org.apache.commons.collections.map

Class CaseInsensitiveMap

Implemented Interfaces:
Cloneable, Map, Serializable, IterableMap

public class CaseInsensitiveMap
extends AbstractHashedMap
implements Serializable, Cloneable

A case-insensitive Map.

As entries are added to the map, keys are converted to all lowercase. A new key is compared to existing keys by comparing newKey.toString().toLower() to the lowercase values in the current KeySet.

Null keys are supported.

The keySet() method returns all lowercase keys, or nulls.

Example:


  Map map = new CaseInsensitiveMap();
  map.put("One", "One");
  map.put("Two", "Two");
  map.put(null, "Three");
  map.put("one", "Four");
 
creates a CaseInsensitiveMap with three entries.
map.get(null) returns "Three" and map.get("ONE") returns "Four". The Set returned by keySet() equals {"one", "two", null}.
Version:
$Revision: 1.4 $ $Date: 2004/02/18 01:13:19 $
Author:
Commons-Collections team
Since:
Commons Collections 3.0

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.commons.collections.map.AbstractHashedMap

AbstractHashedMap.EntrySet, AbstractHashedMap.EntrySetIterator, AbstractHashedMap.HashEntry, AbstractHashedMap.HashIterator, AbstractHashedMap.HashMapIterator, AbstractHashedMap.KeySet, AbstractHashedMap.KeySetIterator, AbstractHashedMap.Values, AbstractHashedMap.ValuesIterator

Field Summary

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

DEFAULT_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_THRESHOLD, GETKEY_INVALID, GETVALUE_INVALID, MAXIMUM_CAPACITY, NO_NEXT_ENTRY, NO_PREVIOUS_ENTRY, NULL, REMOVE_INVALID, SETVALUE_INVALID, data, entrySet, keySet, loadFactor, modCount, size, threshold, values

Constructor Summary

CaseInsensitiveMap()
Constructs a new empty map with default size and load factor.
CaseInsensitiveMap(Map map)
Constructor copying elements from another map.
CaseInsensitiveMap(int initialCapacity)
Constructs a new, empty map with the specified initial capacity.
CaseInsensitiveMap(int initialCapacity, float loadFactor)
Constructs a new, empty map with the specified initial capacity and load factor.

Method Summary

Object
clone()
Clones the map without cloning the keys or values.
protected Object
convertKey(Object key)
Overrides convertKey() from AbstractHashedMap to convert keys to lower case.

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

addEntry, addMapping, calculateNewCapacity, calculateThreshold, checkCapacity, clear, clone, containsKey, containsValue, convertKey, createEntry, createEntrySetIterator, createKeySetIterator, createValuesIterator, destroyEntry, doReadObject, doWriteObject, ensureCapacity, entryHashCode, entryKey, entryNext, entrySet, entryValue, equals, get, getEntry, hash, hashCode, hashIndex, init, isEmpty, isEqualKey, isEqualValue, keySet, mapIterator, put, putAll, remove, removeEntry, removeMapping, reuseEntry, size, toString, updateEntry, values

Constructor Details

CaseInsensitiveMap

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

CaseInsensitiveMap

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

Keys will be converted to lower case strings, which may cause some entries to be removed (if string representation of keys differ only by character case).

Parameters:
map - the map to copy

CaseInsensitiveMap

public CaseInsensitiveMap(int initialCapacity)
Constructs a new, empty map with the specified initial capacity.
Parameters:
initialCapacity - the initial capacity

CaseInsensitiveMap

public CaseInsensitiveMap(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

Method Details

clone

public Object clone()
Clones the map without cloning the keys or values.
Overrides:
clone in interface AbstractHashedMap
Returns:
a shallow clone

convertKey

protected Object convertKey(Object key)
Overrides convertKey() from AbstractHashedMap to convert keys to lower case.

Returns null if key is null.

Overrides:
convertKey in interface AbstractHashedMap
Parameters:
key - the key convert
Returns:
the converted key

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