1 /* 2 * Copyright (c) 2003, 2005, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package javax.xml.xpath; 27 28 import javax.xml.namespace.QName; 29 30 /** 31 * <p><code>XPathVariableResolver</code> provides access to the set of user defined XPath variables.</p> 32 * 33 * <p>The <code>XPathVariableResolver</code> and the XPath evaluator must adhere to a contract that 34 * cannot be directly enforced by the API. Although variables may be mutable, 35 * that is, an application may wish to evaluate the same XPath expression more 36 * than once with different variable values, in the course of evaluating any 37 * single XPath expression, a variable's value <strong><em>must</em></strong> 38 * not change.</p> 39 * 40 * @author <a href="mailto:Norman.Walsh@Sun.com">Norman Walsh</a> 41 * @author <a href="mailto:Jeff.Suttor@Sun.com">Jeff Suttor</a> 42 * @since 1.5 43 */ 44 public interface XPathVariableResolver { 45 /** 46 * <p>Find a variable in the set of available variables.</p> 47 * 48 * <p>If <code>variableName</code> is <code>null</code>, then a <code>NullPointerException</code> is thrown.</p> 49 * 50 * @param variableName The <code>QName</code> of the variable name. 51 * 52 * @return The variables value, or <code>null</code> if no variable named <code>variableName</code> 53 * exists. The value returned must be of a type appropriate for the underlying object model. 54 * 55 * @throws NullPointerException If <code>variableName</code> is <code>null</code>. 56 */ resolveVariable(QName variableName)57 public Object resolveVariable(QName variableName); 58 } 59