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/* |
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* %W% %E% |
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* |
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* Copyright 2006 Sun Microsystems, Inc. All rights reserved. |
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* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. |
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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</code> 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</code> can grow or shrink as needed to accommodate |
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* adding and removing items after the <code>Vector</code> has been created.<p> |
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* |
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* Each vector tries to optimize storage management by maintaining a |
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* <code>capacity</code> and a <code>capacityIncrement</code>. The |
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* <code>capacity</code> 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</code>. 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. <p> |
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* |
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* As of the Java 2 platform v1.2, this class has been retrofitted to |
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* implement List, so that it becomes a part of Java's collection framework. |
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* Unlike the new collection implementations, Vector is synchronized.<p> |
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* |
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* The Iterators returned by Vector's iterator and listIterator |
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* methods are <em>fail-fast</em>: if the Vector is structurally modified |
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* at any time after the Iterator is created, in any way except through the |
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* Iterator's own remove or add methods, the Iterator will throw a |
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* ConcurrentModificationException. Thus, in the face of concurrent |
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* modification, the Iterator fails quickly and cleanly, rather than risking |
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* arbitrary, non-deterministic behavior at an undetermined time in the future. |
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* The Enumerations returned by Vector's elements method are <em>not</em> |
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* 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 <tt>ConcurrentModificationException</tt> 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><p> |
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* |
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* This class is a member of the |
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* <a href="{@docRoot}/../guide/collections/index.html"> |
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* Java Collections Framework</a>. |
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* |
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* @author Lee Boynton |
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* @author Jonathan Payne |
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* @version %I%, %G% |
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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.<p> |
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* |
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* 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 <tt>Vector</tt> object. |
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* Components <tt>elementData[0]</tt> through |
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* <tt>elementData[elementCount-1]</tt> 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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* @exception 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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* @exception 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 <tt>10</tt> 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 <tt>k</tt> in this vector is copied into |
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* component <tt>k</tt> of <tt>anArray</tt>. |
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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 <tt>elementData</tt>, |
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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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* <tt>minCapacity</tt>, then its capacity is increased by replacing its |
