com.google.cloud.dataflow.sdk.util.common

Class PeekingReiterator<T>

java.lang.Object

com.google.cloud.dataflow.sdk.util.common.PeekingReiterator<T>

Type Parameters:

T - the type of elements returned by this iterator

All Implemented Interfaces:

Reiterator<T>, Iterator<T>

public final class PeekingReiterator<T>
extends Object
implements Reiterator<T>

A Reiterator that supports one-element lookahead during iteration.

Constructor Summary

Constructors

Constructor and Description
PeekingReiterator(Reiterator<T> iterator)

Method Summary

Modifier and Type	Method and Description
PeekingReiterator<T>	copy() Returns a copy of the current Reiterator.
boolean	hasNext()
T	next()
T	peek() Returns the element that would be returned by next(), without actually consuming the element.
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 Detail

PeekingReiterator

public PeekingReiterator(Reiterator<T> iterator)

Method Detail

hasNext

public boolean hasNext()

Specified by:

hasNext in interface Iterator<T>

next

public T next()

Specified by:

next in interface Iterator<T>

remove

public void remove()

If peek() is called, remove is disallowed until next() has been subsequently called.

Specified by:

remove in interface Iterator<T>

copy

public PeekingReiterator<T> copy()

Description copied from interface: Reiterator

Returns a copy of the current Reiterator. The copy's iteration state is logically independent of the current iterator; each may be advanced without affecting the other.

The returned Reiterator is not guaranteed to return referentially identical iteration results as the original Reiterator, although Object.equals(java.lang.Object) will typically return true for the corresponding elements of each if the original source is logically immutable.

Specified by:

copy in interface Reiterator<T>

peek

public T peek()

Returns the element that would be returned by next(), without actually consuming the element.

Throws:

NoSuchElementException - if there is no next element