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/* |
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* Copyright 1994-2007 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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* The {@code Vector} class implements a growable array of |
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* objects. Like an array, it contains components that can be |
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* accessed using an integer index. However, the size of a |
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* {@code Vector} can grow or shrink as needed to accommodate |
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* adding and removing items after the {@code Vector} has been created. |
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* |
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* <p>Each vector tries to optimize storage management by maintaining a |
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* {@code capacity} and a {@code capacityIncrement}. The |
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* {@code capacity} is always at least as large as the vector |
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* size; it is usually larger because as components are added to the |
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* vector, the vector's storage increases in chunks the size of |
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* {@code capacityIncrement}. An application can increase the |
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* capacity of a vector before inserting a large number of |
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* components; this reduces the amount of incremental reallocation. |
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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 vector 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. The {@link Enumeration Enumerations} returned by |
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* the {@link #elements() elements} method are <em>not</em> fail-fast. |
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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>As of the Java 2 platform v1.2, this class was retrofitted to |
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* implement the {@link List} interface, making it a member of the |
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* <a href="{@docRoot}/../technotes/guides/collections/index.html"> Java |
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* Collections Framework</a>. Unlike the new collection |
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* implementations, {@code Vector} is synchronized. |
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* |
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* @author Lee Boynton |
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* @author Jonathan Payne |
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* @see Collection |
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* @see List |
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* @see ArrayList |
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* @see LinkedList |
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* @since JDK1.0 |
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*/ |
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public class Vector<E> |
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extends AbstractList<E> |
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implements List<E>, RandomAccess, Cloneable, java.io.Serializable |
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{ |
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/** |
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* The array buffer into which the components of the vector are |
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* stored. The capacity of the vector is the length of this array buffer, |
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* and is at least large enough to contain all the vector's elements. |
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* |
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* <p>Any array elements following the last element in the Vector are null. |
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* |
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* @serial |
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*/ |
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protected Object[] elementData; |
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|
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/** |
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* The number of valid components in this {@code Vector} object. |
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* Components {@code elementData[0]} through |
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* {@code elementData[elementCount-1]} are the actual items. |
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* |
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* @serial |
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*/ |
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protected int elementCount; |
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|
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/** |
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* The amount by which the capacity of the vector is automatically |
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* incremented when its size becomes greater than its capacity. If |
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* the capacity increment is less than or equal to zero, the capacity |
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* of the vector is doubled each time it needs to grow. |
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* |
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* @serial |
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*/ |
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protected int capacityIncrement; |
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|
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/** use serialVersionUID from JDK 1.0.2 for interoperability */ |
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private static final long serialVersionUID = -2767605614048989439L; |
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|
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/** |
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* Constructs an empty vector with the specified initial capacity and |
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* capacity increment. |
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* |
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* @param initialCapacity the initial capacity of the vector |
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* @param capacityIncrement the amount by which the capacity is |
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* increased when the vector overflows |
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* @throws IllegalArgumentException if the specified initial capacity |