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* internal data array, kept in the field <tt>elementData</tt>, 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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* <tt>capacityIncrement</tt>, unless the value of |
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* <tt>capacityIncrement</tt> 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 <tt>minCapacity</tt>, then the new capacity will |
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* be <tt>minCapacity</tt>. |
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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 java.util.Vector#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</code> 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</code> 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 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 <tt>elementData</tt> |
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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</code> 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</code> 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 <tt>Enumeration</tt> object will generate all items in |
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* this vector. The first item generated is the item at index <tt>0</tt>, |
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* then the item at index <tt>1</tt>, 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 Enumeration |
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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 (E)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 <tt>true</tt> if this vector contains the specified element. |
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* More formally, returns <tt>true</tt> if and only if this vector |
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* contains 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 vector is to be tested |
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* @return <tt>true</tt> 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 <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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* @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 <tt>index</tt>, or returns -1 if |
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* the element is not found. |
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* More formally, returns the lowest index <tt>i</tt> 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 <tt>index</tt> or later in the vector; |
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* <tt>-1</tt> 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 <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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* @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 |
387 |
* this vector, searching backwards from <tt>index</tt>, or returns -1 if |
388 |
* the element is not found. |
389 |
* More formally, returns the highest index <tt>i</tt> such that |
390 |
* <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. |
392 |
* |
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* @param o element to search for |
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* @param index index to start searching backwards from |
395 |
* @return the index of the last occurrence of the element at position |
396 |
* less than or equal to <tt>index</tt> 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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*/ |
401 |
public synchronized int lastIndexOf(Object o, int index) { |
402 |
if (index >= elementCount) |
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throw new IndexOutOfBoundsException(index + " >= "+ elementCount); |
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|
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if (o == null) { |
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for (int i = index; i >= 0; i--) |
407 |
if (elementData[i]==null) |
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return i; |
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} else { |
410 |
for (int i = index; i >= 0; i--) |
411 |
if (o.equals(elementData[i])) |
412 |
return i; |
413 |
} |
414 |
return -1; |
415 |
} |
416 |
|
417 |
/** |
418 |
* Returns the component at the specified index.<p> |
419 |
* |
420 |
* This method is identical in functionality to the get method |
421 |
* (which is part of the List interface). |
422 |
* |
423 |
* @param index an index into this vector |
424 |
* @return the component at the specified index |
425 |
* @exception ArrayIndexOutOfBoundsException if the <tt>index</tt> |
426 |
* is negative or not less than the current size of this |
427 |
* <tt>Vector</tt> object. |
428 |
* @see #get(int) |
