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 <code>XPathResult</code> interface represents the result of the * evaluation of an XPath 1.0 expression within the context of a particular * node. Since evaluation of an XPath expression can result in various * result types, this object makes it possible to discover and manipulate * the type and value of the result. * <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 XPathResult { // XPathResultType /** * This code does not represent a specific type. An evaluation of an XPath * expression will never produce this type. If this type is requested, * then the evaluation returns whatever type naturally results from * evaluation of the expression. * <br>If the natural result is a node set when <code>ANY_TYPE</code> was * requested, then <code>UNORDERED_NODE_ITERATOR_TYPE</code> is always * the resulting type. Any other representation of a node set must be * explicitly requested. */ public static final short ANY_TYPE = 0; /** * The result is a number as defined by . Document modification does not * invalidate the number, but may mean that reevaluation would not yield * the same number. */ public static final short NUMBER_TYPE = 1; /** * The result is a string as defined by . Document modification does not * invalidate the string, but may mean that the string no longer * corresponds to the current document. */ public static final short STRING_TYPE = 2; /** * The result is a boolean as defined by . Document modification does not * invalidate the boolean, but may mean that reevaluation would not * yield the same boolean. */ public static final short BOOLEAN_TYPE = 3; /** * The result is a node set as defined by that will be accessed * iteratively, which may not produce nodes in a particular order. * Document modification invalidates the iteration. * <br>This is the default type returned if the result is a node set and * <code>ANY_TYPE</code> is requested. */ public static final short UNORDERED_NODE_ITERATOR_TYPE = 4; /** * The result is a node set as defined by that will be accessed * iteratively, which will produce document-ordered nodes. Document * modification invalidates the iteration. */ public static final short ORDERED_NODE_ITERATOR_TYPE = 5; /** * The result is a node set as defined by that will be accessed as a * snapshot list of nodes that may not be in a particular order. * Document modification does not invalidate the snapshot but may mean * that reevaluation would not yield the same snapshot and nodes in the * snapshot may have been altered, moved, or removed from the document. */ public static final short UNORDERED_NODE_SNAPSHOT_TYPE = 6; /** * The result is a node set as defined by that will be accessed as a * snapshot list of nodes that will be in original document order. * Document modification does not invalidate the snapshot but may mean * that reevaluation would not yield the same snapshot and nodes in the * snapshot may have been altered, moved, or removed from the document. */ public static final short ORDERED_NODE_SNAPSHOT_TYPE = 7; /** * The result is a node set as defined by and will be accessed as a * single node, which may be <code>null</code>if the node set is empty. * Document modification does not invalidate the node, but may mean that * the result node no longer corresponds to the current document. This * is a convenience that permits optimization since the implementation * can stop once any node in the in the resulting set has been found. * <br>If there are more than one node in the actual result, the single * node returned might not be the first in document order. */ public static final short ANY_UNORDERED_NODE_TYPE = 8; /** * The result is a node set as defined by and will be accessed as a * single node, which may be <code>null</code> if the node set is empty. * Document modification does not invalidate the node, but may mean that * the result node no longer corresponds to the current document. This * is a convenience that permits optimization since the implementation * can stop once the first node in document order of the resulting set * has been found. * <br>If there are more than one node in the actual result, the single * node returned will be the first in document order. */ public static final short FIRST_ORDERED_NODE_TYPE = 9; /** * A code representing the type of this result, as defined by the type * constants. */ public short getResultType(); /** * The value of this number result. If the native double type of the DOM * binding does not directly support the exact IEEE 754 result of the * XPath expression, then it is up to the definition of the binding * binding to specify how the XPath number is converted to the native * binding number. * @exception XPathException * TYPE_ERR: raised if <code>resultType</code> is not * <code>NUMBER_TYPE</code>. */ public double getNumberValue() throws XPathException; /** * The value of this string result. * @exception XPathException * TYPE_ERR: raised if <code>resultType</code> is not * <code>STRING_TYPE</code>. */ public String getStringValue() throws XPathException; /** * The value of this boolean result. * @exception XPathException * TYPE_ERR: raised if <code>resultType</code> is not * <code>BOOLEAN_TYPE</code>. */ public boolean getBooleanValue() throws XPathException; /** * The value of this single node result, which may be <code>null</code>. * @exception XPathException * TYPE_ERR: raised if <code>resultType</code> is not * <code>ANY_UNORDERED_NODE_TYPE</code> or * <code>FIRST_ORDERED_NODE_TYPE</code>. */ public Node getSingleNodeValue() throws XPathException; /** * Signifies that the iterator has become invalid. True if * <code>resultType</code> is <code>UNORDERED_NODE_ITERATOR_TYPE</code> * or <code>ORDERED_NODE_ITERATOR_TYPE</code> and the document has been * modified since this result was returned. */ public boolean getInvalidIteratorState(); /** * The number of nodes in the result snapshot. Valid values for * snapshotItem indices are <code>0</code> to * <code>snapshotLength-1</code> inclusive. * @exception XPathException * TYPE_ERR: raised if <code>resultType</code> is not * <code>UNORDERED_NODE_SNAPSHOT_TYPE</code> or * <code>ORDERED_NODE_SNAPSHOT_TYPE</code>. */ public int getSnapshotLength() throws XPathException; /** * Iterates and returns the next node from the node set or * <code>null</code>if there are no more nodes. * @return Returns the next node. * @exception XPathException * TYPE_ERR: raised if <code>resultType</code> is not * <code>UNORDERED_NODE_ITERATOR_TYPE</code> or * <code>ORDERED_NODE_ITERATOR_TYPE</code>. * @exception DOMException * INVALID_STATE_ERR: The document has been mutated since the result was * returned. */ public Node iterateNext() throws XPathException, DOMException; /** * Returns the <code>index</code>th item in the snapshot collection. If * <code>index</code> is greater than or equal to the number of nodes in * the list, this method returns <code>null</code>. Unlike the iterator * result, the snapshot does not become invalid, but may not correspond * to the current document if it is mutated. * @param index Index into the snapshot collection. * @return The node at the <code>index</code>th position in the * <code>NodeList</code>, or <code>null</code> if that is not a valid * index. * @exception XPathException * TYPE_ERR: raised if <code>resultType</code> is not * <code>UNORDERED_NODE_SNAPSHOT_TYPE</code> or * <code>ORDERED_NODE_SNAPSHOT_TYPE</code>. */ public Node snapshotItem(int index) throws XPathException; }