/*
* Copyright (c) 1994, 2017, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
*
*
*
*
*
*
*
*
*
*
*
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*
*
*
*
*
*
*
*/
package java.util;
import java.io.
IOException;
import java.io.
ObjectInputStream;
import java.io.
StreamCorruptedException;
import java.util.function.
Consumer;
import java.util.function.
Predicate;
import java.util.function.
UnaryOperator;
/**
* The {@code Vector} 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 Vector} can grow or shrink as needed to accommodate
* adding and removing items after the {@code Vector} has been created.
*
* <p>Each vector tries to optimize storage management by maintaining a
* {@code capacity} and a {@code capacityIncrement}. The
* {@code capacity} 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}. An application can increase the
* capacity of a vector before inserting a large number of
* components; this reduces the amount of incremental reallocation.
*
* <p><a name="fail-fast">
* The iterators returned by this class's {@link #iterator() iterator} and
* {@link #listIterator(int) listIterator} methods are <em>fail-fast</em></a>:
* if the vector is structurally modified at any time after the iterator is
* created, in any way except through the iterator's own
* {@link ListIterator#remove() remove} or
* {@link ListIterator#add(Object) add} methods, the iterator will throw a
* {@link 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 {@link Enumeration Enumerations} returned by
* the {@link #elements() 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 {@code ConcurrentModificationException} 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>As of the Java 2 platform v1.2, this class was retrofitted to
* implement the {@link List} interface, making it a member of the
* <a href="{@docRoot}/../technotes/guides/collections/index.html">
* Java Collections Framework</a>. Unlike the new collection
* implementations, {@code Vector} is synchronized. If a thread-safe
* implementation is not needed, it is recommended to use {@link
* ArrayList} in place of {@code Vector}.
*
* @author Lee Boynton
* @author Jonathan Payne
* @see Collection
* @see LinkedList
* @since JDK1.0
*/
public class
Vector<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 Vector are null.
*
* @serial
*/
protected
Object[]
elementData;
/**
* The number of valid components in this {@code Vector} object.
* Components {@code elementData[0]} through
* {@code elementData[elementCount-1]} 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
* @throws IllegalArgumentException if the specified initial capacity
* is negative
*/
public
Vector(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
* @throws IllegalArgumentException if the specified initial capacity
* is negative
*/
public
Vector(int
initialCapacity) {
this(
initialCapacity, 0);
}
/**
* Constructs an empty vector so that its internal data array
* has size {@code 10} and its standard capacity increment is
* zero.
*/
public
Vector() {
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
Vector(
Collection<? extends E>
c) {
elementData =
c.
toArray();
elementCount =
elementData.length;
// c.toArray might (incorrectly) not return Object[] (see 6260652)
if (
elementData.
getClass() !=
Object[].class)
elementData =
Arrays.
copyOf(
elementData,
elementCount,
Object[].class);
}
/**
* Copies the components of this vector into the specified array.
* The item at index {@code k} in this vector is copied into
* component {@code k} of {@code anArray}.
*
* @param anArray the array into which the components get copied
* @throws NullPointerException if the given array is null
* @throws IndexOutOfBoundsException if the specified array is not
* large enough to hold all the components of this vector
* @throws ArrayStoreException if a component of this vector is not of
* a runtime type that can be stored in the specified array
* @see #toArray(Object[])
*/
public synchronized 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 {@code elementData},
* with a smaller one. An application can use this operation to
* minimize the storage of a vector.
*/
public synchronized void
trimToSize() {
modCount++;
int
oldCapacity =
elementData.length;
if (
elementCount <
oldCapacity) {
elementData =
Arrays.
copyOf(
elementData,
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
* {@code minCapacity}, then its capacity is increased by replacing its
* internal data array, kept in the field {@code elementData}, with a
* larger one. The size of the new data array will be the old size plus
* {@code capacityIncrement}, unless the value of
* {@code capacityIncrement} 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 {@code minCapacity}, then the new capacity will
* be {@code minCapacity}.
