Tapestry 5.1 Woodstox

In my last post I suspected the Woodstox lib to be the reason that Tapestry 5.1 does not work on Google App Engine (GAE).

So, I tried to eliminate the Woodstox lib and just use Stax – and it turned out to be really easy. The only problem was that the standard Stax parser does not handle DTDs in a nice way – you have to parse them yourself.

Changes to Tapestry:

• use XMLInputFactory instead of XMLInputFactory2 in TemplateParserImpl
• remove inputFactory.configureForSpeed(); in TemplateParserImpl
• use XMLStreamReader instead of XMLStreamReader2 in StaxTemplateParser
• change the dtd() method StaxTemplateParser to (this could be nicer):

  private void dtd() throws XMLStreamException
  {
      String dtd = reader.getText();
      String[] dtdElements = dtd.split(" ");
      if(dtdElements.length > 3)
      {
          String rootName = dtdElements[1];
          String publicId = null;
          String systemId = null;
          if("PUBLIC".equals(dtdElements[2]))
          {
              publicId = dtdElements[3];
              if(dtdElements.length > 4)
                  systemId = dtdElements[4];
          }
          else if("SYSTEM".equals(dtdElements[2]))
          {
              systemId = dtdElements[3];
          }
          tokenAccumulator.add(new DTDToken(rootName, publicId, systemId, getLocation()));
      }
  }

I have eliminated Woodstox – Tapestry runs now on plain Stax (included in JRE). But it still does not work on GAE – seems that the whole Stax package is locked and cannot be used. Maybe I give it another try. Hmmm.