/*
* @(#)ModVector.java 1.94 03/06/22
*
* Copyright 2003 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package javathreads.examples.ch14;
/**
* The <code>ModVector</code> class implements a growable array of
* objects. Like an array, it contains components that can be
* accessed using an integer index. However, the size of a
* <code>ModVector</code> can grow or shrink as needed to accommodate
* adding and removing items after the <code>ModVector</code> has been created.<p>
*
* Each vector tries to optimize storage management by maintaining a
* <code>capacity</code> and a <code>capacityIncrement</code>. The
* <code>capacity</code> is always at least as large as the vector
* size; it is usually larger because as components are added to the
* vector, the vector's storage increases in chunks the size of
* <code>capacityIncrement</code>. An application can increase the
* capacity of a vector before inserting a large number of
* components; this reduces the amount of incremental reallocation. <p>
*
* As of the Java 2 platform v1.2, this class has been retrofitted to
* implement List, so that it becomes a part of Java's collection framework.
* Unlike the new collection implementations, ModVector is synchronized.<p>
*
* The Iterators returned by ModVector's iterator and listIterator
* methods are <em>fail-fast</em>: if the ModVector is structurally modified
* at any time after the Iterator is created, in any way except through the
* Iterator's own remove or add methods, the Iterator will throw a
* ConcurrentModificationException. Thus, in the face of concurrent
* modification, the Iterator fails quickly and cleanly, rather than risking
* arbitrary, non-deterministic behavior at an undetermined time in the future.
* The Enumerations returned by ModVector's elements method are <em>not</em>
* fail-fast.
*
* <p>Note that the fail-fast behavior of an iterator cannot be guaranteed
* as it is, generally speaking, impossible to make any hard guarantees in the
* presence of unsynchronized concurrent modification. Fail-fast iterators
* throw <tt>ConcurrentModificationException</tt> on a best-effort basis.
* Therefore, it would be wrong to write a program that depended on this
* exception for its correctness: <i>the fail-fast behavior of iterators
* should be used only to detect bugs.</i><p>
*
* This class is a member of the
* <a href="{@docRoot}/../guide/collections/index.html">
* Java Collections Framework</a>.
*
* @author Lee Boynton
* @author Jonathan Payne
* @version 1.94, 06/22/03
* @see Collection
* @see List
* @see ArrayList
* @see LinkedList
* @since JDK1.0
*/
import java.util.*;
public class ModVector<E>
extends AbstractList<E>
implements List<E>, RandomAccess, Cloneable, java.io.Serializable
{
/**
* The array buffer into which the components of the vector are
* stored. The capacity of the vector is the length of this array buffer,
* and is at least large enough to contain all the vector's elements.<p>
*
* Any array elements following the last element in the ModVector are null.
*
* @serial
*/
protected Object[] elementData;
/**
* The number of valid components in this <tt>ModVector</tt> object.
* Components <tt>elementData[0]</tt> through
* <tt>elementData[elementCount-1]</tt> are the actual items.
*
* @serial
*/
protected int elementCount;
/**
* The amount by which the capacity of the vector is automatically
* incremented when its size becomes greater than its capacity. If
* the capacity increment is less than or equal to zero, the capacity
* of the vector is doubled each time it needs to grow.
*
* @serial
*/
protected int capacityIncrement;
/** use serialVersionUID from JDK 1.0.2 for interoperability */
private static final long serialVersionUID = -2767605614048989439L;
/**
* Constructs an empty vector with the specified initial capacity and
* capacity increment.
*
* @param initialCapacity the initial capacity of the vector.
* @param capacityIncrement the amount by which the capacity is
* increased when the vector overflows.
* @exception IllegalArgumentException if the specified initial capacity
* is negative
*/
public ModVector(int initialCapacity, int capacityIncrement) {
super();
if (initialCapacity < 0)
throw new IllegalArgumentException("Illegal Capacity: "+
initialCapacity);
this.elementData = new Object[initialCapacity];
this.capacityIncrement = capacityIncrement;
}
/**
* Constructs an empty vector with the specified initial capacity and
* with its capacity increment equal to zero.
*
* @param initialCapacity the initial capacity of the vector.
* @exception IllegalArgumentException if the specified initial capacity
* is negative
*/
public ModVector(int initialCapacity) {
this(initialCapacity, 0);
}
/**
* Constructs an empty vector so that its internal data array
* has size <tt>10</tt> and its standard capacity increment is
* zero.
