Package org.apache.sis.internal.util

Class EmptyQueue<E>

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractQueue<E>

org.apache.sis.internal.util.EmptyQueue<E>

Type Parameters:

E - type of elements in the collection.

All Implemented Interfaces:

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

final class EmptyQueue<E>
extends AbstractQueue<E>
implements Serializable

An immutable and serializable empty queue.

Since:

0.3

Version:

0.3

Field Summary

Fields

Modifier and Type	Field	Description
(package private) static final Queue	INSTANCE	The singleton instance to be returned by CollectionsExt.emptyQueue().
private static final long	serialVersionUID	For cross-version compatibility.

Constructor Summary

Constructors

Modifier	Constructor	Description
private	EmptyQueue()	Do not allow instantiation except for the singleton.

Method Summary

Modifier and Type	Method	Description
void	clear()
boolean	isEmpty()
Iterator<E>	iterator()
boolean	offer(E e)
E	peek()
E	poll()
protected Object	readResolve()	Returns the singleton instance on deserialization.
int	size()

Methods inherited from class java.util.AbstractQueue

add, addAll, element, remove

Methods inherited from class java.util.AbstractCollection

contains, containsAll, remove, removeAll, retainAll, 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

contains, containsAll, equals, hashCode, parallelStream, remove, removeAll, removeIf, retainAll, spliterator, stream, toArray, toArray

Methods inherited from interface java.lang.Iterable

forEach

Field Details

serialVersionUID

private static final long serialVersionUID

For cross-version compatibility.

See Also:

• Constant Field Values

INSTANCE

static final Queue INSTANCE

The singleton instance to be returned by CollectionsExt.emptyQueue(). This is not parameterized on intent.

Constructor Details

EmptyQueue

private EmptyQueue()

Do not allow instantiation except for the singleton.

Method Details

clear

public void clear()

Specified by:

clear in interface Collection<E>

Overrides:

clear in class AbstractQueue<E>

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Collection<E>

Overrides:

isEmpty in class AbstractCollection<E>

size

public int size()

Specified by:

size in interface Collection<E>

Specified by:

size in class AbstractCollection<E>

iterator

public Iterator<E> iterator()

Specified by:

iterator in interface Collection<E>

Specified by:

iterator in interface Iterable<E>

Specified by:

iterator in class AbstractCollection<E>

offer

public boolean offer(E e)

Specified by:

offer in interface Queue<E>

poll

public E poll()

Specified by:

poll in interface Queue<E>

peek

public E peek()

Specified by:

peek in interface Queue<E>

readResolve

protected Object readResolve()
                      throws ObjectStreamException

Returns the singleton instance on deserialization.

Throws:

ObjectStreamException