com.hp.hpl.jena.util.iterator
Class UniqueExtendedIterator

java.lang.Object
  com.hp.hpl.jena.util.iterator.NiceIterator
      com.hp.hpl.jena.util.iterator.WrappedIterator
          com.hp.hpl.jena.util.iterator.UniqueExtendedIterator

All Implemented Interfaces:

ClosableIterator, ExtendedIterator, java.util.Iterator

public class UniqueExtendedIterator
extends WrappedIterator

A variant on the closable/extended iterator that filters out duplicate values. There is one complication that the value which filtering is done on might not be the actual value to be returned by the iterator.

Version:

$Revision: 1.16 $ on $Date: 2008/01/02 12:07:36 $

Author:

Dave Reynolds

Constructor Summary

UniqueExtendedIterator(java.util.Iterator underlying)
Constructor.

Method Summary

static ExtendedIterator	create(java.util.Iterator it) Factory method for generating an iterator that is guaranteed only to return one instance of every result from the wrapped iterator it.
boolean	hasNext() hasNext: defer to the base iterator
java.lang.Object	next() next: defer to the base iterator

Methods inherited from class com.hp.hpl.jena.util.iterator.WrappedIterator

close, close, createNoRemove, forTestingOnly_getBase, remove

Methods inherited from class com.hp.hpl.jena.util.iterator.NiceIterator

andThen, andThen, asList, asSet, emptyIterator, filterDrop, filterKeep, mapWith, removeNext, toList, toSet

Methods inherited from class java.lang.Object

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

Constructor Detail

UniqueExtendedIterator

public UniqueExtendedIterator(java.util.Iterator underlying)

Constructor. Note the use of create(java.util.Iterator) as reliable means of creating a unique iterator without double-wrapping iterators that are already unique iterators.

Method Detail

create

public static ExtendedIterator create(java.util.Iterator it)

Factory method for generating an iterator that is guaranteed only to return one instance of every result from the wrapped iterator it.

Parameters:

it - An iterator to wrap

Returns:

A iterator that returns the elements of the wrapped iterator exactly once. If it is already a unique extended iteator, it is not further wrapped.

hasNext

public boolean hasNext()

Description copied from class: WrappedIterator

hasNext: defer to the base iterator

Specified by:

hasNext in interface java.util.Iterator

Overrides:

hasNext in class WrappedIterator

See Also:

Iterator.hasNext()

next

public java.lang.Object next()

Description copied from class: WrappedIterator

next: defer to the base iterator

Specified by:

next in interface java.util.Iterator

Overrides:

next in class WrappedIterator

See Also:

Iterator.next()