429 |
* @see List |
430 |
*/ |
431 |
public synchronized E elementAt(int index) { |
432 |
if (index >= elementCount) { |
433 |
throw new ArrayIndexOutOfBoundsException(index + " >= " + elementCount); |
434 |
} |
435 |
|
436 |
return (E)elementData[index]; |
437 |
} |
438 |
|
439 |
/** |
440 |
* Returns the first component (the item at index <tt>0</tt>) of |
441 |
* this vector. |
442 |
* |
443 |
* @return the first component of this vector |
444 |
* @exception NoSuchElementException if this vector has no components |
445 |
*/ |
446 |
public synchronized E firstElement() { |
447 |
if (elementCount == 0) { |
448 |
throw new NoSuchElementException(); |
449 |
} |
450 |
return (E)elementData[0]; |
451 |
} |
452 |
|
453 |
/** |
454 |
* Returns the last component of the vector. |
455 |
* |
456 |
* @return the last component of the vector, i.e., the component at index |
457 |
* <code>size() - 1</code>. |
458 |
* @exception NoSuchElementException if this vector is empty |
459 |
*/ |
460 |
public synchronized E lastElement() { |
461 |
if (elementCount == 0) { |
462 |
throw new NoSuchElementException(); |
463 |
} |
464 |
return (E)elementData[elementCount - 1]; |
465 |
} |
466 |
|
467 |
/** |
468 |
* Sets the component at the specified <code>index</code> of this |
469 |
* vector to be the specified object. The previous component at that |
470 |
* position is discarded.<p> |
471 |
* |
472 |
* The index must be a value greater than or equal to <code>0</code> |
473 |
* and less than the current size of the vector. <p> |
474 |
* |
475 |
* This method is identical in functionality to the set method |
476 |
* (which is part of the List interface). Note that the set method reverses |
477 |
* the order of the parameters, to more closely match array usage. Note |
478 |
* also that the set method returns the old value that was stored at the |
479 |
* specified position. |
480 |
* |
481 |
* @param obj what the component is to be set to |
482 |
* @param index the specified index |
483 |
* @exception ArrayIndexOutOfBoundsException if the index was invalid |
484 |
* @see #size() |
485 |
* @see List |
486 |
* @see #set(int, java.lang.Object) |
487 |
*/ |
488 |
public synchronized void setElementAt(E obj, int index) { |
489 |
if (index >= elementCount) { |
490 |
throw new ArrayIndexOutOfBoundsException(index + " >= " + |
491 |
elementCount); |
492 |
} |
493 |
elementData[index] = obj; |
494 |
} |
495 |
|
496 |
/** |
497 |
* Deletes the component at the specified index. Each component in |
498 |
* this vector with an index greater or equal to the specified |
499 |
* <code>index</code> is shifted downward to have an index one |
500 |
* smaller than the value it had previously. The size of this vector |
501 |
* is decreased by <tt>1</tt>.<p> |
502 |
* |
503 |
* The index must be a value greater than or equal to <code>0</code> |
504 |
* and less than the current size of the vector. <p> |
505 |
* |
506 |
* This method is identical in functionality to the remove method |
507 |
* (which is part of the List interface). Note that the remove method |
508 |
* returns the old value that was stored at the specified position. |
509 |
* |
510 |
* @param index the index of the object to remove |
511 |
* @exception ArrayIndexOutOfBoundsException if the index was invalid |
512 |
* @see #size() |
513 |
* @see #remove(int) |
514 |
* @see List |
515 |
*/ |
516 |
public synchronized void removeElementAt(int index) { |
517 |
modCount++; |
518 |
if (index >= elementCount) { |
519 |
throw new ArrayIndexOutOfBoundsException(index + " >= " + |
520 |
elementCount); |
521 |
} |
522 |
else if (index < 0) { |
523 |
throw new ArrayIndexOutOfBoundsException(index); |
524 |
} |
525 |
int j = elementCount - index - 1; |
526 |
if (j > 0) { |
527 |
System.arraycopy(elementData, index + 1, elementData, index, j); |
528 |
} |
529 |
elementCount--; |
530 |
elementData[elementCount] = null; /* to let gc do its work */ |
531 |
} |
532 |
|
533 |
/** |
534 |
* Inserts the specified object as a component in this vector at the |
535 |
* specified <code>index</code>. Each component in this vector with |
536 |
* an index greater or equal to the specified <code>index</code> is |
537 |
* shifted upward to have an index one greater than the value it had |
538 |
* previously. <p> |
539 |
* |
540 |
* The index must be a value greater than or equal to <code>0</code> |
541 |
* and less than or equal to the current size of the vector. (If the |
542 |
* index is equal to the current size of the vector, the new element |
543 |
* is appended to the Vector.)<p> |
544 |
* |
545 |
* This method is identical in functionality to the add(Object, int) method |
546 |
* (which is part of the List interface). Note that the add method reverses |
547 |
* the order of the parameters, to more closely match array usage. |
548 |
* |
549 |
* @param obj the component to insert |
550 |
* @param index where to insert the new component |