*
* @param minCapacity the desired minimum capacity
*/
public synchronized void
ensureCapacity(int
minCapacity) {
if (
minCapacity > 0) {
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 #ensureCapacity(int)
*/
private void
ensureCapacityHelper(int
minCapacity) {
// overflow-conscious code
if (
minCapacity -
elementData.length > 0)
grow(
minCapacity);
}
/**
* The maximum size of array to allocate.
* Some VMs reserve some header words in an array.
* Attempts to allocate larger arrays may result in
* OutOfMemoryError: Requested array size exceeds VM limit
*/
private static final int
MAX_ARRAY_SIZE =
Integer.
MAX_VALUE - 8;
private void
grow(int
minCapacity) {
// overflow-conscious code
int
oldCapacity =
elementData.length;
int
newCapacity =
oldCapacity + ((
capacityIncrement > 0) ?
capacityIncrement :
oldCapacity);
if (
newCapacity -
minCapacity < 0)
newCapacity =
minCapacity;
if (
newCapacity -
MAX_ARRAY_SIZE > 0)
newCapacity =
hugeCapacity(
minCapacity);
elementData =
Arrays.
copyOf(
elementData,
newCapacity);
}
private static int
hugeCapacity(int
minCapacity) {
if (
minCapacity < 0) // overflow
throw new
OutOfMemoryError();
return (
minCapacity >
MAX_ARRAY_SIZE) ?
Integer.
MAX_VALUE :
MAX_ARRAY_SIZE;
}
/**
* Sets the size of this vector. If the new size is greater than the
* current size, new {@code null} 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} and greater are discarded.
*
* @param newSize the new size of this vector
* @throws ArrayIndexOutOfBoundsException if the new size is negative
*/
public synchronized 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 {@code elementData}
* of this vector)
*/
public synchronized int
capacity() {
return
elementData.length;
}
/**
* Returns the number of components in this vector.
*
* @return the number of components in this vector
*/
public synchronized int
size() {
return
elementCount;
}
/**
* Tests if this vector has no components.
*
* @return {@code true} if and only if this vector has
* no components, that is, its size is zero;
* {@code false} otherwise.
*/
public synchronized boolean
isEmpty() {
return
elementCount == 0;
}
/**
* Returns an enumeration of the components of this vector. The
* returned {@code Enumeration} object will generate all items in
* this vector. The first item generated is the item at index {@code 0},
* then the item at index {@code 1}, and so on.
*
* @return an enumeration of the components of this vector
* @see Iterator
*/
public
Enumeration<E>
elements() {
return new
Enumeration<E>() {
int
count = 0;
public boolean
hasMoreElements() {
return
count <
elementCount;
}
public E
nextElement() {
synchronized (
Vector.this) {
if (
count <
elementCount) {
return
elementData(
count++);
}
}
throw new
NoSuchElementException("Vector Enumeration");
}
};
}
/**
* Returns {@code true} if this vector contains the specified element.
* More formally, returns {@code true} if and only if this vector
* contains at least one element {@code e} such that
* <tt>(o==null ? e==null : o.equals(e))</tt>.
*
* @param o element whose presence in this vector is to be tested
* @return {@code true} if this vector contains the specified element
*/
public boolean
contains(
Object o) {
return
indexOf(
o, 0) >= 0;
}
/**
* Returns the index of the first occurrence of the specified element
* in this vector, or -1 if this vector does not contain the element.
* More formally, returns the lowest index {@code i} such that
* <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>,
* or -1 if there is no such index.
*
* @param o element to search for
* @return the index of the first occurrence of the specified element in
* this vector, or -1 if this vector does not contain the element
*/
public int
indexOf(
Object o) {
return
indexOf(
o, 0);
}
/**
* Returns the index of the first occurrence of the specified element in
* this vector, searching forwards from {@code index}, or returns -1 if
* the element is not found.
* More formally, returns the lowest index {@code i} such that
* <tt>(i >= index && (o==null ? get(i)==null : o.equals(get(i))))</tt>,
* or -1 if there is no such index.