*/
public ModVector() {
this(10);
}
/**
* Constructs a vector containing the elements of the specified
* collection, in the order they are returned by the collection's
* iterator.
*
* @param c the collection whose elements are to be placed into this
* vector.
* @throws NullPointerException if the specified collection is null.
* @since 1.2
*/
public ModVector(Collection<? extends E> c) {
elementCount = c.size();
// 10% for growth
elementData = new Object[
(int)Math.min((elementCount*110L)/100,Integer.MAX_VALUE)];
c.toArray(elementData);
}
/**
* Copies the components of this vector into the specified array. The
* item at index <tt>k</tt> in this vector is copied into component
* <tt>k</tt> of <tt>anArray</tt>. The array must be big enough to hold
* all the objects in this vector, else an
* <tt>IndexOutOfBoundsException</tt> is thrown.
*
* @param anArray the array into which the components get copied.
* @throws NullPointerException if the given array is null.
*/
public void copyInto(Object[] anArray) {
System.arraycopy(elementData, 0, anArray, 0, elementCount);
}
/**
* Trims the capacity of this vector to be the vector's current
* size. If the capacity of this vector is larger than its current
* size, then the capacity is changed to equal the size by replacing
* its internal data array, kept in the field <tt>elementData</tt>,
* with a smaller one. An application can use this operation to
* minimize the storage of a vector.
*/
public void trimToSize() {
modCount++;
int oldCapacity = elementData.length;
if (elementCount < oldCapacity) {
Object oldData[] = elementData;
elementData = new Object[elementCount];
System.arraycopy(oldData, 0, elementData, 0, elementCount);
}
}
/**
* Increases the capacity of this vector, if necessary, to ensure
* that it can hold at least the number of components specified by
* the minimum capacity argument.
*
* <p>If the current capacity of this vector is less than
* <tt>minCapacity</tt>, then its capacity is increased by replacing its
* internal data array, kept in the field <tt>elementData</tt>, with a
* larger one. The size of the new data array will be the old size plus
* <tt>capacityIncrement</tt>, unless the value of
* <tt>capacityIncrement</tt> is less than or equal to zero, in which case
* the new capacity will be twice the old capacity; but if this new size
* is still smaller than <tt>minCapacity</tt>, then the new capacity will
* be <tt>minCapacity</tt>.
*
* @param minCapacity the desired minimum capacity.
*/
public void ensureCapacity(int minCapacity) {
modCount++;
ensureCapacityHelper(minCapacity);
}
/**
* This implements the unsynchronized semantics of ensureCapacity.
* Synchronized methods in this class can internally call this
* method for ensuring capacity without incurring the cost of an
* extra synchronization.
*
* @see java.util.ModVector#ensureCapacity(int)
*/
private void ensureCapacityHelper(int minCapacity) {
int oldCapacity = elementData.length;
if (minCapacity > oldCapacity) {
Object[] oldData = elementData;
int newCapacity = (capacityIncrement > 0) ?
(oldCapacity + capacityIncrement) : (oldCapacity * 2);
if (newCapacity < minCapacity) {
newCapacity = minCapacity;
}
elementData = new Object[newCapacity];
System.arraycopy(oldData, 0, elementData, 0, elementCount);
}
}
/**
* Sets the size of this vector. If the new size is greater than the
* current size, new <code>null</code> items are added to the end of
* the vector. If the new size is less than the current size, all
* components at index <code>newSize</code> and greater are discarded.
*
* @param newSize the new size of this vector.
* @throws ArrayIndexOutOfBoundsException if new size is negative.
*/
public void setSize(int newSize) {
modCount++;
if (newSize > elementCount) {
ensureCapacityHelper(newSize);
} else {
for (int i = newSize ; i < elementCount ; i++) {
elementData[i] = null;
}
}
elementCount = newSize;
}
/**
* Returns the current capacity of this vector.
*
* @return the current capacity (the length of its internal
* data array, kept in the field <tt>elementData</tt>
* of this vector).
*/
public int capacity() {
return elementData.length;
}
/**
* Returns the number of components in this vector.
*
* @return the number of components in this vector.
*/
public int size() {
return elementCount;
}
/**
* Tests if this vector has no components.
*
* @return <code>true</code> if and only if this vector has
* no components, that is, its size is zero;
* <code>false</code> otherwise.