551 |
* @exception ArrayIndexOutOfBoundsException if the index was invalid |
552 |
* @see #size() |
553 |
* @see #add(int, Object) |
554 |
* @see List |
555 |
*/ |
556 |
public synchronized void insertElementAt(E obj, int index) { |
557 |
modCount++; |
558 |
if (index > elementCount) { |
559 |
throw new ArrayIndexOutOfBoundsException(index |
560 |
+ " > " + elementCount); |
561 |
} |
562 |
ensureCapacityHelper(elementCount + 1); |
563 |
System.arraycopy(elementData, index, elementData, index + 1, elementCount - index); |
564 |
elementData[index] = obj; |
565 |
elementCount++; |
566 |
} |
567 |
|
568 |
/** |
569 |
* Adds the specified component to the end of this vector, |
570 |
* increasing its size by one. The capacity of this vector is |
571 |
* increased if its size becomes greater than its capacity. <p> |
572 |
* |
573 |
* This method is identical in functionality to the add(Object) method |
574 |
* (which is part of the List interface). |
575 |
* |
576 |
* @param obj the component to be added |
577 |
* @see #add(Object) |
578 |
* @see List |
579 |
*/ |
580 |
public synchronized void addElement(E obj) { |
581 |
modCount++; |
582 |
ensureCapacityHelper(elementCount + 1); |
583 |
elementData[elementCount++] = obj; |
584 |
} |
585 |
|
586 |
/** |
587 |
* Removes the first (lowest-indexed) occurrence of the argument |
588 |
* from this vector. If the object is found in this vector, each |
589 |
* component in the vector with an index greater or equal to the |
590 |
* object's index is shifted downward to have an index one smaller |
591 |
* than the value it had previously.<p> |
592 |
* |
593 |
* This method is identical in functionality to the remove(Object) |
594 |
* method (which is part of the List interface). |
595 |
* |
596 |
* @param obj the component to be removed |
597 |
* @return <code>true</code> if the argument was a component of this |
598 |
* vector; <code>false</code> otherwise. |
599 |
* @see List#remove(Object) |
600 |
* @see List |
601 |
*/ |
602 |
public synchronized boolean removeElement(Object obj) { |
603 |
modCount++; |
604 |
int i = indexOf(obj); |
605 |
if (i >= 0) { |
606 |
removeElementAt(i); |
607 |
return true; |
608 |
} |
609 |
return false; |
610 |
} |
611 |
|
612 |
/** |
613 |
* Removes all components from this vector and sets its size to zero.<p> |
614 |
* |
615 |
* This method is identical in functionality to the clear method |
616 |
* (which is part of the List interface). |
617 |
* |
618 |
* @see #clear |
619 |
* @see List |
620 |
*/ |
621 |
public synchronized void removeAllElements() { |
622 |
modCount++; |
623 |
// Let gc do its work |
624 |
for (int i = 0; i < elementCount; i++) |
625 |
elementData[i] = null; |
626 |
|
627 |
elementCount = 0; |
628 |
} |
629 |
|
630 |
/** |
631 |
* Returns a clone of this vector. The copy will contain a |
632 |
* reference to a clone of the internal data array, not a reference |
633 |
* to the original internal data array of this <tt>Vector</tt> object. |
634 |
* |
635 |
* @return a clone of this vector |
636 |
*/ |
637 |
public synchronized Object clone() { |
638 |
try { |
639 |
Vector<E> v = (Vector<E>) super.clone(); |
640 |
v.elementData = Arrays.copyOf(elementData, elementCount); |
641 |
v.modCount = 0; |
642 |
return v; |
643 |
} catch (CloneNotSupportedException e) { |
644 |
// this shouldn't happen, since we are Cloneable |
645 |
throw new InternalError(); |
646 |
} |
647 |
} |
648 |
|
649 |
/** |
650 |
* Returns an array containing all of the elements in this Vector |
651 |
* in the correct order. |
652 |
* |
653 |
* @since 1.2 |
654 |
*/ |
655 |
public synchronized Object[] toArray() { |
656 |
return Arrays.copyOf(elementData, elementCount); |
657 |
} |
658 |
|
659 |
/** |
660 |
* Returns an array containing all of the elements in this Vector in the |
661 |
* correct order; the runtime type of the returned array is that of the |
662 |
* specified array. If the Vector fits in the specified array, it is |
663 |
* returned therein. Otherwise, a new array is allocated with the runtime |
664 |
* type of the specified array and the size of this Vector.<p> |
665 |
* |
666 |
* If the Vector fits in the specified array with room to spare |
667 |
* (i.e., the array has more elements than the Vector), |
668 |
* the element in the array immediately following the end of the |
669 |
* Vector is set to null. (This is useful in determining the length |
670 |
* of the Vector <em>only</em> if the caller knows that the Vector |
671 |
* does not contain any null elements.) |
672 |
* |
673 |
* @param a the array into which the elements of the Vector are to |
674 |
* be stored, if it is big enough; otherwise, a new array of the |
675 |
* same runtime type is allocated for this purpose. |
676 |
* @return an array containing the elements of the Vector |
677 |
* @exception ArrayStoreException the runtime type of a is not a supertype |
678 |
