Class FilteredIterator<T>

java.lang.Object

org.apache.commons.functor.core.collection.FilteredIterator<T>

Type Parameters:

T - the Iterator generic type

All Implemented Interfaces:

Iterator<T>

public final class FilteredIterator<T>
extends Object
implements Iterator<T>

Iterator that filters another Iterator by only passing through those elements that are matched by a specified UnaryPredicate.

Version:

$Revision$ $Date$

Field Summary

Fields

Modifier and Type	Field	Description
private boolean	canRemove	Flag to mark current iterator element can be removed.
private final Iterator<? extends T>	iterator	The wrapped iterator.
private T	next	Reference to next element has to be returned by this iterator.
private boolean	nextSet	Flag to mark this iterator has more elements or not.
private final UnaryPredicate<? super T>	predicate	The predicate used to test this Iterator elements.

Constructor Summary

Constructors

Constructor	Description
FilteredIterator(Iterator<? extends T> iterator, UnaryPredicate<? super T> predicate)	Create a new FilteredIterator.

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object obj)
static <T> Iterator<T>	filter(Iterator<? extends T> iter, UnaryPredicate<? super T> pred)	Get a filtered Iterator instance applying pred to iter.
int	hashCode()
boolean	hasNext()
T	next()
void	remove()
private T	returnNext()	Get the next element.
private boolean	setNext()	Set next element.
String	toString()

Methods inherited from class Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface Iterator

forEachRemaining

Field Details

predicate

private final UnaryPredicate<? super T> predicate

The predicate used to test this Iterator elements.

iterator

private final Iterator<? extends T> iterator

The wrapped iterator.

next

private T next

Reference to next element has to be returned by this iterator.

nextSet

private boolean nextSet

Flag to mark this iterator has more elements or not.

canRemove

private boolean canRemove

Flag to mark current iterator element can be removed.

Constructor Details

FilteredIterator

public FilteredIterator(Iterator<? extends T> iterator,
 UnaryPredicate<? super T> predicate)

Create a new FilteredIterator.

Parameters:

iterator - to filter

predicate - to apply

Method Details

hasNext

public boolean hasNext()

Specified by:

hasNext in interface Iterator<T>

See Also:

• Iterator.hasNext()

next

public T next()

Specified by:

next in interface Iterator<T>

See Also:

• Iterator.next()

remove

public void remove()

Specified by:

remove in interface Iterator<T>

See Also:

• Iterator.remove()

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

filter

public static <T> Iterator<T> filter(Iterator<? extends T> iter,
 UnaryPredicate<? super T> pred)

Get a filtered Iterator instance applying pred to iter.

Type Parameters:

T - the input iterator generic type

Parameters:

iter - to filter

pred - to apply

Returns:

Iterator

setNext

private boolean setNext()

Set next element.

Returns:

whether the current iterator position is valid

returnNext

private T returnNext()

Get the next element.

Returns:

next element.