How can I declare a namespace using Java 1.5

[Ulrich Heeger]

Hi everyone,
In java 1.4, I used saxon and there I had the possibility to declare a namespace like following:

 
XPathFactory xpf = XPathFactory.newInstance(XPathConstants.DOM_OBJECT_MODEL);
XPath xpe = xpf.newXPath();
StandaloneContext context = new StandaloneContext();
context.declareNamespace("a", "namespaceY");
javax.xml.namespace.NamespaceContext namespaceContext = 
new net.sf.saxon.xpath.NamespaceContextImpl(context);
xpe.setNamespaceContext(namespaceContext);   

Since 1.5, XPath is included in the Java API, but I can't find any possibility to declare a namespace like above.
Can you help me? Thanks in advance,
Ulrich