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* is negative |
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*/ |
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public Vector(int initialCapacity, int capacityIncrement) { |
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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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this.capacityIncrement = capacityIncrement; |
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} |
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|
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/** |
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* Constructs an empty vector with the specified initial capacity and |
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* with its capacity increment equal to zero. |
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* |
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* @param initialCapacity the initial capacity of the vector |
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* @throws IllegalArgumentException if the specified initial capacity |
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* is negative |
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*/ |
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public Vector(int initialCapacity) { |
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this(initialCapacity, 0); |
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} |
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|
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/** |
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* Constructs an empty vector so that its internal data array |
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* has size {@code 10} and its standard capacity increment is |
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* zero. |
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*/ |
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public Vector() { |
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this(10); |
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} |
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|
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/** |
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* Constructs a vector 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 |
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* vector |
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* @throws NullPointerException if the specified collection is null |
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* @since 1.2 |
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*/ |
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public Vector(Collection<? extends E> c) { |
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elementData = c.toArray(); |
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elementCount = 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, elementCount, Object[].class); |
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} |
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|
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/** |
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* Copies the components of this vector into the specified array. |
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* The item at index {@code k} in this vector is copied into |
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* component {@code k} of {@code anArray}. |
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* |
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* @param anArray the array into which the components get copied |
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* @throws NullPointerException if the given array is null |
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* @throws IndexOutOfBoundsException if the specified array is not |
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* large enough to hold all the components of this vector |
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* @throws ArrayStoreException if a component of this vector is not of |
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* a runtime type that can be stored in the specified array |
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* @see #toArray(Object[]) |
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*/ |
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public synchronized void copyInto(Object[] anArray) { |
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System.arraycopy(elementData, 0, anArray, 0, elementCount); |
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} |
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|
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/** |
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* Trims the capacity of this vector to be the vector's current |
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* size. If the capacity of this vector is larger than its current |
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* size, then the capacity is changed to equal the size by replacing |
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* its internal data array, kept in the field {@code elementData}, |
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* with a smaller one. An application can use this operation to |
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* minimize the storage of a vector. |
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*/ |
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public synchronized void trimToSize() { |
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modCount++; |
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int oldCapacity = elementData.length; |
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if (elementCount < oldCapacity) { |
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elementData = Arrays.copyOf(elementData, elementCount); |
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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 vector, if necessary, to ensure |
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* that it can hold at least the number of components specified by |
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* the minimum capacity argument. |
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* |
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* <p>If the current capacity of this vector is less than |
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* {@code minCapacity}, then its capacity is increased by replacing its |
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* internal data array, kept in the field {@code elementData}, with a |
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* larger one. The size of the new data array will be the old size plus |
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* {@code capacityIncrement}, unless the value of |
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* {@code capacityIncrement} is less than or equal to zero, in which case |
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* the new capacity will be twice the old capacity; but if this new size |