*
* @param o element to search for
* @param index index to start searching from
* @return the index of the first occurrence of the element in
* this vector at position {@code index} or later in the vector;
* {@code -1} if the element is not found.
* @throws IndexOutOfBoundsException if the specified index is negative
* @see Object#equals(Object)
*/
public synchronized int
indexOf(
Object o, int
index) {
if (
o == null) {
for (int
i =
index ;
i <
elementCount ;
i++)
if (
elementData[
i]==null)
return
i;
} else {
for (int
i =
index ;
i <
elementCount ;
i++)
if (
o.
equals(
elementData[
i]))
return
i;
}
return -1;
}
/**
* Returns the index of the last occurrence of the specified element
* in this vector, or -1 if this vector does not contain the element.
* More formally, returns the highest index {@code i} such that
* <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>,
* or -1 if there is no such index.
*
* @param o element to search for
* @return the index of the last occurrence of the specified element in
* this vector, or -1 if this vector does not contain the element
*/
public synchronized int
lastIndexOf(
Object o) {
return
lastIndexOf(
o,
elementCount-1);
}
/**
* Returns the index of the last occurrence of the specified element in
* this vector, searching backwards from {@code index}, or returns -1 if
* the element is not found.
* More formally, returns the highest index {@code i} such that
* <tt>(i <= index && (o==null ? get(i)==null : o.equals(get(i))))</tt>,
* or -1 if there is no such index.
*
* @param o element to search for
* @param index index to start searching backwards from
* @return the index of the last occurrence of the element at position
* less than or equal to {@code index} in this vector;
* -1 if the element is not found.
* @throws IndexOutOfBoundsException if the specified index is greater
* than or equal to the current size of this vector
*/
public synchronized int
lastIndexOf(
Object o, int
index) {
if (
index >=
elementCount)
throw new
IndexOutOfBoundsException(
index + " >= "+
elementCount);
if (
o == null) {
for (int
i =
index;
i >= 0;
i--)
if (
elementData[
i]==null)
return
i;
} else {
for (int
i =
index;
i >= 0;
i--)
if (
o.
equals(
elementData[
i]))
return
i;
}
return -1;
}
/**
* Returns the component at the specified index.
*
* <p>This method is identical in functionality to the {@link #get(int)}
* method (which is part of the {@link List} interface).
*
* @param index an index into this vector
* @return the component at the specified index
* @throws ArrayIndexOutOfBoundsException if the index is out of range
* ({@code index < 0 || index >= size()})
*/
public synchronized E
elementAt(int
index) {
if (
index >=
elementCount) {
throw new
ArrayIndexOutOfBoundsException(
index + " >= " +
elementCount);
}
return
elementData(
index);
}
/**
* Returns the first component (the item at index {@code 0}) of
* this vector.
*
* @return the first component of this vector
* @throws NoSuchElementException if this vector has no components
*/
public synchronized E
firstElement() {
if (
elementCount == 0) {
throw new
NoSuchElementException();
}
return
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>.
* @throws NoSuchElementException if this vector is empty
*/
public synchronized E
lastElement() {
if (
elementCount == 0) {
throw new
NoSuchElementException();
}
return
elementData(
elementCount - 1);
}
/**
* Sets the component at the specified {@code index} 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}
* and less than the current size of the vector.
*
* <p>This method is identical in functionality to the
* {@link #set(int, Object) set(int, E)}
* method (which is part of the {@link List} interface). Note that the
* {@code set} method reverses the order of the parameters, to more closely
* match array usage. Note also that the {@code 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
* @throws ArrayIndexOutOfBoundsException if the index is out of range
* ({@code index < 0 || index >= size()})
*/
public synchronized 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} is shifted downward to have an index one
* smaller than the value it had previously. The size of this vector
* is decreased by {@code 1}.
*
* <p>The index must be a value greater than or equal to {@code 0}
* and less than the current size of the vector.
*
* <p>This method is identical in functionality to the {@link #remove(int)}
* method (which is part of the {@link List} interface). Note that the
* {@code remove} method returns the old value that was stored at the
* specified position.