* of the runtime type of every element in this Vector |
679 |
* @throws NullPointerException if the given array is null |
680 |
* @since 1.2 |
681 |
*/ |
682 |
public synchronized <T> T[] toArray(T[] a) { |
683 |
if (a.length < elementCount) |
684 |
return (T[]) Arrays.copyOf(elementData, elementCount, a.getClass()); |
685 |
|
686 |
System.arraycopy(elementData, 0, a, 0, elementCount); |
687 |
|
688 |
if (a.length > elementCount) |
689 |
a[elementCount] = null; |
690 |
|
691 |
return a; |
692 |
} |
693 |
|
694 |
// Positional Access Operations |
695 |
|
696 |
/** |
697 |
* Returns the element at the specified position in this Vector. |
698 |
* |
699 |
* @param index index of the element to return |
700 |
* @return object at the specified index |
701 |
* @exception ArrayIndexOutOfBoundsException index is out of range (index |
702 |
* < 0 || index >= size()) |
703 |
* @since 1.2 |
704 |
*/ |
705 |
public synchronized E get(int index) { |
706 |
if (index >= elementCount) |
707 |
throw new ArrayIndexOutOfBoundsException(index); |
708 |
|
709 |
return (E)elementData[index]; |
710 |
} |
711 |
|
712 |
/** |
713 |
* Replaces the element at the specified position in this Vector with the |
714 |
* specified element. |
715 |
* |
716 |
* @param index index of the element to replace |
717 |
* @param element element to be stored at the specified position |
718 |
* @return the element previously at the specified position |
719 |
* @exception ArrayIndexOutOfBoundsException index out of range |
720 |
* (index < 0 || index >= size()) |
721 |
* @since 1.2 |
722 |
*/ |
723 |
public synchronized E set(int index, E element) { |
724 |
if (index >= elementCount) |
725 |
throw new ArrayIndexOutOfBoundsException(index); |
726 |
|
727 |
Object oldValue = elementData[index]; |
728 |
elementData[index] = element; |
729 |
return (E)oldValue; |
730 |
} |
731 |
|
732 |
/** |
733 |
* Appends the specified element to the end of this Vector. |
734 |
* |
735 |
* @param e element to be appended to this Vector |
736 |
* @return <tt>true</tt> (as specified by {@link Collection#add}) |
737 |
* @since 1.2 |
738 |
*/ |
739 |
public synchronized boolean add(E e) { |
740 |
modCount++; |
741 |
ensureCapacityHelper(elementCount + 1); |
742 |
elementData[elementCount++] = e; |
743 |
return true; |
744 |
} |
745 |
|
746 |
/** |
747 |
* Removes the first occurrence of the specified element in this Vector |
748 |
* If the Vector does not contain the element, it is unchanged. More |
749 |
* formally, removes the element with the lowest index i such that |
750 |
* <code>(o==null ? get(i)==null : o.equals(get(i)))</code> (if such |
751 |
* an element exists). |
752 |
* |
753 |
* @param o element to be removed from this Vector, if present |
754 |
* @return true if the Vector contained the specified element |
755 |
* @since 1.2 |
756 |
*/ |
757 |
public boolean remove(Object o) { |
758 |
return removeElement(o); |
759 |
} |
760 |
|
761 |
/** |
762 |
* Inserts the specified element at the specified position in this Vector. |
763 |
* Shifts the element currently at that position (if any) and any |
764 |
* subsequent elements to the right (adds one to their indices). |
765 |
* |
766 |
* @param index index at which the specified element is to be inserted |
767 |
* @param element element to be inserted |
768 |
* @exception ArrayIndexOutOfBoundsException index is out of range |
769 |
* (index < 0 || index > size()) |
770 |
* @since 1.2 |
771 |
*/ |
772 |
public void add(int index, E element) { |
773 |
insertElementAt(element, index); |
774 |
} |
775 |
|
776 |
/** |
777 |
* Removes the element at the specified position in this Vector. |
778 |
* Shifts any subsequent elements to the left (subtracts one from their |
779 |
* indices). Returns the element that was removed from the Vector. |
780 |
* |
781 |
* @exception ArrayIndexOutOfBoundsException index out of range (index |
782 |
* < 0 || index >= size()) |
783 |
* @param index the index of the element to be removed |
784 |
* @return element that was removed |
785 |
* @since 1.2 |
786 |
*/ |
787 |
public synchronized E remove(int index) { |
788 |
modCount++; |
789 |
if (index >= elementCount) |
790 |
throw new ArrayIndexOutOfBoundsException(index); |
791 |
Object oldValue = elementData[index]; |
792 |
|
793 |
int numMoved = elementCount - index - 1; |
794 |
if (numMoved > 0) |
795 |
System.arraycopy(elementData, index+1, elementData, index, |
796 |
numMoved); |
797 |
elementData[--elementCount] = null; // Let gc do its work |
798 |
|
799 |
return (E)oldValue; |
800 |
} |
801 |
|
802 |
/** |
803 |
* Removes all of the elements from this Vector. The Vector will |
804 |
* be empty after this call returns (unless it throws an exception). |
805 |
* |
806 |
* @since 1.2 |
807 |
*/ |
808 |
public void clear() { |
809 |
removeAllElements(); |
810 |
} |
811 |
|
812 |
// Bulk Operations |
813 |
|
814 |
/** |
815 |
