edu.tum.cs.commons.collections
Class UnmodifiableMap<K,V>

java.lang.Object
  edu.tum.cs.commons.collections.UnmodifiableMap<K,V>

All Implemented Interfaces:

Serializable, Map<K,V>

Direct Known Subclasses:

UnmodifiableSortedMap

public class UnmodifiableMap<K,V>
extends Object
implements Map<K,V>, Serializable

This is a wrapper for a Map prohibiting all calls which would modify its contents. As the construction of this class is performed in constant time it is prefered over copying the map (which takes linear time). Using this class is also preferred to using the unmodifiableX() in class Collections as they return the collection base type that does not signal, that the object ist unmodifiable. Using the classes in this package makes unmodifiability more explicit.

All prohibited methods throw an UnsupportedOperationException. The class is nearly the same as the one returned by Collections.unmodifiableMap(Map), but by making it a public class we can make the return value of some methods more explicit.

This map is serializable if the wrapped map is serializable.

Version:

$Revision: 26283 $

Author:

Benjamin Hummel, $Author: juergens $

See Also:

Serialized Form

Rating:

GREEN Hash: 4BC4212A490EEF9A14859C79C22B8A4D

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K,V>

Constructor Summary

UnmodifiableMap(Map<K,V> m)
Creates a new unmodifiable map from another map.

Method Summary

void	clear() Operation is not supported.
boolean	containsKey(Object key)
boolean	containsValue(Object value)
UnmodifiableSet<Map.Entry<K,V>>	entrySet()
V	get(Object key)
boolean	isEmpty()
UnmodifiableSet<K>	keySet()
V	put(K arg0, V arg1) Operation is not supported.
void	putAll(Map<? extends K,? extends V> arg0) Operation is not supported.
V	remove(Object arg0) Operation is not supported.
int	size()
String	toString() Returns a string representation of this map.
UnmodifiableCollection<V>	values()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map

equals, hashCode

Constructor Detail

UnmodifiableMap

public UnmodifiableMap(Map<K,V> m)

Creates a new unmodifiable map from another map. All modifications to the underlying map will directly be visible in this wrapper.

Method Detail

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Map<K,V>

size

public int size()

Specified by:

size in interface Map<K,V>

containsKey

public boolean containsKey(Object key)

Specified by:

containsKey in interface Map<K,V>

containsValue

public boolean containsValue(Object value)

Specified by:

containsValue in interface Map<K,V>

get

public V get(Object key)

Specified by:

get in interface Map<K,V>

keySet

public UnmodifiableSet<K> keySet()

Specified by:

keySet in interface Map<K,V>

values

public UnmodifiableCollection<V> values()

Specified by:

values in interface Map<K,V>

entrySet

public UnmodifiableSet<Map.Entry<K,V>> entrySet()

Specified by:

entrySet in interface Map<K,V>

clear

public void clear()

Operation is not supported.

Specified by:

clear in interface Map<K,V>

Throws:

UnsupportedOperationException

put

public V put(K arg0,
             V arg1)

Operation is not supported.

Specified by:

put in interface Map<K,V>

Throws:

UnsupportedOperationException

putAll

public void putAll(Map<? extends K,? extends V> arg0)

Operation is not supported.

Specified by:

putAll in interface Map<K,V>

Throws:

UnsupportedOperationException

remove

public V remove(Object arg0)

Operation is not supported.

Specified by:

remove in interface Map<K,V>

Throws:

UnsupportedOperationException

toString

public String toString()

Returns a string representation of this map.

Overrides:

toString in class Object