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dl |
1.1 |
/* |
2 |
jsr166 |
1.18 |
* Copyright 1997-2007 Sun Microsystems, Inc. All Rights Reserved. |
3 |
jsr166 |
1.17 |
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
4 |
dl |
1.1 |
* |
5 |
jsr166 |
1.17 |
* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. Sun designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Sun in the LICENSE file that accompanied this code. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
13 |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
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* CA 95054 USA or visit www.sun.com if you need additional information or |
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* have any questions. |
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dl |
1.1 |
*/ |
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package java.util; |
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/** |
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jsr166 |
1.13 |
* This class provides a skeletal implementation of the {@link List} |
30 |
dl |
1.1 |
* interface to minimize the effort required to implement this interface |
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* backed by a "random access" data store (such as an array). For sequential |
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1.13 |
* access data (such as a linked list), {@link AbstractSequentialList} should |
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1.12 |
* be used in preference to this class. |
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dl |
1.1 |
* |
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jsr166 |
1.13 |
* <p>To implement an unmodifiable list, the programmer needs only to extend |
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* this class and provide implementations for the {@link #get(int)} and |
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* {@link List#size() size()} methods. |
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dl |
1.1 |
* |
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jsr166 |
1.13 |
* <p>To implement a modifiable list, the programmer must additionally |
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* override the {@link #set(int, Object) set(int, E)} method (which otherwise |
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* throws an {@code UnsupportedOperationException}). If the list is |
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* variable-size the programmer must additionally override the |
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* {@link #add(int, Object) add(int, E)} and {@link #remove(int)} methods. |
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dl |
1.1 |
* |
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jsr166 |
1.12 |
* <p>The programmer should generally provide a void (no argument) and collection |
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jsr166 |
1.13 |
* constructor, as per the recommendation in the {@link Collection} interface |
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1.12 |
* specification. |
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1.1 |
* |
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jsr166 |
1.12 |
* <p>Unlike the other abstract collection implementations, the programmer does |
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1.1 |
* <i>not</i> have to provide an iterator implementation; the iterator and |
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* list iterator are implemented by this class, on top of the "random access" |
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jsr166 |
1.13 |
* methods: |
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* {@link #get(int)}, |
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* {@link #set(int, Object) set(int, E)}, |
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* {@link #add(int, Object) add(int, E)} and |
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* {@link #remove(int)}. |
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dl |
1.1 |
* |
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jsr166 |
1.13 |
* <p>The documentation for each non-abstract method in this class describes its |
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1.1 |
* implementation in detail. Each of these methods may be overridden if the |
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1.12 |
* collection being implemented admits a more efficient implementation. |
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1.1 |
* |
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1.12 |
* <p>This class is a member of the |
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1.11 |
* <a href="{@docRoot}/../technotes/guides/collections/index.html"> |
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1.1 |
* Java Collections Framework</a>. |
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* |
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* @author Josh Bloch |
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* @author Neal Gafter |
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* @since 1.2 |
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*/ |
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public abstract class AbstractList<E> extends AbstractCollection<E> implements List<E> { |
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/** |
