Package org.apache.commons.collections4.collection

Class UnmodifiableCollection<E>

java.lang.Object

org.apache.commons.collections4.collection.AbstractCollectionDecorator<E>

org.apache.commons.collections4.collection.UnmodifiableCollection<E>

Type Parameters:

E - The type of the elements in the collection.

All Implemented Interfaces:

Serializable, Iterable<E>, Collection<E>, Unmodifiable

public final class UnmodifiableCollection<E>
extends AbstractCollectionDecorator<E>
implements Unmodifiable

Decorates another Collection to ensure it can't be altered.

This class is Serializable from Commons Collections 3.1.

Attempts to modify it will result in an UnsupportedOperationException.

Since:

3.0

See Also:

• Serialized Form

Method Summary

Modifier and Type	Method	Description
boolean	add(E object)	Always throws UnsupportedOperationException.
boolean	addAll(Collection<? extends E> coll)	Always throws UnsupportedOperationException.
void	clear()	Always throws UnsupportedOperationException.
Iterator<E>	iterator()
boolean	remove(Object object)	Always throws UnsupportedOperationException.
boolean	removeAll(Collection<?> coll)	Always throws UnsupportedOperationException.
boolean	removeIf(Predicate<? super E> filter)	Always throws UnsupportedOperationException.
boolean	retainAll(Collection<?> coll)	Always throws UnsupportedOperationException.
static <T> Collection<T>	unmodifiableCollection(Collection<? extends T> coll)	Creates an unmodifiable collection.

Methods inherited from class org.apache.commons.collections4.collection.AbstractCollectionDecorator

contains, containsAll, decorated, isEmpty, setCollection, size, toArray, toArray, toString

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, parallelStream, spliterator, stream

Methods inherited from interface java.lang.Iterable

forEach

Method Details

unmodifiableCollection

public static <T> Collection<T> unmodifiableCollection(Collection<? extends T> coll)

Creates an unmodifiable collection.

If the collection passed in is already unmodifiable, it is returned.

Type Parameters:

T - The type of the elements in the collection.

Parameters:

coll - The collection to decorate, must not be null.

Returns:

An unmodifiable collection.

Throws:

NullPointerException - if collection is null.

Since:

4.0

add

public boolean add(E object)

Always throws UnsupportedOperationException.

Specified by:

add in interface Collection<E>

Overrides:

add in class AbstractCollectionDecorator<E>

Parameters:

object - Ignored.

Throws:

UnsupportedOperationException - Always thrown.

addAll

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

Always throws UnsupportedOperationException.

Specified by:

addAll in interface Collection<E>

Overrides:

addAll in class AbstractCollectionDecorator<E>

Throws:

UnsupportedOperationException - Always thrown.

clear

public void clear()

Always throws UnsupportedOperationException.

Specified by:

clear in interface Collection<E>

Overrides:

clear in class AbstractCollectionDecorator<E>

Throws:

UnsupportedOperationException - Always thrown.

iterator

public Iterator<E> iterator()

Specified by:

iterator in interface Collection<E>

Specified by:

iterator in interface Iterable<E>

Overrides:

iterator in class AbstractCollectionDecorator<E>

remove

public boolean remove(Object object)

Always throws UnsupportedOperationException.

Specified by:

remove in interface Collection<E>

Overrides:

remove in class AbstractCollectionDecorator<E>

Parameters:

object - Ignored.

Throws:

UnsupportedOperationException - Always thrown.

removeAll

public boolean removeAll(Collection<?> coll)

Always throws UnsupportedOperationException.

Specified by:

removeAll in interface Collection<E>

Overrides:

removeAll in class AbstractCollectionDecorator<E>

Parameters:

coll - Ignored.

Throws:

UnsupportedOperationException - Always thrown.

removeIf

public boolean removeIf(Predicate<? super E> filter)

Always throws UnsupportedOperationException.

Specified by:

removeIf in interface Collection<E>

Overrides:

removeIf in class AbstractCollectionDecorator<E>

Parameters:

filter - Ignored.

Throws:

UnsupportedOperationException - Always thrown.

Since:

4.4

retainAll

public boolean retainAll(Collection<?> coll)

Always throws UnsupportedOperationException.

Specified by:

retainAll in interface Collection<E>

Overrides:

retainAll in class AbstractCollectionDecorator<E>

Parameters:

coll - Ignored.

Throws:

UnsupportedOperationException - Always thrown.