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/* |
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* Copyright 1997-2007 Sun Microsystems, Inc. All Rights Reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* 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 |
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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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*/ |
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|
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package java.util; |
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|
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/** |
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* This class provides a skeletal implementation of the {@link List} |
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* 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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* access data (such as a linked list), {@link AbstractSequentialList} should |
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* be used in preference to this class. |
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* |
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* <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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* |
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* <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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* |
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* <p>The programmer should generally provide a void (no argument) and collection |
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* constructor, as per the recommendation in the {@link Collection} interface |
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* specification. |
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* |
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* <p>Unlike the other abstract collection implementations, the programmer does |
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* <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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* 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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* |
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* <p>The documentation for each non-abstract method in this class describes its |
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* implementation in detail. Each of these methods may be overridden if the |
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* collection being implemented admits a more efficient implementation. |
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* |
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* <p>This class is a member of the |
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* <a href="{@docRoot}/../technotes/guides/collections/index.html"> |
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* 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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|
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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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/** |
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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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* <p>This implementation calls {@code add(size(), e)}. |
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* |
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* <p>Note that this implementation throws an |
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* {@code UnsupportedOperationException} unless |
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* {@link #add(int, Object) add(int, E)} is overridden. |
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* |
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* @param e element to be appended to this list |
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* @return {@code true} (as specified by {@link Collection#add}) |
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* @throws UnsupportedOperationException if the {@code add} operation |
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* is not supported by this list |
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* @throws ClassCastException if the class of the specified element |
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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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*/ |
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public boolean add(E e) { |
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add(size(), e); |
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return true; |
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} |
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|
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/** |
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* {@inheritDoc} |
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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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/** |
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* {@inheritDoc} |
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* |
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* <p>This implementation always throws an |
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* {@code UnsupportedOperationException}. |
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* |
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* @throws UnsupportedOperationException {@inheritDoc} |
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* @throws ClassCastException {@inheritDoc} |
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* @throws NullPointerException {@inheritDoc} |
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* @throws IllegalArgumentException {@inheritDoc} |
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* @throws IndexOutOfBoundsException {@inheritDoc} |
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*/ |
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public E set(int index, E element) { |
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throw new UnsupportedOperationException(); |
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} |
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|
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/** |
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* {@inheritDoc} |
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* |
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* <p>This implementation always throws an |
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* {@code UnsupportedOperationException}. |
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* |
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* @throws UnsupportedOperationException {@inheritDoc} |
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* @throws ClassCastException {@inheritDoc} |
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* @throws NullPointerException {@inheritDoc} |
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* @throws IllegalArgumentException {@inheritDoc} |
