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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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* Resizable-array implementation of the <tt>List</tt> interface. Implements |
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* all optional list operations, and permits all elements, including |
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* <tt>null</tt>. In addition to implementing the <tt>List</tt> interface, |
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* this class provides methods to manipulate the size of the array that is |
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* used internally to store the list. (This class is roughly equivalent to |
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* <tt>Vector</tt>, except that it is unsynchronized.) |
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* |
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* <p>The <tt>size</tt>, <tt>isEmpty</tt>, <tt>get</tt>, <tt>set</tt>, |
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* <tt>iterator</tt>, and <tt>listIterator</tt> operations run in constant |
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* time. The <tt>add</tt> operation runs in <i>amortized constant time</i>, |
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* that is, adding n elements requires O(n) time. All of the other operations |
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* run in linear time (roughly speaking). The constant factor is low compared |
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* to that for the <tt>LinkedList</tt> implementation. |
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* |
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* <p>Each <tt>ArrayList</tt> instance has a <i>capacity</i>. The capacity is |
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* the size of the array used to store the elements in the list. It is always |
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* at least as large as the list size. As elements are added to an ArrayList, |
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* its capacity grows automatically. The details of the growth policy are not |
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* specified beyond the fact that adding an element has constant amortized |
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* time cost. |
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* |
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* <p>An application can increase the capacity of an <tt>ArrayList</tt> instance |
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* before adding a large number of elements using the <tt>ensureCapacity</tt> |
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* operation. This may reduce the amount of incremental reallocation. |
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* |
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* <p><strong>Note that this implementation is not synchronized.</strong> |
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* If multiple threads access an <tt>ArrayList</tt> instance concurrently, |
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* and at least one of the threads modifies the list structurally, it |
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* <i>must</i> be synchronized externally. (A structural modification is |
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* any operation that adds or deletes one or more elements, or explicitly |
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* resizes the backing array; merely setting the value of an element is not |
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* a structural modification.) This is typically accomplished by |
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* synchronizing on some object that naturally encapsulates the list. |
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* |
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* If no such object exists, the list should be "wrapped" using the |
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* {@link Collections#synchronizedList Collections.synchronizedList} |
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* method. This is best done at creation time, to prevent accidental |
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* unsynchronized access to the list:<pre> |
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* List list = Collections.synchronizedList(new ArrayList(...));</pre> |
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* |
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* <p><a name="fail-fast"/> |
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* The iterators returned by this class's {@link #iterator() iterator} and |
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* {@link #listIterator(int) listIterator} methods are <em>fail-fast</em>: |
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* if the list is structurally modified at any time after the iterator is |
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* created, in any way except through the iterator's own |
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* {@link ListIterator#remove() remove} or |
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* {@link ListIterator#add(Object) add} methods, the iterator will throw a |
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* {@link ConcurrentModificationException}. Thus, in the face of |
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* concurrent modification, the iterator fails quickly and cleanly, rather |
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* than risking arbitrary, non-deterministic behavior at an undetermined |
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* time in the future. |
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* |
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* <p>Note that the fail-fast behavior of an iterator cannot be guaranteed |
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* as it is, generally speaking, impossible to make any hard guarantees in the |
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* presence of unsynchronized concurrent modification. Fail-fast iterators |
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* throw {@code ConcurrentModificationException} on a best-effort basis. |
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* Therefore, it would be wrong to write a program that depended on this |
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* exception for its correctness: <i>the fail-fast behavior of iterators |
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* should be used only to detect bugs.</i> |
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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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* @see Collection |
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* @see List |
