jade.util.leap

Class EmptyIterator

java.lang.Object

jade.util.leap.EmptyIterator

All Implemented Interfaces:

Iterator

public class EmptyIterator
extends Object
implements Iterator

Singleton Iterator for an empty collection. The usage of the singleton-pattern for this simple object allows just to save some memory.

Version:

0.9

Author:

Fabio Bellifemine, TILAB

Field Summary

Fields

Modifier and Type	Field and Description
private static Iterator	it

Constructor Summary

Constructors

Modifier	Constructor and Description
private	EmptyIterator() Constructor declaration

Method Summary

Modifier and Type	Method and Description
static Iterator	getInstance() Returns the singleton EmptyIterator object.
boolean	hasNext() Checks whether the iterator can scan further.
Object	next() Retrieves the next element in the collection scanned by this iterator.
void	remove() Remove the element pointed to by this iterator from the collection.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.Iterator

forEachRemaining

Field Detail

it

private static final Iterator it

Constructor Detail

EmptyIterator

private EmptyIterator()

Constructor declaration

Method Detail

getInstance

public static Iterator getInstance()

Returns the singleton EmptyIterator object. Most of the methods of this class are instance methods and must be invoked with respect to the singleton object.

hasNext

public boolean hasNext()

Checks whether the iterator can scan further.

Specified by:

hasNext in interface Iterator

Returns:

This method always returns false.

next

public Object next()

Retrieves the next element in the collection scanned by this iterator.

Specified by:

next in interface Iterator

Returns:

This method always throws an exception.

Throws:

NoSuchElementException - Always, because the underlying collection is always empty.

remove

public void remove()

Remove the element pointed to by this iterator from the collection.

Specified by:

remove in interface Iterator

Throws:

RuntimeException - Always, because the underlying collection is always empty.