the page for the TLD of the
  custom tag library being validated.
  @param page   a wrapper around the XML representation of the page
  being validated.
  @return null, if the page is valid; otherwise, a ValidationMessage[]
  containing one or more messages indicating why the page is not valid.