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* @see LinkedList |
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* @see Vector |
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* @since 1.2 |
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*/ |
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|
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public class ArrayList<E> extends AbstractList<E> |
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implements List<E>, RandomAccess, Cloneable, java.io.Serializable |
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{ |
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private static final long serialVersionUID = 8683452581122892189L; |
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|
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/** |
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* The array buffer into which the elements of the ArrayList are stored. |
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* The capacity of the ArrayList is the length of this array buffer. |
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*/ |
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private transient Object[] elementData; |
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|
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/** |
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* The size of the ArrayList (the number of elements it contains). |
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* |
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* @serial |
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*/ |
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private int size; |
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|
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/** |
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* Constructs an empty list with the specified initial capacity. |
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* |
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* @param initialCapacity the initial capacity of the list |
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* @exception IllegalArgumentException if the specified initial capacity |
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* is negative |
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*/ |
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public ArrayList(int initialCapacity) { |
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super(); |
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if (initialCapacity < 0) |
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throw new IllegalArgumentException("Illegal Capacity: "+ |
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initialCapacity); |
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this.elementData = new Object[initialCapacity]; |
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} |
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|
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/** |
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* Constructs an empty list with an initial capacity of ten. |
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*/ |
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public ArrayList() { |
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this(10); |
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} |
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|
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/** |
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* Constructs a list containing the elements of the specified |
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* collection, in the order they are returned by the collection's |
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* iterator. |
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* |
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* @param c the collection whose elements are to be placed into this list |
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* @throws NullPointerException if the specified collection is null |
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*/ |
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public ArrayList(Collection<? extends E> c) { |
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elementData = c.toArray(); |
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size = elementData.length; |
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// c.toArray might (incorrectly) not return Object[] (see 6260652) |
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if (elementData.getClass() != Object[].class) |
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elementData = Arrays.copyOf(elementData, size, Object[].class); |
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} |
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|
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/** |
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* Trims the capacity of this <tt>ArrayList</tt> instance to be the |
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* list's current size. An application can use this operation to minimize |
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* the storage of an <tt>ArrayList</tt> instance. |
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*/ |
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public void trimToSize() { |
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modCount++; |
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int oldCapacity = elementData.length; |
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if (size < oldCapacity) { |
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elementData = Arrays.copyOf(elementData, size); |
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} |
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} |
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|
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/** |
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* Increases the capacity of this <tt>ArrayList</tt> instance, if |
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* necessary, to ensure that it can hold at least the number of elements |
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* specified by the minimum capacity argument. |
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* |
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* @param minCapacity the desired minimum capacity |
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*/ |
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public void ensureCapacity(int minCapacity) { |
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modCount++; |
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int oldCapacity = elementData.length; |
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if (minCapacity > oldCapacity) { |
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Object oldData[] = elementData; |
