com.sun.org.apache.xalan.internal.xsltc.trax.SAX2DOM has the following code:

-----------------
    public SAX2DOM() throws ParserConfigurationException {
final DocumentBuilderFactory factory =
DocumentBuilderFactory.newInstance();
_document = factory.newDocumentBuilder().newDocument();
_root = _document;
    }

    public SAX2DOM(Node root) throws ParserConfigurationException {
_root = root;
if (root instanceof Document) {
_document = (Document)root;
}
else if (root != null) {
_document = root.getOwnerDocument();
}
else {
final DocumentBuilderFactory factory =
DocumentBuilderFactory.newInstance();
_document = factory.newDocumentBuilder().newDocument();
_root = _document;
}
    }
-----------------

This is showing up as a hot spot in JAX-WS because a new DocumentBuilderFactory is created every time. The factory should be created only once and set to a static final field, then reused.