*/
public boolean isEmpty() {
return elementCount == 0;
}
/**
* Returns an enumeration of the components of this vector. The
* returned <tt>Enumeration</tt> object will generate all items in
* this vector. The first item generated is the item at index <tt>0</tt>,
* then the item at index <tt>1</tt>, and so on.
*
* @return an enumeration of the components of this vector.
* @see Enumeration
* @see Iterator
*/
public Enumeration<E> elements() {
return new Enumeration<E>() {
int count = 0;
public boolean hasMoreElements() {
return count < elementCount;
}
public E nextElement() {
synchronized (ModVector.this) {
if (count < elementCount) {
return (E)elementData[count++];
}
}
throw new NoSuchElementException("ModVector Enumeration");
}
};
}
/**
* Tests if the specified object is a component in this vector.
*
* @param elem an object.
* @return <code>true</code> if and only if the specified object
* is the same as a component in this vector, as determined by the
* <tt>equals</tt> method; <code>false</code> otherwise.
*/
public boolean contains(Object elem) {
return indexOf(elem, 0) >= 0;
}
/**
* Searches for the first occurence of the given argument, testing
* for equality using the <code>equals</code> method.
*
* @param elem an object.
* @return the index of the first occurrence of the argument in this
* vector, that is, the smallest value <tt>k</tt> such that
* <tt>elem.equals(elementData[k])</tt> is <tt>true</tt>;
* returns <code>-1</code> if the object is not found.
* @see Object#equals(Object)
*/
public int indexOf(Object elem) {
return indexOf(elem, 0);
}
/**
* Searches for the first occurence of the given argument, beginning
* the search at <code>index</code>, and testing for equality using
* the <code>equals</code> method.
*
* @param elem an object.
* @param index the non-negative index to start searching from.
* @return the index of the first occurrence of the object argument in
* this vector at position <code>index</code> or later in the
* vector, that is, the smallest value <tt>k</tt> such that
* <tt>elem.equals(elementData[k]) && (k >= index)</tt> is
* <tt>true</tt>; returns <code>-1</code> if the object is not
* found. (Returns <code>-1</code> if <tt>index</tt> >= the
* current size of this <tt>ModVector</tt>.)
* @exception IndexOutOfBoundsException if <tt>index</tt> is negative.
* @see Object#equals(Object)
*/
public int indexOf(Object elem, int index) {
if (elem == null) {
for (int i = index ; i < elementCount ; i++)
if (elementData[i]==null)
return i;
} else {
for (int i = index ; i < elementCount ; i++)
if (elem.equals(elementData[i]))
return i;
}
return -1;
}
/**
* Returns the index of the last occurrence of the specified object in
* this vector.
*
* @param elem the desired component.
* @return the index of the last occurrence of the specified object in
* this vector, that is, the largest value <tt>k</tt> such that
* <tt>elem.equals(elementData[k])</tt> is <tt>true</tt>;
* returns <code>-1</code> if the object is not found.
*/
public int lastIndexOf(Object elem) {
return lastIndexOf(elem, elementCount-1);
}
/**
* Searches backwards for the specified object, starting from the
* specified index, and returns an index to it.
*
* @param elem the desired component.
* @param index the index to start searching from.
* @return the index of the last occurrence of the specified object in this
* vector at position less than or equal to <code>index</code> in
* the vector, that is, the largest value <tt>k</tt> such that
* <tt>elem.equals(elementData[k]) && (k <= index)</tt> is
* <tt>true</tt>; <code>-1</code> if the object is not found.
* (Returns <code>-1</code> if <tt>index</tt> is negative.)
* @exception IndexOutOfBoundsException if <tt>index</tt> is greater
* than or equal to the current size of this vector.
*/
public int lastIndexOf(Object elem, int index) {
if (index >= elementCount)
throw new IndexOutOfBoundsException(index + " >= "+ elementCount);
if (elem == null) {
for (int i = index; i >= 0; i--)
if (elementData[i]==null)
return i;
} else {
for (int i = index; i >= 0; i--)
if (elem.equals(elementData[i]))
return i;
}
return -1;
}
/**
* Returns the component at the specified index.<p>
*
* This method is identical in functionality to the get method
* (which is part of the List interface).
*
* @param index an index into this vector.
* @return the component at the specified index.
* @exception ArrayIndexOutOfBoundsException if the <tt>index</tt>
* is negative or not less than the current size of this
* <tt>ModVector</tt> object.