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int newCapacity = (oldCapacity * 3)/2 + 1; |
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if (newCapacity < minCapacity) |
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newCapacity = minCapacity; |
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// minCapacity is usually close to size, so this is a win: |
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elementData = Arrays.copyOf(elementData, newCapacity); |
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} |
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} |
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|
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/** |
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* Returns the number of elements in this list. |
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* |
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* @return the number of elements in this list |
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*/ |
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public int size() { |
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return size; |
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} |
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|
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/** |
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* Returns <tt>true</tt> if this list contains no elements. |
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* |
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* @return <tt>true</tt> if this list contains no elements |
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*/ |
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public boolean isEmpty() { |
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return size == 0; |
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} |
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|
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/** |
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* Returns <tt>true</tt> if this list contains the specified element. |
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* More formally, returns <tt>true</tt> if and only if this list contains |
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* at least one element <tt>e</tt> such that |
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* <tt>(o==null ? e==null : o.equals(e))</tt>. |
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* |
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* @param o element whose presence in this list is to be tested |
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* @return <tt>true</tt> if this list contains the specified element |
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*/ |
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public boolean contains(Object o) { |
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return indexOf(o) >= 0; |
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} |
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|
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/** |
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* Returns the index of the first occurrence of the specified element |
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* in this list, or -1 if this list does not contain the element. |
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* More formally, returns the lowest index <tt>i</tt> such that |
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* <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>, |
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* or -1 if there is no such index. |
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*/ |
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public int indexOf(Object o) { |
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if (o == null) { |
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for (int i = 0; i < size; i++) |
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if (elementData[i]==null) |
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return i; |
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} else { |
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for (int i = 0; i < size; i++) |
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if (o.equals(elementData[i])) |
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return i; |
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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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* Returns the index of the last occurrence of the specified element |
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* in this list, or -1 if this list does not contain the element. |
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* More formally, returns the highest index <tt>i</tt> such that |
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* <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>, |
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* or -1 if there is no such index. |
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*/ |
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public int lastIndexOf(Object o) { |
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if (o == null) { |
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for (int i = size-1; i >= 0; i--) |
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if (elementData[i]==null) |
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return i; |
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} else { |
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for (int i = size-1; i >= 0; i--) |
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if (o.equals(elementData[i])) |
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return i; |
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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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* Returns a shallow copy of this <tt>ArrayList</tt> instance. (The |
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* elements themselves are not copied.) |
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* |
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* @return a clone of this <tt>ArrayList</tt> instance |
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*/ |
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public Object clone() { |
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try { |
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@SuppressWarnings("unchecked") |
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ArrayList<E> v = (ArrayList<E>) super.clone(); |
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v.elementData = Arrays.copyOf(elementData, size); |
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v.modCount = 0; |
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return v; |
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} catch (CloneNotSupportedException e) { |
