Package org.apache.commons.collections4.iterators

Class BoundedIterator<E>

java.lang.Object

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

Type Parameters:

E - the type of elements returned by this iterator.

All Implemented Interfaces:

Iterator<E>

public class BoundedIterator<E>
extends Object
implements Iterator<E>

Decorates another iterator to return elements in a specific range.

The decorated iterator is bounded in the range [offset, offset+max). The offset corresponds to the position of the first element to be returned from the decorated iterator, and max is the maximum number of elements to be returned at most.

In case an offset parameter other than 0 is provided, the decorated iterator is immediately advanced to this position, skipping all elements before that position.

Since:

4.1

Constructor Summary

Constructors

Constructor	Description
BoundedIterator(Iterator<? extends E> iterator, long offset, long max)	Decorates the specified iterator to return at most the given number of elements, skipping all elements until the iterator reaches the position at offset.

Method Summary

Modifier and Type	Method	Description
boolean	hasNext()
E	next()
void	remove()

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

BoundedIterator

public BoundedIterator(Iterator<? extends E> iterator,
 long offset,
 long max)

Decorates the specified iterator to return at most the given number of elements, skipping all elements until the iterator reaches the position at offset.

The iterator is immediately advanced until it reaches the position at offset, incurring O(n) time.

Parameters:

iterator - the iterator to be decorated

offset - the index of the first element of the decorated iterator to return

max - the maximum number of elements of the decorated iterator to return

Throws:

NullPointerException - if iterator is null

IllegalArgumentException - if either offset or max is negative

Method Details

hasNext

public boolean hasNext()

Specified by:

hasNext in interface Iterator<E>

next

public E next()

Specified by:

next in interface Iterator<E>

remove

public void remove()

In case an offset other than 0 was specified, the underlying iterator will be advanced to this position upon creation. A call to remove() will still result in an IllegalStateException if no explicit call to next() has been made prior to calling remove().

Specified by:

remove in interface Iterator<E>