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* @throws IndexOutOfBoundsException {@inheritDoc} |
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*/ |
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public void add(int index, E element) { |
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throw new UnsupportedOperationException(); |
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} |
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|
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/** |
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* {@inheritDoc} |
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* |
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* <p>This implementation always throws an |
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* {@code UnsupportedOperationException}. |
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* |
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* @throws UnsupportedOperationException {@inheritDoc} |
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* @throws IndexOutOfBoundsException {@inheritDoc} |
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*/ |
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public E remove(int index) { |
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throw new UnsupportedOperationException(); |
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} |
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|
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|
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// Search Operations |
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|
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/** |
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* {@inheritDoc} |
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* |
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* <p>This implementation first gets a list iterator (with |
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* {@code listIterator()}). Then, it iterates over the list until the |
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* specified element is found or the end of the list is reached. |
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* |
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* @throws ClassCastException {@inheritDoc} |
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* @throws NullPointerException {@inheritDoc} |
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*/ |
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public int indexOf(Object o) { |
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ListIterator<E> e = listIterator(); |
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if (o==null) { |
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while (e.hasNext()) |
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if (e.next()==null) |
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return e.previousIndex(); |
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} else { |
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while (e.hasNext()) |
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if (o.equals(e.next())) |
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return e.previousIndex(); |
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} |
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return -1; |
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} |
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|
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/** |
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* {@inheritDoc} |
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* |
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* <p>This implementation first gets a list iterator that points to the end |
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* of the list (with {@code listIterator(size())}). Then, it iterates |
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* backwards over the list until the specified element is found, or the |
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* beginning of the list is reached. |
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* |
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* @throws ClassCastException {@inheritDoc} |
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* @throws NullPointerException {@inheritDoc} |
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*/ |
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public int lastIndexOf(Object o) { |
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ListIterator<E> e = listIterator(size()); |
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if (o==null) { |
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while (e.hasPrevious()) |
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if (e.previous()==null) |
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return e.nextIndex(); |
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} else { |
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while (e.hasPrevious()) |
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if (o.equals(e.previous())) |
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return e.nextIndex(); |
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} |
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return -1; |
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} |
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|
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|
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// Bulk Operations |
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|
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/** |
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* Removes all of the elements from this list (optional operation). |
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* The list will be empty after this call returns. |
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* |
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* <p>This implementation calls {@code removeRange(0, size())}. |
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* |
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* <p>Note that this implementation throws an |
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* {@code UnsupportedOperationException} unless {@code remove(int |
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* index)} or {@code removeRange(int fromIndex, int toIndex)} is |
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* overridden. |
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* |
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* @throws UnsupportedOperationException if the {@code clear} operation |
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* is not supported by this list |
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*/ |
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public void clear() { |
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removeRange(0, size()); |
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} |
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|
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/** |
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* {@inheritDoc} |
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* |
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* <p>This implementation gets an iterator over the specified collection |