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// this shouldn't happen, since we are Cloneable |
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throw new InternalError(); |
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} |
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} |
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|
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/** |
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* Returns an array containing all of the elements in this list |
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* in proper sequence (from first to last element). |
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* |
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* <p>The returned array will be "safe" in that no references to it are |
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* maintained by this list. (In other words, this method must allocate |
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* a new array). The caller is thus free to modify the returned array. |
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* |
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* <p>This method acts as bridge between array-based and collection-based |
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* APIs. |
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* |
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* @return an array containing all of the elements in this list in |
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* proper sequence |
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*/ |
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public Object[] toArray() { |
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return Arrays.copyOf(elementData, size); |
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} |
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|
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/** |
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* Returns an array containing all of the elements in this list in proper |
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* sequence (from first to last element); the runtime type of the returned |
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* array is that of the specified array. If the list fits in the |
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* specified array, it is returned therein. Otherwise, a new array is |
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* allocated with the runtime type of the specified array and the size of |
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* this list. |
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* |
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* <p>If the list fits in the specified array with room to spare |
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* (i.e., the array has more elements than the list), the element in |
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* the array immediately following the end of the collection is set to |
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* <tt>null</tt>. (This is useful in determining the length of the |
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* list <i>only</i> if the caller knows that the list does not contain |
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* any null elements.) |
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* |
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* @param a the array into which the elements of the list are to |
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* be stored, if it is big enough; otherwise, a new array of the |
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* same runtime type is allocated for this purpose. |
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* @return an array containing the elements of the list |
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* @throws ArrayStoreException if the runtime type of the specified array |
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* is not a supertype of the runtime type of every element in |
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* this list |
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* @throws NullPointerException if the specified array is null |
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*/ |
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@SuppressWarnings("unchecked") |
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public <T> T[] toArray(T[] a) { |
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if (a.length < size) |
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// Make a new array of a's runtime type, but my contents: |
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return (T[]) Arrays.copyOf(elementData, size, a.getClass()); |
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System.arraycopy(elementData, 0, a, 0, size); |
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if (a.length > size) |
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a[size] = null; |
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return a; |
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} |
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|
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// Positional Access Operations |
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|
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@SuppressWarnings("unchecked") |
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E elementData(int index) { |
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return (E) elementData[index]; |
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} |
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|
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/** |
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* Returns the element at the specified position in this list. |
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* |
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* @param index index of the element to return |
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* @return the element at the specified position in this list |
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* @throws IndexOutOfBoundsException {@inheritDoc} |
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*/ |
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public E get(int index) { |
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rangeCheck(index); |
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|
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return elementData(index); |
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} |
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|
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/** |
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* Replaces the element at the specified position in this list with |
