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

java.lang.Object
  edu.tum.cs.commons.collections.UnmodifiableCollection<E>

All Implemented Interfaces:

Serializable, Iterable<E>, Collection<E>

Direct Known Subclasses:

UnmodifiableList, UnmodifiableSet

public class UnmodifiableCollection<E>
extends Object
implements Collection<E>, Serializable

This is a wrapper for a Collection prohibiting all calls which would modify its contents. As the construction of this class is performed in constant time it is preferred over copying the collection (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 is 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.unmodifiableCollection(Collection), but by making it a public class we can make the return value of some methods more explicit.

This collection is serializable if the wrapped collection is serializable.

Version:

$Revision: 26283 $

Author:

Benjamin Hummel, $Author: juergens $

See Also:

Serialized Form

Rating:

GREEN Hash: E7479B41B1D5AFEB227EFF86689F0DAA

Constructor Summary

UnmodifiableCollection(Collection<E> c)
Creates a new unmodifiable collection from another collection.

Method Summary

boolean	add(E arg0) Operation is not supported.
boolean	addAll(Collection<? extends E> arg0) Operation is not supported.
void	clear() Operation is not supported.
boolean	contains(Object o)
boolean	containsAll(Collection<?> other)
boolean	isEmpty()
UnmodifiableIterator<E>	iterator()
boolean	remove(Object arg0) Operation is not supported.
boolean	removeAll(Collection<?> arg0) Operation is not supported.
boolean	retainAll(Collection<?> arg0) Operation is not supported.
int	size()
Object[]	toArray()
<T> T[]	toArray(T[] a)
String	toString() Returns a string representation of this collection.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Collection

equals, hashCode

Constructor Detail

UnmodifiableCollection

public UnmodifiableCollection(Collection<E> c)

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

Method Detail

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Collection<E>

size

public int size()

Specified by:

size in interface Collection<E>

contains

public boolean contains(Object o)

Specified by:

contains in interface Collection<E>

containsAll

public boolean containsAll(Collection<?> other)

Specified by:

containsAll in interface Collection<E>

iterator

public UnmodifiableIterator<E> iterator()

Specified by:

iterator in interface Iterable<E>

Specified by:

iterator in interface Collection<E>

toArray

public Object[] toArray()

Specified by:

toArray in interface Collection<E>

toArray

public <T> T[] toArray(T[] a)

Specified by:

toArray in interface Collection<E>

add

public boolean add(E arg0)

Operation is not supported.

Specified by:

add in interface Collection<E>

Throws:

UnsupportedOperationException

addAll

public boolean addAll(Collection<? extends E> arg0)

Operation is not supported.

Specified by:

addAll in interface Collection<E>

Throws:

UnsupportedOperationException

clear

public void clear()

Operation is not supported.

Specified by:

clear in interface Collection<E>

Throws:

UnsupportedOperationException

remove

public boolean remove(Object arg0)

Operation is not supported.

Specified by:

remove in interface Collection<E>

Throws:

UnsupportedOperationException

removeAll

public boolean removeAll(Collection<?> arg0)

Operation is not supported.

Specified by:

removeAll in interface Collection<E>

Throws:

UnsupportedOperationException

retainAll

public boolean retainAll(Collection<?> arg0)

Operation is not supported.

Specified by:

retainAll in interface Collection<E>

Throws:

UnsupportedOperationException

toString

public String toString()

Returns a string representation of this collection.

Overrides:

toString in class Object