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* Sole constructor. (For invocation by subclass constructors, typically |
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* implicit.) |
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*/ |
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protected AbstractList() { |
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} |
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/** |
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* Appends the specified element to the end of this list (optional |
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* operation). |
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* |
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* <p>Lists that support this operation may place limitations on what |
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* elements may be added to this list. In particular, some |
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* lists will refuse to add null elements, and others will impose |
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* restrictions on the type of elements that may be added. List |
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* classes should clearly specify in their documentation any restrictions |
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* on what elements may be added. |
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* |
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jsr166 |
1.12 |
* <p>This implementation calls {@code add(size(), e)}. |
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dl |
1.1 |
* |
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* <p>Note that this implementation throws an |
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jsr166 |
1.13 |
* {@code UnsupportedOperationException} unless |
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* {@link #add(int, Object) add(int, E)} is overridden. |
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dl |
1.1 |
* |
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* @param e element to be appended to this list |
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jsr166 |
1.12 |
* @return {@code true} (as specified by {@link Collection#add}) |
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* @throws UnsupportedOperationException if the {@code add} operation |
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dl |
1.1 |
* is not supported by this list |
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* @throws ClassCastException if the class of the specified element |
101 |
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* prevents it from being added to this list |
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* @throws NullPointerException if the specified element is null and this |
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* list does not permit null elements |
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* @throws IllegalArgumentException if some property of this element |
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* prevents it from being added to this list |
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*/ |
107 |
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public boolean add(E e) { |
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jsr166 |
1.19 |
add(size(), e); |
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return true; |
110 |
dl |
1.1 |
} |
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/** |
113 |
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* {@inheritDoc} |
114 |
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* |
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* @throws IndexOutOfBoundsException {@inheritDoc} |
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*/ |
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abstract public E get(int index); |
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/** |
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* {@inheritDoc} |
121 |
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* |
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* <p>This implementation always throws an |
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jsr166 |
1.12 |
* {@code UnsupportedOperationException}. |
124 |
dl |
1.1 |
* |
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* @throws UnsupportedOperationException {@inheritDoc} |
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* @throws ClassCastException {@inheritDoc} |
127 |
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* @throws NullPointerException {@inheritDoc} |
128 |
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* @throws IllegalArgumentException {@inheritDoc} |
129 |
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* @throws IndexOutOfBoundsException {@inheritDoc} |
130 |
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*/ |
131 |
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public E set(int index, E element) { |
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jsr166 |
1.19 |
throw new UnsupportedOperationException(); |
133 |
dl |
1.1 |
} |
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135 |
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/** |
136 |
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* {@inheritDoc} |
137 |
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* |
138 |
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* <p>This implementation always throws an |
