org.apache.commons.collections4.queue

Class UnmodifiableQueue<E>

java.lang.Object

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

org.apache.commons.collections4.queue.AbstractQueueDecorator<E>

org.apache.commons.collections4.queue.UnmodifiableQueue<E>

Type Parameters:

E - the type of elements held in this queue

All Implemented Interfaces:

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

public final class UnmodifiableQueue<E>
extends AbstractQueueDecorator<E>
implements Unmodifiable

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

Attempts to modify it will result in an UnsupportedOperationException.

Since:

4.0

See Also:

Serialized Form

Method Summary

Modifier and Type	Method and Description
boolean	add(java.lang.Object object)
boolean	addAll(java.util.Collection<? extends E> coll)
void	clear()
java.util.Iterator<E>	iterator()
boolean	offer(E obj)
E	poll()
E	remove()
boolean	remove(java.lang.Object object)
boolean	removeAll(java.util.Collection<?> coll)
boolean	removeIf(java.util.function.Predicate<? super E> filter)
boolean	retainAll(java.util.Collection<?> coll)
static <E> java.util.Queue<E>	unmodifiableQueue(java.util.Queue<? extends E> queue) Factory method to create an unmodifiable queue.

Methods inherited from class org.apache.commons.collections4.queue.AbstractQueueDecorator

element, peek

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

contains, containsAll, isEmpty, size, toArray, toArray, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

contains, containsAll, equals, hashCode, isEmpty, parallelStream, size, spliterator, stream, toArray, toArray

Methods inherited from interface java.lang.Iterable

forEach

Method Detail

unmodifiableQueue

public static <E> java.util.Queue<E> unmodifiableQueue(java.util.Queue<? extends E> queue)

Factory method to create an unmodifiable queue.

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

Type Parameters:

E - the type of the elements in the queue

Parameters:

queue - the queue to decorate, must not be null

Returns:

an unmodifiable Queue

Throws:

java.lang.NullPointerException - if queue is null

iterator

public java.util.Iterator<E> iterator()

Specified by:

iterator in interface java.lang.Iterable<E>

Specified by:

iterator in interface java.util.Collection<E>

Overrides:

iterator in class AbstractCollectionDecorator<E>

add

public boolean add(java.lang.Object object)

Specified by:

add in interface java.util.Collection<E>

Specified by:

add in interface java.util.Queue<E>

Overrides:

add in class AbstractCollectionDecorator<E>

addAll

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

Specified by:

addAll in interface java.util.Collection<E>

Overrides:

addAll in class AbstractCollectionDecorator<E>

clear

public void clear()

Specified by:

clear in interface java.util.Collection<E>

Overrides:

clear in class AbstractCollectionDecorator<E>

remove

public boolean remove(java.lang.Object object)

Specified by:

remove in interface java.util.Collection<E>

Overrides:

remove in class AbstractCollectionDecorator<E>

removeIf

public boolean removeIf(java.util.function.Predicate<? super E> filter)

Specified by:

removeIf in interface java.util.Collection<E>

Overrides:

removeIf in class AbstractCollectionDecorator<E>

Since:

4.4

removeAll

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

Specified by:

removeAll in interface java.util.Collection<E>

Overrides:

removeAll in class AbstractCollectionDecorator<E>

retainAll

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

Specified by:

retainAll in interface java.util.Collection<E>

Overrides:

retainAll in class AbstractCollectionDecorator<E>

offer

public boolean offer(E obj)

Specified by:

offer in interface java.util.Queue<E>

Overrides:

offer in class AbstractQueueDecorator<E>

poll

public E poll()

Specified by:

poll in interface java.util.Queue<E>

Overrides:

poll in class AbstractQueueDecorator<E>

remove

public E remove()

Specified by:

remove in interface java.util.Queue<E>

Overrides:

remove in class AbstractQueueDecorator<E>