// make the dom, find the ogc:Filter node
try {
Document dom = DomUtil.makeDomFromString(sbXml.toString(),true);
CswNamespaces ns = new CswNamespaces();
XPath xpath = XPathFactory.newInstance().newXPath();
xpath.setNamespaceContext(ns.makeNamespaceContext());
Node ndFilter = null;
Node ndConstraint = (Node)xpath.evaluate("csw:Constraint",dom,XPathConstants.NODE);
if (ndConstraint != null) {
ndFilter = (Node)xpath.evaluate("ogc:Filter",ndConstraint,XPathConstants.NODE);;