Java tutorial
/* * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ /* * This file is available under and governed by the GNU General Public * License version 2 only, as published by the Free Software Foundation. * However, the following notice accompanied the original version of this * file and, per its terms, should not be removed: * * Copyright (c) 2002 World Wide Web Consortium, * (Massachusetts Institute of Technology, Institut National de * Recherche en Informatique et en Automatique, Keio University). All * Rights Reserved. This program is distributed under the W3C's Software * Intellectual Property License. This program is distributed in the * hope that it will be useful, but WITHOUT ANY WARRANTY; without even * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR * PURPOSE. * See W3C License http://www.w3.org/Consortium/Legal/ for more details. */ package org.w3c.dom.xpath; import org.w3c.dom.Node; import org.w3c.dom.DOMException; /** * The evaluation of XPath expressions is provided by * <code>XPathEvaluator</code>. In a DOM implementation which supports the * XPath 3.0 feature, as described above, the <code>XPathEvaluator</code> * interface will be implemented on the same object which implements the * <code>Document</code> interface permitting it to be obtained by the usual * binding-specific method such as casting or by using the DOM Level 3 * getInterface method. In this case the implementation obtained from the * Document supports the XPath DOM module and is compatible with the XPath * 1.0 specification. * <p>Evaluation of expressions with specialized extension functions or * variables may not work in all implementations and is, therefore, not * portable. <code>XPathEvaluator</code> implementations may be available * from other sources that could provide specific support for specialized * extension functions or variables as would be defined by other * specifications. * <p>See also the <a href='https://www.w3.org/TR/DOM-Level-3-XPath/'>Document Object Model (DOM) Level 3 XPath Specification</a>. */ public interface XPathEvaluator { /** * Creates a parsed XPath expression with resolved namespaces. This is * useful when an expression will be reused in an application since it * makes it possible to compile the expression string into a more * efficient internal form and preresolve all namespace prefixes which * occur within the expression. * @param expression The XPath expression string to be parsed. * @param resolver The <code>resolver</code> permits translation of * prefixes within the XPath expression into appropriate namespace URIs * . If this is specified as <code>null</code>, any namespace prefix * within the expression will result in <code>DOMException</code> * being thrown with the code <code>NAMESPACE_ERR</code>. * @return The compiled form of the XPath expression. * @exception XPathException * INVALID_EXPRESSION_ERR: Raised if the expression is not legal * according to the rules of the <code>XPathEvaluator</code>i * @exception DOMException * NAMESPACE_ERR: Raised if the expression contains namespace prefixes * which cannot be resolved by the specified * <code>XPathNSResolver</code>. */ public XPathExpression createExpression(String expression, XPathNSResolver resolver) throws XPathException, DOMException; /** * Adapts any DOM node to resolve namespaces so that an XPath expression * can be easily evaluated relative to the context of the node where it * appeared within the document. This adapter works like the DOM Level 3 * method <code>lookupNamespaceURI</code> on nodes in resolving the * namespaceURI from a given prefix using the current information * available in the node's hierarchy at the time lookupNamespaceURI is * called. also correctly resolving the implicit xml prefix. * @param nodeResolver The node to be used as a context for namespace * resolution. * @return <code>XPathNSResolver</code> which resolves namespaces with * respect to the definitions in scope for a specified node. */ public XPathNSResolver createNSResolver(Node nodeResolver); /** * Evaluates an XPath expression string and returns a result of the * specified type if possible. * @param expression The XPath expression string to be parsed and * evaluated. * @param contextNode The <code>context</code> is context node for the * evaluation of this XPath expression. If the XPathEvaluator was * obtained by casting the <code>Document</code> then this must be * owned by the same document and must be a <code>Document</code>, * <code>Element</code>, <code>Attribute</code>, <code>Text</code>, * <code>CDATASection</code>, <code>Comment</code>, * <code>ProcessingInstruction</code>, or <code>XPathNamespace</code> * node. If the context node is a <code>Text</code> or a * <code>CDATASection</code>, then the context is interpreted as the * whole logical text node as seen by XPath, unless the node is empty * in which case it may not serve as the XPath context. * @param resolver The <code>resolver</code> permits translation of * prefixes within the XPath expression into appropriate namespace URIs * . If this is specified as <code>null</code>, any namespace prefix * within the expression will result in <code>DOMException</code> * being thrown with the code <code>NAMESPACE_ERR</code>. * @param type If a specific <code>type</code> is specified, then the * result will be returned as the corresponding type.For XPath 1.0 * results, this must be one of the codes of the * <code>XPathResult</code> interface. * @param result The <code>result</code> specifies a specific result * object which may be reused and returned by this method. If this is * specified as <code>null</code>or the implementation does not reuse * the specified result, a new result object will be constructed and * returned.For XPath 1.0 results, this object will be of type * <code>XPathResult</code>. * @return The result of the evaluation of the XPath expression.For XPath * 1.0 results, this object will be of type <code>XPathResult</code>. * @exception XPathException * INVALID_EXPRESSION_ERR: Raised if the expression is not legal * according to the rules of the <code>XPathEvaluator</code>i * <br>TYPE_ERR: Raised if the result cannot be converted to return the * specified type. * @exception DOMException * NAMESPACE_ERR: Raised if the expression contains namespace prefixes * which cannot be resolved by the specified * <code>XPathNSResolver</code>. * <br>WRONG_DOCUMENT_ERR: The Node is from a document that is not * supported by this <code>XPathEvaluator</code>. * <br>NOT_SUPPORTED_ERR: The Node is not a type permitted as an XPath * context node or the request type is not permitted by this * <code>XPathEvaluator</code>. */ public Object evaluate(String expression, Node contextNode, XPathNSResolver resolver, short type, Object result) throws XPathException, DOMException; }