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* the specified element. |
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* |
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* @param index index of the element to replace |
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* @param element element to be stored at the specified position |
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* @return the element previously at the specified position |
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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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rangeCheck(index); |
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|
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E oldValue = elementData(index); |
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elementData[index] = element; |
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return oldValue; |
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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. |
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* |
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* @param e element to be appended to this list |
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* @return <tt>true</tt> (as specified by {@link Collection#add}) |
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*/ |
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public boolean add(E e) { |
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ensureCapacity(size + 1); // Increments modCount!! |
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elementData[size++] = e; |
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return true; |
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} |
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|
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/** |
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* Inserts the specified element at the specified position in this |
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* list. Shifts the element currently at that position (if any) and |
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* any subsequent elements to the right (adds one to their indices). |
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* |
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* @param index index at which the specified element is to be inserted |
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* @param element element to be inserted |
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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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rangeCheckForAdd(index); |
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|
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ensureCapacity(size+1); // Increments modCount!! |
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System.arraycopy(elementData, index, elementData, index + 1, |
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size - index); |
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elementData[index] = element; |
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size++; |
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} |
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|
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/** |
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* Removes the element at the specified position in this list. |
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* Shifts any subsequent elements to the left (subtracts one from their |
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* indices). |
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* |
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* @param index the index of the element to be removed |
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* @return the element that was removed from the list |
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* @throws IndexOutOfBoundsException {@inheritDoc} |
410 |
*/ |
411 |
public E remove(int index) { |
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rangeCheck(index); |
413 |
|
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modCount++; |
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E oldValue = elementData(index); |
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|
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int numMoved = size - index - 1; |
418 |
if (numMoved > 0) |
419 |
System.arraycopy(elementData, index+1, elementData, index, |
420 |
numMoved); |
421 |
elementData[--size] = null; // Let gc do its work |
422 |
|
423 |
return oldValue; |
424 |
} |
425 |
|
426 |
/** |
427 |
* Removes the first occurrence of the specified element from this list, |
428 |
* if it is present. If the list does not contain the element, it is |
429 |
* unchanged. More formally, removes the element with the lowest index |
430 |
* <tt>i</tt> such that |
431 |
* <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt> |
432 |
* (if such an element exists). Returns <tt>true</tt> if this list |
433 |
* contained the specified element (or equivalently, if this list |
434 |
* changed as a result of the call). |
435 |
* |
436 |
* @param o element to be removed from this list, if present |
437 |
* @return <tt>true</tt> if this list contained the specified element |
438 |
*/ |
439 |
public boolean remove(Object o) { |
440 |
if (o == null) { |
441 |
for (int index = 0; index < size; index++) |
442 |
if (elementData[index] == null) { |
443 |
fastRemove(index); |
444 |
return true; |
445 |
} |
446 |
} else { |
447 |
for (int index = 0; index < size; index++) |
448 |
if (o.equals(elementData[index])) { |
449 |
fastRemove(index); |
450 |
return true; |
451 |
} |
452 |
} |
453 |
return false; |
454 |
} |
455 |
|
456 |
/* |
457 |
* Private remove method that skips bounds checking and does not |
458 |
* return the value removed. |
459 |
*/ |
460 |
private void fastRemove(int index) { |
461 |
modCount++; |
462 |
int numMoved = size - index - 1; |
463 |
if (numMoved > 0) |
464 |
System.arraycopy(elementData, index+1, elementData, index, |
465 |
numMoved); |
466 |
elementData[--size] = null; // Let gc do its work |
467 |
} |
468 |
|
469 |
/** |
470 |
* Removes all of the elements from this list. The list will |
471 |
* be empty after this call returns. |
472 |
*/ |
473 |
public void clear() { |
474 |
modCount++; |
475 |
|
476 |
// Let gc do its work |
477 |
for (int i = 0; i < size; i++) |
478 |
elementData[i] = null; |
479 |
|
480 |
size = 0; |
481 |
} |
482 |
|
483 |
/** |
484 |
* Appends all of the elements in the specified collection to the end of |
485 |
* this list, in the order that they are returned by the |
486 |
* specified collection's Iterator. The behavior of this operation is |
487 |
* undefined if the specified collection is modified while the operation |
488 |
* is in progress. (This implies that the behavior of this call is |
489 |
* undefined if the specified collection is this list, and this |
490 |