*
* @param index the index of the object to remove
* @throws ArrayIndexOutOfBoundsException if the index is out of range
* ({@code index < 0 || index >= size()})
*/
public synchronized 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}. Each component in this vector with
* an index greater or equal to the specified {@code index} 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}
* 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 Vector.)
*
* <p>This method is identical in functionality to the
* {@link #add(int, Object) add(int, E)}
* method (which is part of the {@link List} interface). Note that the
* {@code 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
* @throws ArrayIndexOutOfBoundsException if the index is out of range
* ({@code index < 0 || index > size()})
*/
public synchronized 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
* {@link #add(Object) add(E)}
* method (which is part of the {@link List} interface).
*
* @param obj the component to be added
*/
public synchronized 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
* {@link #remove(Object)} method (which is part of the
* {@link List} interface).
*
* @param obj the component to be removed
* @return {@code true} if the argument was a component of this
* vector; {@code false} otherwise.
*/
public synchronized 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 {@link #clear}
* method (which is part of the {@link List} interface).
*/
public synchronized 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 {@code Vector} object.
*
* @return a clone of this vector
*/
public synchronized
Object clone() {
try {
@
SuppressWarnings("unchecked")
Vector<E>
v = (
Vector<E>) super.clone();
v.
elementData =
Arrays.
copyOf(
elementData,
elementCount);
v.
modCount = 0;
return
v;
} catch (
CloneNotSupportedException e) {
// this shouldn't happen, since we are Cloneable
throw new
InternalError(
e);
}
}
/**
* Returns an array containing all of the elements in this Vector
* in the correct order.
*
* @since 1.2
*/
public synchronized
Object[]
toArray() {
return
Arrays.
copyOf(
elementData,
elementCount);
}
/**
* Returns an array containing all of the elements in this Vector in the
* correct order; the runtime type of the returned array is that of the
* specified array. If the Vector 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 Vector.
*
* <p>If the Vector fits in the specified array with room to spare
* (i.e., the array has more elements than the Vector),
* the element in the array immediately following the end of the
* Vector is set to null. (This is useful in determining the length
* of the Vector <em>only</em> if the caller knows that the Vector
* does not contain any null elements.)
*
* @param a the array into which the elements of the Vector 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 Vector
* @throws ArrayStoreException if the runtime type of a is not a supertype
* of the runtime type of every element in this Vector
* @throws NullPointerException if the given array is null
* @since 1.2
*/
@
SuppressWarnings("unchecked")
public synchronized <T> T[]
toArray(T[]
a) {
if (
a.length <
elementCount)
return (T[])
Arrays.
copyOf(
elementData,
elementCount,
a.
getClass());
System.
arraycopy(
elementData, 0,
a, 0,
elementCount);
if (
a.length >
elementCount)
a[
elementCount] = null;
return
a;
}
// Positional Access Operations
@
SuppressWarnings("unchecked")
E
elementData(int
index) {
return (E)
elementData[
index];
}
/**
* Returns the element at the specified position in this Vector.
*
* @param index index of the element to return
* @return object at the specified index
* @throws ArrayIndexOutOfBoundsException if the index is out of range
* ({@code index < 0 || index >= size()})
* @since 1.2
*/
public synchronized E
get(int
index) {
if (
index >=
elementCount)
throw new
ArrayIndexOutOfBoundsException(
index);
return
elementData(
index);
}
/**
* Replaces the element at the specified position in this Vector with the
* specified element.
*
* @param index index of the element to replace
* @param element element to be stored at the specified position
* @return the element previously at the specified position
* @throws ArrayIndexOutOfBoundsException if the index is out of range
* ({@code index < 0 || index >= size()})
* @since 1.2
*/
public synchronized E
set(int
index, E
element) {
if (
index >=
elementCount)
throw new
ArrayIndexOutOfBoundsException(
index);
E
oldValue =
elementData(
index);
elementData[
index] =
element;
return
oldValue;
}
/**
* Appends the specified element to the end of this Vector.
