TUM CCSM Commons

edu.tum.cs.commons.collections
Class IdentityHashSet<E>

java.lang.Object
  extended by java.util.AbstractCollection<E>
      extended by java.util.AbstractSet<E>
          extended by edu.tum.cs.commons.collections.IdentityHashSet<E>
All Implemented Interfaces:
java.lang.Iterable<E>, java.util.Collection<E>, java.util.Set<E>

public class IdentityHashSet<E>
extends java.util.AbstractSet<E>

This class implements a set based on referential equality similar to JDK class IdentityHashMap. This class can be e.g. used to implement listener lists that should not rely on the listeners equals()-methods.

The implementation is based on class HashSet that also uses an underlying hash map.

Version:
$Rev: 26283 $
Author:
Florian Deissenboeck, $Author: juergens $
Rating:
GREEN Hash: A3753EB461A1466EFCA699DCE847468B

Constructor Summary
IdentityHashSet()
          Create new identity hash set.
IdentityHashSet(java.util.Collection<? extends E> collection)
          Create new identity hash set from an existing collection.
IdentityHashSet(int expectedMaxSize)
          Create new identity hash set with an expected maximum size.
 
Method Summary
 boolean add(E o)
          Adds the specified element to this set if it is not already present.
 void clear()
          Removes all of the elements from this set.
 IdentityHashSet<E> clone()
          Returns a shallow copy of this IdentityHashSet instance: the elements themselves are not cloned.
 boolean contains(java.lang.Object o)
          Returns true if this set contains the specified element.
 boolean isEmpty()
          Returns true if this set contains no elements.
 java.util.Iterator<E> iterator()
          Return iterator over the set.
 boolean remove(java.lang.Object o)
          Removes the specified element from this set if it is present.
 int size()
          Get set size.
 
Methods inherited from class java.util.AbstractSet
equals, hashCode, removeAll
 
Methods inherited from class java.util.AbstractCollection
addAll, containsAll, retainAll, toArray, toArray, toString
 
Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface java.util.Set
addAll, containsAll, retainAll, toArray, toArray
 

Constructor Detail

IdentityHashSet

public IdentityHashSet()
Create new identity hash set.


IdentityHashSet

public IdentityHashSet(java.util.Collection<? extends E> collection)
Create new identity hash set from an existing collection.


IdentityHashSet

public IdentityHashSet(int expectedMaxSize)
Create new identity hash set with an expected maximum size.

Method Detail

add

public boolean add(E o)
Adds the specified element to this set if it is not already present.

Specified by:
add in interface java.util.Collection<E>
Specified by:
add in interface java.util.Set<E>
Overrides:
add in class java.util.AbstractCollection<E>
Parameters:
o - element to be added to this set.
Returns:
true if the set did not already contain the specified element.

clear

public void clear()
Removes all of the elements from this set.

Specified by:
clear in interface java.util.Collection<E>
Specified by:
clear in interface java.util.Set<E>
Overrides:
clear in class java.util.AbstractCollection<E>

clone

public IdentityHashSet<E> clone()
Returns a shallow copy of this IdentityHashSet instance: the elements themselves are not cloned.

Overrides:
clone in class java.lang.Object
Returns:
a shallow copy of this set.

contains

public boolean contains(java.lang.Object o)
Returns true if this set contains the specified element.

Specified by:
contains in interface java.util.Collection<E>
Specified by:
contains in interface java.util.Set<E>
Overrides:
contains in class java.util.AbstractCollection<E>
Parameters:
o - element whose presence in this set is to be tested.
Returns:
true if this set contains the specified element.

isEmpty

public boolean isEmpty()
Returns true if this set contains no elements.

Specified by:
isEmpty in interface java.util.Collection<E>
Specified by:
isEmpty in interface java.util.Set<E>
Overrides:
isEmpty in class java.util.AbstractCollection<E>
Returns:
true if this set contains no elements.

iterator

public java.util.Iterator<E> iterator()
Return iterator over the set.

Specified by:
iterator in interface java.lang.Iterable<E>
Specified by:
iterator in interface java.util.Collection<E>
Specified by:
iterator in interface java.util.Set<E>
Specified by:
iterator in class java.util.AbstractCollection<E>

remove

public boolean remove(java.lang.Object o)
Removes the specified element from this set if it is present.

Specified by:
remove in interface java.util.Collection<E>
Specified by:
remove in interface java.util.Set<E>
Overrides:
remove in class java.util.AbstractCollection<E>
Parameters:
o - object to be removed from this set, if present.
Returns:
true if the set contained the specified element.

size

public int size()
Get set size.

Specified by:
size in interface java.util.Collection<E>
Specified by:
size in interface java.util.Set<E>
Specified by:
size in class java.util.AbstractCollection<E>

TUM CCSM Commons

TUM CCSM Commons - 2.7