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* is still smaller than {@code minCapacity}, then the new capacity will |
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* be {@code minCapacity}. |
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* |
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* @param minCapacity the desired minimum capacity |
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*/ |
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public synchronized void ensureCapacity(int minCapacity) { |
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modCount++; |
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ensureCapacityHelper(minCapacity); |
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} |
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|
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/** |
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* This implements the unsynchronized semantics of ensureCapacity. |
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* Synchronized methods in this class can internally call this |
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* method for ensuring capacity without incurring the cost of an |
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* extra synchronization. |
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* |
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* @see #ensureCapacity(int) |
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*/ |
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private void ensureCapacityHelper(int minCapacity) { |
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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 = (capacityIncrement > 0) ? |
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(oldCapacity + capacityIncrement) : (oldCapacity * 2); |
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if (newCapacity < minCapacity) { |
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newCapacity = minCapacity; |
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} |
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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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* Sets the size of this vector. If the new size is greater than the |
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* current size, new {@code null} items are added to the end of |
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* the vector. If the new size is less than the current size, all |
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* components at index {@code newSize} and greater are discarded. |
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* |
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* @param newSize the new size of this vector |
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* @throws ArrayIndexOutOfBoundsException if the new size is negative |
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*/ |
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public synchronized void setSize(int newSize) { |
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modCount++; |
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if (newSize > elementCount) { |
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ensureCapacityHelper(newSize); |
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} else { |
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for (int i = newSize ; i < elementCount ; i++) { |
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elementData[i] = null; |
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} |
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} |
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elementCount = newSize; |
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} |
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|
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/** |
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* Returns the current capacity of this vector. |
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* |
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* @return the current capacity (the length of its internal |
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* data array, kept in the field {@code elementData} |
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* of this vector) |
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*/ |
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public synchronized int capacity() { |
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return elementData.length; |
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} |
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|
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/** |
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* Returns the number of components in this vector. |
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* |
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* @return the number of components in this vector |
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*/ |
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public synchronized int size() { |
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return elementCount; |
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} |
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|
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/** |
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* Tests if this vector has no components. |
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* |
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* @return {@code true} if and only if this vector has |
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* no components, that is, its size is zero; |
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* {@code false} otherwise. |
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*/ |
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public synchronized boolean isEmpty() { |
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return elementCount == 0; |
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} |
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|
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/** |
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* Returns an enumeration of the components of this vector. The |
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* returned {@code Enumeration} object will generate all items in |
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* this vector. The first item generated is the item at index {@code 0}, |
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* then the item at index {@code 1}, and so on. |
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* |
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* @return an enumeration of the components of this vector |
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* @see Iterator |
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*/ |
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public Enumeration<E> elements() { |
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return new Enumeration<E>() { |