* Returns true if this Vector contains all of the elements in the |
816 |
* specified Collection. |
817 |
* |
818 |
* @param c a collection whose elements will be tested for containment |
819 |
* in this Vector |
820 |
* @return true if this Vector contains all of the elements in the |
821 |
* specified collection |
822 |
* @throws NullPointerException if the specified collection is null |
823 |
*/ |
824 |
public synchronized boolean containsAll(Collection<?> c) { |
825 |
return super.containsAll(c); |
826 |
} |
827 |
|
828 |
/** |
829 |
* Appends all of the elements in the specified Collection to the end of |
830 |
* this Vector, in the order that they are returned by the specified |
831 |
* Collection's Iterator. The behavior of this operation is undefined if |
832 |
* the specified Collection is modified while the operation is in progress. |
833 |
* (This implies that the behavior of this call is undefined if the |
834 |
* specified Collection is this Vector, and this Vector is nonempty.) |
835 |
* |
836 |
* @param c elements to be inserted into this Vector |
837 |
* @return <tt>true</tt> if this Vector changed as a result of the call |
838 |
* @throws NullPointerException if the specified collection is null |
839 |
* @since 1.2 |
840 |
*/ |
841 |
public synchronized boolean addAll(Collection<? extends E> c) { |
842 |
modCount++; |
843 |
Object[] a = c.toArray(); |
844 |
int numNew = a.length; |
845 |
ensureCapacityHelper(elementCount + numNew); |
846 |
System.arraycopy(a, 0, elementData, elementCount, numNew); |
847 |
elementCount += numNew; |
848 |
return numNew != 0; |
849 |
} |
850 |
|
851 |
/** |
852 |
* Removes from this Vector all of its elements that are contained in the |
853 |
* specified Collection. |
854 |
* |
855 |
* @param c a collection of elements to be removed from the Vector |
856 |
* @return true if this Vector changed as a result of the call |
857 |
* @throws ClassCastException if the types of one or more elements |
858 |
* in this vector are incompatible with the specified |
859 |
* collection (optional) |
860 |
* @throws NullPointerException if this vector contains one or more null |
861 |
* elements and the specified collection does not support null |
862 |
* elements (optional), or if the specified collection is null |
863 |
* @since 1.2 |
864 |
*/ |
865 |
public synchronized boolean removeAll(Collection<?> c) { |
866 |
return super.removeAll(c); |
867 |
} |
868 |
|
869 |
/** |
870 |
* Retains only the elements in this Vector that are contained in the |
871 |
* specified Collection. In other words, removes from this Vector all |
872 |
* of its elements that are not contained in the specified Collection. |
873 |
* |
874 |
* @param c a collection of elements to be retained in this Vector |
875 |
* (all other elements are removed) |
876 |
* @return true if this Vector changed as a result of the call |
877 |
* @throws ClassCastException if the types of one or more elements |
878 |
* in this vector are incompatible with the specified |
879 |
* collection (optional) |
880 |
* @throws NullPointerException if this vector contains one or more null |
881 |
* elements and the specified collection does not support null |
882 |
* elements (optional), or if the specified collection is null |
883 |
* @since 1.2 |
884 |
*/ |
885 |
public synchronized boolean retainAll(Collection<?> c) { |
886 |
return super.retainAll(c); |
887 |
} |
888 |
|
889 |
/** |
890 |
* Inserts all of the elements in the specified Collection into this |
891 |
* Vector at the specified position. Shifts the element currently at |
892 |
* that position (if any) and any subsequent elements to the right |
893 |
* (increases their indices). The new elements will appear in the Vector |
894 |
* in the order that they are returned by the specified Collection's |
895 |
* iterator. |
896 |
* |
897 |
* @param index index at which to insert the first element from the |
898 |
* specified collection |
899 |
* @param c elements to be inserted into this Vector |
900 |
* @return <tt>true</tt> if this Vector changed as a result of the call |
901 |
* @exception ArrayIndexOutOfBoundsException index out of range (index |
902 |
* < 0 || index > size()) |
903 |
* @throws NullPointerException if the specified collection is null |
904 |
* @since 1.2 |
905 |
*/ |
906 |
public synchronized boolean addAll(int index, Collection<? extends E> c) { |
907 |
modCount++; |
908 |
if (index < 0 || index > elementCount) |
909 |
throw new ArrayIndexOutOfBoundsException(index); |
910 |
|
911 |
Object[] a = c.toArray(); |
912 |
int numNew = a.length; |
913 |
ensureCapacityHelper(elementCount + numNew); |
914 |
|
915 |
int numMoved = elementCount - index; |
916 |
if (numMoved > 0) |
917 |
System.arraycopy(elementData, index, elementData, index + numNew, |
918 |
numMoved); |
919 |
|
920 |
System.arraycopy(a, 0, elementData, index, numNew); |
921 |
elementCount += numNew; |
922 |
return numNew != 0; |
