public Object clone() 
{
        try {
            return super.clone();
        }
        catch (CloneNotSupportedException e) {
            // Of course, it's supported.
            e.printStackTrace();
            return null;
        }
}

 public Pointer getNamespaceContextPointer() 
{
        return pointer;
}

 public String getNamespaceURI(String prefix) 
{
        String uri = (String) namespaceMap.get(prefix);
        if (uri == null && pointer != null) {
            uri = pointer.getNamespaceURI(prefix);
        }
//        System.err.println("For prefix " + prefix + " URI=" + uri);
        return uri;
}

Given a prefix, returns a registered namespace URI. If the requested prefix was not defined explicitly using the registerNamespace method, JXPathContext will then check the context node to see if the prefix is defined there. See setNamespaceContextPointer .

 public String getPrefix(String namespaceURI) 
{
        if (reverseMap == null) {
            reverseMap = new HashMap();
            NodeIterator ni = pointer.namespaceIterator();
            if (ni != null) {
                for (int position = 1; ni.setPosition(position); position++) {
                    NodePointer nsPointer = ni.getNodePointer();
                    QName qname = nsPointer.getName();
                    reverseMap.put(qname.getPrefix(), qname.getName());
                }
            }
            Iterator it = namespaceMap.entrySet().iterator();
            while (it.hasNext()) {
                Map.Entry entry = (Map.Entry) it.next();
                reverseMap.put(entry.getValue(), entry.getKey());
            }
        }
        String prefix = (String) reverseMap.get(namespaceURI);
        return prefix;
}

 public boolean isSealed() 
{
        return sealed;
}

 public  void registerNamespace(String prefix,
    String namespaceURI) 
{
        namespaceMap.put(prefix, namespaceURI);
        reverseMap = null;
}

Registers a namespace prefix.

 public  void seal() 
{
        sealed = true;
}

 public  void setNamespaceContextPointer(NodePointer pointer) 
{
        this.pointer = pointer;
}

Register a namespace for the expression context.