* given.
* @see #get(int)
* @see List
*/
public E elementAt(int index) {
if (index >= elementCount) {
throw new ArrayIndexOutOfBoundsException(index + " >= " + elementCount);
}
return (E)elementData[index];
}
/**
* Returns the first component (the item at index <tt>0</tt>) of
* this vector.
*
* @return the first component of this vector.
* @exception NoSuchElementException if this vector has no components.
*/
public E firstElement() {
if (elementCount == 0) {
throw new NoSuchElementException();
}
return (E)elementData[0];
}
/**
* Returns the last component of the vector.
*
* @return the last component of the vector, i.e., the component at index
* <code>size() - 1</code>.
* @exception NoSuchElementException if this vector is empty.
*/
public E lastElement() {
if (elementCount == 0) {
throw new NoSuchElementException();
}
return (E)elementData[elementCount - 1];
}
/**
* Sets the component at the specified <code>index</code> of this
* vector to be the specified object. The previous component at that
* position is discarded.<p>
*
* The index must be a value greater than or equal to <code>0</code>
* and less than the current size of the vector. <p>
*
* This method is identical in functionality to the set method
* (which is part of the List interface). Note that the set method reverses
* the order of the parameters, to more closely match array usage. Note
* also that the set method returns the old value that was stored at the
* specified position.
*
* @param obj what the component is to be set to.
* @param index the specified index.
* @exception ArrayIndexOutOfBoundsException if the index was invalid.
* @see #size()
* @see List
* @see #set(int, java.lang.Object)
*/
public void setElementAt(E obj, int index) {
if (index >= elementCount) {
throw new ArrayIndexOutOfBoundsException(index + " >= " +
elementCount);
}
elementData[index] = obj;
}
/**
* Deletes the component at the specified index. Each component in
* this vector with an index greater or equal to the specified
* <code>index</code> is shifted downward to have an index one
* smaller than the value it had previously. The size of this vector
* is decreased by <tt>1</tt>.<p>
*
* The index must be a value greater than or equal to <code>0</code>
* and less than the current size of the vector. <p>
*
* This method is identical in functionality to the remove method
* (which is part of the List interface). Note that the remove method
* returns the old value that was stored at the specified position.
*
* @param index the index of the object to remove.
* @exception ArrayIndexOutOfBoundsException if the index was invalid.
* @see #size()
* @see #remove(int)
* @see List
*/
public void removeElementAt(int index) {
modCount++;
if (index >= elementCount) {
throw new ArrayIndexOutOfBoundsException(index + " >= " +
elementCount);
}
else if (index < 0) {
throw new ArrayIndexOutOfBoundsException(index);
}
int j = elementCount - index - 1;
if (j > 0) {
System.arraycopy(elementData, index + 1, elementData, index, j);
}
elementCount--;
elementData[elementCount] = null; /* to let gc do its work */
}
/**
* Inserts the specified object as a component in this vector at the
* specified <code>index</code>. Each component in this vector with
* an index greater or equal to the specified <code>index</code> is
* shifted upward to have an index one greater than the value it had
* previously. <p>
*
* The index must be a value greater than or equal to <code>0</code>
* and less than or equal to the current size of the vector. (If the
* index is equal to the current size of the vector, the new element
* is appended to the ModVector.)<p>
*
* This method is identical in functionality to the add(Object, int) method
* (which is part of the List interface). Note that the add method reverses
* the order of the parameters, to more closely match array usage.
*
* @param obj the component to insert.
* @param index where to insert the new component.
* @exception ArrayIndexOutOfBoundsException if the index was invalid.
* @see #size()
* @see #add(int, Object)
* @see List
*/
public void insertElementAt(E obj, int index) {
modCount++;
if (index > elementCount) {
throw new ArrayIndexOutOfBoundsException(index
+ " > " + elementCount);
}
ensureCapacityHelper(elementCount + 1);
System.arraycopy(elementData, index, elementData, index + 1, elementCount - index);
elementData[index] = obj;
elementCount++;
}
/**
* Adds the specified component to the end of this vector,
* increasing its size by one. The capacity of this vector is
* increased if its size becomes greater than its capacity. <p>
*
* This method is identical in functionality to the add(Object) method
* (which is part of the List interface).
*
* @param obj the component to be added.
