public XMLSchema getXMLSchema() {
    if (_xmlSchema == null) {
      XMLSchemaImpl xmlSchema = new XMLSchemaImpl();

      xmlSchema.setSchemaLanguage("http://www.w3.org/2001/XMLSchema");
      xmlSchema.setSystemId("http://www.liferay.com/dtd/liferay-ddm-structure_6_2_0.xsd");

      _xmlSchema = xmlSchema;
    }

    return _xmlSchema;
  }
  protected void validateDDMXSD(String xsd) throws Exception {
    DDMXMLImpl ddmXMLImpl = new DDMXMLImpl();

    XMLSchemaImpl xmlSchema = new XMLSchemaImpl();

    xmlSchema.setSchemaLanguage("http://www.w3.org/2001/XMLSchema");
    xmlSchema.setSystemId("http://www.liferay.com/dtd/liferay-ddm-structure_6_2_0.xsd");

    ddmXMLImpl.setXMLSchema(xmlSchema);

    ddmXMLImpl.validateXML(xsd);
  }