jdk1.7之vector

vector是线程安全的

public class Vector<E> extends AbstractList<E> implements List<E>, RandomAccess, Cloneable, java.io.Serializable {


protected Object[] elementData;


protected int elementCount;




protected int capacityIncrement;




private static final long serialVersionUID = -2767605614048989439L;


public Vector(int initialCapacity, int capacityIncrement) {
super();
if (initialCapacity < 0)
throw new IllegalArgumentException("Illegal Capacity: " + initialCapacity);
this.elementData = new Object[initialCapacity];
this.capacityIncrement = capacityIncrement;
}


public Vector(int initialCapacity) {
this(initialCapacity, 0);
}


public Vector() {
this(10);
}


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);
}


public synchronized void copyInto(Object[] anArray) {
System.arraycopy(elementData, 0, anArray, 0, elementCount);
}


public synchronized void trimToSize() {
modCount++;
int oldCapacity = elementData.length;
if (elementCount < oldCapacity) {
elementData = Arrays.copyOf(elementData, elementCount);
}
}


public synchronized void ensureCapacity(int minCapacity) {
if (minCapacity > 0) {
modCount++;
ensureCapacityHelper(minCapacity);
}
}


private void ensureCapacityHelper(int minCapacity) {
// overflow-conscious code
if (minCapacity - elementData.length > 0)
grow(minCapacity);
}


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;
}


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;
}


public synchronized int capacity() {
return elementData.length;
}


public synchronized int size() {
return elementCount;
}


public synchronized boolean isEmpty() {
return elementCount == 0;
}


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");
}
};
}


public boolean contains(Object o) {
return indexOf(o, 0) >= 0;
}


public int indexOf(Object o) {
return indexOf(o, 0);
}


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;
}


public synchronized int lastIndexOf(Object o) {
return lastIndexOf(o, elementCount - 1);
}


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;
}


public synchronized E elementAt(int index) {
if (index >= elementCount) {
throw new ArrayIndexOutOfBoundsException(index + " >= " + elementCount);
}


return elementData(index);
}


public synchronized E firstElement() {
if (elementCount == 0) {
throw new NoSuchElementException();
}
return elementData(0);
}


public synchronized E lastElement() {
if (elementCount == 0) {
throw new NoSuchElementException();
}
return elementData(elementCount - 1);
}


public synchronized void setElementAt(E obj, int index) {
if (index >= elementCount) {
throw new ArrayIndexOutOfBoundsException(index + " >= " + elementCount);
}
elementData[index] = obj;
}


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 */
}


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++;
}


public synchronized void addElement(E obj) {
modCount++;
ensureCapacityHelper(elementCount + 1);
elementData[elementCount++] = obj;
}


public synchronized boolean removeElement(Object obj) {
modCount++;
int i = indexOf(obj);
if (i >= 0) {
removeElementAt(i);
return true;
}
return false;
}


public synchronized void removeAllElements() {
modCount++;
// Let gc do its work
for (int i = 0; i < elementCount; i++)
elementData[i] = null;


elementCount = 0;
}


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();
}
}


public synchronized Object[] toArray() {
return Arrays.copyOf(elementData, elementCount);
}


@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];
}


public synchronized E get(int index) {
if (index >= elementCount)
throw new ArrayIndexOutOfBoundsException(index);


return elementData(index);
}


public synchronized E set(int index, E element) {
if (index >= elementCount)
throw new ArrayIndexOutOfBoundsException(index);


E oldValue = elementData(index);
elementData[index] = element;
return oldValue;
}


public synchronized boolean add(E e) {
modCount++;
ensureCapacityHelper(elementCount + 1);
elementData[elementCount++] = e;
return true;
}


public boolean remove(Object o) {
return removeElement(o);
}


public void add(int index, E element) {
insertElementAt(element, index);
}


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;
}


public void clear() {
removeAllElements();
}




public synchronized boolean containsAll(Collection<?> c) {
return super.containsAll(c);
}


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;
}


public synchronized boolean removeAll(Collection<?> c) {
return super.removeAll(c);
}


public synchronized boolean retainAll(Collection<?> c) {
return super.retainAll(c);
}


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;
}




public synchronized boolean equals(Object o) {
return super.equals(o);
}




public synchronized int hashCode() {
return super.hashCode();
}


public synchronized String toString() {
return super.toString();
}


public synchronized List<E> subList(int fromIndex, int toIndex) {
return Collections.synchronizedList(super.subList(fromIndex, toIndex), this);
}


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;
}


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();
}


public synchronized ListIterator<E> listIterator(int index) {
if (index < 0 || index > elementCount)
throw new IndexOutOfBoundsException("Index: " + index);
return new ListItr(index);
}


public synchronized ListIterator<E> listIterator() {
return new ListItr(0);
}


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;
}


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;
}
}
}