139 |
jsr166 |
1.12 |
* {@code UnsupportedOperationException}. |
140 |
dl |
1.1 |
* |
141 |
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* @throws UnsupportedOperationException {@inheritDoc} |
142 |
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* @throws ClassCastException {@inheritDoc} |
143 |
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* @throws NullPointerException {@inheritDoc} |
144 |
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* @throws IllegalArgumentException {@inheritDoc} |
145 |
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* @throws IndexOutOfBoundsException {@inheritDoc} |
146 |
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*/ |
147 |
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public void add(int index, E element) { |
148 |
jsr166 |
1.19 |
throw new UnsupportedOperationException(); |
149 |
dl |
1.1 |
} |
150 |
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151 |
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/** |
152 |
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* {@inheritDoc} |
153 |
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* |
154 |
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* <p>This implementation always throws an |
155 |
jsr166 |
1.12 |
* {@code UnsupportedOperationException}. |
156 |
dl |
1.1 |
* |
157 |
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* @throws UnsupportedOperationException {@inheritDoc} |
158 |
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* @throws IndexOutOfBoundsException {@inheritDoc} |
159 |
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*/ |
160 |
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public E remove(int index) { |
161 |
jsr166 |
1.19 |
throw new UnsupportedOperationException(); |
162 |
dl |
1.1 |
} |
163 |
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164 |
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|
165 |
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// Search Operations |
166 |
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|
167 |
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/** |
168 |
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* {@inheritDoc} |
169 |
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* |
170 |
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* <p>This implementation first gets a list iterator (with |
171 |
jsr166 |
1.12 |
* {@code listIterator()}). Then, it iterates over the list until the |
172 |
dl |
1.1 |
* specified element is found or the end of the list is reached. |
173 |
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* |
174 |
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* @throws ClassCastException {@inheritDoc} |
175 |
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* @throws NullPointerException {@inheritDoc} |
176 |
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*/ |
177 |
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public int indexOf(Object o) { |
178 |
jsr166 |
1.19 |
ListIterator<E> e = listIterator(); |
179 |
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if (o==null) { |
180 |
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while (e.hasNext()) |
181 |
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if (e.next()==null) |
182 |
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return e.previousIndex(); |
183 |
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} else { |
184 |
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while (e.hasNext()) |
185 |
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if (o.equals(e.next())) |
186 |
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return e.previousIndex(); |
187 |
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} |
188 |
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return -1; |
189 |
dl |
1.1 |
} |
190 |
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191 |
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/** |
192 |
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* {@inheritDoc} |
193 |
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* |
194 |
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* <p>This implementation first gets a list iterator that points to the end |
195 |
jsr166 |
1.12 |
* of the list (with {@code listIterator(size())}). Then, it iterates |
196 |
dl |
1.1 |
* backwards over the list until the specified element is found, or the |
197 |
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* beginning of the list is reached. |
198 |
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* |
199 |
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* @throws ClassCastException {@inheritDoc} |
200 |
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* @throws NullPointerException {@inheritDoc} |
201 |
|
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*/ |
202 |
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public int lastIndexOf(Object o) { |
203 |
jsr166 |
1.19 |
ListIterator<E> e = listIterator(size()); |
204 |
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if (o==null) { |
205 |
|
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while (e.hasPrevious()) |
206 |
|
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if (e.previous()==null) |
207 |
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return e.nextIndex(); |
208 |
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} else { |
209 |
|