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* and iterates over it, inserting the elements obtained from the |
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* iterator into this list at the appropriate position, one at a time, |
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* using {@code add(int, E)}. |
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* Many implementations will override this method for efficiency. |
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* |
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* <p>Note that this implementation throws an |
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* {@code UnsupportedOperationException} unless |
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* {@link #add(int, Object) add(int, E)} is overridden. |
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* |
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* @throws UnsupportedOperationException {@inheritDoc} |
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* @throws ClassCastException {@inheritDoc} |
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* @throws NullPointerException {@inheritDoc} |
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* @throws IllegalArgumentException {@inheritDoc} |
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* @throws IndexOutOfBoundsException {@inheritDoc} |
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*/ |
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public boolean addAll(int index, Collection<? extends E> c) { |
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rangeCheckForAdd(index); |
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boolean modified = false; |
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for (E e : c) { |
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add(index++, e); |
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modified = true; |
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} |
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return modified; |
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} |
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|
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|
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// Iterators |
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|
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/** |
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* Returns an iterator over the elements in this list in proper sequence. |
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* |
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* <p>This implementation returns a straightforward implementation of the |
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* iterator interface, relying on the backing list's {@code size()}, |
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* {@code get(int)}, and {@code remove(int)} methods. |
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* |
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* <p>Note that the iterator returned by this method will throw an |
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* {@link UnsupportedOperationException} in response to its |
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* {@code remove} method unless the list's {@code remove(int)} method is |
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* overridden. |
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* |
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* <p>This implementation can be made to throw runtime exceptions in the |
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* face of concurrent modification, as described in the specification |
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* for the (protected) {@link #modCount} field. |
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* |
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* @return an iterator over the elements in this list in proper sequence |
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*/ |
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public Iterator<E> iterator() { |
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return new Itr(); |
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} |
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|
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/** |
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* {@inheritDoc} |
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* |
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* <p>This implementation returns {@code listIterator(0)}. |
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* |
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* @see #listIterator(int) |
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*/ |
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public ListIterator<E> listIterator() { |
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return listIterator(0); |
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} |
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|
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/** |
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* {@inheritDoc} |
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* |
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* <p>This implementation returns a straightforward implementation of the |
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* {@code ListIterator} interface that extends the implementation of the |
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* {@code Iterator} interface returned by the {@code iterator()} method. |
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* The {@code ListIterator} implementation relies on the backing list's |
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* {@code get(int)}, {@code set(int, E)}, {@code add(int, E)} |
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* and {@code remove(int)} methods. |
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* |
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* <p>Note that the list iterator returned by this implementation will |
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* throw an {@link UnsupportedOperationException} in response to its |
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* {@code remove}, {@code set} and {@code add} methods unless the |
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* list's {@code remove(int)}, {@code set(int, E)}, and |
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* {@code add(int, E)} methods are overridden. |
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* |
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* <p>This implementation can be made to throw runtime exceptions in the |
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* face of concurrent modification, as described in the specification for |
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* the (protected) {@link #modCount} field. |
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* |
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* @throws IndexOutOfBoundsException {@inheritDoc} |
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*/ |
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public ListIterator<E> listIterator(final int index) { |