* @see #add(Object)
* @see List
*/
public void addElement(E obj) {
modCount++;
ensureCapacityHelper(elementCount + 1);
elementData[elementCount++] = obj;
}
/**
* Removes the first (lowest-indexed) occurrence of the argument
* from this vector. If the object is found in this vector, each
* component in the vector with an index greater or equal to the
* object's index is shifted downward to have an index one smaller
* than the value it had previously.<p>
*
* This method is identical in functionality to the remove(Object)
* method (which is part of the List interface).
*
* @param obj the component to be removed.
* @return <code>true</code> if the argument was a component of this
* vector; <code>false</code> otherwise.
* @see List#remove(Object)
* @see List
*/
public boolean removeElement(Object obj) {
modCount++;
int i = indexOf(obj);
if (i >= 0) {
removeElementAt(i);
return true;
}
return false;
}
/**
* Removes all components from this vector and sets its size to zero.<p>
*
* This method is identical in functionality to the clear method
* (which is part of the List interface).
*
* @see #clear
* @see List
*/
public void removeAllElements() {
modCount++;
// Let gc do its work
for (int i = 0; i < elementCount; i++)
elementData[i] = null;
elementCount = 0;
}
/**
* Returns a clone of this vector. The copy will contain a
* reference to a clone of the internal data array, not a reference
* to the original internal data array of this <tt>ModVector</tt> object.
*
* @return a clone of this vector.
*/
public Object clone() {
try {
ModVector<E> v = (ModVector<E>) super.clone();
v.elementData = new Object[elementCount];
System.arraycopy(elementData, 0, v.elementData, 0, elementCount);
v.modCount = 0;
return v;
} catch (CloneNotSupportedException e) {
// this shouldn't happen, since we are Cloneable
throw new InternalError();
}
}
/**
* Returns an array containing all of the elements in this ModVector
* in the correct order.
*
* @since 1.2
*/
public Object[] toArray() {
Object[] result = new Object[elementCount];
System.arraycopy(elementData, 0, result, 0, elementCount);
return result;
}
/**
* Returns an array containing all of the elements in this ModVector in the
* correct order; the runtime type of the returned array is that of the
* specified array. If the ModVector fits in the specified array, it is
* returned therein. Otherwise, a new array is allocated with the runtime
* type of the specified array and the size of this ModVector.<p>
*
* If the ModVector fits in the specified array with room to spare
* (i.e., the array has more elements than the ModVector),
* the element in the array immediately following the end of the
* ModVector is set to null. This is useful in determining the length
* of the ModVector <em>only</em> if the caller knows that the ModVector
* does not contain any null elements.
*
* @param a the array into which the elements of the ModVector are to
* be stored, if it is big enough; otherwise, a new array of the
* same runtime type is allocated for this purpose.
* @return an array containing the elements of the ModVector.
* @exception ArrayStoreException the runtime type of a is not a supertype
* of the runtime type of every element in this ModVector.
* @throws NullPointerException if the given array is null.
* @since 1.2
*/
public <T> T[] toArray(T[] a) {
if (a.length < elementCount)
a = (T[])java.lang.reflect.Array.newInstance(
a.getClass().getComponentType(), elementCount);
System.arraycopy(elementData, 0, a, 0, elementCount);
if (a.length > elementCount)
a[elementCount] = null;
return a;
}
// Positional Access Operations
/**
* Returns the element at the specified position in this ModVector.
*
* @param index index of element to return.
* @return object at the specified index
* @exception ArrayIndexOutOfBoundsException index is out of range (index
* < 0 || index >= size()).
* @since 1.2
*/
public E get(int index) {
if (index >= elementCount)
throw new ArrayIndexOutOfBoundsException(index);
return (E)elementData[index];
}
/**
* Replaces the element at the specified position in this ModVector with the
* specified element.
*
* @param index index of element to replace.
* @param element element to be stored at the specified position.
* @return the element previously at the specified position.
* @exception ArrayIndexOutOfBoundsException index out of range
* (index < 0 || index >= size()).
* @since 1.2
*/
public E set(int index, E element) {
if (index >= elementCount)
throw new ArrayIndexOutOfBoundsException(index);
Object oldValue = elementData[index];
elementData[index] = element;
return (E)oldValue;
}
/**
* Appends the specified element to the end of this ModVector.
*
* @param o element to be appended to this ModVector.
* @return true (as per the general contract of Collection.add).