*
* @param e element to be appended to this Vector
* @return {@code true} (as specified by {@link Collection#add})
* @since 1.2
*/
public synchronized boolean
add(E
e) {
modCount++;
ensureCapacityHelper(
elementCount + 1);
elementData[
elementCount++] =
e;
return true;
}
/**
* Removes the first occurrence of the specified element in this Vector
* If the Vector 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)))} (if such
* an element exists).
*
* @param o element to be removed from this Vector, if present
* @return true if the Vector 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 Vector.
* 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
* @throws ArrayIndexOutOfBoundsException if the index is out of range
* ({@code 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 Vector.
* Shifts any subsequent elements to the left (subtracts one from their
* indices). Returns the element that was removed from the Vector.
*
* @throws ArrayIndexOutOfBoundsException if the index is out of range
* ({@code index < 0 || index >= size()})
* @param index the index of the element to be removed
* @return element that was removed
* @since 1.2
*/
public synchronized E
remove(int
index) {
modCount++;
if (
index >=
elementCount)
throw new
ArrayIndexOutOfBoundsException(
index);
E
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
oldValue;
}
/**
* Removes all of the elements from this Vector. The Vector 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 Vector contains all of the elements in the
* specified Collection.
*
* @param c a collection whose elements will be tested for containment
* in this Vector
* @return true if this Vector contains all of the elements in the
* specified collection
* @throws NullPointerException if the specified collection is null
*/
public synchronized boolean
containsAll(
Collection<?>
c) {
return super.containsAll(
c);
}
/**
* Appends all of the elements in the specified Collection to the end of
* this Vector, 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 Vector, and this Vector is nonempty.)
*
* @param c elements to be inserted into this Vector
* @return {@code true} if this Vector changed as a result of the call
* @throws NullPointerException if the specified collection is null
* @since 1.2
*/
public synchronized 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 Vector all of its elements that are contained in the
* specified Collection.
*
* @param c a collection of elements to be removed from the Vector
* @return true if this Vector changed as a result of the call
* @throws ClassCastException if the types of one or more elements
* in this vector are incompatible with the specified
* collection
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @throws NullPointerException if this vector contains one or more null
* elements and the specified collection does not support null
* elements
* (<a href="Collection.html#optional-restrictions">optional</a>),
* or if the specified collection is null
* @since 1.2
*/
public synchronized boolean
removeAll(
Collection<?>
c) {
return super.removeAll(
c);
}
/**
* Retains only the elements in this Vector that are contained in the
* specified Collection. In other words, removes from this Vector all
* of its elements that are not contained in the specified Collection.
*
* @param c a collection of elements to be retained in this Vector
* (all other elements are removed)
* @return true if this Vector changed as a result of the call
* @throws ClassCastException if the types of one or more elements
* in this vector are incompatible with the specified
* collection
* (<a href="Collection.html#optional-restrictions">optional</a>)
* @throws NullPointerException if this vector contains one or more null
* elements and the specified collection does not support null
* elements
* (<a href="Collection.html#optional-restrictions">optional</a>),
* or if the specified collection is null
* @since 1.2
*/
public synchronized boolean
retainAll(
Collection<?>
c) {
return super.retainAll(
c);
}
/**
* Inserts all of the elements in the specified Collection into this
* Vector 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 Vector
* in the order that they are returned by the specified Collection's
* iterator.
*
* @param index index at which to insert the first element from the
* specified collection
* @param c elements to be inserted into this Vector
* @return {@code true} if this Vector changed as a result of the call
* @throws ArrayIndexOutOfBoundsException if the index is out of range
* ({@code index < 0 || index > size()})
* @throws NullPointerException if the specified collection is null
* @since 1.2
*/
public synchronized 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 Vector 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} and
* {@code e2} are <em>equal</em> if {@code (e1==null ? e2==null :
* e1.equals(e2))}.) 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 Vector
* @return true if the specified Object is equal to this Vector
*/
public synchronized boolean
equals(
Object o) {
return super.equals(
o);
}
/**
* Returns the hash code value for this Vector.
*/
public synchronized int
hashCode() {
return super.hashCode();
}
/**
* Returns a string representation of this Vector, containing
* the String representation of each element.