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while (e.hasPrevious()) |
210 |
|
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if (o.equals(e.previous())) |
211 |
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return e.nextIndex(); |
212 |
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} |
213 |
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return -1; |
214 |
dl |
1.1 |
} |
215 |
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|
216 |
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|
217 |
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// Bulk Operations |
218 |
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|
219 |
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/** |
220 |
|
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* Removes all of the elements from this list (optional operation). |
221 |
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* The list will be empty after this call returns. |
222 |
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* |
223 |
jsr166 |
1.12 |
* <p>This implementation calls {@code removeRange(0, size())}. |
224 |
dl |
1.1 |
* |
225 |
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* <p>Note that this implementation throws an |
226 |
jsr166 |
1.12 |
* {@code UnsupportedOperationException} unless {@code remove(int |
227 |
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* index)} or {@code removeRange(int fromIndex, int toIndex)} is |
228 |
dl |
1.1 |
* overridden. |
229 |
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* |
230 |
jsr166 |
1.12 |
* @throws UnsupportedOperationException if the {@code clear} operation |
231 |
dl |
1.1 |
* is not supported by this list |
232 |
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*/ |
233 |
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public void clear() { |
234 |
|
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removeRange(0, size()); |
235 |
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} |
236 |
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|
237 |
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/** |
238 |
|
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* {@inheritDoc} |
239 |
|
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* |
240 |
jsr166 |
1.13 |
* <p>This implementation gets an iterator over the specified collection |
241 |
|
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* and iterates over it, inserting the elements obtained from the |
242 |
|
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* iterator into this list at the appropriate position, one at a time, |
243 |
|
|
* using {@code add(int, E)}. |
244 |
|
|
* Many implementations will override this method for efficiency. |
245 |
dl |
1.1 |
* |
246 |
|
|
* <p>Note that this implementation throws an |
247 |
jsr166 |
1.13 |
* {@code UnsupportedOperationException} unless |
248 |
|
|
* {@link #add(int, Object) add(int, E)} is overridden. |
249 |
dl |
1.1 |
* |
250 |
|
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* @throws UnsupportedOperationException {@inheritDoc} |
251 |
|
|
* @throws ClassCastException {@inheritDoc} |
252 |
|
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* @throws NullPointerException {@inheritDoc} |
253 |
|
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* @throws IllegalArgumentException {@inheritDoc} |
254 |
|
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* @throws IndexOutOfBoundsException {@inheritDoc} |
255 |
|
|
*/ |
256 |
|
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public boolean addAll(int index, Collection<? extends E> c) { |
257 |
jsr166 |
1.19 |
rangeCheckForAdd(index); |
258 |
|
|
boolean modified = false; |
259 |
|
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Iterator<? extends E> e = c.iterator(); |
260 |
|
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while (e.hasNext()) { |
261 |
|
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add(index++, e.next()); |
262 |
|
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modified = true; |
263 |
|
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} |
264 |
|
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return modified; |
265 |
dl |
1.1 |
} |
266 |
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|
267 |
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|
268 |
|
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// Iterators |
269 |
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|
270 |
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/** |
271 |
jsr166 |
1.14 |
* Returns an iterator over the elements in this list in proper sequence. |
272 |
dl |
1.1 |
* |
273 |
jsr166 |
1.13 |
* <p>This implementation returns a straightforward implementation of the |
274 |
jsr166 |
1.12 |
* iterator interface, relying on the backing list's {@code size()}, |
275 |
jsr166 |
1.13 |
* {@code get(int)}, and {@code remove(int)} methods. |
276 |
dl |
1.1 |
* |
277 |
jsr166 |
1.13 |
* <p>Note that the iterator returned by this method will throw an |
278 |
jsr166 |
1.18 |
* {@link UnsupportedOperationException} in response to its |
279 |
jsr166 |
1.12 |
* {@code remove} method unless the list's {@code remove(int)} method is |
280 |
jsr166 |
1.13 |
* overridden. |
281 |
dl |
1.1 |
* |
282 |
jsr166 |
1.13 |
* <p>This implementation can be made to throw runtime exceptions in the |
283 |
|
|
* face of concurrent modification, as described in the specification |
284 |
jsr166 |
1.18 |
* for the (protected) {@link #modCount} field. |