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int count = 0; |
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|
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public boolean hasMoreElements() { |
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return count < elementCount; |
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} |
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|
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public E nextElement() { |
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synchronized (Vector.this) { |
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if (count < elementCount) { |
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return elementData(count++); |
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} |
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} |
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throw new NoSuchElementException("Vector Enumeration"); |
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} |
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}; |
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} |
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|
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/** |
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* Returns {@code true} if this vector contains the specified element. |
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* More formally, returns {@code true} if and only if this vector |
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* contains at least one element {@code e} 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 vector is to be tested |
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* @return {@code true} if this vector 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) >= 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 vector, or -1 if this vector does not contain the element. |
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* More formally, returns the lowest index {@code i} 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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* @param o element to search for |
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* @return the index of the first occurrence of the specified element in |
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* this vector, or -1 if this vector does not contain the element |
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*/ |
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public int indexOf(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 in |
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* this vector, searching forwards from {@code index}, or returns -1 if |
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* the element is not found. |
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* More formally, returns the lowest index {@code i} such that |
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* <tt>(i >= index && (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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* @param o element to search for |
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* @param index index to start searching from |
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* @return the index of the first occurrence of the element in |
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* this vector at position {@code index} or later in the vector; |
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* {@code -1} if the element is not found. |
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* @throws IndexOutOfBoundsException if the specified index is negative |
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* @see Object#equals(Object) |
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*/ |
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public synchronized int indexOf(Object o, int index) { |
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if (o == null) { |
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for (int i = index ; i < elementCount ; 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 = index ; i < elementCount ; 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 vector, or -1 if this vector does not contain the element. |
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* More formally, returns the highest index {@code i} 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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* @param o element to search for |
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* @return the index of the last occurrence of the specified element in |
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* this vector, or -1 if this vector does not contain the element |
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*/ |
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public synchronized int lastIndexOf(Object o) { |
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return lastIndexOf(o, elementCount-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 in |
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* this vector, searching backwards from {@code index}, or returns -1 if |
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* the element is not found. |
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* More formally, returns the highest index {@code i} such that |
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* <tt>(i <= index && (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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* @param o element to search for |
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* @param index index to start searching backwards from |
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* @return the index of the last occurrence of the element at position |
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* less than or equal to {@code index} in this vector; |
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* -1 if the element is not found. |
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* @throws IndexOutOfBoundsException if the specified index is greater |
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* than or equal to the current size of this vector |
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*/ |
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public synchronized int lastIndexOf(Object o, int index) { |
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if (index >= elementCount) |
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throw new IndexOutOfBoundsException(index + " >= "+ elementCount); |
421 |
|
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if (o == null) { |
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for (int i = index; i >= 0; i--) |
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if (elementData[i]==null) |
425 |
return i; |
426 |
} else { |
427 |
for (int i = index; i >= 0; i--) |
428 |
if (o.equals(elementData[i])) |
429 |
return i; |
430 |
} |
431 |
return -1; |
432 |
} |
433 |
|
434 |
/** |
435 |
* Returns the component at the specified index. |
436 |
* |
437 |
