org.apache.commons.collections.map
Class IdentityMap

java.lang.Object
  |
  +--java.util.AbstractMap
        |
        +--org.apache.commons.collections.map.AbstractHashedMap
              |
              +--org.apache.commons.collections.map.IdentityMap

All Implemented Interfaces:

java.lang.Cloneable, IterableMap, java.util.Map, java.io.Serializable

public class IdentityMap

extends AbstractHashedMap

implements java.io.Serializable, java.lang.Cloneable

A Map implementation that matches keys and values based on == not equals().

This map will violate the detail of various Map and map view contracts. As a general rule, don't compare this map to other maps.

Since:

Commons Collections 3.0

Version:

$Revision: 1.5 $ $Date: 2004/02/18 01:13:19 $

Author:

java util HashMap, Stephen Colebourne

See Also:

Serialized Form

Constructor Summary

IdentityMap()
Constructs a new empty map with default size and load factor.

IdentityMap(int initialCapacity)
Constructs a new, empty map with the specified initial capacity.

IdentityMap(int initialCapacity, float loadFactor)
Constructs a new, empty map with the specified initial capacity and load factor.

IdentityMap(java.util.Map map)
Constructor copying elements from another map.

Method Summary

java.lang.Object

clone() Clones the map without cloning the keys or values.

Methods inherited from class org.apache.commons.collections.map.AbstractHashedMap

clear, containsKey, containsValue, entrySet, equals, get, hashCode, isEmpty, keySet, mapIterator, put, putAll, remove, size, toString, values

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

IdentityMap

public IdentityMap()

Constructs a new empty map with default size and load factor.

IdentityMap

public IdentityMap(int initialCapacity)

Constructs a new, empty map with the specified initial capacity.

Parameters:

initialCapacity - the initial capacity

Throws:

java.lang.IllegalArgumentException - if the initial capacity is less than one

IdentityMap

public IdentityMap(int initialCapacity,
                   float loadFactor)

Constructs a new, empty map with the specified initial capacity and load factor.

Parameters:

initialCapacity - the initial capacity

loadFactor - the load factor

Throws:

java.lang.IllegalArgumentException - if the initial capacity is less than one

java.lang.IllegalArgumentException - if the load factor is less than zero

IdentityMap

public IdentityMap(java.util.Map map)

Constructor copying elements from another map.

Parameters:

map - the map to copy

Throws:

java.lang.NullPointerException - if the map is null

Method Detail

clone

public java.lang.Object clone()

Clones the map without cloning the keys or values.

Overrides:

clone in class AbstractHashedMap

Returns:

a shallow clone