public class

ArrayListIterator

extends ArrayIterator
implements ListIterator<E> ResettableListIterator
java.lang.Object
   ↳ org.apache.commons.collections.iterators.ArrayIterator
     ↳ org.apache.commons.collections.iterators.ArrayListIterator

Class Overview

Implements a ListIterator over an array.

The array can be either an array of object or of primitives. If you know that you have an object array, the ObjectArrayListIterator class is a better choice, as it will perform better.

This iterator does not support add(Object) or remove(), as the array cannot be changed in size. The set(Object) method is supported however.

See Also

Summary

Fields
protected int lastItemIndex Holds the index of the last item returned by a call to next() or previous().
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Inherited Fields
From class org.apache.commons.collections.iterators.ArrayIterator
Public Constructors
ArrayListIterator()
Constructor for use with setArray.
ArrayListIterator(Object array)
Constructs an ArrayListIterator that will iterate over the values in the specified array.
ArrayListIterator(Object array, int startIndex)
Constructs an ArrayListIterator that will iterate over the values in the specified array from a specific start index.
ArrayListIterator(Object array, int startIndex, int endIndex)
Construct an ArrayListIterator that will iterate over a range of values in the specified array.
Public Methods
void add(Object o)
This iterator does not support modification of its backing collection, and so will always throw an UnsupportedOperationException when this method is invoked.
boolean hasPrevious()
Returns true if there are previous elements to return from the array.
Object next()
Gets the next element from the array.
int nextIndex()
Gets the next index to be retrieved.
Object previous()
Gets the previous element from the array.
int previousIndex()
Gets the index of the item to be retrieved if previous() is called.
void reset()
Resets the iterator back to the start index.
void set(Object o)
Sets the element under the cursor.
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Inherited Methods
From class org.apache.commons.collections.iterators.ArrayIterator
From class java.lang.Object
From interface java.util.Iterator
From interface java.util.ListIterator
From interface org.apache.commons.collections.ResettableIterator
From interface org.apache.commons.collections.ResettableListIterator

Fields

protected int lastItemIndex

Holds the index of the last item returned by a call to next() or previous(). This is set to -1 if neither method has yet been invoked. lastItemIndex is used to to implement the set(E) method.

Public Constructors

public ArrayListIterator ()

Constructor for use with setArray.

Using this constructor, the iterator is equivalent to an empty iterator until setArray(Object) is called to establish the array to iterate over.

public ArrayListIterator (Object array)

Constructs an ArrayListIterator that will iterate over the values in the specified array.

Parameters
array the array to iterate over
Throws
IllegalArgumentException if array is not an array.
NullPointerException if array is null

public ArrayListIterator (Object array, int startIndex)

Constructs an ArrayListIterator that will iterate over the values in the specified array from a specific start index.

Parameters
array the array to iterate over
startIndex the index to start iterating at
Throws
IllegalArgumentException if array is not an array.
NullPointerException if array is null
IndexOutOfBoundsException if the start index is out of bounds

public ArrayListIterator (Object array, int startIndex, int endIndex)

Construct an ArrayListIterator that will iterate over a range of values in the specified array.

Parameters
array the array to iterate over
startIndex the index to start iterating at
endIndex the index (exclusive) to finish iterating at
Throws
IllegalArgumentException if array is not an array.
IndexOutOfBoundsException if the start or end index is out of bounds
IllegalArgumentException if end index is before the start
NullPointerException if array is null

Public Methods

public void add (Object o)

This iterator does not support modification of its backing collection, and so will always throw an UnsupportedOperationException when this method is invoked.

Throws
UnsupportedOperationException always thrown.
See Also

public boolean hasPrevious ()

Returns true if there are previous elements to return from the array.

Returns
  • true if there is a previous element to return

public Object next ()

Gets the next element from the array.

Returns
  • the next element
Throws
NoSuchElementException if there is no next element

public int nextIndex ()

Gets the next index to be retrieved.

Returns
  • the index of the item to be retrieved next

public Object previous ()

Gets the previous element from the array.

Returns
  • the previous element
Throws
NoSuchElementException if there is no previous element

public int previousIndex ()

Gets the index of the item to be retrieved if previous() is called.

Returns
  • the index of the item to be retrieved next

public void reset ()

Resets the iterator back to the start index.

public void set (Object o)

Sets the element under the cursor.

This method sets the element that was returned by the last call to next() of previous().

Note: ListIterator implementations that support add() and remove() only allow set() to be called once per call to next() or previous (see the ListIterator javadoc for more details). Since this implementation does not support add() or remove(), set() may be called as often as desired.

See Also