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rangeCheckForAdd(index); |
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|
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return new ListItr(index); |
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} |
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|
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private class Itr implements Iterator<E> { |
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/** |
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* Index of element to be returned by subsequent call to next. |
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*/ |
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int cursor = 0; |
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|
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/** |
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* Index of element returned by most recent call to next or |
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* previous. Reset to -1 if this element is deleted by a call |
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* to remove. |
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*/ |
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int lastRet = -1; |
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|
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/** |
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* The modCount value that the iterator believes that the backing |
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* List should have. If this expectation is violated, the iterator |
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* has detected concurrent modification. |
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*/ |
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int expectedModCount = modCount; |
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|
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public boolean hasNext() { |
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return cursor != size(); |
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} |
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|
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public E next() { |
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checkForComodification(); |
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try { |
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int i = cursor; |
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E next = get(i); |
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lastRet = i; |
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cursor = i + 1; |
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return next; |
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} catch (IndexOutOfBoundsException e) { |
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checkForComodification(); |
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throw new NoSuchElementException(); |
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} |
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} |
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|
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public void remove() { |
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if (lastRet < 0) |
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throw new IllegalStateException(); |
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checkForComodification(); |
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|
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try { |
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AbstractList.this.remove(lastRet); |
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if (lastRet < cursor) |
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cursor--; |
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lastRet = -1; |
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expectedModCount = modCount; |
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} catch (IndexOutOfBoundsException e) { |
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throw new ConcurrentModificationException(); |
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} |
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} |
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|
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final void checkForComodification() { |
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if (modCount != expectedModCount) |
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throw new ConcurrentModificationException(); |
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} |
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} |
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|
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private class ListItr extends Itr implements ListIterator<E> { |
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ListItr(int index) { |
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cursor = index; |
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} |
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|
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public boolean hasPrevious() { |
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return cursor != 0; |
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} |
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|
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public E previous() { |
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checkForComodification(); |
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try { |
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int i = cursor - 1; |
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E previous = get(i); |
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lastRet = cursor = i; |
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return previous; |
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} catch (IndexOutOfBoundsException e) { |
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checkForComodification(); |
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throw new NoSuchElementException(); |
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} |
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} |
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|
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public int nextIndex() { |
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return cursor; |
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} |
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|
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public int previousIndex() { |
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return cursor-1; |
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} |
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|
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public void set(E e) { |
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if (lastRet < 0) |
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throw new IllegalStateException(); |
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checkForComodification(); |
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|
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try { |
