// $Id: XPathFunctionResolver.java,v 1.7 2004/04/01 16:07:17 ndw Exp $ /* * @(#)XPathFunctionResolver.java 1.6 04/07/26 * * Copyright 2004 Sun Microsystems, Inc. All rights reserved. * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. */ package javax.xml.xpath; import javax.xml.namespace.QName; /** *
XPathFunctionResolver
provides access to the set of user defined XPathFunction
s.
XPath functions are resolved by name and arity. * The resolver is not needed for XPath built-in functions and the resolver * cannot be used to override those functions.
* *In particular, the resolver is only called for functions in an another
* namespace (functions with an explicit prefix). This means that you cannot
* use the XPathFunctionResolver
to implement specifications
* like XML-Signature Syntax
* and Processing which extend the function library of XPath 1.0 in the
* same namespace. This is a consequence of the design of the resolver.
If you wish to implement additional built-in functions, you will have to * extend the underlying implementation directly.
* * @author Norman Walsh * @author Jeff Suttor * @version $Revision: 1.7 $, $Date: 2004/04/01 16:07:17 $ * @see XML Path Language (XPath) Version 1.0, Core Function Library * @since 1.5 */ public interface XPathFunctionResolver { /** *Find a function in the set of available functions.
* *If functionName
or arity
is null
, then a NullPointerException
is thrown.
null
if no function named functionName
with arity
arguments exists.
*
* @throws NullPointerException If functionName
or arity
is null
.
*/
public XPathFunction resolveFunction(QName functionName, int arity);
}