285 |
dl |
1.1 |
* |
286 |
|
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* @return an iterator over the elements in this list in proper sequence |
287 |
|
|
*/ |
288 |
|
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public Iterator<E> iterator() { |
289 |
jsr166 |
1.19 |
return new Itr(); |
290 |
dl |
1.1 |
} |
291 |
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|
292 |
|
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/** |
293 |
|
|
* {@inheritDoc} |
294 |
|
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* |
295 |
jsr166 |
1.12 |
* <p>This implementation returns {@code listIterator(0)}. |
296 |
dl |
1.1 |
* |
297 |
|
|
* @see #listIterator(int) |
298 |
|
|
*/ |
299 |
|
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public ListIterator<E> listIterator() { |
300 |
jsr166 |
1.19 |
return listIterator(0); |
301 |
dl |
1.1 |
} |
302 |
|
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|
303 |
|
|
/** |
304 |
|
|
* {@inheritDoc} |
305 |
|
|
* |
306 |
|
|
* <p>This implementation returns a straightforward implementation of the |
307 |
jsr166 |
1.12 |
* {@code ListIterator} interface that extends the implementation of the |
308 |
|
|
* {@code Iterator} interface returned by the {@code iterator()} method. |
309 |
|
|
* The {@code ListIterator} implementation relies on the backing list's |
310 |
jsr166 |
1.14 |
* {@code get(int)}, {@code set(int, E)}, {@code add(int, E)} |
311 |
jsr166 |
1.12 |
* and {@code remove(int)} methods. |
312 |
dl |
1.1 |
* |
313 |
|
|
* <p>Note that the list iterator returned by this implementation will |
314 |
jsr166 |
1.18 |
* throw an {@link UnsupportedOperationException} in response to its |
315 |
jsr166 |
1.12 |
* {@code remove}, {@code set} and {@code add} methods unless the |
316 |
jsr166 |
1.13 |
* list's {@code remove(int)}, {@code set(int, E)}, and |
317 |
|
|
* {@code add(int, E)} methods are overridden. |
318 |
dl |
1.1 |
* |
319 |
|
|
* <p>This implementation can be made to throw runtime exceptions in the |
320 |
|
|
* face of concurrent modification, as described in the specification for |
321 |
jsr166 |
1.18 |
* the (protected) {@link #modCount} field. |
322 |
dl |
1.1 |
* |
323 |
|
|
* @throws IndexOutOfBoundsException {@inheritDoc} |
324 |
|
|
*/ |
325 |
|
|
public ListIterator<E> listIterator(final int index) { |
326 |
jsr166 |
1.19 |
rangeCheckForAdd(index); |
327 |
dl |
1.1 |
|
328 |
jsr166 |
1.19 |
return new ListItr(index); |
329 |
dl |
1.1 |
} |
330 |
|
|
|
331 |
|
|
private class Itr implements Iterator<E> { |
332 |
jsr166 |
1.19 |
/** |
333 |
|
|
* Index of element to be returned by subsequent call to next. |
334 |
|
|
*/ |
335 |
|
|
int cursor = 0; |
336 |
|
|
|
337 |
|
|
/** |
338 |
|
|
* Index of element returned by most recent call to next or |
339 |
|
|
* previous. Reset to -1 if this element is deleted by a call |
340 |
|
|
* to remove. |
341 |
|
|
*/ |
342 |
|
|
int lastRet = -1; |
343 |
|
|
|
344 |
|
|
/** |
345 |
|
|
* The modCount value that the iterator believes that the backing |
346 |
|
|
* List should have. If this expectation is violated, the iterator |
347 |
|
|
* has detected concurrent modification. |
348 |
|
|
*/ |
349 |
|
|
int expectedModCount = modCount; |
350 |
dl |
1.1 |
|
351 |
jsr166 |
1.19 |
public boolean hasNext() { |
352 |
dl |
1.4 |
return cursor != size(); |
353 |
jsr166 |
1.19 |
} |
354 |
dl |
1.1 |
|
355 |
jsr166 |
1.19 |
public E next() { |
356 |
dl |
1.8 |
checkForComodification(); |
357 |
jsr166 |
1.19 |
try { |
358 |
|
|
int i = cursor; |
359 |
|
|
E next = get(i); |
360 |
|
|
lastRet = i; |
361 |
|
|
cursor = i + 1; |
362 |
|
|
return next; |
363 |
|
|
} catch (IndexOutOfBoundsException e) { |
364 |
|
|
checkForComodification(); |
365 |
|
|
throw new NoSuchElementException(); |
366 |
|
|
} |
367 |
|
|
} |
368 |
|
|
|
369 |
|
|
public void remove() { |
370 |
|
|
if (lastRet < 0) |
371 |
|
|
throw new IllegalStateException(); |
372 |
dl |
1.8 |
checkForComodification(); |
373 |
|
|
|
374 |
jsr166 |
1.19 |
try { |
375 |
|
|
AbstractList.this.remove(lastRet); |
376 |
|
|
if (lastRet < cursor) |
377 |
|
|
cursor--; |
378 |
|
|
lastRet = -1; |
379 |
|
|
expectedModCount = modCount; |
380 |
|
|
} catch (IndexOutOfBoundsException e) { |
381 |
|
|
throw new ConcurrentModificationException(); |
382 |
|
|
} |
383 |
|
|
} |
384 |
|
|
|
385 |
|
|
final void checkForComodification() { |
386 |
|
|
if (modCount != expectedModCount) |
387 |
|
|
throw new ConcurrentModificationException(); |
388 |
|
|
} |
389 |
dl |
1.1 |
} |
390 |
jsr166 |
1.6 |
|
391 |
dl |
1.4 |
private class ListItr extends Itr implements ListIterator<E> { |
392 |
jsr166 |
1.19 |
ListItr(int index) { |
393 |
|
|
cursor = index; |
394 |
|
|
} |
395 |
|
|
|
396 |
|
|
public boolean hasPrevious() { |
397 |
|
|
return cursor != 0; |
398 |
|
|
} |
399 |
dl |
1.1 |
|
400 |
dl |
1.8 |
public E previous() { |
401 |
|
|
checkForComodification(); |
402 |
|
|
try { |
403 |
|
|
int i = cursor - 1; |
404 |
|
|
E previous = get(i); |
405 |
|
|
lastRet = cursor = i; |
406 |
|
|
return previous; |
407 |
|
|
} catch (IndexOutOfBoundsException e) { |
408 |
|
|
checkForComodification(); |
409 |
|
|
throw new NoSuchElementException(); |
410 |
|
|
} |
411 |
|
|
} |
412 |
|
|
|
413 |
jsr166 |
1.19 |
public int nextIndex() { |
414 |
|
|
return cursor; |
415 |
|
|
} |
416 |
|
|
|
417 |
|
|
public int previousIndex() { |
418 |
|
|
return cursor-1; |
419 |
|
|
} |
420 |
|
|
|
421 |
|
|
public void set(E e) { |
422 |
|
|
if (lastRet < 0) |
