org.conqat.lib.commons.collections

Class UnmodifiableCollection<E>

java.lang.Object

org.conqat.lib.commons.collections.UnmodifiableCollection<E>

All Implemented Interfaces:

java.io.Serializable, java.lang.Iterable<E>, java.util.Collection<E>

Direct Known Subclasses:

UnmodifiableList, UnmodifiableSet

public class UnmodifiableCollection<E>
extends java.lang.Object
implements java.util.Collection<E>, java.io.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.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
UnmodifiableCollection(java.util.Collection<E> c) Creates a new unmodifiable collection from another collection.

Method Summary

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

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

parallelStream, removeIf, spliterator, stream

Methods inherited from interface java.lang.Iterable

forEach

Constructor Detail

UnmodifiableCollection

public UnmodifiableCollection(java.util.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 java.util.Collection<E>

size

public int size()

Specified by:

size in interface java.util.Collection<E>

contains

public boolean contains(java.lang.Object o)

Specified by:

contains in interface java.util.Collection<E>

containsAll

public boolean containsAll(java.util.Collection<?> other)

Specified by:

containsAll in interface java.util.Collection<E>

iterator

public UnmodifiableIterator<E> iterator()

Specified by:

iterator in interface java.lang.Iterable<E>

Specified by:

iterator in interface java.util.Collection<E>

toArray

public java.lang.Object[] toArray()

Specified by:

toArray in interface java.util.Collection<E>

toArray

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

Specified by:

toArray in interface java.util.Collection<E>

add

public boolean add(E arg0)

Operation is not supported.

Specified by:

add in interface java.util.Collection<E>

addAll

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

Operation is not supported.

Specified by:

addAll in interface java.util.Collection<E>

clear

public void clear()

Operation is not supported.

Specified by:

clear in interface java.util.Collection<E>

remove

public boolean remove(java.lang.Object arg0)

Operation is not supported.

Specified by:

remove in interface java.util.Collection<E>

removeAll

public boolean removeAll(java.util.Collection<?> arg0)

Operation is not supported.

Specified by:

removeAll in interface java.util.Collection<E>

retainAll

public boolean retainAll(java.util.Collection<?> arg0)

Operation is not supported.

Specified by:

retainAll in interface java.util.Collection<E>

toString

public java.lang.String toString()

Returns a string representation of this collection.

Overrides:

toString in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)

Specified by:

equals in interface java.util.Collection<E>

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Specified by:

hashCode in interface java.util.Collection<E>

Overrides:

hashCode in class java.lang.Object