* <p>This method is identical in functionality to the {@link #get(int)} |
438 |
* method (which is part of the {@link List} interface). |
439 |
* |
440 |
* @param index an index into this vector |
441 |
* @return the component at the specified index |
442 |
* @throws ArrayIndexOutOfBoundsException if the index is out of range |
443 |
* ({@code index < 0 || index >= size()}) |
444 |
*/ |
445 |
public synchronized E elementAt(int index) { |
446 |
if (index >= elementCount) { |
447 |
throw new ArrayIndexOutOfBoundsException(index + " >= " + elementCount); |
448 |
} |
449 |
|
450 |
return elementData(index); |
451 |
} |
452 |
|
453 |
/** |
454 |
* Returns the first component (the item at index {@code 0}) of |
455 |
* this vector. |
456 |
* |
457 |
* @return the first component of this vector |
458 |
* @throws NoSuchElementException if this vector has no components |
459 |
*/ |
460 |
public synchronized E firstElement() { |
461 |
if (elementCount == 0) { |
462 |
throw new NoSuchElementException(); |
463 |
} |
464 |
return elementData(0); |
465 |
} |
466 |
|
467 |
/** |
468 |
* Returns the last component of the vector. |
469 |
* |
470 |
* @return the last component of the vector, i.e., the component at index |
471 |
* <code>size() - 1</code>. |
472 |
* @throws NoSuchElementException if this vector is empty |
473 |
*/ |
474 |
public synchronized E lastElement() { |
475 |
if (elementCount == 0) { |
476 |
throw new NoSuchElementException(); |
477 |
} |
478 |
return elementData(elementCount - 1); |
479 |
} |
480 |
|
481 |
/** |
482 |
* Sets the component at the specified {@code index} of this |
483 |
* vector to be the specified object. The previous component at that |
484 |
* position is discarded. |
485 |
* |
486 |
* <p>The index must be a value greater than or equal to {@code 0} |
487 |
* and less than the current size of the vector. |
488 |
* |
489 |
* <p>This method is identical in functionality to the |
490 |
* {@link #set(int, Object) set(int, E)} |
491 |
* method (which is part of the {@link List} interface). Note that the |
492 |
* {@code set} method reverses the order of the parameters, to more closely |
493 |
* match array usage. Note also that the {@code set} method returns the |
494 |
* old value that was stored at the specified position. |
495 |
* |
496 |
* @param obj what the component is to be set to |
497 |
* @param index the specified index |
498 |
* @throws ArrayIndexOutOfBoundsException if the index is out of range |
499 |
* ({@code index < 0 || index >= size()}) |
500 |
*/ |
501 |
public synchronized void setElementAt(E obj, int index) { |
502 |
if (index >= elementCount) { |
503 |
throw new ArrayIndexOutOfBoundsException(index + " >= " + |
504 |
elementCount); |
505 |
} |
506 |
elementData[index] = obj; |
507 |
} |
508 |
|
509 |
/** |
510 |
* Deletes the component at the specified index. Each component in |
511 |
* this vector with an index greater or equal to the specified |
512 |
* {@code index} is shifted downward to have an index one |
513 |
* smaller than the value it had previously. The size of this vector |
514 |
* is decreased by {@code 1}. |
515 |
* |
516 |
* <p>The index must be a value greater than or equal to {@code 0} |
517 |
* and less than the current size of the vector. |
518 |
* |
519 |
* <p>This method is identical in functionality to the {@link #remove(int)} |
520 |
* method (which is part of the {@link List} interface). Note that the |
521 |
* {@code remove} method returns the old value that was stored at the |
522 |
* specified position. |
523 |
* |
524 |
* @param index the index of the object to remove |
525 |
* @throws ArrayIndexOutOfBoundsException if the index is out of range |
526 |
* ({@code index < 0 || index >= size()}) |
527 |
*/ |
528 |
public synchronized void removeElementAt(int index) { |
529 |
modCount++; |
530 |
if (index >= elementCount) { |
531 |
throw new ArrayIndexOutOfBoundsException(index + " >= " + |
532 |
elementCount); |
533 |
} |
534 |
else if (index < 0) { |
535 |
throw new ArrayIndexOutOfBoundsException(index); |
536 |
} |
537 |
int j = elementCount - index - 1; |
538 |
if (j > 0) { |
539 |
System.arraycopy(elementData, index + 1, elementData, index, j); |
540 |
} |
541 |
elementCount--; |
542 |
elementData[elementCount] = null; /* to let gc do its work */ |
543 |
} |
544 |
|
545 |
/** |
546 |
* Inserts the specified object as a component in this vector at the |
547 |
* specified {@code index}. Each component in this vector with |
548 |
* an index greater or equal to the specified {@code index} is |
549 |
* shifted upward to have an index one greater than the value it had |
550 |
* previously. |
551 |
* |
552 |
* <p>The index must be a value greater than or equal to {@code 0} |
553 |
* and less than or equal to the current size of the vector. (If the |
554 |
* index is equal to the current size of the vector, the new element |
555 |
* is appended to the Vector.) |
556 |
* |
557 |
* <p>This method is identical in functionality to the |
558 |
* {@link #add(int, Object) add(int, E)} |
559 |
* method (which is part of the {@link List} interface). Note that the |
560 |
* {@code add} method reverses the order of the parameters, to more closely |
561 |
* match array usage. |
562 |
* |
563 |
* @param obj the component to insert |
564 |
* @param index where to insert the new component |
565 |
* @throws ArrayIndexOutOfBoundsException if the index is out of range |
566 |
* ({@code index < 0 || index > size()}) |
567 |
*/ |
568 |
public synchronized void insertElementAt(E obj, int index) { |
569 |
modCount++; |
570 |
if (index > elementCount) { |
571 |
throw new ArrayIndexOutOfBoundsException(index |
572 |
+ " > " + elementCount); |
573 |
} |
574 |
ensureCapacityHelper(elementCount + 1); |
575 |
System.arraycopy(elementData, index, elementData, index + 1, elementCount - index); |
576 |
elementData[index] = obj; |
577 |
elementCount++; |
578 |
} |
579 |
|
580 |
/** |
581 |
* Adds the specified component to the end of this vector, |
582 |
* increasing its size by one. The capacity of this vector is |
583 |
* increased if its size becomes greater than its capacity. |
584 |
* |
585 |
* <p>This method is identical in functionality to the |
586 |
* {@link #add(Object) add(E)} |
587 |
* method (which is part of the {@link List} interface). |
588 |
* |
589 |
* @param obj the component to be added |
590 |
*/ |
591 |
public synchronized void addElement(E obj) { |
592 |
modCount++; |
593 |
ensureCapacityHelper(elementCount + 1); |
594 |
elementData[elementCount++] = obj; |
595 |
} |
596 |
|
597 |
/** |
598 |
* Removes the first (lowest-indexed) occurrence of the argument |
599 |
* from this vector. If the object is found in this vector, each |
600 |
* component in the vector with an index greater or equal to the |
601 |
* object's index is shifted downward to have an index one smaller |
602 |
* than the value it had previously. |
603 |
* |
604 |
* <p>This method is identical in functionality to the |
605 |
* {@link #remove(Object)} method (which is part of the |
606 |
* {@link List} interface). |
607 |
* |
608 |
* @param obj the component to be removed |
609 |
* @return {@code true} if the argument was a component of this |
610 |
* vector; {@code false} otherwise. |
611 |
*/ |
612 |
public synchronized boolean removeElement(Object obj) { |