* list is nonempty.) |
491 |
* |
492 |
* @param c collection containing elements to be added to this list |
493 |
* @return <tt>true</tt> if this list changed as a result of the call |
494 |
* @throws NullPointerException if the specified collection is null |
495 |
*/ |
496 |
public boolean addAll(Collection<? extends E> c) { |
497 |
Object[] a = c.toArray(); |
498 |
int numNew = a.length; |
499 |
ensureCapacity(size + numNew); // Increments modCount |
500 |
System.arraycopy(a, 0, elementData, size, numNew); |
501 |
size += numNew; |
502 |
return numNew != 0; |
503 |
} |
504 |
|
505 |
/** |
506 |
* Inserts all of the elements in the specified collection into this |
507 |
* list, starting at the specified position. Shifts the element |
508 |
* currently at that position (if any) and any subsequent elements to |
509 |
* the right (increases their indices). The new elements will appear |
510 |
* in the list in the order that they are returned by the |
511 |
* specified collection's iterator. |
512 |
* |
513 |
* @param index index at which to insert the first element from the |
514 |
* specified collection |
515 |
* @param c collection containing elements to be added to this list |
516 |
* @return <tt>true</tt> if this list changed as a result of the call |
517 |
* @throws IndexOutOfBoundsException {@inheritDoc} |
518 |
* @throws NullPointerException if the specified collection is null |
519 |
*/ |
520 |
public boolean addAll(int index, Collection<? extends E> c) { |
521 |
rangeCheckForAdd(index); |
522 |
|
523 |
Object[] a = c.toArray(); |
524 |
int numNew = a.length; |
525 |
ensureCapacity(size + numNew); // Increments modCount |
526 |
|
527 |
int numMoved = size - index; |
528 |
if (numMoved > 0) |
529 |
System.arraycopy(elementData, index, elementData, index + numNew, |
530 |
numMoved); |
531 |
|
532 |
System.arraycopy(a, 0, elementData, index, numNew); |
533 |
size += numNew; |
534 |
return numNew != 0; |
535 |
} |
536 |
|
537 |
/** |
538 |
* Removes from this list all of the elements whose index is between |
539 |
* {@code fromIndex}, inclusive, and {@code toIndex}, exclusive. |
540 |
* Shifts any succeeding elements to the left (reduces their index). |
541 |
* This call shortens the list by {@code (toIndex - fromIndex)} elements. |
542 |
* (If {@code toIndex==fromIndex}, this operation has no effect.) |
543 |
* |
544 |
* @throws IndexOutOfBoundsException if {@code fromIndex} or |
545 |
* {@code toIndex} is out of range |
546 |
* ({@code fromIndex < 0 || |
547 |
* fromIndex >= size() || |
548 |
* toIndex > size() || |
549 |
* toIndex < fromIndex}) |
550 |
*/ |
551 |
protected void removeRange(int fromIndex, int toIndex) { |
552 |
modCount++; |
553 |
int numMoved = size - toIndex; |
554 |
System.arraycopy(elementData, toIndex, elementData, fromIndex, |
555 |
numMoved); |
556 |
|
557 |
// Let gc do its work |
558 |
int newSize = size - (toIndex-fromIndex); |
559 |
while (size != newSize) |
560 |
elementData[--size] = null; |
561 |
} |
562 |
|
563 |
/** |
564 |
* Checks if the given index is in range. If not, throws an appropriate |
565 |
* runtime exception. This method does *not* check if the index is |
566 |
* negative: It is always used immediately prior to an array access, |
567 |
* which throws an ArrayIndexOutOfBoundsException if index is negative. |
568 |
*/ |
569 |
private void rangeCheck(int index) { |
570 |
if (index >= size) |
571 |
throw new IndexOutOfBoundsException(outOfBoundsMsg(index)); |
572 |
} |
573 |
|
574 |
/** |
575 |
* A version of rangeCheck used by add and addAll. |
576 |
*/ |
577 |
private void rangeCheckForAdd(int index) { |
578 |
if (index > size || index < 0) |
579 |
throw new IndexOutOfBoundsException(outOfBoundsMsg(index)); |
580 |
} |
581 |
|
582 |
/** |
583 |
* Constructs an IndexOutOfBoundsException detail message. |
584 |
* Of the many possible refactorings of the error handling code, |
585 |
* this "outlining" performs best with both server and client VMs. |
586 |
*/ |
587 |
private String outOfBoundsMsg(int index) { |
588 |
return "Index: "+index+", Size: "+size; |
589 |
} |
590 |
|
591 |
/** |
592 |
* Removes from this list all of its elements that are contained in the |
593 |
* specified collection. |
594 |
* |
595 |
* @param c collection containing elements to be removed from this list |
596 |
* @return {@code true} if this list changed as a result of the call |
597 |
* @throws ClassCastException if the class of an element of this list |
598 |
* is incompatible with the specified collection (optional) |
599 |
* @throws NullPointerException if this list contains a null element and the |
600 |
* specified collection does not permit null elements (optional), |
601 |
* or if the specified collection is null |
602 |
* @see Collection#contains(Object) |
603 |
*/ |
604 |
public boolean removeAll(Collection<?> c) { |
605 |
return batchRemove(c, false); |
606 |
} |
607 |
|
608 |
/** |
609 |
* Retains only the elements in this list that are contained in the |
610 |
* specified collection. In other words, removes from this list all |
611 |
* of its elements that are not contained in the specified collection. |
612 |
* |
613 |
* @param c collection containing elements to be retained in this list |
614 |
* @return {@code true} if this list changed as a result of the call |
615 |
* @throws ClassCastException if the class of an element of this list |
616 |
* is incompatible with the specified collection (optional) |
617 |
* @throws NullPointerException if this list contains a null element and the |
618 |
* specified collection does not permit null elements (optional), |
619 |
* or if the specified collection is null |
620 |
* @see Collection#contains(Object) |
621 |
*/ |
622 |
public boolean retainAll(Collection<?> c) { |
623 |
return batchRemove(c, true); |
624 |
} |
625 |
|
626 |
private boolean batchRemove(Collection<?> c, boolean complement) { |
627 |
final Object[] elementData = this.elementData; |
628 |
int r = 0, w = 0; |
629 |
boolean modified = false; |
630 |
try { |
631 |
for (; r < size; r++) |
632 |
if (c.contains(elementData[r]) == complement) |
633 |
elementData[w++] = elementData[r]; |
634 |
} finally { |
635 |
// Preserve behavioral compatibility with AbstractCollection, |
636 |
// even if c.contains() throws. |
637 |
if (r != size) { |
638 |
System.arraycopy(elementData, r, |
639 |
elementData, w, |
640 |
size - r); |
641 |
w += size - r; |
642 |
} |
643 |
if (w != size) { |
644 |
for (int i = w; i < size; i++) |
645 |
elementData[i] = null; |
646 |
modCount += size - w; |
647 |
size = w; |
648 |
modified = true; |
649 |
} |
650 |
} |
651 |
return modified; |
652 |
} |
653 |
|
654 |
/** |
655 |
* Save the state of the <tt>ArrayList</tt> instance to a stream (that |
656 |
* is, serialize it). |
657 |
* |
658 |
* @serialData The length of the array backing the <tt>ArrayList</tt> |
659 |
* instance is emitted (int), followed by all of its elements |
660 |
* (each an <tt>Object</tt>) in the proper order. |
661 |
*/ |
662 |
private void writeObject(java.io.ObjectOutputStream s) |
663 |
throws java.io.IOException{ |
664 |
