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

java.lang.Object
  extended by org.apache.commons.collections.collection.AbstractCollectionDecorator<E>
      extended by 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


Copyright © 2005-2005 Apache Software Foundation, Matt Hall, John Watkinson. All Rights Reserved.