923 |
} |
924 |
|
925 |
/** |
926 |
* Compares the specified Object with this Vector for equality. Returns |
927 |
* true if and only if the specified Object is also a List, both Lists |
928 |
* have the same size, and all corresponding pairs of elements in the two |
929 |
* Lists are <em>equal</em>. (Two elements <code>e1</code> and |
930 |
* <code>e2</code> are <em>equal</em> if <code>(e1==null ? e2==null : |
931 |
* e1.equals(e2))</code>.) In other words, two Lists are defined to be |
932 |
* equal if they contain the same elements in the same order. |
933 |
* |
934 |
* @param o the Object to be compared for equality with this Vector |
935 |
* @return true if the specified Object is equal to this Vector |
936 |
*/ |
937 |
public synchronized boolean equals(Object o) { |
938 |
return super.equals(o); |
939 |
} |
940 |
|
941 |
/** |
942 |
* Returns the hash code value for this Vector. |
943 |
*/ |
944 |
public synchronized int hashCode() { |
945 |
return super.hashCode(); |
946 |
} |
947 |
|
948 |
/** |
949 |
* Returns a string representation of this Vector, containing |
950 |
* the String representation of each element. |
951 |
*/ |
952 |
public synchronized String toString() { |
953 |
return super.toString(); |
954 |
} |
955 |
|
956 |
/** |
957 |
* Returns a view of the portion of this List between fromIndex, |
958 |
* inclusive, and toIndex, exclusive. (If fromIndex and toIndex are |
959 |
* equal, the returned List is empty.) The returned List is backed by this |
960 |
* List, so changes in the returned List are reflected in this List, and |
961 |
* vice-versa. The returned List supports all of the optional List |
962 |
* operations supported by this List.<p> |
963 |
* |
964 |
* This method eliminates the need for explicit range operations (of |
965 |
* the sort that commonly exist for arrays). Any operation that expects |
966 |
* a List can be used as a range operation by operating on a subList view |
967 |
* instead of a whole List. For example, the following idiom |
968 |
* removes a range of elements from a List: |
969 |
* <pre> |
970 |
* list.subList(from, to).clear(); |
971 |
* </pre> |
972 |
* Similar idioms may be constructed for indexOf and lastIndexOf, |
973 |
* and all of the algorithms in the Collections class can be applied to |
974 |
* a subList.<p> |
975 |
* |
976 |
* The semantics of the List returned by this method become undefined if |
977 |
* the backing list (i.e., this List) is <i>structurally modified</i> in |
978 |
* any way other than via the returned List. (Structural modifications are |
979 |
* those that change the size of the List, or otherwise perturb it in such |
980 |
* a fashion that iterations in progress may yield incorrect results.) |
981 |
* |
982 |
* @param fromIndex low endpoint (inclusive) of the subList |
983 |
* @param toIndex high endpoint (exclusive) of the subList |
984 |
* @return a view of the specified range within this List |
985 |
* @throws IndexOutOfBoundsException endpoint index value out of range |
986 |
* <code>(fromIndex < 0 || toIndex > size)</code> |
987 |
* @throws IllegalArgumentException endpoint indices out of order |
988 |
* <code>(fromIndex > toIndex)</code> |
989 |
*/ |
990 |
public synchronized List<E> subList(int fromIndex, int toIndex) { |
991 |
return Collections.synchronizedList(super.subList(fromIndex, toIndex), |
992 |
this); |
993 |
} |
994 |
|
995 |
/** |
996 |
* Removes from this List all of the elements whose index is between |
997 |
* fromIndex, inclusive and toIndex, exclusive. Shifts any succeeding |
998 |
* elements to the left (reduces their index). |
999 |
* This call shortens the ArrayList by (toIndex - fromIndex) elements. (If |
1000 |
* toIndex==fromIndex, this operation has no effect.) |
1001 |
* |
1002 |
* @param fromIndex index of first element to be removed |
1003 |
* @param toIndex index after last element to be removed |
1004 |
*/ |
1005 |
protected synchronized void removeRange(int fromIndex, int toIndex) { |
1006 |
modCount++; |
1007 |
int numMoved = elementCount - toIndex; |
1008 |
System.arraycopy(elementData, toIndex, elementData, fromIndex, |
1009 |
numMoved); |
1010 |
|
1011 |
// Let gc do its work |
1012 |
int newElementCount = elementCount - (toIndex-fromIndex); |
1013 |
while (elementCount != newElementCount) |
1014 |
elementData[--elementCount] = null; |
1015 |
} |
1016 |
|
1017 |
/** |
1018 |
* Save the state of the <tt>Vector</tt> instance to a stream (that |
1019 |
* is, serialize it). This method is present merely for synchronization. |
1020 |
* It just calls the default writeObject method. |
1021 |
*/ |
1022 |
private synchronized void writeObject(java.io.ObjectOutputStream s) |
1023 |
throws java.io.IOException |
1024 |
{ |
1025 |
s.defaultWriteObject(); |
1026 |
} |
1027 |
|
1028 |
/** |
1029 |
* Returns a list-iterator of the elements in this list (in proper |
1030 |
