| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||||||
| PrecedingAxisIterator |
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| 4.6;4.6 |
| 1 | package org.jaxen.util; |
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| 2 | ||
| 3 | /* |
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| 4 | * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/util/PrecedingAxisIterator.java,v 1.8 2005/07/24 11:51:14 elharo Exp $ |
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| 5 | * $Revision: 1.8 $ |
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| 6 | * $Date: 2005/07/24 11:51:14 $ |
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| 7 | * |
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| 8 | * ==================================================================== |
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| 9 | * |
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| 10 | * Copyright (C) 2000-2005 bob mcwhirter & James Strachan. |
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| 11 | * All rights reserved. |
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| 12 | * |
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| 13 | * Redistribution and use in source and binary forms, with or without |
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| 14 | * modification, are permitted provided that the following conditions |
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| 15 | * are met: |
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| 16 | * |
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| 17 | * 1. Redistributions of source code must retain the above copyright |
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| 18 | * notice, this list of conditions, and the following disclaimer. |
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| 19 | * |
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| 20 | * 2. Redistributions in binary form must reproduce the above copyright |
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| 21 | * notice, this list of conditions, and the disclaimer that follows |
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| 22 | * these conditions in the documentation and/or other materials |
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| 23 | * provided with the distribution. |
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| 24 | * |
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| 25 | * 3. The name "Jaxen" must not be used to endorse or promote products |
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| 26 | * derived from this software without prior written permission. For |
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| 27 | * written permission, please contact license@jaxen.org. |
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| 28 | * |
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| 29 | * 4. Products derived from this software may not be called "Jaxen", nor |
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| 30 | * may "Jaxen" appear in their name, without prior written permission |
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| 31 | * from the Jaxen Project Management (pm@jaxen.org). |
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| 32 | * |
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| 33 | * In addition, we request (but do not require) that you include in the |
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| 34 | * end-user documentation provided with the redistribution and/or in the |
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| 35 | * software itself an acknowledgement equivalent to the following: |
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| 36 | * "This product includes software developed by the |
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| 37 | * Jaxen Project <http://www.jaxen.org/>." |
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| 38 | * Alternatively, the acknowledgment may be graphical using the logos |
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| 39 | * available at http://www.jaxen.org/ |
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| 40 | * |
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| 41 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
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| 42 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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| 43 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
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| 44 | * DISCLAIMED. IN NO EVENT SHALL THE Jaxen AUTHORS OR THE PROJECT |
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| 45 | * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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| 46 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
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| 47 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
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| 48 | * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
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| 49 | * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
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| 50 | * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
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| 51 | * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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| 52 | * SUCH DAMAGE. |
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| 53 | * |
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| 54 | * ==================================================================== |
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| 55 | * This software consists of voluntary contributions made by many |
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| 56 | * individuals on behalf of the Jaxen Project and was originally |
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| 57 | * created by bob mcwhirter <bob@werken.com> and |
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| 58 | * James Strachan <jstrachan@apache.org>. For more information on the |
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| 59 | * Jaxen Project, please see <http://www.jaxen.org/>. |
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| 60 | * |
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| 61 | * $Id: PrecedingAxisIterator.java,v 1.8 2005/07/24 11:51:14 elharo Exp $ |
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| 62 | */ |
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| 63 | ||
| 64 | import org.jaxen.JaxenConstants; |
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| 65 | import org.jaxen.JaxenRuntimeException; |
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| 66 | import org.jaxen.Navigator; |
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| 67 | import org.jaxen.UnsupportedAxisException; |
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| 68 | ||
| 69 | import java.util.ArrayList; |
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| 70 | import java.util.Iterator; |
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| 71 | import java.util.ListIterator; |
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| 72 | import java.util.NoSuchElementException; |
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| 73 | ||
| 74 | /** |
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| 75 | * This implementation of 'preceding' works like so: |
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| 76 | * the preceding axis includes preceding-siblings of this node and their |