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AbstractList.this.set(lastRet, e); |
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expectedModCount = modCount; |
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} catch (IndexOutOfBoundsException ex) { |
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throw new ConcurrentModificationException(); |
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} |
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} |
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|
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public void add(E e) { |
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checkForComodification(); |
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|
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try { |
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int i = cursor; |
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AbstractList.this.add(i, e); |
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lastRet = -1; |
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cursor = i + 1; |
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expectedModCount = modCount; |
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} catch (IndexOutOfBoundsException ex) { |
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throw new ConcurrentModificationException(); |
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} |
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} |
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} |
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|
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/** |
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* {@inheritDoc} |
450 |
* |
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* <p>This implementation returns a list that subclasses |
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* {@code AbstractList}. The subclass stores, in private fields, the |
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* offset of the subList within the backing list, the size of the subList |
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* (which can change over its lifetime), and the expected |
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* {@code modCount} value of the backing list. There are two variants |
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* of the subclass, one of which implements {@code RandomAccess}. |
457 |
* If this list implements {@code RandomAccess} the returned list will |
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* be an instance of the subclass that implements {@code RandomAccess}. |
459 |
* |
460 |
* <p>The subclass's {@code set(int, E)}, {@code get(int)}, |
461 |
* {@code add(int, E)}, {@code remove(int)}, {@code addAll(int, |
462 |
* Collection)} and {@code removeRange(int, int)} methods all |
463 |
* delegate to the corresponding methods on the backing abstract list, |
464 |
* after bounds-checking the index and adjusting for the offset. The |
465 |
* {@code addAll(Collection c)} method merely returns {@code addAll(size, |
466 |
* c)}. |
467 |
* |
468 |
* <p>The {@code listIterator(int)} method returns a "wrapper object" |
469 |
* over a list iterator on the backing list, which is created with the |
470 |
* corresponding method on the backing list. The {@code iterator} method |
471 |
* merely returns {@code listIterator()}, and the {@code size} method |
472 |
* merely returns the subclass's {@code size} field. |
473 |
* |
474 |
* <p>All methods first check to see if the actual {@code modCount} of |
475 |
* the backing list is equal to its expected value, and throw a |
476 |
* {@code ConcurrentModificationException} if it is not. |
477 |
* |
478 |
* @throws IndexOutOfBoundsException if an endpoint index value is out of range |
479 |
* {@code (fromIndex < 0 || toIndex > size)} |
480 |
* @throws IllegalArgumentException if the endpoint indices are out of order |
481 |
* {@code (fromIndex > toIndex)} |
482 |
*/ |
483 |
public List<E> subList(int fromIndex, int toIndex) { |
484 |
return (this instanceof RandomAccess ? |
485 |
new RandomAccessSubList<E>(this, fromIndex, toIndex) : |
486 |
new SubList<E>(this, fromIndex, toIndex)); |
487 |
} |
488 |
|
489 |
// Comparison and hashing |
490 |
|
491 |
/** |
492 |
* Compares the specified object with this list for equality. Returns |
493 |
* {@code true} if and only if the specified object is also a list, both |
494 |
* lists have the same size, and all corresponding pairs of elements in |
495 |
* the two lists are <i>equal</i>. (Two elements {@code e1} and |
496 |
* {@code e2} are <i>equal</i> if {@code (e1==null ? e2==null : |
497 |
* e1.equals(e2))}.) In other words, two lists are defined to be |
498 |
* equal if they contain the same elements in the same order.<p> |
499 |
* |
500 |
* This implementation first checks if the specified object is this |
501 |
* list. If so, it returns {@code true}; if not, it checks if the |
502 |
* specified object is a list. If not, it returns {@code false}; if so, |
503 |
* it iterates over both lists, comparing corresponding pairs of elements. |
504 |
* If any comparison returns {@code false}, this method returns |
505 |
* {@code false}. If either iterator runs out of elements before the |
506 |
* other it returns {@code false} (as the lists are of unequal length); |
507 |
* otherwise it returns {@code true} when the iterations complete. |
508 |
* |
509 |
* @param o the object to be compared for equality with this list |
510 |
* @return {@code true} if the specified object is equal to this list |
511 |
*/ |
512 |
public boolean equals(Object o) { |
513 |
if (o == this) |
514 |
return true; |
515 |
if (!(o instanceof List)) |
516 |
return false; |
517 |
|
518 |
ListIterator<E> e1 = listIterator(); |
519 |
ListIterator e2 = ((List) o).listIterator(); |
520 |
while(e1.hasNext() && e2.hasNext()) { |
521 |
E o1 = e1.next(); |
522 |
Object o2 = e2.next(); |
523 |
if (!(o1==null ? o2==null : o1.equals(o2))) |
524 |
return false; |
525 |
} |
526 |
return !(e1.hasNext() || e2.hasNext()); |
527 |
} |
528 |
|
529 |
/** |
530 |
* Returns the hash code value for this list. |
531 |
* |
532 |
* <p>This implementation uses exactly the code that is used to define the |
533 |
* list hash function in the documentation for the {@link List#hashCode} |
534 |
* method. |
535 |
* |
536 |
* @return the hash code value for this list |
537 |
*/ |
538 |
public int hashCode() { |
539 |
int hashCode = 1; |
540 |
for (E e : this) |
541 |
hashCode = 31*hashCode + (e==null ? 0 : e.hashCode()); |
542 |
return hashCode; |
543 |
} |
544 |
|
545 |
/** |
546 |
* Removes from this list all of the elements whose index is between |
547 |
* {@code fromIndex}, inclusive, and {@code toIndex}, exclusive. |
548 |
* Shifts any succeeding elements to the left (reduces their index). |
549 |
* This call shortens the list by {@code (toIndex - fromIndex)} elements. |
550 |
* (If {@code toIndex==fromIndex}, this operation has no effect.) |
551 |
* |
552 |
* <p>This method is called by the {@code clear} operation on this list |
553 |
* and its subLists. Overriding this method to take advantage of |
554 |
* the internals of the list implementation can <i>substantially</i> |
555 |
* improve the performance of the {@code clear} operation on this list |
556 |
* and its subLists. |
557 |
* |
558 |
* <p>This implementation gets a list iterator positioned before |
559 |