*/
public synchronized
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 if an endpoint index value is out of range
* {@code (fromIndex < 0 || toIndex > size)}
* @throws IllegalArgumentException if the endpoint indices are out of order
* {@code (fromIndex > toIndex)}
*/
public synchronized
List<E>
subList(int
fromIndex, int
toIndex) {
return
Collections.
synchronizedList(super.subList(
fromIndex,
toIndex),
this);
}
/**
* Removes from this list all of the elements whose index is between
* {@code fromIndex}, inclusive, and {@code toIndex}, exclusive.
* Shifts any succeeding elements to the left (reduces their index).
* This call shortens the list by {@code (toIndex - fromIndex)} elements.
* (If {@code toIndex==fromIndex}, this operation has no effect.)
*/
protected synchronized 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;
}
/**
* Loads a {@code Vector} instance from a stream
* (that is, deserializes it).
* This method performs checks to ensure the consistency
* of the fields.
*
* @param in the stream
* @throws java.io.IOException if an I/O error occurs
* @throws ClassNotFoundException if the stream contains data
* of a non-existing class
*/
private void
readObject(
ObjectInputStream in)
throws
IOException,
ClassNotFoundException {
ObjectInputStream.
GetField gfields =
in.
readFields();
int
count =
gfields.
get("elementCount", 0);
Object[]
data = (
Object[])
gfields.
get("elementData", null);
if (
count < 0 ||
data == null ||
count >
data.length) {
throw new
StreamCorruptedException("Inconsistent vector internals");
}
elementCount =
count;
elementData =
data.
clone();
}
/**
* Save the state of the {@code Vector} instance to a stream (that
* is, serialize it).
* This method performs synchronization to ensure the consistency
* of the serialized data.
*/
private void
writeObject(java.io.
ObjectOutputStream s)
throws java.io.
IOException {
final java.io.
ObjectOutputStream.
PutField fields =
s.
putFields();
final
Object[]
data;
synchronized (this) {
fields.
put("capacityIncrement",
capacityIncrement);
fields.
put("elementCount",
elementCount);
data =
elementData.
clone();
}
fields.
put("elementData",
data);
s.
writeFields();
}
/**
* Returns a list iterator over the elements in this list (in proper
* sequence), starting at the specified position in the list.
* The specified index indicates the first element that would be
* returned by an initial call to {@link ListIterator#next next}.
* An initial call to {@link ListIterator#previous previous} would
* return the element with the specified index minus one.
*
* <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
*
* @throws IndexOutOfBoundsException {@inheritDoc}
*/
public synchronized
ListIterator<E>
listIterator(int
index) {
if (
index < 0 ||
index >
elementCount)
throw new
IndexOutOfBoundsException("Index: "+
index);
return new
ListItr(
index);
}
/**
* Returns a list iterator over the elements in this list (in proper
* sequence).
*
* <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
*
* @see #listIterator(int)
*/
public synchronized
ListIterator<E>
listIterator() {
return new
ListItr(0);
}
/**
* Returns an iterator over the elements in this list in proper sequence.
*
* <p>The returned iterator is <a href="#fail-fast"><i>fail-fast</i></a>.
*
* @return an iterator over the elements in this list in proper sequence
*/
public synchronized
Iterator<E>
iterator() {
return new
Itr();
}
/**
* An optimized version of AbstractList.Itr
*/
private class
Itr implements
Iterator<E> {
int
cursor; // index of next element to return
int
lastRet = -1; // index of last element returned; -1 if no such
int
expectedModCount =
modCount;
public boolean
hasNext() {
// Racy but within spec, since modifications are checked
// within or after synchronization in next/previous
return
cursor !=
elementCount;
}
public E
next() {
synchronized (
Vector.this) {
checkForComodification();
int
i =
cursor;
if (
i >=
elementCount)
throw new
NoSuchElementException();
cursor =
i + 1;
return
elementData(
lastRet =
i);
}
}
public void
remove() {
if (
lastRet == -1)
throw new
IllegalStateException();
synchronized (
Vector.this) {
checkForComodification();
Vector.this.