613 |
modCount++; |
614 |
int i = indexOf(obj); |
615 |
if (i >= 0) { |
616 |
removeElementAt(i); |
617 |
return true; |
618 |
} |
619 |
return false; |
620 |
} |
621 |
|
622 |
/** |
623 |
* Removes all components from this vector and sets its size to zero. |
624 |
* |
625 |
* <p>This method is identical in functionality to the {@link #clear} |
626 |
* method (which is part of the {@link List} interface). |
627 |
*/ |
628 |
public synchronized void removeAllElements() { |
629 |
modCount++; |
630 |
// Let gc do its work |
631 |
for (int i = 0; i < elementCount; i++) |
632 |
elementData[i] = null; |
633 |
|
634 |
elementCount = 0; |
635 |
} |
636 |
|
637 |
/** |
638 |
* Returns a clone of this vector. The copy will contain a |
639 |
* reference to a clone of the internal data array, not a reference |
640 |
* to the original internal data array of this {@code Vector} object. |
641 |
* |
642 |
* @return a clone of this vector |
643 |
*/ |
644 |
public synchronized Object clone() { |
645 |
try { |
646 |
@SuppressWarnings("unchecked") |
647 |
Vector<E> v = (Vector<E>) super.clone(); |
648 |
v.elementData = Arrays.copyOf(elementData, elementCount); |
649 |
v.modCount = 0; |
650 |
return v; |
651 |
} catch (CloneNotSupportedException e) { |
652 |
// this shouldn't happen, since we are Cloneable |
653 |
throw new InternalError(); |
654 |
} |
655 |
} |
656 |
|
657 |
/** |
658 |
* Returns an array containing all of the elements in this Vector |
659 |
* in the correct order. |
660 |
* |
661 |
* @since 1.2 |
662 |
*/ |
663 |
public synchronized Object[] toArray() { |
664 |
return Arrays.copyOf(elementData, elementCount); |
665 |
} |
666 |
|
667 |
/** |
668 |
* Returns an array containing all of the elements in this Vector in the |
669 |
* correct order; the runtime type of the returned array is that of the |
670 |
* specified array. If the Vector fits in the specified array, it is |
671 |
* returned therein. Otherwise, a new array is allocated with the runtime |
672 |
* type of the specified array and the size of this Vector. |
673 |
* |
674 |
* <p>If the Vector fits in the specified array with room to spare |
675 |
* (i.e., the array has more elements than the Vector), |
676 |
* the element in the array immediately following the end of the |
677 |
* Vector is set to null. (This is useful in determining the length |
678 |
* of the Vector <em>only</em> if the caller knows that the Vector |
679 |
* does not contain any null elements.) |
680 |
* |
681 |
* @param a the array into which the elements of the Vector are to |
682 |
* be stored, if it is big enough; otherwise, a new array of the |
683 |
* same runtime type is allocated for this purpose. |
684 |
* @return an array containing the elements of the Vector |
685 |
* @throws ArrayStoreException if the runtime type of a is not a supertype |
686 |
* of the runtime type of every element in this Vector |
687 |
* @throws NullPointerException if the given array is null |
688 |
* @since 1.2 |
689 |
*/ |
690 |
@SuppressWarnings("unchecked") |
691 |
public synchronized <T> T[] toArray(T[] a) { |
692 |
if (a.length < elementCount) |
693 |
return (T[]) Arrays.copyOf(elementData, elementCount, a.getClass()); |
694 |
|
695 |
System.arraycopy(elementData, 0, a, 0, elementCount); |
696 |
|
697 |
if (a.length > elementCount) |
698 |
a[elementCount] = null; |
699 |
|
700 |
return a; |
701 |
} |
702 |
|
703 |
// Positional Access Operations |
704 |
|
705 |
@SuppressWarnings("unchecked") |
706 |
E elementData(int index) { |
707 |
return (E) elementData[index]; |
708 |
} |
709 |
|
710 |
/** |
711 |
* Returns the element at the specified position in this Vector. |
712 |
* |
713 |
* @param index index of the element to return |
714 |
* @return object at the specified index |
715 |
* @throws ArrayIndexOutOfBoundsException if the index is out of range |
716 |
* ({@code index < 0 || index >= size()}) |
717 |
* @since 1.2 |
718 |
*/ |
719 |
public synchronized E get(int index) { |
720 |
if (index >= elementCount) |
721 |
throw new ArrayIndexOutOfBoundsException(index); |
722 |
|
723 |
return elementData(index); |
724 |
} |
725 |
|
726 |
/** |
727 |
* Replaces the element at the specified position in this Vector with the |
728 |
* specified element. |
729 |
* |
730 |
* @param index index of the element to replace |
731 |
* @param element element to be stored at the specified position |
732 |
* @return the element previously at the specified position |
733 |
* @throws ArrayIndexOutOfBoundsException if the index is out of range |
734 |
* ({@code index < 0 || index >= size()}) |
735 |
* @since 1.2 |
736 |
*/ |
737 |
public synchronized E set(int index, E element) { |
738 |
if (index >= elementCount) |
739 |
throw new ArrayIndexOutOfBoundsException(index); |
740 |
|
741 |
E oldValue = elementData(index); |
742 |
elementData[index] = element; |
743 |
return oldValue; |
744 |
} |
745 |
|
746 |
/** |
747 |
* Appends the specified element to the end of this Vector. |
748 |
* |
749 |
* @param e element to be appended to this Vector |
750 |
* @return {@code true} (as specified by {@link Collection#add}) |
751 |
* @since 1.2 |
752 |
*/ |
753 |
public synchronized boolean add(E e) { |
754 |
modCount++; |
755 |
ensureCapacityHelper(elementCount + 1); |
756 |
elementData[elementCount++] = e; |
757 |
return true; |
758 |
} |
759 |
|
760 |
/** |
761 |
* Removes the first occurrence of the specified element in this Vector |
762 |
* If the Vector does not contain the element, it is unchanged. More |
763 |
* formally, removes the element with the lowest index i such that |
764 |
* {@code (o==null ? get(i)==null : o.equals(get(i)))} (if such |
765 |
* an element exists). |
766 |
* |
767 |
* @param o element to be removed from this Vector, if present |
768 |
* @return true if the Vector contained the specified element |
769 |
* @since 1.2 |
770 |
*/ |
771 |
public boolean remove(Object o) { |
772 |
return removeElement(o); |
773 |
} |
774 |
|
775 |
/** |
776 |
* Inserts the specified element at the specified position in this Vector. |
777 |
* Shifts the element currently at that position (if any) and any |
778 |
* subsequent elements to the right (adds one to their indices). |
779 |
* |
780 |
* @param index index at which the specified element is to be inserted |
781 |
* @param element element to be inserted |
782 |
* @throws ArrayIndexOutOfBoundsException if the index is out of range |
783 |
* ({@code index < 0 || index > size()}) |
784 |
* @since 1.2 |
785 |
*/ |
786 |
public void add(int index, E element) { |
787 |
insertElementAt(element, index); |
788 |
} |
789 |
|
790 |
/** |
791 |
* Removes the element at the specified position in this Vector. |
792 |
* Shifts any subsequent elements to the left (subtracts one from their |
793 |
* indices). Returns the element that was removed from the Vector. |
794 |
* |
795 |
* @throws ArrayIndexOutOfBoundsException if the index is out of range |
796 |
* ({@code index < 0 || index >= size()}) |
797 |
* @param index the index of the element to be removed |
798 |
* @return element that was removed |
799 |
* @since 1.2 |
800 |
*/ |
801 |
public synchronized E remove(int index) { |
802 |
modCount++; |
803 |
if (index >= elementCount) |
804 |
throw new ArrayIndexOutOfBoundsException(index); |
