Package org.apache.commons.collections4.iterators

Class FilterListIterator<E>

java.lang.Object

org.apache.commons.collections4.iterators.FilterListIterator<E>

Type Parameters:

E - The type of elements returned by this iterator.

All Implemented Interfaces:

Iterator<E>, ListIterator<E>

public class FilterListIterator<E>
extends Object
implements ListIterator<E>

Decorates another ListIterator using a predicate to filter elements.

This iterator decorates the underlying iterator, only allowing through those elements that match the specified Predicate.

Since:

2.0

Constructor Summary

Constructors

Constructor	Description
FilterListIterator()	Constructs a new FilterListIterator that will not function until setListIterator and setPredicate are invoked.
FilterListIterator(ListIterator<? extends E> iterator)	Constructs a new FilterListIterator that will not function until setPredicate is invoked.
FilterListIterator(ListIterator<? extends E> iterator, Predicate<? super E> predicate)	Constructs a new FilterListIterator.
FilterListIterator(Predicate<? super E> predicate)	Constructs a new FilterListIterator that will not function until setListIterator is invoked.

Method Summary

Modifier and Type	Method	Description
void	add(E o)	Always throws UnsupportedOperationException.
ListIterator<? extends E>	getListIterator()	Gets the iterator this iterator is using.
Predicate<? super E>	getPredicate()	Gets the predicate this iterator is using.
boolean	hasNext()
boolean	hasPrevious()
E	next()
int	nextIndex()
E	previous()
int	previousIndex()
void	remove()	Always throws UnsupportedOperationException.
void	set(E e)	Always throws UnsupportedOperationException.
void	setListIterator(ListIterator<? extends E> iterator)	Sets the iterator for this iterator to use.
void	setPredicate(Predicate<? super E> predicate)	Sets the predicate this the iterator to use.

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

FilterListIterator

public FilterListIterator()

Constructs a new FilterListIterator that will not function until setListIterator and setPredicate are invoked.

FilterListIterator

public FilterListIterator(ListIterator<? extends E> iterator)

Constructs a new FilterListIterator that will not function until setPredicate is invoked.

Parameters:

iterator - The iterator to use

FilterListIterator

public FilterListIterator(ListIterator<? extends E> iterator,
 Predicate<? super E> predicate)

Constructs a new FilterListIterator.

Parameters:

iterator - The iterator to use

predicate - The predicate to use

FilterListIterator

public FilterListIterator(Predicate<? super E> predicate)

Constructs a new FilterListIterator that will not function until setListIterator is invoked.

Parameters:

predicate - The predicate to use.

Method Details

add

public void add(E o)

Always throws UnsupportedOperationException.

Specified by:

add in interface ListIterator<E>

Parameters:

o - ignored.

Throws:

UnsupportedOperationException - Always thrown.

getListIterator

public ListIterator<? extends E> getListIterator()

Gets the iterator this iterator is using.

Returns:

The iterator.

getPredicate

public Predicate<? super E> getPredicate()

Gets the predicate this iterator is using.

Returns:

The predicate.

hasNext

public boolean hasNext()

Specified by:

hasNext in interface Iterator<E>

Specified by:

hasNext in interface ListIterator<E>

hasPrevious

public boolean hasPrevious()

Specified by:

hasPrevious in interface ListIterator<E>

next

public E next()

Specified by:

next in interface Iterator<E>

Specified by:

next in interface ListIterator<E>

nextIndex

public int nextIndex()

Specified by:

nextIndex in interface ListIterator<E>

previous

public E previous()

Specified by:

previous in interface ListIterator<E>

previousIndex

public int previousIndex()

Specified by:

previousIndex in interface ListIterator<E>

remove

public void remove()

Always throws UnsupportedOperationException.

Specified by:

remove in interface Iterator<E>

Specified by:

remove in interface ListIterator<E>

Throws:

UnsupportedOperationException - Always thrown.

set

public void set(E e)

Always throws UnsupportedOperationException.

Specified by:

set in interface ListIterator<E>

Parameters:

e - ignored.

Throws:

UnsupportedOperationException - Always thrown.

setListIterator

public void setListIterator(ListIterator<? extends E> iterator)

Sets the iterator for this iterator to use. If iteration has started, this effectively resets the iterator.

Parameters:

iterator - The iterator to use

setPredicate

public void setPredicate(Predicate<? super E> predicate)

Sets the predicate this the iterator to use.

Parameters:

predicate - The transformer to use