* sequence), starting at the specified position in the list. |
1031 |
* Obeys the general contract of <tt>List.listIterator(int)</tt>.<p> |
1032 |
* |
1033 |
* The list-iterator is <i>fail-fast</i>: if the list is structurally |
1034 |
* modified at any time after the Iterator is created, in any way except |
1035 |
* through the list-iterator's own <tt>remove</tt> or <tt>add</tt> |
1036 |
* methods, the list-iterator will throw a |
1037 |
* <tt>ConcurrentModificationException</tt>. Thus, in the face of |
1038 |
* concurrent modification, the iterator fails quickly and cleanly, rather |
1039 |
* than risking arbitrary, non-deterministic behavior at an undetermined |
1040 |
* time in the future. |
1041 |
* |
1042 |
* @param index index of the first element to be returned from the |
1043 |
* list-iterator (by a call to <tt>next</tt>) |
1044 |
* @return a ListIterator of the elements in this list (in proper |
1045 |
* sequence), starting at the specified position in the list |
1046 |
* @throws IndexOutOfBoundsException {@inheritDoc} |
1047 |
* @see List#listIterator(int) |
1048 |
*/ |
1049 |
public synchronized ListIterator<E> listIterator(int index) { |
1050 |
if (index < 0 || index > elementCount) |
1051 |
throw new IndexOutOfBoundsException("Index: "+index); |
1052 |
return new VectorIterator(index); |
1053 |
} |
1054 |
|
1055 |
/** |
1056 |
* {@inheritDoc} |
1057 |
*/ |
1058 |
public synchronized ListIterator<E> listIterator() { |
1059 |
return new VectorIterator(0); |
1060 |
} |
1061 |
|
1062 |
/** |
1063 |
* Returns an iterator over the elements in this list in proper sequence. |
1064 |
* |
1065 |
* @return an iterator over the elements in this list in proper sequence |
1066 |
*/ |
1067 |
public synchronized Iterator<E> iterator() { |
1068 |
return new VectorIterator(0); |
1069 |
} |
1070 |
|
1071 |
/** |
1072 |
* A streamlined version of AbstractList.ListItr. |
1073 |
*/ |
1074 |
private final class VectorIterator implements ListIterator<E> { |
1075 |
int cursor; // current position |
1076 |
int lastRet; // index of last returned element |
1077 |
int expectedModCount; // to check for CME |
1078 |
|
1079 |
VectorIterator(int index) { |
1080 |
cursor = index; |
1081 |
expectedModCount = modCount; |
1082 |
lastRet = -1; |
1083 |
} |
1084 |
|
1085 |
public boolean hasNext() { |
1086 |
// Racy but within spec, since modifications are checked |
1087 |
// within or after synchronization in next/previous |
1088 |
return cursor != elementCount; |
1089 |
} |
1090 |
|
1091 |
public boolean hasPrevious() { |
1092 |
return cursor != 0; |
1093 |
} |
1094 |
|
1095 |
public int nextIndex() { |
1096 |
return cursor; |
1097 |
} |
1098 |
|
1099 |
public int previousIndex() { |
1100 |
return cursor - 1; |
1101 |
} |
1102 |
|
1103 |
public E next() { |
1104 |
try { |
1105 |
int i = cursor; |
1106 |
E next = get(i); |
1107 |
lastRet = i; |
1108 |
cursor = i + 1; |
1109 |
return next; |
1110 |
} catch (IndexOutOfBoundsException ex) { |
1111 |
throw new NoSuchElementException(); |
1112 |
} finally { |
1113 |
if (expectedModCount != modCount) |
1114 |
throw new ConcurrentModificationException(); |
1115 |
} |
1116 |
} |
1117 |
|
1118 |
public E previous() { |
1119 |
try { |
1120 |
int i = cursor - 1; |
1121 |
E prev = get(i); |
1122 |
lastRet = i; |
1123 |
cursor = i; |
1124 |
return prev; |
1125 |
} catch (IndexOutOfBoundsException ex) { |
1126 |
throw new NoSuchElementException(); |
1127 |
} finally { |
1128 |
if (expectedModCount != modCount) |
1129 |
throw new ConcurrentModificationException(); |
1130 |
} |
1131 |
} |
1132 |
|
1133 |
public void remove() { |
1134 |
if (lastRet == -1) |
1135 |
throw new IllegalStateException(); |
1136 |
if (expectedModCount != modCount) |
1137 |
throw new ConcurrentModificationException(); |
1138 |
try { |
1139 |
Vector.this.remove(lastRet); |
1140 |
if (lastRet < cursor) |
1141 |
cursor--; |
1142 |
lastRet = -1; |
1143 |
expectedModCount = modCount; |
1144 |
} catch (IndexOutOfBoundsException ex) { |
1145 |
throw new ConcurrentModificationException(); |
1146 |
} |
1147 |
} |
1148 |
|
1149 |
public void set(E e) { |
1150 |
if (lastRet == -1) |
1151 |
throw new IllegalStateException(); |
1152 |
if (expectedModCount != modCount) |
1153 |
throw new ConcurrentModificationException(); |
1154 |
try { |
1155 |
Vector.this.set(lastRet, e); |
1156 |
expectedModCount = modCount; |
1157 |
} catch (IndexOutOfBoundsException ex) { |
1158 |
throw new ConcurrentModificationException(); |
1159 |
} |
1160 |
} |
1161 |
|
1162 |
public void add(E e) { |
1163 |
if (expectedModCount != modCount) |
1164 |
throw new ConcurrentModificationException(); |
1165 |
try { |
1166 |
int i = cursor; |
1167 |
Vector.this.add(i, e); |
1168 |
cursor = i + 1; |
1169 |
lastRet = -1; |
1170 |
expectedModCount = modCount; |
1171 |
} catch (IndexOutOfBoundsException ex) { |
1172 |
throw new ConcurrentModificationException(); |
1173 |
} |
1174 |
} |
1175 |
} |
1176 |
} |