423 |
|
|
throw new IllegalStateException(); |
424 |
dl |
1.8 |
checkForComodification(); |
425 |
|
|
|
426 |
jsr166 |
1.19 |
try { |
427 |
|
|
AbstractList.this.set(lastRet, e); |
428 |
|
|
expectedModCount = modCount; |
429 |
|
|
} catch (IndexOutOfBoundsException ex) { |
430 |
|
|
throw new ConcurrentModificationException(); |
431 |
|
|
} |
432 |
|
|
} |
433 |
dl |
1.1 |
|
434 |
jsr166 |
1.19 |
public void add(E e) { |
435 |
dl |
1.8 |
checkForComodification(); |
436 |
|
|
|
437 |
jsr166 |
1.19 |
try { |
438 |
|
|
int i = cursor; |
439 |
|
|
AbstractList.this.add(i, e); |
440 |
|
|
lastRet = -1; |
441 |
|
|
cursor = i + 1; |
442 |
|
|
expectedModCount = modCount; |
443 |
|
|
} catch (IndexOutOfBoundsException ex) { |
444 |
|
|
throw new ConcurrentModificationException(); |
445 |
|
|
} |
446 |
|
|
} |
447 |
dl |
1.1 |
} |
448 |
|
|
|
449 |
|
|
/** |
450 |
|
|
* {@inheritDoc} |
451 |
|
|
* |
452 |
|
|
* <p>This implementation returns a list that subclasses |
453 |
jsr166 |
1.12 |
* {@code AbstractList}. The subclass stores, in private fields, the |
454 |
dl |
1.1 |
* offset of the subList within the backing list, the size of the subList |
455 |
|
|
* (which can change over its lifetime), and the expected |
456 |
jsr166 |
1.12 |
* {@code modCount} value of the backing list. There are two variants |
457 |
|
|
* of the subclass, one of which implements {@code RandomAccess}. |
458 |
|
|
* If this list implements {@code RandomAccess} the returned list will |
459 |
|
|
* be an instance of the subclass that implements {@code RandomAccess}. |
460 |
|
|
* |
461 |
jsr166 |
1.14 |
* <p>The subclass's {@code set(int, E)}, {@code get(int)}, |
462 |
|
|
* {@code add(int, E)}, {@code remove(int)}, {@code addAll(int, |
463 |
jsr166 |
1.12 |
* Collection)} and {@code removeRange(int, int)} methods all |
464 |
dl |
1.1 |
* delegate to the corresponding methods on the backing abstract list, |
465 |
|
|
* after bounds-checking the index and adjusting for the offset. The |
466 |
jsr166 |
1.12 |
* {@code addAll(Collection c)} method merely returns {@code addAll(size, |
467 |
|
|
* c)}. |
468 |
dl |
1.1 |
* |
469 |
jsr166 |
1.12 |
* <p>The {@code listIterator(int)} method returns a "wrapper object" |
470 |
dl |
1.1 |
* over a list iterator on the backing list, which is created with the |
471 |
jsr166 |
1.12 |
* corresponding method on the backing list. The {@code iterator} method |
472 |
|
|
* merely returns {@code listIterator()}, and the {@code size} method |
473 |
|
|
* merely returns the subclass's {@code size} field. |
474 |
dl |
1.1 |
* |
475 |
jsr166 |
1.12 |
* <p>All methods first check to see if the actual {@code modCount} of |
476 |
dl |
1.1 |
* the backing list is equal to its expected value, and throw a |
477 |
jsr166 |
1.12 |
* {@code ConcurrentModificationException} if it is not. |
478 |
dl |
1.1 |
* |
479 |
jsr166 |
1.18 |
* @throws IndexOutOfBoundsException if an endpoint index value is out of range |
480 |
jsr166 |
1.14 |
* {@code (fromIndex < 0 || toIndex > size)} |
481 |
dl |
1.1 |
* @throws IllegalArgumentException if the endpoint indices are out of order |
482 |
jsr166 |
1.14 |
* {@code (fromIndex > toIndex)} |
483 |
dl |
1.1 |
*/ |
484 |
|
|
public List<E> subList(int fromIndex, int toIndex) { |
485 |
|
|
return (this instanceof RandomAccess ? |
486 |
jsr166 |
1.18 |
new RandomAccessSubList<E>(this, fromIndex, toIndex) : |
487 |
|
|
new SubList<E>(this, fromIndex, toIndex)); |
488 |
dl |
1.1 |
} |
489 |
|
|
|
490 |
|
|
// Comparison and hashing |
491 |
|
|
|
492 |
|
|
/** |
493 |
|
|
* Compares the specified object with this list for equality. Returns |
494 |
jsr166 |
1.12 |
* {@code true} if and only if the specified object is also a list, both |
495 |
dl |
1.1 |
* lists have the same size, and all corresponding pairs of elements in |
496 |
jsr166 |
1.12 |
* the two lists are <i>equal</i>. (Two elements {@code e1} and |
497 |
|
|
* {@code e2} are <i>equal</i> if {@code (e1==null ? e2==null : |
498 |
|
|
* e1.equals(e2))}.) In other words, two lists are defined to be |
499 |
jsr166 |
1.18 |
* equal if they contain the same elements in the same order.<p> |
500 |
dl |
1.1 |
* |
501 |
jsr166 |
1.18 |
* This implementation first checks if the specified object is this |
502 |
jsr166 |
1.12 |
* list. If so, it returns {@code true}; if not, it checks if the |
503 |
|
|
* specified object is a list. If not, it returns {@code false}; if so, |
504 |
dl |
1.1 |
* it iterates over both lists, comparing corresponding pairs of elements. |
505 |
jsr166 |
1.12 |
* If any comparison returns {@code false}, this method returns |
506 |
|
|
* {@code false}. If either iterator runs out of elements before the |
507 |
|
|
* other it returns {@code false} (as the lists are of unequal length); |
508 |
|
|
* otherwise it returns {@code true} when the iterations complete. |
509 |
dl |
1.1 |
* |
510 |
|
|
* @param o the object to be compared for equality with this list |
511 |
jsr166 |
1.12 |
* @return {@code true} if the specified object is equal to this list |
512 |
dl |
1.1 |
*/ |
513 |
|
|
public boolean equals(Object o) { |
514 |
jsr166 |
1.19 |
if (o == this) |
515 |
|
|
return true; |
516 |
|
|
if (!(o instanceof List)) |
517 |
|
|
return false; |
518 |
|
|
|
519 |
|
|
ListIterator<E> e1 = listIterator(); |
520 |
|
|
ListIterator e2 = ((List) o).listIterator(); |
521 |
|
|
while(e1.hasNext() && e2.hasNext()) { |
522 |
|
|
E o1 = e1.next(); |
523 |
|
|
Object o2 = e2.next(); |
524 |
|
|
if (!(o1==null ? o2==null : o1.equals(o2))) |