remove(
lastRet);
expectedModCount =
modCount;
}
cursor =
lastRet;
lastRet = -1;
}
@
Override
public void
forEachRemaining(
Consumer<? super E>
action) {
Objects.
requireNonNull(
action);
synchronized (
Vector.this) {
final int
size =
elementCount;
int
i =
cursor;
if (
i >=
size) {
return;
}
@
SuppressWarnings("unchecked")
final E[]
elementData = (E[])
Vector.this.
elementData;
if (
i >=
elementData.length) {
throw new
ConcurrentModificationException();
}
while (
i !=
size &&
modCount ==
expectedModCount) {
action.
accept(
elementData[
i++]);
}
// update once at end of iteration to reduce heap write traffic
cursor =
i;
lastRet =
i - 1;
checkForComodification();
}
}
final void
checkForComodification() {
if (
modCount !=
expectedModCount)
throw new
ConcurrentModificationException();
}
}
/**
* An optimized version of AbstractList.ListItr
*/
final class
ListItr extends
Itr implements
ListIterator<E> {
ListItr(int
index) {
super();
cursor =
index;
}
public boolean
hasPrevious() {
return
cursor != 0;
}
public int
nextIndex() {
return
cursor;
}
public int
previousIndex() {
return
cursor - 1;
}
public E
previous() {
synchronized (
Vector.this) {
checkForComodification();
int
i =
cursor - 1;
if (
i < 0)
throw new
NoSuchElementException();
cursor =
i;
return
elementData(
lastRet =
i);
}
}
public void
set(E
e) {
if (
lastRet == -1)
throw new
IllegalStateException();
synchronized (
Vector.this) {
checkForComodification();
Vector.this.
set(
lastRet,
e);
}
}
public void
add(E
e) {
int
i =
cursor;
synchronized (
Vector.this) {
checkForComodification();
Vector.this.
add(
i,
e);
expectedModCount =
modCount;
}
cursor =
i + 1;
lastRet = -1;
}
}
@
Override
public synchronized void
forEach(
Consumer<? super E>
action) {
Objects.
requireNonNull(
action);
final int
expectedModCount =
modCount;
@
SuppressWarnings("unchecked")
final E[]
elementData = (E[]) this.
elementData;
final int
elementCount = this.
elementCount;
for (int
i=0;
modCount ==
expectedModCount &&
i <
elementCount;
i++) {
action.
accept(
elementData[
i]);
}
if (
modCount !=
expectedModCount) {
throw new
ConcurrentModificationException();
}
}
@
Override
@
SuppressWarnings("unchecked")
public synchronized boolean
removeIf(
Predicate<? super E>
filter) {
Objects.
requireNonNull(
filter);
// figure out which elements are to be removed
// any exception thrown from the filter predicate at this stage
// will leave the collection unmodified
int
removeCount = 0;
final int
size =
elementCount;
final
BitSet removeSet = new
BitSet(
size);
final int
expectedModCount =
modCount;
for (int
i=0;
modCount ==
expectedModCount &&
i <
size;
i++) {
@
SuppressWarnings("unchecked")
final E
element = (E)
elementData[
i];
if (
filter.
test(
element)) {
removeSet.
set(
i);
removeCount++;
}
}
if (
modCount !=
expectedModCount) {
throw new
ConcurrentModificationException();
}
// shift surviving elements left over the spaces left by removed elements
final boolean
anyToRemove =
removeCount > 0;
if (
anyToRemove) {
final int
newSize =
size -
removeCount;
for (int
i=0,
j=0; (
i <
size) && (
j <
newSize);
i++,
j++) {
i =
removeSet.
nextClearBit(
i);
elementData[
j] =
elementData[
i];
}
for (int
k=
newSize;
k <
size;
k++) {
elementData[
k] = null; // Let gc do its work
}
elementCount =
newSize;
if (
modCount !=
expectedModCount) {
throw new
ConcurrentModificationException();
}
modCount++;
}
return
anyToRemove;
}
@
Override
@
SuppressWarnings("unchecked")
public synchronized void
replaceAll(
UnaryOperator<E>
operator) {
Objects.