* {@code fromIndex}, and repeatedly calls {@code ListIterator.next} |
560 |
* followed by {@code ListIterator.remove} until the entire range has |
561 |
* been removed. <b>Note: if {@code ListIterator.remove} requires linear |
562 |
* time, this implementation requires quadratic time.</b> |
563 |
* |
564 |
* @param fromIndex index of first element to be removed |
565 |
* @param toIndex index after last element to be removed |
566 |
*/ |
567 |
protected void removeRange(int fromIndex, int toIndex) { |
568 |
ListIterator<E> it = listIterator(fromIndex); |
569 |
for (int i=0, n=toIndex-fromIndex; i<n; i++) { |
570 |
it.next(); |
571 |
it.remove(); |
572 |
} |
573 |
} |
574 |
|
575 |
/** |
576 |
* The number of times this list has been <i>structurally modified</i>. |
577 |
* Structural modifications are those that change the size of the |
578 |
* list, or otherwise perturb it in such a fashion that iterations in |
579 |
* progress may yield incorrect results. |
580 |
* |
581 |
* <p>This field is used by the iterator and list iterator implementation |
582 |
* returned by the {@code iterator} and {@code listIterator} methods. |
583 |
* If the value of this field changes unexpectedly, the iterator (or list |
584 |
* iterator) will throw a {@code ConcurrentModificationException} in |
585 |
* response to the {@code next}, {@code remove}, {@code previous}, |
586 |
* {@code set} or {@code add} operations. This provides |
587 |
* <i>fail-fast</i> behavior, rather than non-deterministic behavior in |
588 |
* the face of concurrent modification during iteration. |
589 |
* |
590 |
* <p><b>Use of this field by subclasses is optional.</b> If a subclass |
591 |
* wishes to provide fail-fast iterators (and list iterators), then it |
592 |
* merely has to increment this field in its {@code add(int, E)} and |
593 |
* {@code remove(int)} methods (and any other methods that it overrides |
594 |
* that result in structural modifications to the list). A single call to |
595 |
* {@code add(int, E)} or {@code remove(int)} must add no more than |
596 |
* one to this field, or the iterators (and list iterators) will throw |
597 |
* bogus {@code ConcurrentModificationExceptions}. If an implementation |
598 |
* does not wish to provide fail-fast iterators, this field may be |
599 |
* ignored. |
600 |
*/ |
601 |
protected transient int modCount = 0; |
602 |
|
603 |
private void rangeCheckForAdd(int index) { |
604 |
if (index < 0 || index > size()) |
605 |
throw new IndexOutOfBoundsException(outOfBoundsMsg(index)); |
606 |
} |
607 |
|
608 |
private String outOfBoundsMsg(int index) { |
609 |
return "Index: "+index+", Size: "+size(); |
610 |
} |
611 |
} |
612 |
|
613 |
class SubList<E> extends AbstractList<E> { |
614 |
private final AbstractList<E> l; |
615 |
private final int offset; |
616 |
private int size; |
617 |
|
618 |
SubList(AbstractList<E> list, int fromIndex, int toIndex) { |
619 |
if (fromIndex < 0) |
620 |
throw new IndexOutOfBoundsException("fromIndex = " + fromIndex); |
621 |
if (toIndex > list.size()) |
622 |
throw new IndexOutOfBoundsException("toIndex = " + toIndex); |
623 |
if (fromIndex > toIndex) |
624 |
throw new IllegalArgumentException("fromIndex(" + fromIndex + |
625 |
") > toIndex(" + toIndex + ")"); |
626 |
l = list; |
627 |
offset = fromIndex; |
628 |
size = toIndex - fromIndex; |
629 |
this.modCount = l.modCount; |
630 |
} |
631 |
|
632 |
public E set(int index, E element) { |
633 |
rangeCheck(index); |
634 |
checkForComodification(); |
635 |
return l.set(index+offset, element); |
636 |
} |
637 |
|
638 |
public E get(int index) { |
639 |
rangeCheck(index); |
640 |
checkForComodification(); |
641 |
return l.get(index+offset); |
642 |
} |
643 |
|
644 |
public int size() { |
645 |
checkForComodification(); |
646 |
return size; |
647 |
} |
648 |
|
649 |
public void add(int index, E element) { |
650 |
rangeCheckForAdd(index); |
651 |
checkForComodification(); |
652 |
l.add(index+offset, element); |
653 |
this.modCount = l.modCount; |
654 |
size++; |
655 |
} |
656 |
|
657 |
public E remove(int index) { |
658 |
rangeCheck(index); |
659 |
checkForComodification(); |
660 |
E result = l.remove(index+offset); |
661 |
this.modCount = l.modCount; |
662 |
size--; |
663 |
return result; |
664 |
} |
665 |
|
666 |
protected void removeRange(int fromIndex, int toIndex) { |
667 |
checkForComodification(); |
668 |
l.removeRange(fromIndex+offset, toIndex+offset); |
669 |
this.modCount = l.modCount; |
670 |
size -= (toIndex-fromIndex); |
671 |
} |
672 |
|
673 |
public boolean addAll(Collection<? extends E> c) { |
674 |
return addAll(size, c); |
675 |
} |
676 |
|
677 |
public boolean addAll(int index, Collection<? extends E> c) { |
678 |
rangeCheckForAdd(index); |
679 |
int cSize = c.size(); |
680 |
if (cSize==0) |
681 |
return false; |
682 |
|
683 |
checkForComodification(); |
684 |
l.addAll(offset+index, c); |
685 |
this.modCount = l.modCount; |
686 |
size += cSize; |
687 |
return true; |
688 |
} |
689 |
|
690 |
public Iterator<E> iterator() { |
691 |
return listIterator(); |
692 |
} |
693 |
|
694 |
public ListIterator<E> listIterator(final int index) { |
695 |
checkForComodification(); |
696 |
rangeCheckForAdd(index); |
697 |
|
698 |
return new ListIterator<E>() { |
699 |
private final ListIterator<E> i = l.listIterator(index+offset); |
700 |
|
701 |
public boolean hasNext() { |
702 |
return nextIndex() < size; |
703 |
} |
704 |
|
705 |
public E next() { |
706 |
if (hasNext()) |
707 |
return i.next(); |
708 |
else |
709 |
throw new NoSuchElementException(); |
710 |
} |
711 |
|
712 |
public boolean hasPrevious() { |
713 |
return previousIndex() >= 0; |
714 |
} |
715 |
|
716 |
public E previous() { |
717 |
if (hasPrevious()) |
718 |
return i.previous(); |
719 |
else |
720 |
throw new NoSuchElementException(); |
721 |
} |
722 |
|
723 |
public int nextIndex() { |
724 |
return i.nextIndex() - offset; |
725 |
} |
726 |
|
727 |
public int previousIndex() { |
728 |
return i.previousIndex() - offset; |
729 |
} |
730 |
|
731 |
public void remove() { |
732 |
i.remove(); |
733 |
SubList.this.modCount = l.modCount; |
734 |
size--; |
735 |
} |
736 |
|
737 |
public void set(E e) { |
738 |
i.set(e); |
739 |
} |
740 |
|
741 |
public void add(E e) { |
742 |
i.add(e); |
743 |
SubList.this.modCount = l.modCount; |
744 |
size++; |
745 |
} |
746 |
}; |
747 |
} |
748 |
|
749 |
public List<E> subList(int fromIndex, int toIndex) { |
750 |
return new SubList<E>(this, fromIndex, toIndex); |
751 |
} |
752 |
|
753 |
private void rangeCheck(int index) { |
754 |
if (index < 0 || index >= size) |
755 |
throw new IndexOutOfBoundsException(outOfBoundsMsg(index)); |
756 |
} |
757 |
|
758 |
private void rangeCheckForAdd(int index) { |
759 |
if (index < 0 || index > size) |
760 |
throw new IndexOutOfBoundsException(outOfBoundsMsg(index)); |
761 |
} |
762 |
|
763 |
private String outOfBoundsMsg(int index) { |
764 |
return "Index: "+index+", Size: "+size; |
765 |
} |
766 |
|
767 |
private void checkForComodification() { |
768 |
if (this.modCount != l.modCount) |
769 |
throw new ConcurrentModificationException(); |
770 |
} |
771 |
} |
772 |
|
773 |
class RandomAccessSubList<E> extends SubList<E> implements RandomAccess { |
774 |
RandomAccessSubList(AbstractList<E> list, int fromIndex, int toIndex) { |
775 |
super(list, fromIndex, toIndex); |
776 |
} |
777 |
|
778 |
public List<E> subList(int fromIndex, int toIndex) { |
779 |
return new RandomAccessSubList<E>(this, fromIndex, toIndex); |
780 |
} |
781 |
} |