525 |
|
|
return false; |
526 |
|
|
} |
527 |
|
|
return !(e1.hasNext() || e2.hasNext()); |
528 |
dl |
1.1 |
} |
529 |
|
|
|
530 |
|
|
/** |
531 |
jsr166 |
1.13 |
* Returns the hash code value for this list. |
532 |
dl |
1.1 |
* |
533 |
jsr166 |
1.13 |
* <p>This implementation uses exactly the code that is used to define the |
534 |
dl |
1.1 |
* list hash function in the documentation for the {@link List#hashCode} |
535 |
|
|
* method. |
536 |
|
|
* |
537 |
|
|
* @return the hash code value for this list |
538 |
|
|
*/ |
539 |
|
|
public int hashCode() { |
540 |
jsr166 |
1.19 |
int hashCode = 1; |
541 |
|
|
for (E e : this) |
542 |
|
|
hashCode = 31*hashCode + (e==null ? 0 : e.hashCode()); |
543 |
|
|
return hashCode; |
544 |
dl |
1.1 |
} |
545 |
|
|
|
546 |
|
|
/** |
547 |
|
|
* Removes from this list all of the elements whose index is between |
548 |
jsr166 |
1.12 |
* {@code fromIndex}, inclusive, and {@code toIndex}, exclusive. |
549 |
dl |
1.1 |
* Shifts any succeeding elements to the left (reduces their index). |
550 |
jsr166 |
1.18 |
* This call shortens the list by {@code (toIndex - fromIndex)} elements. |
551 |
|
|
* (If {@code toIndex==fromIndex}, this operation has no effect.) |
552 |
dl |
1.1 |
* |
553 |
jsr166 |
1.13 |
* <p>This method is called by the {@code clear} operation on this list |
554 |
dl |
1.1 |
* and its subLists. Overriding this method to take advantage of |
555 |
|
|
* the internals of the list implementation can <i>substantially</i> |
556 |
jsr166 |
1.12 |
* improve the performance of the {@code clear} operation on this list |
557 |
jsr166 |
1.13 |
* and its subLists. |
558 |
dl |
1.1 |
* |
559 |
jsr166 |
1.13 |
* <p>This implementation gets a list iterator positioned before |
560 |
jsr166 |
1.12 |
* {@code fromIndex}, and repeatedly calls {@code ListIterator.next} |
561 |
|
|
* followed by {@code ListIterator.remove} until the entire range has |
562 |
|
|
* been removed. <b>Note: if {@code ListIterator.remove} requires linear |
563 |
dl |
1.1 |
* time, this implementation requires quadratic time.</b> |
564 |
|
|
* |
565 |
|
|
* @param fromIndex index of first element to be removed |
566 |
|
|
* @param toIndex index after last element to be removed |
567 |
|
|
*/ |
568 |
|
|
protected void removeRange(int fromIndex, int toIndex) { |
569 |
|
|
ListIterator<E> it = listIterator(fromIndex); |
570 |
|
|
for (int i=0, n=toIndex-fromIndex; i<n; i++) { |
571 |
|
|
it.next(); |
572 |
|
|
it.remove(); |
573 |
|
|
} |
574 |
|
|
} |
575 |
|
|
|
576 |
|
|
/** |
577 |
|
|
* The number of times this list has been <i>structurally modified</i>. |
578 |
|
|
* Structural modifications are those that change the size of the |
579 |
|
|
* list, or otherwise perturb it in such a fashion that iterations in |
580 |
jsr166 |
1.13 |
* progress may yield incorrect results. |
581 |
dl |
1.1 |
* |
582 |
jsr166 |
1.13 |
* <p>This field is used by the iterator and list iterator implementation |
583 |
jsr166 |
1.12 |
* returned by the {@code iterator} and {@code listIterator} methods. |
584 |
dl |
1.1 |
* If the value of this field changes unexpectedly, the iterator (or list |
585 |
jsr166 |
1.12 |
* iterator) will throw a {@code ConcurrentModificationException} in |
586 |
|
|
* response to the {@code next}, {@code remove}, {@code previous}, |
587 |
|
|
* {@code set} or {@code add} operations. This provides |
588 |
dl |
1.1 |
* <i>fail-fast</i> behavior, rather than non-deterministic behavior in |
589 |
jsr166 |
1.13 |
* the face of concurrent modification during iteration. |
590 |
dl |
1.1 |
* |
591 |
jsr166 |
1.13 |
* <p><b>Use of this field by subclasses is optional.</b> If a subclass |
592 |
dl |
1.1 |
* wishes to provide fail-fast iterators (and list iterators), then it |
593 |
jsr166 |
1.14 |
* merely has to increment this field in its {@code add(int, E)} and |
594 |
jsr166 |
1.12 |
* {@code remove(int)} methods (and any other methods that it overrides |
595 |
dl |
1.1 |
* that result in structural modifications to the list). A single call to |
596 |
jsr166 |
1.14 |
* {@code add(int, E)} or {@code remove(int)} must add no more than |
597 |
dl |
1.1 |
* one to this field, or the iterators (and list iterators) will throw |
598 |
jsr166 |
1.12 |
* bogus {@code ConcurrentModificationExceptions}. If an implementation |
599 |
dl |
1.1 |
* does not wish to provide fail-fast iterators, this field may be |
600 |
|
|
* ignored. |
601 |
|
|
*/ |
602 |
|
|
protected transient int modCount = 0; |
603 |
jsr166 |
1.18 |
|
604 |
|
|
private void rangeCheckForAdd(int index) { |
605 |
jsr166 |
1.19 |
if (index < 0 || index > size()) |
606 |
|
|
throw new IndexOutOfBoundsException(outOfBoundsMsg(index)); |
607 |
jsr166 |
1.18 |
} |
608 |
|
|
|
609 |
|
|
private String outOfBoundsMsg(int index) { |
610 |
jsr166 |
1.19 |
return "Index: "+index+", Size: "+size(); |
611 |
jsr166 |
1.18 |
} |
612 |
dl |
1.1 |
} |
613 |
|
|
|
614 |
|
|
class SubList<E> extends AbstractList<E> { |
615 |
jsr166 |
1.18 |
private final AbstractList<E> l; |
616 |
|
|
private final int offset; |
617 |
|
|
private int size; |
618 |
|
|
|
619 |
|
|
SubList(AbstractList<E> list, int fromIndex, int toIndex) { |
620 |
dl |
1.1 |
if (fromIndex < 0) |
621 |
|
|
throw new IndexOutOfBoundsException("fromIndex = " + fromIndex); |
622 |
jsr166 |
1.18 |
if (toIndex > list.size()) |
623 |
dl |
1.1 |
throw new IndexOutOfBoundsException("toIndex = " + toIndex); |
624 |
|
|
if (fromIndex > toIndex) |
625 |
|
|
throw new IllegalArgumentException("fromIndex(" + fromIndex + |
