com.google.common.collect

Class ForwardingIterator<T>

java.lang.Object

com.google.common.collect.ForwardingObject

com.google.common.collect.ForwardingIterator<T>

All Implemented Interfaces:

Iterator<T>

Direct Known Subclasses:

ForwardingListIterator

@GwtCompatible
public abstract class ForwardingIterator<T>
extends ForwardingObject
implements Iterator<T>

An iterator which forwards all its method calls to another iterator. Subclasses should override one or more methods to modify the behavior of the backing iterator as desired per the decorator pattern.

default method warning: This class forwards calls to only some default methods. Specifically, it forwards calls only for methods that existed before default methods were introduced. For newer methods, like forEachRemaining, it inherits their default implementations. When those implementations invoke methods, they invoke methods on the ForwardingIterator.

Since:

2.0

Author:

Kevin Bourrillion

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ForwardingIterator() Constructor for use by subclasses.

Method Summary

Modifier and Type	Method and Description
protected abstract Iterator<T>	delegate() Returns the backing delegate instance that methods are forwarded to.
boolean	hasNext() Returns true if the iteration has more elements.
T	next() Returns the next element in the iteration.
void	remove() Removes from the underlying collection the last element returned by this iterator (optional operation).

Methods inherited from class com.google.common.collect.ForwardingObject

toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Iterator

forEachRemaining

Constructor Detail

ForwardingIterator

protected ForwardingIterator()

Constructor for use by subclasses.

Method Detail

delegate

protected abstract Iterator<T> delegate()

Description copied from class: ForwardingObject

Returns the backing delegate instance that methods are forwarded to. Abstract subclasses generally override this method with an abstract method that has a more specific return type, such as ForwardingSet.delegate(). Concrete subclasses override this method to supply the instance being decorated.

Specified by:

delegate in class ForwardingObject

hasNext

public boolean hasNext()

Description copied from interface: java.util.Iterator

Returns true if the iteration has more elements. (In other words, returns true if Iterator.next() would return an element rather than throwing an exception.)

Specified by:

hasNext in interface Iterator<T>

Returns:

true if the iteration has more elements

next

@CanIgnoreReturnValue
public T next()

Description copied from interface: java.util.Iterator

Returns the next element in the iteration.

Specified by:

next in interface Iterator<T>

Returns:

the next element in the iteration

remove

public void remove()

Description copied from interface: java.util.Iterator

Removes from the underlying collection the last element returned by this iterator (optional operation). This method can be called only once per call to Iterator.next(). The behavior of an iterator is unspecified if the underlying collection is modified while the iteration is in progress in any way other than by calling this method.

Specified by:

remove in interface Iterator<T>