requireNonNull(
operator);
final int
expectedModCount =
modCount;
final int
size =
elementCount;
for (int
i=0;
modCount ==
expectedModCount &&
i <
size;
i++) {
elementData[
i] =
operator.
apply((E)
elementData[
i]);
}
if (
modCount !=
expectedModCount) {
throw new
ConcurrentModificationException();
}
modCount++;
}
@
SuppressWarnings("unchecked")
@
Override
public synchronized void
sort(
Comparator<? super E>
c) {
final int
expectedModCount =
modCount;
Arrays.
sort((E[])
elementData, 0,
elementCount,
c);
if (
modCount !=
expectedModCount) {
throw new
ConcurrentModificationException();
}
modCount++;
}
/**
* Creates a <em><a href="Spliterator.html#binding">late-binding</a></em>
* and <em>fail-fast</em> {@link Spliterator} over the elements in this
* list.
*
* <p>The {@code Spliterator} reports {@link Spliterator#SIZED},
* {@link Spliterator#SUBSIZED}, and {@link Spliterator#ORDERED}.
* Overriding implementations should document the reporting of additional
* characteristic values.
*
* @return a {@code Spliterator} over the elements in this list
* @since 1.8
*/
@
Override
public
Spliterator<E>
spliterator() {
return new
VectorSpliterator<>(this, null, 0, -1, 0);
}
/** Similar to ArrayList Spliterator */
static final class
VectorSpliterator<E> implements
Spliterator<E> {
private final
Vector<E>
list;
private
Object[]
array;
private int
index; // current index, modified on advance/split
private int
fence; // -1 until used; then one past last index
private int
expectedModCount; // initialized when fence set
/** Create new spliterator covering the given range */
VectorSpliterator(
Vector<E>
list,
Object[]
array, int
origin, int
fence,
int
expectedModCount) {
this.
list =
list;
this.
array =
array;
this.
index =
origin;
this.
fence =
fence;
this.
expectedModCount =
expectedModCount;
}
private int
getFence() { // initialize on first use
int
hi;
if ((
hi =
fence) < 0) {
synchronized(
list) {
array =
list.
elementData;
expectedModCount =
list.
modCount;
hi =
fence =
list.
elementCount;
}
}
return
hi;
}
public
Spliterator<E>
trySplit() {
int
hi =
getFence(),
lo =
index,
mid = (
lo +
hi) >>> 1;
return (
lo >=
mid) ? null :
new
VectorSpliterator<E>(
list,
array,
lo,
index =
mid,
expectedModCount);
}
@
SuppressWarnings("unchecked")
public boolean
tryAdvance(
Consumer<? super E>
action) {
int
i;
if (
action == null)
throw new
NullPointerException();
if (
getFence() > (
i =
index)) {
index =
i + 1;
action.
accept((E)
array[
i]);
if (
list.
modCount !=
expectedModCount)
throw new
ConcurrentModificationException();
return true;
}
return false;
}
@
SuppressWarnings("unchecked")
public void
forEachRemaining(
Consumer<? super E>
action) {
int
i,
hi; // hoist accesses and checks from loop
Vector<E>
lst;
Object[]
a;
if (
action == null)
throw new
NullPointerException();
if ((
lst =
list) != null) {
if ((
hi =
fence) < 0) {
synchronized(
lst) {
expectedModCount =
lst.
modCount;
a =
array =
lst.
elementData;
hi =
fence =
lst.
elementCount;
}
}
else
a =
array;
if (
a != null && (
i =
index) >= 0 && (
index =
hi) <=
a.length) {
while (
i <
hi)
action.
accept((E)
a[
i++]);
if (
lst.
modCount ==
expectedModCount)
return;
}
}
throw new
ConcurrentModificationException();
}
public long
estimateSize() {
return (long) (
getFence() -
index);
}
public int
characteristics() {
return
Spliterator.
ORDERED |
Spliterator.
SIZED |
Spliterator.
SUBSIZED;
}
}
}