626 |
|
|
") > toIndex(" + toIndex + ")"); |
627 |
jsr166 |
1.18 |
l = list; |
628 |
|
|
offset = fromIndex; |
629 |
|
|
size = toIndex - fromIndex; |
630 |
|
|
this.modCount = l.modCount; |
631 |
dl |
1.1 |
} |
632 |
|
|
|
633 |
|
|
public E set(int index, E element) { |
634 |
jsr166 |
1.18 |
rangeCheck(index); |
635 |
|
|
checkForComodification(); |
636 |
|
|
return l.set(index+offset, element); |
637 |
dl |
1.1 |
} |
638 |
|
|
|
639 |
|
|
public E get(int index) { |
640 |
jsr166 |
1.18 |
rangeCheck(index); |
641 |
|
|
checkForComodification(); |
642 |
|
|
return l.get(index+offset); |
643 |
dl |
1.1 |
} |
644 |
|
|
|
645 |
|
|
public int size() { |
646 |
jsr166 |
1.18 |
checkForComodification(); |
647 |
|
|
return size; |
648 |
dl |
1.1 |
} |
649 |
|
|
|
650 |
|
|
public void add(int index, E element) { |
651 |
jsr166 |
1.19 |
rangeCheckForAdd(index); |
652 |
jsr166 |
1.18 |
checkForComodification(); |
653 |
|
|
l.add(index+offset, element); |
654 |
|
|
this.modCount = l.modCount; |
655 |
|
|
size++; |
656 |
dl |
1.1 |
} |
657 |
|
|
|
658 |
|
|
public E remove(int index) { |
659 |
jsr166 |
1.18 |
rangeCheck(index); |
660 |
|
|
checkForComodification(); |
661 |
|
|
E result = l.remove(index+offset); |
662 |
|
|
this.modCount = l.modCount; |
663 |
|
|
size--; |
664 |
dl |
1.1 |
return result; |
665 |
|
|
} |
666 |
|
|
|
667 |
|
|
protected void removeRange(int fromIndex, int toIndex) { |
668 |
jsr166 |
1.18 |
checkForComodification(); |
669 |
|
|
l.removeRange(fromIndex+offset, toIndex+offset); |
670 |
|
|
this.modCount = l.modCount; |
671 |
|
|
size -= (toIndex-fromIndex); |
672 |
dl |
1.1 |
} |
673 |
|
|
|
674 |
|
|
public boolean addAll(Collection<? extends E> c) { |
675 |
jsr166 |
1.18 |
return addAll(size, c); |
676 |
dl |
1.1 |
} |
677 |
|
|
|
678 |
|
|
public boolean addAll(int index, Collection<? extends E> c) { |
679 |
jsr166 |
1.19 |
rangeCheckForAdd(index); |
680 |
dl |
1.1 |
int cSize = c.size(); |
681 |
|
|
if (cSize==0) |
682 |
|
|
return false; |
683 |
|
|
|
684 |
jsr166 |
1.18 |
checkForComodification(); |
685 |
|
|
l.addAll(offset+index, c); |
686 |
|
|
this.modCount = l.modCount; |
687 |
|
|
size += cSize; |
688 |
dl |
1.1 |
return true; |
689 |
|
|
} |
690 |
|
|
|
691 |
|
|
public Iterator<E> iterator() { |
692 |
jsr166 |
1.18 |
return listIterator(); |
693 |
dl |
1.8 |
} |
694 |
|
|
|
695 |
jsr166 |
1.18 |
public ListIterator<E> listIterator(final int index) { |
696 |
|
|
checkForComodification(); |
697 |
jsr166 |
1.19 |
rangeCheckForAdd(index); |
698 |
dl |
1.1 |
|
699 |
jsr166 |
1.18 |
return new ListIterator<E>() { |
700 |
|
|
private final ListIterator<E> i = l.listIterator(index+offset); |
701 |
dl |
1.1 |
|
702 |
jsr166 |
1.18 |
public boolean hasNext() { |
703 |
|
|
return nextIndex() < size; |
704 |
|
|
} |
705 |
dl |
1.1 |
|
706 |
jsr166 |
1.18 |
public E next() { |
707 |
|
|
if (hasNext()) |
708 |
|
|
return i.next(); |
709 |
|
|
else |
710 |
|
|
throw new NoSuchElementException(); |
711 |
|
|
} |
712 |
dl |
1.1 |
|
713 |
jsr166 |
1.18 |
public boolean hasPrevious() { |
714 |
|
|
return previousIndex() >= 0; |
715 |
|
|
} |
716 |
dl |
1.1 |
|
717 |
jsr166 |
1.18 |
public E previous() { |
718 |
|
|
if (hasPrevious()) |
719 |
|
|
return i.previous(); |
720 |
|
|
else |
721 |
|
|
throw new NoSuchElementException(); |
722 |
|
|
} |
723 |
dl |
1.1 |
|
724 |
jsr166 |
1.18 |
public int nextIndex() { |
725 |
|
|
return i.nextIndex() - offset; |
726 |
|
|
} |
727 |
dl |
1.1 |
|
728 |
jsr166 |
1.18 |
public int previousIndex() { |
729 |
|
|
return i.previousIndex() - offset; |
730 |
dl |
1.1 |
} |
731 |
|
|
|
732 |
jsr166 |
1.18 |
public void remove() { |
733 |
|
|
i.remove(); |
734 |
|
|
SubList.this.modCount = l.modCount; |
735 |
|
|
size--; |
736 |
dl |
1.1 |
} |
737 |
|
|
|
738 |
jsr166 |
1.18 |
public void set(E e) { |
739 |
|
|
i.set(e); |
740 |
dl |
1.1 |
} |
741 |
|
|
|
742 |
jsr166 |
1.18 |
public void add(E e) { |
743 |
|
|
i.add(e); |
744 |
|
|
SubList.this.modCount = l.modCount; |
745 |
|
|
size++; |
746 |
dl |
1.1 |
} |
747 |
jsr166 |
1.18 |
}; |
748 |
|
|
} |
749 |
|
|
|
750 |
|
|
public List<E> subList(int fromIndex, int toIndex) { |
751 |
|
|
return new SubList<E>(this, fromIndex, toIndex); |
752 |
|
|
} |
753 |
|
|
|
754 |
|
|
private void rangeCheck(int index) { |
755 |
|
|
if (index < 0 || index >= size) |
756 |
|
|
throw new IndexOutOfBoundsException(outOfBoundsMsg(index)); |
757 |
|
|
} |
758 |
|
|
|
759 |
|
|
private void rangeCheckForAdd(int index) { |
760 |
jsr166 |
1.19 |
if (index < 0 || index > size) |
761 |
|
|
throw new IndexOutOfBoundsException(outOfBoundsMsg(index)); |
762 |
jsr166 |
1.18 |
} |
763 |
dl |
1.1 |
|
764 |
jsr166 |
1.18 |
private String outOfBoundsMsg(int index) { |
765 |
jsr166 |
1.19 |
return "Index: "+index+", Size: "+size; |
766 |
dl |
1.1 |
} |
767 |
|
|
|
768 |
jsr166 |
1.18 |
private void checkForComodification() { |
769 |
|
|
if (this.modCount != l.modCount) |
770 |
|
|
throw new ConcurrentModificationException(); |
771 |
|
|
} |
772 |
dl |
1.1 |
} |
773 |
|
|
|
774 |
|
|
class RandomAccessSubList<E> extends SubList<E> implements RandomAccess { |
775 |
jsr166 |
1.18 |
RandomAccessSubList(AbstractList<E> list, int fromIndex, int toIndex) { |
776 |
|
|
super(list, fromIndex, toIndex); |
777 |
dl |
1.1 |
} |
778 |
|
|
|
779 |
|
|
public List<E> subList(int fromIndex, int toIndex) { |
780 |
jsr166 |
1.18 |
return new RandomAccessSubList<E>(this, fromIndex, toIndex); |
781 |
dl |
1.1 |
} |
782 |
|
|
} |