Package com.github.basking2.sdsai.itrex.iterators

Class PagingIterator<T>

java.lang.Object

com.github.basking2.sdsai.itrex.iterators.PagingIterator<T>

Type Parameters:

T - The type of elements to page.

All Implemented Interfaces:

Iterator<Iterator<T>>

public class PagingIterator<T>
extends Object
implements Iterator<Iterator<T>>

This iterator wraps its input iterator in HeadIterators until no elements remain in the source iterator. This structures the computation into pages of data. Users of this class must take care, all HeadIterator instances share the source iterator and calling them in parallel will yield unexpected results. A returned iterator should be exhausted before another is called.

Constructor Summary

Constructors

Constructor	Description
PagingIterator(int pageSize, Iterator<T> iterator)

Method Summary

Modifier and Type	Method	Description
boolean	hasNext()	Returns true if the source iterator has more elements to be paged over.
Iterator<T>	next()	Return a PagingIterator for the source iterator.

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, remove

Constructor Details

PagingIterator

public PagingIterator(int pageSize,
 Iterator<T> iterator)

Method Details

hasNext

public boolean hasNext()

Returns true if the source iterator has more elements to be paged over. If the user is consuming an iterator returned by a call to next(), this may return inconsistent results.

Specified by:

hasNext in interface Iterator<T>

Returns:

true if the source iterator has more elements to be paged over.

next

public Iterator<T> next()

Return a PagingIterator for the source iterator. The previously returned iterator must be empty.

Specified by:

next in interface Iterator<T>

Returns:

A HeadIterator that pages over elements of the input iterator.

Throws:

IllegalStateException - when the previously returned iterator is not fully consumed.