Package org.apache.commons.collections4.queue

Class SynchronizedQueue<E>

java.lang.Object

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

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

Type Parameters:

E - the type of the elements in the collection

All Implemented Interfaces:

Serializable, Iterable<E>, Collection<E>, Queue<E>

public class SynchronizedQueue<E>
extends SynchronizedCollection<E>
implements Queue<E>

Decorates another Queue to synchronize its behavior for a multithreaded environment.

Methods are synchronized, then forwarded to the decorated queue. Iterators must be separately synchronized around the loop.

Since:

4.2

See Also:

• Serialized Form

Field Summary

Fields inherited from class org.apache.commons.collections4.collection.SynchronizedCollection

lock

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	SynchronizedQueue(Queue<E> queue)	Constructor that wraps (not copies).
protected	SynchronizedQueue(Queue<E> queue, Object lock)	Constructor that wraps (not copies).

Method Summary

Modifier and Type	Method	Description
protected Queue<E>	decorated()	Gets the queue being decorated.
E	element()
boolean	equals(Object object)
int	hashCode()
boolean	offer(E e)
E	peek()
E	poll()
E	remove()
static <E> SynchronizedQueue<E>	synchronizedQueue(Queue<E> queue)	Factory method to create a synchronized queue.

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

add, addAll, clear, contains, containsAll, isEmpty, iterator, remove, removeAll, removeIf, retainAll, size, synchronizedCollection, 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

addAll, clear, contains, containsAll, isEmpty, iterator, parallelStream, remove, removeAll, removeIf, retainAll, size, spliterator, stream, toArray, toArray

Methods inherited from interface java.lang.Iterable

forEach

Methods inherited from interface java.util.Queue

add

Constructor Details

SynchronizedQueue

protected SynchronizedQueue(Queue<E> queue)

Constructor that wraps (not copies).

Parameters:

queue - the queue to decorate, must not be null

Throws:

NullPointerException - if queue is null

SynchronizedQueue

protected SynchronizedQueue(Queue<E> queue,
 Object lock)

Constructor that wraps (not copies).

Parameters:

queue - the queue to decorate, must not be null

lock - the lock to use, must not be null

Throws:

NullPointerException - if queue or lock is null

Method Details

synchronizedQueue

public static <E> SynchronizedQueue<E> synchronizedQueue(Queue<E> queue)

Factory method to create a synchronized queue.

Type Parameters:

E - the type of the elements in the queue

Parameters:

queue - the queue to decorate, must not be null

Returns:

a new synchronized Queue

Throws:

NullPointerException - if queue is null

decorated

protected Queue<E> decorated()

Gets the queue being decorated.

Overrides:

decorated in class SynchronizedCollection<E>

Returns:

the decorated queue

element

public E element()

Specified by:

element in interface Queue<E>

equals

public boolean equals(Object object)

Specified by:

equals in interface Collection<E>

Overrides:

equals in class SynchronizedCollection<E>

hashCode

public int hashCode()

Specified by:

hashCode in interface Collection<E>

Overrides:

hashCode in class SynchronizedCollection<E>

offer

public boolean offer(E e)

Specified by:

offer in interface Queue<E>

peek

public E peek()

Specified by:

peek in interface Queue<E>

poll

public E poll()

Specified by:

poll in interface Queue<E>

remove

public E remove()

Specified by:

remove in interface Queue<E>