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>

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

Version:

$Id: UnmodifiableQueue.java 1543167 2013-11-18 21:21:32Z ggregory $

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
private static long	serialVersionUID Serialization version

Constructor Summary

Constructors

Modifier	Constructor and Description
private	UnmodifiableQueue(java.util.Queue<? extends E> queue) Constructor that wraps (not copies).

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()
private void	readObject(java.io.ObjectInputStream in) Read the collection in using a custom routine.
E	remove()
boolean	remove(java.lang.Object object)
boolean	removeAll(java.util.Collection<?> coll)
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.
private void	writeObject(java.io.ObjectOutputStream out) Write the collection out using a custom routine.

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

decorated, element, peek

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

contains, containsAll, equals, hashCode, isEmpty, setCollection, size, toArray, toArray, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Collection

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

Methods inherited from interface java.lang.Iterable

forEach

Field Detail

serialVersionUID

private static final long serialVersionUID

Serialization version

See Also:

Constant Field Values

Constructor Detail

UnmodifiableQueue

private UnmodifiableQueue(java.util.Queue<? extends E> queue)

Constructor that wraps (not copies).

Parameters:

queue - the queue to decorate, must not be null

Throws:

java.lang.IllegalArgumentException - if queue is null

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.IllegalArgumentException - if queue is null

writeObject

private void writeObject(java.io.ObjectOutputStream out)
                  throws java.io.IOException

Write the collection out using a custom routine.

Parameters:

out - the output stream

Throws:

java.io.IOException - if an I/O error occurs while writing to the output stream

readObject

private void readObject(java.io.ObjectInputStream in)
                 throws java.io.IOException,
                        java.lang.ClassNotFoundException

Read the collection in using a custom routine.

Parameters:

in - the input stream

Throws:

java.io.IOException - if an I/O error occurs while reading from the input stream

java.lang.ClassNotFoundException - if the class of a serialized object can not be found

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>

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>