* @since 1.2
*/
public boolean add(E o) {
modCount++;
ensureCapacityHelper(elementCount + 1);
elementData[elementCount++] = o;
return true;
}
/**
* Removes the first occurrence of the specified element in this ModVector
* If the ModVector does not contain the element, it is unchanged. More
* formally, removes the element with the lowest index i such that
* <code>(o==null ? get(i)==null : o.equals(get(i)))</code> (if such
* an element exists).
*
* @param o element to be removed from this ModVector, if present.
* @return true if the ModVector contained the specified element.
* @since 1.2
*/
public boolean remove(Object o) {
return removeElement(o);
}
/**
* Inserts the specified element at the specified position in this ModVector.
* Shifts the element currently at that position (if any) and any
* subsequent elements to the right (adds one to their indices).
*
* @param index index at which the specified element is to be inserted.
* @param element element to be inserted.
* @exception ArrayIndexOutOfBoundsException index is out of range
* (index < 0 || index > size()).
* @since 1.2
*/
public void add(int index, E element) {
insertElementAt(element, index);
}
/**
* Removes the element at the specified position in this ModVector.
* shifts any subsequent elements to the left (subtracts one from their
* indices). Returns the element that was removed from the ModVector.
*
* @exception ArrayIndexOutOfBoundsException index out of range (index
* < 0 || index >= size()).
* @param index the index of the element to removed.
* @return element that was removed
* @since 1.2
*/
public E remove(int index) {
modCount++;
if (index >= elementCount)
throw new ArrayIndexOutOfBoundsException(index);
Object oldValue = elementData[index];
int numMoved = elementCount - index - 1;
if (numMoved > 0)
System.arraycopy(elementData, index+1, elementData, index,
numMoved);
elementData[--elementCount] = null; // Let gc do its work
return (E)oldValue;
}
/**
* Removes all of the elements from this ModVector. The ModVector will
* be empty after this call returns (unless it throws an exception).
*
* @since 1.2
*/
public void clear() {
removeAllElements();
}
// Bulk Operations
/**
* Returns true if this ModVector contains all of the elements in the
* specified Collection.
*
* @param c a collection whose elements will be tested for containment
* in this ModVector
* @return true if this ModVector contains all of the elements in the
* specified collection.
* @throws NullPointerException if the specified collection is null.
*/
public boolean containsAll(Collection<?> c) {
return super.containsAll(c);
}
/**
* Appends all of the elements in the specified Collection to the end of
* this ModVector, in the order that they are returned by the specified
* Collection's Iterator. The behavior of this operation is undefined if
* the specified Collection is modified while the operation is in progress.
* (This implies that the behavior of this call is undefined if the
* specified Collection is this ModVector, and this ModVector is nonempty.)
*
* @param c elements to be inserted into this ModVector.
* @return <tt>true</tt> if this ModVector changed as a result of the call.
* @throws NullPointerException if the specified collection is null.
* @since 1.2
*/
public boolean addAll(Collection<? extends E> c) {
modCount++;
Object[] a = c.toArray();
int numNew = a.length;
ensureCapacityHelper(elementCount + numNew);
System.arraycopy(a, 0, elementData, elementCount, numNew);
elementCount += numNew;
return numNew != 0;
}
/**
* Removes from this ModVector all of its elements that are contained in the
* specified Collection.
*
* @param c a collection of elements to be removed from the ModVector
* @return true if this ModVector changed as a result of the call.
* @throws NullPointerException if the specified collection is null.
* @since 1.2
*/
public boolean removeAll(Collection<?> c) {
return super.removeAll(c);
}
/**
* Retains only the elements in this ModVector that are contained in the
* specified Collection. In other words, removes from this ModVector all
* of its elements that are not contained in the specified Collection.
*
* @param c a collection of elements to be retained in this ModVector
* (all other elements are removed)
* @return true if this ModVector changed as a result of the call.
* @throws NullPointerException if the specified collection is null.
* @since 1.2
*/
public boolean retainAll(Collection<?> c) {
return super.retainAll(c);
}
/**
* Inserts all of the elements in in the specified Collection into this
* ModVector at the specified position. Shifts the element currently at
* that position (if any) and any subsequent elements to the right
* (increases their indices). The new elements will appear in the ModVector
* in the order that they are returned by the specified Collection's
* iterator.
*
* @param index index at which to insert first element
* from the specified collection.
* @param c elements to be inserted into this ModVector.