// Write out element count, and any hidden stuff |
665 |
int expectedModCount = modCount; |
666 |
s.defaultWriteObject(); |
667 |
|
668 |
// Write out array length |
669 |
s.writeInt(elementData.length); |
670 |
|
671 |
// Write out all elements in the proper order. |
672 |
for (int i=0; i<size; i++) |
673 |
s.writeObject(elementData[i]); |
674 |
|
675 |
if (modCount != expectedModCount) { |
676 |
throw new ConcurrentModificationException(); |
677 |
} |
678 |
|
679 |
} |
680 |
|
681 |
/** |
682 |
* Reconstitute the <tt>ArrayList</tt> instance from a stream (that is, |
683 |
* deserialize it). |
684 |
*/ |
685 |
private void readObject(java.io.ObjectInputStream s) |
686 |
throws java.io.IOException, ClassNotFoundException { |
687 |
// Read in size, and any hidden stuff |
688 |
s.defaultReadObject(); |
689 |
|
690 |
// Read in array length and allocate array |
691 |
int arrayLength = s.readInt(); |
692 |
Object[] a = elementData = new Object[arrayLength]; |
693 |
|
694 |
// Read in all elements in the proper order. |
695 |
for (int i=0; i<size; i++) |
696 |
a[i] = s.readObject(); |
697 |
} |
698 |
|
699 |
/** |
700 |
* Returns a list iterator over the elements in this list (in proper |
701 |
* sequence), starting at the specified position in the list. |
702 |
* The specified index indicates the first element that would be |
703 |
* returned by an initial call to {@link ListIterator#next next}. |
704 |
* An initial call to {@link ListIterator#previous previous} would |
705 |
* return the element with the specified index minus one. |
706 |
* |
707 |
* <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>. |
708 |
* |
709 |
* @throws IndexOutOfBoundsException {@inheritDoc} |
710 |
*/ |
711 |
public ListIterator<E> listIterator(int index) { |
712 |
if (index < 0 || index > size) |
713 |
throw new IndexOutOfBoundsException("Index: "+index); |
714 |
return new ListItr(index); |
715 |
} |
716 |
|
717 |
/** |
718 |
* Returns a list iterator over the elements in this list (in proper |
719 |
* sequence). |
720 |
* |
721 |
* <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>. |
722 |
* |
723 |
* @see #listIterator(int) |
724 |
*/ |
725 |
public ListIterator<E> listIterator() { |
726 |
return new ListItr(0); |
727 |
} |
728 |
|
729 |
/** |
730 |
* Returns an iterator over the elements in this list in proper sequence. |
731 |
* |
732 |
* <p>The returned iterator is <a href="#fail-fast"><i>fail-fast</i></a>. |
733 |
* |
734 |
* @return an iterator over the elements in this list in proper sequence |
735 |
*/ |
736 |
public Iterator<E> iterator() { |
737 |
return new Itr(); |
738 |
} |
739 |
|
740 |
/** |
741 |
* An optimized version of AbstractList.Itr |
742 |
*/ |
743 |
private class Itr implements Iterator<E> { |
744 |
int cursor; // index of next element to return |
745 |
int lastRet = -1; // index of last element returned; -1 if no such |
746 |
int expectedModCount = modCount; |
747 |
|
748 |
public boolean hasNext() { |
749 |
return cursor != size; |
750 |
} |
751 |
|
752 |
@SuppressWarnings("unchecked") |
753 |
public E next() { |
754 |
checkForComodification(); |
755 |
int i = cursor; |
756 |
if (i >= size) |
757 |
throw new NoSuchElementException(); |
758 |
Object[] elementData = ArrayList.this.elementData; |
759 |
if (i >= elementData.length) |
760 |
throw new ConcurrentModificationException(); |
761 |
cursor = i + 1; |
762 |
return (E) elementData[lastRet = i]; |
763 |
} |
764 |
|
765 |
public void remove() { |
766 |
if (lastRet < 0) |
767 |
throw new IllegalStateException(); |
768 |
checkForComodification(); |
769 |
|
770 |
try { |
771 |
ArrayList.this.remove(lastRet); |
772 |
cursor = lastRet; |
773 |
lastRet = -1; |
774 |
expectedModCount = modCount; |
775 |
} catch (IndexOutOfBoundsException ex) { |
776 |
throw new ConcurrentModificationException(); |
777 |
} |
778 |
} |
779 |
|
780 |
final void checkForComodification() { |
781 |
if (modCount != expectedModCount) |
782 |
throw new ConcurrentModificationException(); |
783 |
} |
784 |
} |
785 |
|
786 |
/** |
787 |
* An optimized version of AbstractList.ListItr |
788 |
*/ |
789 |
private class ListItr extends Itr implements ListIterator<E> { |
790 |
ListItr(int index) { |
791 |
super(); |
792 |
cursor = index; |
793 |
} |
794 |
|
795 |
public boolean hasPrevious() { |
796 |
return cursor != 0; |
797 |
} |
798 |
|
799 |
public int nextIndex() { |
800 |
return cursor; |
801 |
} |
802 |
|
803 |
public int previousIndex() { |
804 |
return cursor - 1; |
805 |
} |
806 |
|
807 |
@SuppressWarnings("unchecked") |
808 |
public E previous() { |
809 |
checkForComodification(); |
810 |
int i = cursor - 1; |
811 |
if (i < 0) |
812 |
throw new NoSuchElementException(); |
813 |
Object[] elementData = ArrayList.this.elementData; |
814 |
if (i >= elementData.length) |
815 |
throw new ConcurrentModificationException(); |
816 |
cursor = i; |
817 |
return (E) elementData[lastRet = i]; |
818 |
} |
819 |
|
820 |
public void set(E e) { |
821 |
if (lastRet < 0) |
822 |
throw new IllegalStateException(); |
823 |
checkForComodification(); |
824 |
|
825 |
try { |
826 |
ArrayList.this.set(lastRet, e); |
827 |
} catch (IndexOutOfBoundsException ex) { |
828 |
throw new ConcurrentModificationException(); |
829 |
} |
830 |
} |
831 |
|
832 |
public void add(E e) { |
833 |
checkForComodification(); |
834 |
|
835 |
try { |
836 |
int i = cursor; |
837 |
ArrayList.this.add(i, e); |
838 |
cursor = i + 1; |
839 |
lastRet = -1; |
840 |
expectedModCount = modCount; |
841 |
} catch (IndexOutOfBoundsException ex) { |
842 |
throw new ConcurrentModificationException(); |
843 |
} |
844 |
} |
845 |
} |
846 |
|
847 |
/** |
848 |
* Returns a view of the portion of this list between the specified |
849 |
* {@code fromIndex}, inclusive, and {@code toIndex}, exclusive. (If |
850 |
* {@code fromIndex} and {@code toIndex} are equal, the returned list is |
851 |
* empty.) The returned list is backed by this list, so non-structural |
852 |
* changes in the returned list are reflected in this list, and vice-versa. |
853 |
* The returned list supports all of the optional list operations. |
854 |
* |
855 |
* <p>This method eliminates the need for explicit range operations (of |
856 |
* the sort that commonly exist for arrays). Any operation that expects |
857 |
* a list can be used as a range operation by passing a subList view |
858 |
* instead of a whole list. For example, the following idiom |
859 |
* removes a range of elements from a list: |
860 |
* <pre> |
861 |
* list.subList(from, to).clear(); |
862 |
* </pre> |
863 |
* Similar idioms may be constructed for {@link #indexOf(Object)} and |
864 |
* {@link #lastIndexOf(Object)}, and all of the algorithms in the |
865 |
* {@link Collections} class can be applied to a subList. |
866 |
* |
867 |
* <p>The semantics of the list returned by this method become undefined if |
868 |
* the backing list (i.e., this list) is <i>structurally modified</i> in |
869 |
* any way other than via the returned list. (Structural modifications are |
870 |
* those that change the size of this list, or otherwise perturb it in such |
871 |
