collectionframework

Class NullIterator<E>

java.lang.Object

collectionframework.NullIterator<E>

All Implemented Interfaces:

java.util.Enumeration<E>, java.util.Iterator<E>

public class NullIterator<E>
extends java.lang.Object
implements java.util.Enumeration<E>, java.util.Iterator<E>

An Iterator/Enumeration that contains one (or zero) elements

Version:

1.0

Author:

Prof. David Bernstein, James Madison University

See Also:

"The Design and Implementation of Multimedia Software © 2011"

Constructor Summary

Constructors

Constructor and Description
NullIterator() Default Constructor.
NullIterator(E element) Explicit Value Constructor.

Method Summary

Modifier and Type	Method and Description
void	clear() Clear this Iterator (so that it no longer has an element).
boolean	hasMoreElements() Returns true if this Enumeration has another element (required by Enumeration).
boolean	hasNext() Returns true if this Iterator has another element (required by Iterator).
E	next() Returns the next element in this Iterator (required by Iterator).
E	nextElement() Returns the next element in this Enumeration (required by Enumeration).
void	remove() Remove the last element from the underlying collection (required by Iterator).
void	reset() Reset this Iterator so that it (again) contains the single element.
void	setElement(E element) Set the single element in this Iterator.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Iterator

forEachRemaining

Constructor Detail

NullIterator

public NullIterator()

Default Constructor.

NullIterator

public NullIterator(E element)

Explicit Value Constructor.

Parameters:

element - The element in the Iterator

Method Detail

clear

public void clear()

Clear this Iterator (so that it no longer has an element).

hasMoreElements

public boolean hasMoreElements()

Returns true if this Enumeration has another element (required by Enumeration).

Specified by:

hasMoreElements in interface java.util.Enumeration<E>

Returns:

true if this Enumeration has another element

hasNext

public boolean hasNext()

Returns true if this Iterator has another element (required by Iterator).

Specified by:

hasNext in interface java.util.Iterator<E>

Returns:

true if this Iterator has another element

nextElement

public E nextElement()
              throws java.util.NoSuchElementException

Returns the next element in this Enumeration (required by Enumeration).

Specified by:

nextElement in interface java.util.Enumeration<E>

Throws:

java.util.NoSuchElementException

next

public E next()
       throws java.util.NoSuchElementException

Returns the next element in this Iterator (required by Iterator).

Specified by:

next in interface java.util.Iterator<E>

Throws:

java.util.NoSuchElementException

remove

public void remove()
            throws java.lang.UnsupportedOperationException

Remove the last element from the underlying collection (required by Iterator). This method is not supported

Specified by:

remove in interface java.util.Iterator<E>

Throws:

java.lang.UnsupportedOperationException

reset

public void reset()

Reset this Iterator so that it (again) contains the single element.

setElement

public void setElement(E element)

Set the single element in this Iterator.

Parameters:

element - The element