org.xshare.base.iterator
Class FilterIterator

java.lang.Object
  |
  +--org.xshare.base.iterator.FilterIterator

All Implemented Interfaces:

java.util.Iterator

public class FilterIterator

extends java.lang.Object

implements java.util.Iterator

Filters the elements of another iteration based on a UnaryPredicate wrapping an given iterator and applying a UnaryPredicate for each element. Only elements, there the predicate is true are returned by this iterator.

Notes On The Implemenation

• Returns all objects - for which the condition passed to the constructor is true - in the same order as they are found in the source iterator.

Version:

$Revision: 1.3 $

Author:

Oliver Fischer

See Also:

RangeIterator

Constructor Summary

FilterIterator(UnaryPredicate pFilterPredicate, java.util.Iterator pSourceIterator)
Creates a new instance of this iterator for a given predicate and iterator.

Method Summary

boolean	hasNext() Checks if there are some elements left, for which the condition given to the constructor is true.
java.lang.Object	next() Returns the next element which fits in the condition set with the constructor of this instance.
void	remove() This method is not supported since this class is only an adapter for another iterator.

Methods inherited from class java.lang.Object

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

Constructor Detail

FilterIterator

public FilterIterator(UnaryPredicate pFilterPredicate,
                      java.util.Iterator pSourceIterator)

Creates a new instance of this iterator for a given predicate and iterator.

Parameters:

pFilterPredicate - an UnaryPredicate which is evaluated for every element of the underlying iterator.

pSourceIterator - an arbitrary iterator which should be filtered according to the criterias expressed in the given predicate.

Method Detail

remove

public void remove()

This method is not supported since this class is only an adapter for another iterator.

Specified by:

remove in interface java.util.Iterator

Throws:

java.lang.UnsupportedOperationException - if this method is called.

next

public java.lang.Object next()

Returns the next element which fits in the condition set with the constructor of this instance.

Specified by:

next in interface java.util.Iterator

Throws:

java.util.NoSuchElementException - if hasNext() denies the that there are objects left.

See Also:

hasNext()

hasNext

public boolean hasNext()

Checks if there are some elements left, for which the condition given to the constructor is true.

Specified by:

hasNext in interface java.util.Iterator

Returns:

a boolean value, which is true if there are some elements left to return via next(). Otherwise false is returned.

See Also:

next()