org.apache.jackrabbit.util
Class WeakIdentityCollection

java.lang.Object
  org.apache.jackrabbit.util.WeakIdentityCollection

All Implemented Interfaces:

Iterable, Collection

public class WeakIdentityCollection
extends Object
implements Collection

WeakIdentityCollection implements a Collection with weak values. Equality of elements is tested using the == operator.

This collection does not hide the fact that the garbage collector will remove a mapping at some point in time. Thus, the Iterator returned by this collection might return null values. The same applies to the method toArray() in both its variants.

Constructor Summary

WeakIdentityCollection(int initialCapacity)
Creates a new WeakIdentityCollection.

Method Summary

boolean	add(Object o) Adds object o to this collection.
boolean	addAll(Collection c)
void	clear() Releases all references held by this collection.
boolean	contains(Object o) Returns true if this collection contains o.
boolean	containsAll(Collection c)
boolean	isEmpty() Returns true if this collection is empty.
Iterator	iterator() Returns an Iterator over the elements of this collection.
boolean	remove(Object o) Removes the object o from this collection if it is present.
boolean	removeAll(Collection c)
boolean	retainAll(Collection c)
int	size() Returns the current size of this collection.
Object[]	toArray() Returns an array containing all of the elements in this collection.
Object[]	toArray(Object[] a) The returned array may contain null elements!

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.Collection

equals, hashCode

Constructor Detail

WeakIdentityCollection

public WeakIdentityCollection(int initialCapacity)

Creates a new WeakIdentityCollection.

Parameters:

initialCapacity - the initial capacity.

Method Detail

size

public int size()

Returns the current size of this collection.

Specified by:

size in interface Collection

Returns:

the current size of this collection.

isEmpty

public boolean isEmpty()

Returns true if this collection is empty.

Specified by:

isEmpty in interface Collection

Returns:

true if this collection is empty.

clear

public void clear()

Releases all references held by this collection.

Specified by:

clear in interface Collection

add

public boolean add(Object o)

Adds object o to this collection.

Specified by:

add in interface Collection

Parameters:

o - the object to add.

Returns:

always true as this collection allows duplicates.

Throws:

NullPointerException - if o is null.

contains

public boolean contains(Object o)

Returns true if this collection contains o.

Specified by:

contains in interface Collection

Parameters:

o - element whose presence in this collection is to be tested.

Returns:

true if this collection contains the specified element

remove

public boolean remove(Object o)

Removes the object o from this collection if it is present.

Specified by:

remove in interface Collection

Parameters:

o - the object to remove.

Returns:

true if this collection changed as a result of the call.

addAll

public boolean addAll(Collection c)

Specified by:

addAll in interface Collection

Throws:

UnsupportedOperationException - always.

containsAll

public boolean containsAll(Collection c)

Specified by:

containsAll in interface Collection

Throws:

UnsupportedOperationException - always.

removeAll

public boolean removeAll(Collection c)

Specified by:

removeAll in interface Collection

Throws:

UnsupportedOperationException - always.

retainAll

public boolean retainAll(Collection c)

Specified by:

retainAll in interface Collection

Throws:

UnsupportedOperationException - always.

iterator

public Iterator iterator()

Returns an Iterator over the elements of this collection. The returned iterator is not fail-fast. That is, it does not throw a ConcurrentModificationException if this collection is modified while iterating over the collection.

Specified by:

iterator in interface Iterable

Specified by:

iterator in interface Collection

Returns:

an Iterator over the elements of this collection.

toArray

public Object[] toArray()

Returns an array containing all of the elements in this collection. The returned array may contain null elements!

Specified by:

toArray in interface Collection

Returns:

an array containing all of the elements in this collection.

toArray

public Object[] toArray(Object[] a)

The returned array may contain null elements!

Specified by:

toArray in interface Collection