org.apache.commons.collections.map

Class HashedMap

public class HashedMap extends AbstractHashedMap implements Serializable, Cloneable

A Map implementation that is a general purpose alternative to HashMap.

This implementation improves on the JDK1.4 HashMap by adding the MapIterator functionality and many methods for subclassing.

Note that HashedMap is not synchronized and is not thread-safe. If you wish to use this map from multiple threads concurrently, you must use appropriate synchronization. The simplest approach is to wrap this map using java.util.Collections#synchronizedMap(Map). This class may throw exceptions when accessed by concurrent threads without synchronization.

Since: Commons Collections 3.0

Version: $Revision: 348007 $ $Date: 2005-11-21 22:52:57 +0000 (Mon, 21 Nov 2005) $

Author: Stephen Colebourne

Constructor Summary
HashedMap()
Constructs a new empty map with default size and load factor.
HashedMap(int initialCapacity)
Constructs a new, empty map with the specified initial capacity.
HashedMap(int initialCapacity, float loadFactor)
Constructs a new, empty map with the specified initial capacity and load factor.
HashedMap(Map map)
Constructor copying elements from another map.
Method Summary
Objectclone()
Clones the map without cloning the keys or values.

Constructor Detail

HashedMap

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

HashedMap

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

Parameters: initialCapacity the initial capacity

Throws: IllegalArgumentException if the initial capacity is less than one

HashedMap

public HashedMap(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: IllegalArgumentException if the initial capacity is less than one IllegalArgumentException if the load factor is less than zero

HashedMap

public HashedMap(Map map)
Constructor copying elements from another map.

Parameters: map the map to copy

Throws: NullPointerException if the map is null

Method Detail

clone

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

Returns: a shallow clone

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