public class

LoopingIterator

extends Object
implements ResettableIterator
java.lang.Object
   ↳ org.apache.commons.collections.iterators.LoopingIterator

Class Overview

An Iterator that restarts when it reaches the end.

The iterator will loop continuously around the provided elements, unless there are no elements in the collection to begin with, or all the elements have been removed.

Concurrent modifications are not directly supported, and for most collection implementations will throw a ConcurrentModificationException.

Summary

Public Constructors
LoopingIterator(Collection coll)
Constructor that wraps a collection.
Public Methods
boolean hasNext()
Has the iterator any more elements.
Object next()
Returns the next object in the collection.
void remove()
Removes the previously retrieved item from the underlying collection.
void reset()
Resets the iterator back to the start of the collection.
int size()
Gets the size of the collection underlying the iterator.
[Expand]
Inherited Methods
From class java.lang.Object
From interface java.util.Iterator
From interface org.apache.commons.collections.ResettableIterator

Public Constructors

public LoopingIterator (Collection coll)

Constructor that wraps a collection.

There is no way to reset an Iterator instance without recreating it from the original source, so the Collection must be passed in.

Parameters
coll the collection to wrap
Throws
NullPointerException if the collection is null

Public Methods

public boolean hasNext ()

Has the iterator any more elements.

Returns false only if the collection originally had zero elements, or all the elements have been removed.

Returns
  • true if there are more elements

public Object next ()

Returns the next object in the collection.

If at the end of the collection, return the first element.

Throws
NoSuchElementException if there are no elements at all. Use hasNext() to avoid this error.

public void remove ()

Removes the previously retrieved item from the underlying collection.

This feature is only supported if the underlying collection's iterator method returns an implementation that supports it.

This method can only be called after at least one next() method call. After a removal, the remove method may not be called again until another next has been performed. If the reset() is called, then remove may not be called until next() is called again.

public void reset ()

Resets the iterator back to the start of the collection.

public int size ()

Gets the size of the collection underlying the iterator.

Returns
  • the current collection size