* a fashion that iterations in progress may yield incorrect results.) |
872 |
* |
873 |
* @throws IndexOutOfBoundsException {@inheritDoc} |
874 |
* @throws IllegalArgumentException {@inheritDoc} |
875 |
*/ |
876 |
public List<E> subList(int fromIndex, int toIndex) { |
877 |
subListRangeCheck(fromIndex, toIndex, size); |
878 |
return new SubList(this, 0, fromIndex, toIndex); |
879 |
} |
880 |
|
881 |
static void subListRangeCheck(int fromIndex, int toIndex, int size) { |
882 |
if (fromIndex < 0) |
883 |
throw new IndexOutOfBoundsException("fromIndex = " + fromIndex); |
884 |
if (toIndex > size) |
885 |
throw new IndexOutOfBoundsException("toIndex = " + toIndex); |
886 |
if (fromIndex > toIndex) |
887 |
throw new IllegalArgumentException("fromIndex(" + fromIndex + |
888 |
") > toIndex(" + toIndex + ")"); |
889 |
} |
890 |
|
891 |
private class SubList extends AbstractList<E> implements RandomAccess { |
892 |
private final AbstractList<E> parent; |
893 |
private final int parentOffset; |
894 |
private final int offset; |
895 |
private int size; |
896 |
|
897 |
SubList(AbstractList<E> parent, |
898 |
int offset, int fromIndex, int toIndex) { |
899 |
this.parent = parent; |
900 |
this.parentOffset = fromIndex; |
901 |
this.offset = offset + fromIndex; |
902 |
this.size = toIndex - fromIndex; |
903 |
this.modCount = ArrayList.this.modCount; |
904 |
} |
905 |
|
906 |
public E set(int index, E e) { |
907 |
rangeCheck(index); |
908 |
checkForComodification(); |
909 |
E oldValue = ArrayList.this.elementData(offset + index); |
910 |
ArrayList.this.elementData[offset + index] = e; |
911 |
return oldValue; |
912 |
} |
913 |
|
914 |
public E get(int index) { |
915 |
rangeCheck(index); |
916 |
checkForComodification(); |
917 |
return ArrayList.this.elementData(offset + index); |
918 |
} |
919 |
|
920 |
public int size() { |
921 |
checkForComodification(); |
922 |
return this.size; |
923 |
} |
924 |
|
925 |
public void add(int index, E e) { |
926 |
rangeCheckForAdd(index); |
927 |
checkForComodification(); |
928 |
parent.add(parentOffset + index, e); |
929 |
this.modCount = parent.modCount; |
930 |
this.size++; |
931 |
} |
932 |
|
933 |
public E remove(int index) { |
934 |
rangeCheck(index); |
935 |
checkForComodification(); |
936 |
E result = parent.remove(parentOffset + index); |
937 |
this.modCount = parent.modCount; |
938 |
this.size--; |
939 |
return result; |
940 |
} |
941 |
|
942 |
protected void removeRange(int fromIndex, int toIndex) { |
943 |
checkForComodification(); |
944 |
parent.removeRange(parentOffset + fromIndex, |
945 |
parentOffset + toIndex); |
946 |
this.modCount = parent.modCount; |
947 |
this.size -= toIndex - fromIndex; |
948 |
} |
949 |
|
950 |
public boolean addAll(Collection<? extends E> c) { |
951 |
return addAll(this.size, c); |
952 |
} |
953 |
|
954 |
public boolean addAll(int index, Collection<? extends E> c) { |
955 |
rangeCheckForAdd(index); |
956 |
int cSize = c.size(); |
957 |
if (cSize==0) |
958 |
return false; |
959 |
|
960 |
checkForComodification(); |
961 |
parent.addAll(parentOffset + index, c); |
962 |
this.modCount = parent.modCount; |
963 |
this.size += cSize; |
964 |
return true; |
965 |
} |
966 |
|
967 |
public Iterator<E> iterator() { |
968 |
return listIterator(); |
969 |
} |
970 |
|
971 |
public ListIterator<E> listIterator(final int index) { |
972 |
checkForComodification(); |
973 |
rangeCheckForAdd(index); |
974 |
|
975 |
return new ListIterator<E>() { |
976 |
int cursor = index; |
977 |
int lastRet = -1; |
978 |
int expectedModCount = ArrayList.this.modCount; |
979 |
|
980 |
public boolean hasNext() { |
981 |
return cursor != SubList.this.size; |
982 |
} |
983 |
|
984 |
@SuppressWarnings("unchecked") |
985 |
public E next() { |
986 |
checkForComodification(); |
987 |
int i = cursor; |
988 |
if (i >= SubList.this.size) |
989 |
throw new NoSuchElementException(); |
990 |
Object[] elementData = ArrayList.this.elementData; |
991 |
if (offset + i >= elementData.length) |
992 |
throw new ConcurrentModificationException(); |
993 |
cursor = i + 1; |
994 |
return (E) elementData[offset + (lastRet = i)]; |
995 |
} |
996 |
|
997 |
public boolean hasPrevious() { |
998 |
return cursor != 0; |
999 |
} |
1000 |
|
1001 |
@SuppressWarnings("unchecked") |
1002 |
public E previous() { |
1003 |
checkForComodification(); |
1004 |
int i = cursor - 1; |
1005 |
if (i < 0) |
1006 |
throw new NoSuchElementException(); |
1007 |
Object[] elementData = ArrayList.this.elementData; |
1008 |
if (offset + i >= elementData.length) |
1009 |
throw new ConcurrentModificationException(); |
1010 |
cursor = i; |
1011 |
return (E) elementData[offset + (lastRet = i)]; |
1012 |
} |
1013 |
|
1014 |
public int nextIndex() { |
1015 |
return cursor; |
1016 |
} |
1017 |
|
1018 |
public int previousIndex() { |
1019 |
return cursor - 1; |
1020 |
} |
1021 |
|
1022 |
public void remove() { |
1023 |
if (lastRet < 0) |
1024 |
throw new IllegalStateException(); |
1025 |
checkForComodification(); |
1026 |
|
1027 |
try { |
1028 |
SubList.this.remove(lastRet); |
1029 |
cursor = lastRet; |
1030 |
lastRet = -1; |
1031 |
expectedModCount = ArrayList.this.modCount; |
1032 |
} catch (IndexOutOfBoundsException ex) { |
1033 |
throw new ConcurrentModificationException(); |
1034 |
} |
1035 |
} |
1036 |
|
1037 |
public void set(E e) { |
1038 |
if (lastRet < 0) |
1039 |
throw new IllegalStateException(); |
1040 |
checkForComodification(); |
1041 |
|
1042 |
try { |
1043 |
ArrayList.this.set(offset + lastRet, e); |
1044 |
} catch (IndexOutOfBoundsException ex) { |
1045 |
throw new ConcurrentModificationException(); |
1046 |
} |
1047 |
} |
1048 |
|
1049 |
public void add(E e) { |
1050 |
checkForComodification(); |
1051 |
|
1052 |
try { |
1053 |
int i = cursor; |
1054 |
SubList.this.add(i, e); |
1055 |
cursor = i + 1; |
1056 |
lastRet = -1; |
1057 |
expectedModCount = ArrayList.this.modCount; |
1058 |
} catch (IndexOutOfBoundsException ex) { |
1059 |
throw new ConcurrentModificationException(); |
1060 |
} |
1061 |
} |
1062 |
|
1063 |
final void checkForComodification() { |
1064 |
if (expectedModCount != ArrayList.this.modCount) |
1065 |
throw new ConcurrentModificationException(); |
1066 |
} |
1067 |
}; |
1068 |
} |
1069 |
|
1070 |
public List<E> subList(int fromIndex, int toIndex) { |
1071 |
subListRangeCheck(fromIndex, toIndex, size); |
1072 |
return new SubList(this, offset, fromIndex, toIndex); |
1073 |
} |
1074 |
|
1075 |
private void rangeCheck(int index) { |
1076 |
if (index < 0 || index >= this.size) |
1077 |
throw new IndexOutOfBoundsException(outOfBoundsMsg(index)); |
1078 |
} |
1079 |
|
1080 |
private void rangeCheckForAdd(int index) { |
1081 |
if (index < 0 || index > this.size) |
1082 |
throw new IndexOutOfBoundsException(outOfBoundsMsg(index)); |
1083 |
} |
1084 |
|
1085 |
private String outOfBoundsMsg(int index) { |
1086 |
return "Index: "+index+", Size: "+this.size; |
1087 |
} |
1088 |
|
1089 |
private void checkForComodification() { |
1090 |
if (ArrayList.this.modCount != this.modCount) |
1091 |
throw new ConcurrentModificationException(); |
1092 |
} |
1093 |
} |
1094 |
} |