01 /*
02 * Copyright 2003-2005 Sun Microsystems, Inc. All Rights Reserved.
03 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
04 *
05 * This code is free software; you can redistribute it and/or modify it
06 * under the terms of the GNU General Public License version 2 only, as
07 * published by the Free Software Foundation. Sun designates this
08 * particular file as subject to the "Classpath" exception as provided
09 * by Sun in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25
26 package javax.xml.xpath;
27
28 import java.util.List;
29
30 /**
31 * <p><code>XPathFunction</code> provides access to XPath functions.</p>
32 *
33 * <p>Functions are identified by QName and arity in XPath.</p>
34 *
35 * @author <a href="mailto:Norman.Walsh@Sun.com">Norman Walsh</a>
36 * @author <a href="mailto:Jeff.Suttor@Sun.com">Jeff Suttor</a>
37 * @version $Revision: 1.2 $, $Date: 2005/06/10 03:50:44 $
38 * @since 1.5
39 */
40 public interface XPathFunction {
41 /**
42 * <p>Evaluate the function with the specified arguments.</p>
43 *
44 * <p>To the greatest extent possible, side-effects should be avoided in the
45 * definition of extension functions. The implementation evaluating an
46 * XPath expression is under no obligation to call extension functions in
47 * any particular order or any particular number of times.</p>
48 *
49 * @param args The arguments, <code>null</code> is a valid value.
50 *
51 * @return The result of evaluating the <code>XPath</code> function as an <code>Object</code>.
52 *
53 * @throws XPathFunctionException If <code>args</code> cannot be evaluated with this <code>XPath</code> function.
54 */
55 public Object evaluate(List args) throws XPathFunctionException;
56 }
|