de.tsl2.nano.collection

Class FilteringIterator<E>

java.lang.Object

de.tsl2.nano.collection.FilteringIterator<E>

All Implemented Interfaces:

Iterator<E>, ListIterator<E>

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

Runtime filtering Iterator. Wraps the Iterator of the given collection. remove() is not supported! Please see getFilteringIterable(Iterable, IPredicate) to wrap your original collection into a filtered collection.

Version:

$Revision$

Author:

Thomas Schneider

Constructor Summary

Constructors

Constructor and Description
FilteringIterator(Iterable<E> parent, IPredicate<E> predicate) constructor

Method Summary

Modifier and Type	Method and Description
void	add(E e)
static <I extends Iterable<T>,T> I	getFilteringIterable(I iterable, IPredicate<T> predicate) creates a proxy using the given iterable instance. if an iterator is requested, the orginal iterator will be wrapped into the FilteringIterator.
static <I extends Map<S,T>,S,T> I	getFilteringMap(I map, IPredicate<T> predicate) creates a proxy using the given map instance. if a key iterator is requested, the orginal iterator will be wrapped into the FilteringIterator.
static Iterable	getIterable(Proxy proxy) ONLY FOR FRAMEWORK-INTERNAL USE!
boolean	hasNext()
boolean	hasPrevious()
E	next()
int	nextIndex()
E	previous()
int	previousIndex()
void	remove()
void	set(E e)
protected int	size() on first call, the size has to be evaluated

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 Detail

FilteringIterator

public FilteringIterator(Iterable<E> parent,
                         IPredicate<E> predicate)

constructor

Parameters:

parent -

predicate -

Method Detail

hasNext

public boolean hasNext()

Specified by:

hasNext in interface Iterator<E>

Specified by:

hasNext in interface ListIterator<E>

next

public E next()

Specified by:

next in interface Iterator<E>

Specified by:

next in interface ListIterator<E>

remove

public void remove()

Specified by:

remove in interface Iterator<E>

Specified by:

remove in interface ListIterator<E>

hasPrevious

public boolean hasPrevious()

Specified by:

hasPrevious in interface ListIterator<E>

previous

public E previous()

Specified by:

previous in interface ListIterator<E>

nextIndex

public int nextIndex()

Specified by:

nextIndex in interface ListIterator<E>

previousIndex

public int previousIndex()

Specified by:

previousIndex in interface ListIterator<E>

set

public void set(E e)

Specified by:

set in interface ListIterator<E>

add

public void add(E e)

Specified by:

add in interface ListIterator<E>

size

protected int size()

on first call, the size has to be evaluated

Returns:

size of iterable

getIterable

public static Iterable getIterable(Proxy proxy)

ONLY FOR FRAMEWORK-INTERNAL USE!

if the given proxy has an invocation handler of type FilteringIterator, the internal used collection will be returned.

Parameters:

proxy - proxy having an invocation handler of type FilteringIterator.

Returns:

internal collection

getFilteringIterable

public static <I extends Iterable<T>,T> I getFilteringIterable(I iterable,
                                                               IPredicate<T> predicate)

creates a proxy using the given iterable instance. if an iterator is requested, the orginal iterator will be wrapped into the FilteringIterator.

As the original instance (the collection) will be preserved, all other methods like size(), contains() etc. will work on the un-filtered content!

Type Parameters:

I - iterable type - mostly at least a collection

T - member type of the iterable

Parameters:

iterable - iterable instance

predicate - item filter/selector

Returns:

proxy, providing the given iterable filtered through the given predicate.

getFilteringMap

public static <I extends Map<S,T>,S,T> I getFilteringMap(I map,
                                                         IPredicate<T> predicate)

creates a proxy using the given map instance. if a key iterator is requested, the orginal iterator will be wrapped into the FilteringIterator.

As the original instance will be preserved, all other methods like size(), contains() etc. will work on the un-filtered content!

Type Parameters:

I - iterable type - mostly at least a collection

T - member type of the iterable

Parameters:

map - iterable instance

predicate - item filter/selector

Returns:

proxy, providing the given iterable filtered through the given predicate.