com.sun.org.apache.xerces.internal.dom.DocumentImpl
com.sun.org.apache.xerces.internal.dom.NodeIteratorImpl
com.sun.org.apache.xerces.internal.parsers.DOMParser

org.w3c.dom.Document document = ...; // Get an XML DOM Document object

org.w3c.dom.NodeIterator iterator = new NodeIteratorImpl(new DocumentImpl(
    document.getDoctype()), document.getDocumentElement(),
    NodeFilter.SHOW_ALL, null, true);

Document = DocumentBuilderFactory.newInstance().newDocumentBuilder.parse(source)

NodeIterator ni = ((DocumentTraversal)document).createNodeIterator(
      document.getDocumentElement(), NodeFilter.SHOW_ALL, null, true);