SAX2 XML validation against schema without targetNamespace

[Alexi Zuo]

HI, I am trying to use Xerces C++ 2.2 to validate xml against an
external schema, and this external schema may be from memory. So the input
pamameter is an InputSource object. So I have to use
SAX2XMLReader::loadGrammar() to load the schema ( I can't use
SAX2XMLReader::setProperty(XMLUni::fgXercesSchemaExternalNoNameSpaceSchemaLocation,...).
The schema does not specify "targetNamespace", and the xml file does not
specify namespace either.  The following code can't pass validation with
Xerces 2.2 library, but CAN pass with Xerces 2.8 library.

Can anybody tell me what I can do? I can only use Xerces C++2.2 library.

  SAX2XMLReader* parser = XMLReaderFactory::createXMLReader();

 parser->setFeature(XMLUni::fgSAX2CoreValidation, true);
 parser->setFeature(XMLUni::fgXercesSchemaFullChecking, true);
  parser->setFeature(XMLUni::fgXercesUseCachedGrammarInParse, true);
 DefaultHandler handler;
 MySAX2Handler error_handler;

 parser->setContentHandler(&handler);
 parser->setErrorHandler(&error_handler);
 parser->setEntityResolver(&handler);

 parser->loadGrammar(*inputSchema*, Grammar::SchemaGrammarType, true);

  parser->parse(xmlFile.c_str());