805 |
E oldValue = elementData(index); |
806 |
|
807 |
int numMoved = elementCount - index - 1; |
808 |
if (numMoved > 0) |
809 |
System.arraycopy(elementData, index+1, elementData, index, |
810 |
numMoved); |
811 |
elementData[--elementCount] = null; // Let gc do its work |
812 |
|
813 |
return oldValue; |
814 |
} |
815 |
|
816 |
/** |
817 |
* Removes all of the elements from this Vector. The Vector will |
818 |
* be empty after this call returns (unless it throws an exception). |
819 |
* |
820 |
* @since 1.2 |
821 |
*/ |
822 |
public void clear() { |
823 |
removeAllElements(); |
824 |
} |
825 |
|
826 |
// Bulk Operations |
827 |
|
828 |
/** |
829 |
* Returns true if this Vector contains all of the elements in the |
830 |
* specified Collection. |
831 |
* |
832 |
* @param c a collection whose elements will be tested for containment |
833 |
* in this Vector |
834 |
* @return true if this Vector contains all of the elements in the |
835 |
* specified collection |
836 |
* @throws NullPointerException if the specified collection is null |
837 |
*/ |
838 |
public synchronized boolean containsAll(Collection<?> c) { |
839 |
return super.containsAll(c); |
840 |
} |
841 |
|
842 |
/** |
843 |
* Appends all of the elements in the specified Collection to the end of |
844 |
* this Vector, in the order that they are returned by the specified |
845 |
* Collection's Iterator. The behavior of this operation is undefined if |
846 |
* the specified Collection is modified while the operation is in progress. |
847 |
* (This implies that the behavior of this call is undefined if the |
848 |
* specified Collection is this Vector, and this Vector is nonempty.) |
849 |
* |
850 |
* @param c elements to be inserted into this Vector |
851 |
* @return {@code true} if this Vector changed as a result of the call |
852 |
* @throws NullPointerException if the specified collection is null |
853 |
* @since 1.2 |
854 |
*/ |
855 |
public synchronized boolean addAll(Collection<? extends E> c) { |
856 |
modCount++; |
857 |
Object[] a = c.toArray(); |
858 |
int numNew = a.length; |
859 |
ensureCapacityHelper(elementCount + numNew); |
860 |
System.arraycopy(a, 0, elementData, elementCount, numNew); |
861 |
elementCount += numNew; |
862 |
return numNew != 0; |
863 |
} |
864 |
|
865 |
/** |
866 |
* Removes from this Vector all of its elements that are contained in the |
867 |
* specified Collection. |
868 |
* |
869 |
* @param c a collection of elements to be removed from the Vector |
870 |
* @return true if this Vector changed as a result of the call |
871 |
* @throws ClassCastException if the types of one or more elements |
872 |
* in this vector are incompatible with the specified |
873 |
* collection (optional) |
874 |
* @throws NullPointerException if this vector contains one or more null |
875 |
* elements and the specified collection does not support null |
876 |
* elements (optional), or if the specified collection is null |
877 |
* @since 1.2 |
878 |
*/ |
879 |
public synchronized boolean removeAll(Collection<?> c) { |
880 |
return super.removeAll(c); |
881 |
} |
882 |
|
883 |
/** |
884 |
* Retains only the elements in this Vector that are contained in the |
885 |
* specified Collection. In other words, removes from this Vector all |
886 |
* of its elements that are not contained in the specified Collection. |
887 |
* |
888 |
* @param c a collection of elements to be retained in this Vector |
889 |
* (all other elements are removed) |
890 |
* @return true if this Vector changed as a result of the call |
891 |
* @throws ClassCastException if the types of one or more elements |
892 |
* in this vector are incompatible with the specified |
893 |
* collection (optional) |
894 |
* @throws NullPointerException if this vector contains one or more null |
895 |
* elements and the specified collection does not support null |
896 |
* elements (optional), or if the specified collection is null |
897 |
* @since 1.2 |
898 |
*/ |
899 |
public synchronized boolean retainAll(Collection<?> c) { |
900 |
return super.retainAll(c); |
901 |
} |
902 |
|
903 |
/** |
904 |
* Inserts all of the elements in the specified Collection into this |
905 |
* Vector at the specified position. Shifts the element currently at |
906 |
* that position (if any) and any subsequent elements to the right |
907 |
* (increases their indices). The new elements will appear in the Vector |
908 |
* in the order that they are returned by the specified Collection's |
909 |
* iterator. |
910 |
* |
911 |
* @param index index at which to insert the first element from the |
912 |
* specified collection |
913 |
* @param c elements to be inserted into this Vector |
914 |
* @return {@code true} if this Vector changed as a result of the call |
915 |
* @throws ArrayIndexOutOfBoundsException if the index is out of range |
916 |
* ({@code index < 0 || index > size()}) |
917 |
* @throws NullPointerException if the specified collection is null |
918 |
* @since 1.2 |
919 |
*/ |
920 |
public synchronized boolean addAll(int index, Collection<? extends E> c) { |
921 |
modCount++; |
922 |
if (index < 0 || index > elementCount) |
923 |
throw new ArrayIndexOutOfBoundsException(index); |
924 |
|
925 |
Object[] a = c.toArray(); |
926 |
int numNew = a.length; |
927 |
ensureCapacityHelper(elementCount + numNew); |
928 |
|
929 |
int numMoved = elementCount - index; |
930 |
if (numMoved > 0) |
931 |
System.arraycopy(elementData, index, elementData, index + numNew, |
932 |
numMoved); |
933 |
|
934 |
System.arraycopy(a, 0, elementData, index, numNew); |
935 |
elementCount += numNew; |
936 |
return numNew != 0; |
937 |
} |
938 |
|
939 |
/** |
940 |
* Compares the specified Object with this Vector for equality. Returns |
941 |
* true if and only if the specified Object is also a List, both Lists |
942 |
* have the same size, and all corresponding pairs of elements in the two |
943 |
* Lists are <em>equal</em>. (Two elements {@code e1} and |
944 |
* {@code e2} are <em>equal</em> if {@code (e1==null ? e2==null : |
945 |
* e1.equals(e2))}.) In other words, two Lists are defined to be |
946 |
* equal if they contain the same elements in the same order. |
947 |
* |
948 |
* @param o the Object to be compared for equality with this Vector |
949 |
* @return true if the specified Object is equal to this Vector |
950 |
*/ |
951 |
public synchronized boolean equals(Object o) { |
952 |
return super.equals(o); |
953 |
} |
954 |
|
955 |
/** |
956 |
* Returns the hash code value for this Vector. |
957 |
*/ |
958 |
public synchronized int hashCode() { |
959 |
return super.hashCode(); |
960 |
} |
961 |
|
962 |
/** |
963 |
* Returns a string representation of this Vector, containing |
964 |
* the String representation of each element. |
965 |
*/ |
966 |
public synchronized String toString() { |
967 |
return super.toString(); |
968 |
} |
969 |
|
970 |
/** |
971 |
* Returns a view of the portion of this List between fromIndex, |
972 |
* inclusive, and toIndex, exclusive. (If fromIndex and toIndex are |
973 |
* equal, the returned List is empty.) The returned List is backed by this |
974 |
* List, so changes in the returned List are reflected in this List, and |
975 |
* vice-versa. The returned List supports all of the optional List |
976 |
* operations supported by this List. |