* @return <tt>true</tt> if this ModVector changed as a result of the call.
* @exception ArrayIndexOutOfBoundsException index out of range (index
* < 0 || index > size()).
* @throws NullPointerException if the specified collection is null.
* @since 1.2
*/
public boolean addAll(int index, Collection<? extends E> c) {
modCount++;
if (index < 0 || index > elementCount)
throw new ArrayIndexOutOfBoundsException(index);
Object[] a = c.toArray();
int numNew = a.length;
ensureCapacityHelper(elementCount + numNew);
int numMoved = elementCount - index;
if (numMoved > 0)
System.arraycopy(elementData, index, elementData, index + numNew,
numMoved);
System.arraycopy(a, 0, elementData, index, numNew);
elementCount += numNew;
return numNew != 0;
}
/**
* Compares the specified Object with this ModVector for equality. Returns
* true if and only if the specified Object is also a List, both Lists
* have the same size, and all corresponding pairs of elements in the two
* Lists are <em>equal</em>. (Two elements <code>e1</code> and
* <code>e2</code> are <em>equal</em> if <code>(e1==null ? e2==null :
* e1.equals(e2))</code>.) In other words, two Lists are defined to be
* equal if they contain the same elements in the same order.
*
* @param o the Object to be compared for equality with this ModVector.
* @return true if the specified Object is equal to this ModVector
*/
public boolean equals(Object o) {
return super.equals(o);
}
/**
* Returns the hash code value for this ModVector.
*/
public int hashCode() {
return super.hashCode();
}
/**
* Returns a string representation of this ModVector, containing
* the String representation of each element.
*/
public String toString() {
return super.toString();
}
/**
* Returns a view of the portion of this List between fromIndex,
* inclusive, and toIndex, exclusive. (If fromIndex and ToIndex are
* equal, the returned List is empty.) The returned List is backed by this
* List, so changes in the returned List are reflected in this List, and
* vice-versa. The returned List supports all of the optional List
* operations supported by this List.<p>
*
* This method eliminates the need for explicit range operations (of
* the sort that commonly exist for arrays). Any operation that expects
* a List can be used as a range operation by operating on a subList view
* instead of a whole List. For example, the following idiom
* removes a range of elements from a List:
* <pre>
* list.subList(from, to).clear();
* </pre>
* Similar idioms may be constructed for indexOf and lastIndexOf,
* and all of the algorithms in the Collections class can be applied to
* a subList.<p>
*
* The semantics of the List returned by this method become undefined if
* the backing list (i.e., this List) is <i>structurally modified</i> in
* any way other than via the returned List. (Structural modifications are
* those that change the size of the List, or otherwise perturb it in such
* a fashion that iterations in progress may yield incorrect results.)
*
* @param fromIndex low endpoint (inclusive) of the subList.
* @param toIndex high endpoint (exclusive) of the subList.
* @return a view of the specified range within this List.
* @throws IndexOutOfBoundsException endpoint index value out of range
* <code>(fromIndex < 0 || toIndex > size)</code>
* @throws IllegalArgumentException endpoint indices out of order
* <code>(fromIndex > toIndex)</code>
*/
public List<E> subList(int fromIndex, int toIndex) {
//return Collections.synchronizedList(super.subList(fromIndex, toIndex),
// this);
return null;
}
/**
* Removes from this List all of the elements whose index is between
* fromIndex, inclusive and toIndex, exclusive. Shifts any succeeding
* elements to the left (reduces their index).
* This call shortens the ArrayList by (toIndex - fromIndex) elements. (If
* toIndex==fromIndex, this operation has no effect.)
*
* @param fromIndex index of first element to be removed.
* @param toIndex index after last element to be removed.
*/
protected void removeRange(int fromIndex, int toIndex) {
modCount++;
int numMoved = elementCount - toIndex;
System.arraycopy(elementData, toIndex, elementData, fromIndex,
numMoved);
// Let gc do its work
int newElementCount = elementCount - (toIndex-fromIndex);
while (elementCount != newElementCount)
elementData[--elementCount] = null;
}
/**
* Save the state of the <tt>ModVector</tt> instance to a stream (that
* is, serialize it). This method is present merely for synchronization.
* It just calls the default readObject method.
*/
private void writeObject(java.io.ObjectOutputStream s)
throws java.io.IOException
{
s.defaultWriteObject();
}
}
|
