Hibernate XML mapping requires using the org.dom4j.Document, as shown in this example:

org.dom4j.Document document = saxReader.read(inputXML);

List users = document.selectNodes("//product");

try {

Session session = HibernateUtil.sessionFactory.openSession();

Transaction transaction = session.beginTransaction();
Session dom4jSession = session.openSession(EntityMode.DOM4J);

Iterator iter = users.iterator();
while (iter.hasNext())

// end while
transaction.commit();
session.close();

If any other type of Document is used for the dom4jSession.saveOrUpdate() call, it throws an exception.

Using SAXReader.read() throws a NoClassDefFound error using JBoss 4.0.5.CR1, unless jaxen (jaxen-1.1-beta-7.jar from the Hibernate 3.2.cr4 download) is added the the server configuration's lib directory.

I submit that jaxen is required to use the XML Mapping facility of Hibernate, and that it's missing from JBoss 4.0.5.CR1.