Package net.cscott.jutil

Class UnmodifiableListIterator<E>

java.lang.Object

net.cscott.jutil.UnmodifiableListIterator<E>

All Implemented Interfaces:

Iterator<E>, ListIterator<E>

public abstract class UnmodifiableListIterator<E>
extends Object
implements ListIterator<E>

UnmodifiableListIterator is an abstract superclass to save you the trouble of implementing the remove(), add(Object) and set(Object) methods over and over again for those list iterators which don't implement them. The name's a bit clunky, but fits with the JDK naming in Collections and such.

Author:

C. Scott Ananian <cananian@alumni.princeton.edu>

Constructor Summary

Constructors

Constructor	Description
UnmodifiableListIterator()

Method Summary

Modifier and Type	Method	Description
final void	add(E o)	Always throws an UnsupportedOperationException.
abstract boolean	hasNext()	Returns true if the list iterator has more elements in the forward direction.
abstract boolean	hasPrevious()	Returns true if the list iterator has more elements in the reverse direction.
abstract E	next()	Returns the next element in the list.
abstract int	nextIndex()	Returns the index of the element that would be returned by a subsequent call to next().
abstract E	previous()	Returns the previous element in the list.
int	previousIndex()	Returns the index of the element that would be returned by a subsequent call to previous().
final void	remove()	Always throws an UnsupportedOperationException.
final void	set(E o)	Always throws an UnsupportedOperationException.

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

Constructor Details

UnmodifiableListIterator

public UnmodifiableListIterator()

Method Details

hasNext

public abstract boolean hasNext()

Returns true if the list iterator has more elements in the forward direction.

Specified by:

hasNext in interface Iterator<E>

Specified by:

hasNext in interface ListIterator<E>

next

public abstract E next()

Returns the next element in the list. This method may be called repeatedly to iterate through the list, or intermixed with calls to previous() to go back and forth. (Note that alternating calls to next() and previous() will return the same element repeatedly.)

Specified by:

next in interface Iterator<E>

Specified by:

next in interface ListIterator<E>

Throws:

NoSuchElementException - if the iteration has no next element.

hasPrevious

public abstract boolean hasPrevious()

Returns true if the list iterator has more elements in the reverse direction.

Specified by:

hasPrevious in interface ListIterator<E>

previous

public abstract E previous()

Returns the previous element in the list. This method may be called repeatedly to iterate through the list backwards, or intermixed with calls to next() to go back and forth. (Note that alternating calls to next() and previous() will return the same element repeatedly.)

Specified by:

previous in interface ListIterator<E>

Throws:

NoSuchElementException - if the iteration has no previous element.

nextIndex

public abstract int nextIndex()

Returns the index of the element that would be returned by a subsequent call to next(). (Returns list size if the list iterator is at the end of the list.)

Specified by:

nextIndex in interface ListIterator<E>

previousIndex

public int previousIndex()

Returns the index of the element that would be returned by a subsequent call to previous(). (Returns -1 if the list iterator is at the beginning of the list.)

Specified by:

previousIndex in interface ListIterator<E>

remove

public final void remove()

Always throws an UnsupportedOperationException.

Specified by:

remove in interface Iterator<E>

Specified by:

remove in interface ListIterator<E>

Throws:

UnsupportedOperationException - always.

set

public final void set(E o)

Always throws an UnsupportedOperationException.

Specified by:

set in interface ListIterator<E>

Throws:

UnsupportedOperationException - always.

add

public final void add(E o)

Always throws an UnsupportedOperationException.

Specified by:

add in interface ListIterator<E>

Throws:

UnsupportedOperationException - always.