977 |
* |
978 |
* <p>This method eliminates the need for explicit range operations (of |
979 |
* the sort that commonly exist for arrays). Any operation that expects |
980 |
* a List can be used as a range operation by operating on a subList view |
981 |
* instead of a whole List. For example, the following idiom |
982 |
* removes a range of elements from a List: |
983 |
* <pre> |
984 |
* list.subList(from, to).clear(); |
985 |
* </pre> |
986 |
* Similar idioms may be constructed for indexOf and lastIndexOf, |
987 |
* and all of the algorithms in the Collections class can be applied to |
988 |
* a subList. |
989 |
* |
990 |
* <p>The semantics of the List returned by this method become undefined if |
991 |
* the backing list (i.e., this List) is <i>structurally modified</i> in |
992 |
* any way other than via the returned List. (Structural modifications are |
993 |
* those that change the size of the List, or otherwise perturb it in such |
994 |
* a fashion that iterations in progress may yield incorrect results.) |
995 |
* |
996 |
* @param fromIndex low endpoint (inclusive) of the subList |
997 |
* @param toIndex high endpoint (exclusive) of the subList |
998 |
* @return a view of the specified range within this List |
999 |
* @throws IndexOutOfBoundsException if an endpoint index value is out of range |
1000 |
* {@code (fromIndex < 0 || toIndex > size)} |
1001 |
* @throws IllegalArgumentException if the endpoint indices are out of order |
1002 |
* {@code (fromIndex > toIndex)} |
1003 |
*/ |
1004 |
public synchronized List<E> subList(int fromIndex, int toIndex) { |
1005 |
return Collections.synchronizedList(super.subList(fromIndex, toIndex), |
1006 |
this); |
1007 |
} |
1008 |
|
1009 |
/** |
1010 |
* Removes from this list all of the elements whose index is between |
1011 |
* {@code fromIndex}, inclusive, and {@code toIndex}, exclusive. |
1012 |
* Shifts any succeeding elements to the left (reduces their index). |
1013 |
* This call shortens the list by {@code (toIndex - fromIndex)} elements. |
1014 |
* (If {@code toIndex==fromIndex}, this operation has no effect.) |
1015 |
*/ |
1016 |
protected synchronized void removeRange(int fromIndex, int toIndex) { |
1017 |
modCount++; |
1018 |
int numMoved = elementCount - toIndex; |
1019 |
System.arraycopy(elementData, toIndex, elementData, fromIndex, |
1020 |
numMoved); |
1021 |
|
1022 |
// Let gc do its work |
1023 |
int newElementCount = elementCount - (toIndex-fromIndex); |
1024 |
while (elementCount != newElementCount) |
1025 |
elementData[--elementCount] = null; |
1026 |
} |
1027 |
|
1028 |
/** |
1029 |
* Save the state of the {@code Vector} instance to a stream (that |
1030 |
* is, serialize it). This method is present merely for synchronization. |
1031 |
* It just calls the default writeObject method. |
1032 |
*/ |
1033 |
private synchronized void writeObject(java.io.ObjectOutputStream s) |
1034 |
throws java.io.IOException |
1035 |
{ |
1036 |
s.defaultWriteObject(); |
1037 |
} |
1038 |
|
1039 |
/** |
1040 |
* Returns a list iterator over the elements in this list (in proper |
1041 |
* sequence), starting at the specified position in the list. |
1042 |
* The specified index indicates the first element that would be |
1043 |
* returned by an initial call to {@link ListIterator#next next}. |
1044 |
* An initial call to {@link ListIterator#previous previous} would |
1045 |
* return the element with the specified index minus one. |
1046 |
* |
1047 |
* <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>. |
1048 |
* |
1049 |
* @throws IndexOutOfBoundsException {@inheritDoc} |
1050 |
*/ |
1051 |
public synchronized ListIterator<E> listIterator(int index) { |
1052 |
if (index < 0 || index > elementCount) |
1053 |
throw new IndexOutOfBoundsException("Index: "+index); |
1054 |
return new ListItr(index); |
1055 |
} |
1056 |
|
1057 |
/** |
1058 |
* Returns a list iterator over the elements in this list (in proper |
1059 |
* sequence). |
1060 |
* |
1061 |
* <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>. |
1062 |
* |
1063 |
* @see #listIterator(int) |
1064 |
*/ |
1065 |
public synchronized ListIterator<E> listIterator() { |
1066 |
return new ListItr(0); |
1067 |
} |
1068 |
|
1069 |
/** |
1070 |
* Returns an iterator over the elements in this list in proper sequence. |
1071 |
* |
1072 |
* <p>The returned iterator is <a href="#fail-fast"><i>fail-fast</i></a>. |
1073 |
* |
1074 |
* @return an iterator over the elements in this list in proper sequence |
1075 |
*/ |
1076 |
public synchronized Iterator<E> iterator() { |
1077 |
return new Itr(); |
1078 |
} |
1079 |
|
1080 |
/** |
1081 |
* An optimized version of AbstractList.Itr |
1082 |
*/ |
1083 |
private class Itr implements Iterator<E> { |
1084 |
int cursor; // index of next element to return |
1085 |
int lastRet = -1; // index of last element returned; -1 if no such |
1086 |
int expectedModCount = modCount; |
1087 |
|
1088 |
public boolean hasNext() { |
1089 |
// Racy but within spec, since modifications are checked |
1090 |
// within or after synchronization in next/previous |
1091 |
return cursor != elementCount; |
1092 |
} |
1093 |
|
1094 |
public E next() { |
1095 |
synchronized (Vector.this) { |
1096 |
checkForComodification(); |
1097 |
int i = cursor; |
1098 |
if (i >= elementCount) |
1099 |
throw new NoSuchElementException(); |
1100 |
cursor = i + 1; |
1101 |
return elementData(lastRet = i); |
1102 |
} |
1103 |
} |
1104 |
|
1105 |
public void remove() { |
1106 |
if (lastRet == -1) |
1107 |
throw new IllegalStateException(); |
1108 |
synchronized (Vector.this) { |
1109 |
checkForComodification(); |
1110 |
Vector.this.remove(lastRet); |
1111 |
expectedModCount = modCount; |
1112 |
} |
1113 |
cursor = lastRet; |
1114 |
lastRet = -1; |
1115 |
} |
1116 |
|
1117 |
final void checkForComodification() { |
1118 |
if (modCount != expectedModCount) |
1119 |
throw new ConcurrentModificationException(); |
1120 |
} |
1121 |
} |
1122 |
|
1123 |
/** |
1124 |
* An optimized version of AbstractList.ListItr |
1125 |
*/ |
1126 |
final class ListItr extends Itr implements ListIterator<E> { |
1127 |
ListItr(int index) { |
1128 |
super(); |
1129 |
cursor = index; |
1130 |
} |
1131 |
|
1132 |
public boolean hasPrevious() { |
1133 |
return cursor != 0; |
1134 |
} |
1135 |
|
1136 |
public int nextIndex() { |
1137 |
return cursor; |
1138 |
} |
1139 |
|
1140 |
public int previousIndex() { |
1141 |
return cursor - 1; |
1142 |
} |
1143 |
|
1144 |
public E previous() { |
1145 |
synchronized (Vector.this) { |
1146 |
checkForComodification(); |
1147 |
int i = cursor - 1; |
1148 |
if (i < 0) |
1149 |
throw new NoSuchElementException(); |
1150 |
cursor = i; |
1151 |
return elementData(lastRet = i); |
1152 |
} |
1153 |
} |
1154 |
|
1155 |
public void set(E e) { |
1156 |
if (lastRet == -1) |
1157 |
throw new IllegalStateException(); |
1158 |
synchronized (Vector.this) { |
1159 |
checkForComodification(); |
1160 |
Vector.this.set(lastRet, e); |
1161 |
} |
1162 |
} |
1163 |
|
1164 |
public void add(E e) { |
1165 |
int i = cursor; |
1166 |
synchronized (Vector.this) { |
1167 |
checkForComodification(); |
1168 |
Vector.this.add(i, e); |
1169 |
expectedModCount = modCount; |
1170 |
} |
1171 |
cursor = i + 1; |
1172 |
lastRet = -1; |
1173 |
} |
1174 |
} |
1175 |
} |