How to use XPath with Namespaces in the xml ?

Question

Hi all,
I need to reference a certain Node in a Document using XPath notation.
The problem is the the XML Document contains Namespaces inside it
f.e.
<xn:SubNetwork id="JRANM">
    <xn:VsDataContainer id="1">
       <xn:vsDataType>vsDataAreas</xn:vsDataType>
    </xn:VsDataContainer>
</xn:SubNetwork >Using DOMXPath (from weblogic.xml.xpath)
  DOMXPath xPath = new DOMXPath("xn:SubNetwork/*");
  Set nodeset = xPath.evaluateAsNodeset(this.xmlRootElement);When I Iterate through the Set I can see it's empty.
(On the other hand without namespaces everything is fine.)
So how can I reference a Node that contains a namespace in it ?
Thanks a lot
Francesco

Answer 1

We use the following class to perform XPath Queries on our XmlBean objects.
Hope this helps,
Craig
import java.util.Set;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.apache.xmlbeans.XmlException;
import org.w3c.dom.Document;
import weblogic.xml.util.StringInputStream;
import weblogic.xml.xpath.DOMXPath;
* Class to encapsulate API specific (i.e. weblogic) XML functions
public class XmlUtil {
     * Returns a set containing objects of type reflected in the query.<br/>
     * e.g.<br/>
     * /saur:tree/saur:treeNode[@label='My Reports']<br/>
     * Returns a Set of TreeNode objects<br/>
     * Sample Code: <br/>
     * <code>
     * Set set = XmlUtil.executeXPathQuery( myQuery, tree.xmlText());
     * for( Iterator iter = set.iterator(); iter.hasNext();) {
     *     TreeNode node = TreeNode.Factory.parse((Node)iter.next());
     *     // Do whatever...
     * </code>
     * @param query
     * @param xml
     * @return
    public static Set executeXPathSetQuery( String query, String xml) throws XmlException {
        try {
            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();   
            factory.setNamespaceAware(true);
            DocumentBuilder builder = factory.newDocumentBuilder();
            StringInputStream in = new StringInputStream(xml);
            Document doc = builder.parse(in);
            DOMXPath xQuery =  new DOMXPath(query);
            return xQuery.evaluateAsNodeset(doc);
        catch(Exception x) {
            throw new XmlException("Error running XPath query", x);
}