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| 77 | * descendants. Also, for each ancestor node of this node, it includes |
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| 78 | * all preceding-siblings of that ancestor, and their descendants. Finally, it |
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| 79 | * includes the ancestor nodes themselves. |
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| 80 | * <p/> |
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| 81 | * The reversed descendant-or-self axes that are required are calculated using a |
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| 82 | * stack of reversed 'child-or-self' axes. When asked for a node, it is always taken |
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| 83 | * from a child-or-self axis. If it was the last node on that axis, the node is returned. |
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| 84 | * Otherwise, this axis is pushed on the stack, and the process is repeated with the child-or-self |
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| 85 | * of the node. Eventually this recurses down to the last descendant of any node, then works |
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| 86 | * back up to the root. |
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| 87 | * <p/> |
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| 88 | * I reckon most object models could provide a faster implementation of the reversed |
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| 89 | * 'children-or-self' used here. |
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| 90 | */ |
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| 91 | public class PrecedingAxisIterator implements Iterator |
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| 92 | { |
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| 93 | private Iterator ancestorOrSelf; |
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| 94 | private Iterator precedingSibling; |
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| 95 | private ListIterator childrenOrSelf; |
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| 96 | private ArrayList stack; |
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| 97 | ||
| 98 | private Navigator navigator; |
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| 99 | ||
| 100 | public PrecedingAxisIterator(Object contextNode, |
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| 101 | Navigator navigator) throws UnsupportedAxisException |
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| 102 | 474 | { |
| 103 | 474 | this.navigator = navigator; |
| 104 | 474 | this.ancestorOrSelf = navigator.getAncestorOrSelfAxisIterator(contextNode); |
| 105 | 474 | this.precedingSibling = JaxenConstants.EMPTY_ITERATOR; |
| 106 | 474 | this.childrenOrSelf = JaxenConstants.EMPTY_LIST_ITERATOR; |
| 107 | 474 | this.stack = new ArrayList(); |
| 108 | 474 | } |
| 109 | ||
| 110 | ||
| 111 | public boolean hasNext() |
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| 112 | { |
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| 113 | try |
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| 114 | { |
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| 115 | 5352 | while (!childrenOrSelf.hasPrevious()) |
| 116 | { |
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| 117 | 2022 | if (stack.isEmpty()) |
| 118 | { |
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| 119 | 2418 | while (!precedingSibling.hasNext()) |
| 120 | { |
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| 121 | 1866 | if (!ancestorOrSelf.hasNext()) |
| 122 | { |
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| 123 | 468 | return false; |
| 124 | } |
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| 125 | 1398 | Object contextNode = ancestorOrSelf.next(); |
| 126 | 1398 | precedingSibling = new PrecedingSiblingAxisIterator(contextNode, navigator); |
| 127 | } |
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| 128 | 552 | Object node = precedingSibling.next(); |
| 129 | 552 | childrenOrSelf = childrenOrSelf(node); |
| 130 | } |
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| 131 | else |
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| 132 | { |
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| 133 | 1002 | childrenOrSelf = (ListIterator) stack.remove(stack.size()-1); |
| 134 | } |
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| 135 | } |
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| 136 | 3330 | return true; |
| 137 | } |
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| 138 | 0 | catch (UnsupportedAxisException e) |
| 139 | { |
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| 140 | 0 | throw new JaxenRuntimeException(e); |
| 141 | } |
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| 142 | } |
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| 143 | ||
| 144 | private ListIterator childrenOrSelf(Object node) |
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| 145 | { |
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| 146 | try |
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| 147 | { |
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| 148 | 1554 | ArrayList reversed = new ArrayList(); |
| 149 | 1554 | reversed.add(node); |
| 150 | 1554 | Iterator childAxisIterator = navigator.getChildAxisIterator(node); |
| 151 | 1554 | if (childAxisIterator != null) |
| 152 | { |
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| 153 | 2556 | while (childAxisIterator.hasNext()) |
| 154 | { |
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| 155 | 1002 | reversed.add(childAxisIterator.next()); |
| 156 | } |
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| 157 | } |
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| 158 | 1554 | return reversed.listIterator(reversed.size()); |
| 159 | } |
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| 160 | 0 | catch (UnsupportedAxisException e) |
| 161 | { |
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| 162 | 0 | throw new JaxenRuntimeException(e); |
| 163 | } |
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| 164 | } |
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| 165 | ||
| 166 | public Object next() throws NoSuchElementException |
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| 167 | { |
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| 168 | 1560 | if (!hasNext()) |
| 169 | { |
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| 170 | 6 | throw new NoSuchElementException(); |
| 171 | } |
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| 172 | while (true) |
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| 173 | { |
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| 174 | 2556 | Object result = childrenOrSelf.previous(); |
| 175 | 2556 | if (childrenOrSelf.hasPrevious()) |
| 176 | { |
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| 177 | // if this isn't 'self' construct 'descendant-or-self' |
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| 178 | 1002 | stack.add(childrenOrSelf); |
| 179 | 1002 | childrenOrSelf = childrenOrSelf(result); |
| 180 | 1002 | continue; |
| 181 | } |
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| 182 | 1554 | return result; |
| 183 | } |
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| 184 | } |
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| 185 | ||
| 186 | ||
| 187 | public void remove() throws UnsupportedOperationException |
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| 188 | { |
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| 189 | 6 | throw new UnsupportedOperationException(); |
| 190 | } |
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| 191 | } |