org.apache.commons.collections.bag
Class AbstractBagDecorator<E>

java.lang.Object
  org.apache.commons.collections.collection.AbstractCollectionDecorator<E>
      org.apache.commons.collections.bag.AbstractBagDecorator<E>

All Implemented Interfaces:

Iterable<E>, Collection<E>, Bag<E>

Direct Known Subclasses:

AbstractSortedBagDecorator, UnmodifiableBag

public abstract class AbstractBagDecorator<E>
extends AbstractCollectionDecorator<E>
implements Bag<E>

Decorates another Bag to provide additional behaviour.

Methods are forwarded directly to the decorated bag.

Since:

Commons Collections 3.0

Version:

$Revision: 1.1.1.1 $ $Date: 2005/05/23 04:33:25 $

Author:

Matt Hall, John Watkinson, Stephen Colebourne

Field Summary

Fields inherited from class org.apache.commons.collections.collection.AbstractCollectionDecorator

collection

Constructor Summary

protected	AbstractBagDecorator() Constructor only used in deserialization, do not use otherwise.
protected	AbstractBagDecorator(Bag<E> bag) Constructor that wraps (not copies).

Method Summary

boolean	add(E object, int count) Adds nCopies copies of the specified object to the Bag.
protected Bag<E>	getBag() Gets the bag being decorated.
int	getCount(E object) Returns the number of occurrences (cardinality) of the given object currently in the bag.
boolean	remove(E object, int count) Removes nCopies copies of the specified object from the Bag.
Set<E>	uniqueSet() Returns a Set of unique elements in the Bag.

Methods inherited from class org.apache.commons.collections.collection.AbstractCollectionDecorator

add, addAll, clear, contains, containsAll, equals, getCollection, hashCode, isEmpty, iterator, remove, removeAll, retainAll, size, toArray, toArray, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.commons.collections.Bag

add, containsAll, iterator, remove, removeAll, retainAll, size

Methods inherited from interface java.util.Collection

addAll, clear, contains, equals, hashCode, isEmpty, toArray, toArray

Constructor Detail

AbstractBagDecorator

protected AbstractBagDecorator()

Constructor only used in deserialization, do not use otherwise.

Since:

Commons Collections 3.1

AbstractBagDecorator

protected AbstractBagDecorator(Bag<E> bag)

Constructor that wraps (not copies).

Parameters:

bag - the bag to decorate, must not be null

Throws:

IllegalArgumentException - if list is null

Method Detail

getBag

protected Bag<E> getBag()

Gets the bag being decorated.

Returns:

the decorated bag

getCount

public int getCount(E object)

Description copied from interface: Bag

Returns the number of occurrences (cardinality) of the given object currently in the bag. If the object does not exist in the bag, return 0.

Specified by:

getCount in interface Bag<E>

Parameters:

object - the object to search for

Returns:

the number of occurrences of the object, zero if not found

add

public boolean add(E object,
                   int count)

Description copied from interface: Bag

Adds nCopies copies of the specified object to the Bag.

If the object is already in the Bag.uniqueSet() then increment its count as reported by Bag.getCount(Object). Otherwise add it to the Bag.uniqueSet() and report its count as nCopies.

Specified by:

add in interface Bag<E>

Parameters:

object - the object to add

count - the number of copies to add

Returns:

true if the object was not already in the uniqueSet

remove

public boolean remove(E object,
                      int count)

Description copied from interface: Bag

Removes nCopies copies of the specified object from the Bag.

If the number of copies to remove is greater than the actual number of copies in the Bag, no error is thrown.

Specified by:

remove in interface Bag<E>

Parameters:

object - the object to remove

count - the number of copies to remove

Returns:

true if this call changed the collection

uniqueSet

public Set<E> uniqueSet()

Description copied from interface: Bag

Returns a Set of unique elements in the Bag.

Uniqueness constraints are the same as those in Set.

Specified by:

uniqueSet in interface Bag<E>

Returns:

the Set of unique Bag elements