java.lang.Object

org.apache.commons.collections.iterators.ArrayIterator

org.apache.commons.collections.iterators.ArrayListIterator

All Implemented Interfaces:: Iterator, ListIterator, ResettableIterator, ResettableListIterator

public class ArrayListIterator extends ArrayIterator implements ListIterator, ResettableListIterator

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 ArrayIterator.remove(), as the array cannot be changed in size. The set(Object) method is supported however.

Since:

Commons Collections 3.0

Version:

$Revision: 647116 $ $Date: 2008-04-11 13:23:08 +0200 (Fri, 11 Apr 2008) $

Author:

Neil O'Toole, Stephen Colebourne, Phil Steitz

See Also:

Field Summary

Fields

Modifier and Type

Field

Description

protected int

lastItemIndex

Holds the index of the last item returned by a call to next() or previous().

Fields inherited from class org.apache.commons.collections.iterators.ArrayIterator
array, endIndex, index, startIndex
Constructor Summary

Constructors

Constructor

Description

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.
Method Summary

Modifier and Type

Method

Description

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.

Methods inherited from class org.apache.commons.collections.iterators.ArrayIterator
checkBound, getArray, hasNext, remove, setArray

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

Methods inherited from interface java.util.ListIterator
hasNext, remove

Field Details
- lastItemIndex
  
  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(java.lang.Object) method.
Constructor Details
- ArrayListIterator
  
  public ArrayListIterator()
  
  Constructor for use with setArray.
  Using this constructor, the iterator is equivalent to an empty iterator until ArrayIterator.setArray(Object) is called to establish the array to iterate over.
- ArrayListIterator
  
  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
- ArrayListIterator
  
  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
- ArrayListIterator
  
  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
Method Details
- hasPrevious
  
  public boolean hasPrevious()
  
  Returns true if there are previous elements to return from the array.
  
  Specified by:
  
  hasPrevious in interface ListIterator
  
  Returns:
  
  true if there is a previous element to return
- previous
  
  public Object previous()
  
  Gets the previous element from the array.
  
  Specified by:
  
  previous in interface ListIterator
  
  Returns:
  
  the previous element
  
  Throws:
  
  NoSuchElementException - if there is no previous element
- next
  
  public Object next()
  
  Gets the next element from the array.
  
  Specified by:
  
  next in interface Iterator
  
  Specified by:
  
  next in interface ListIterator
  
  Overrides:
  
  next in class ArrayIterator
  
  Returns:
  
  the next element
  
  Throws:
  
  NoSuchElementException - if there is no next element
- nextIndex
  
  public int nextIndex()
  
  Gets the next index to be retrieved.
  
  Specified by:
  
  nextIndex in interface ListIterator
  
  Returns:
  
  the index of the item to be retrieved next
- previousIndex
  
  public int previousIndex()
  
  Gets the index of the item to be retrieved if previous() is called.
  
  Specified by:
  
  previousIndex in interface ListIterator
  
  Returns:
  
  the index of the item to be retrieved next
- add
  
  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.
  Specified by:
  
  add in interface ListIterator
  
  Throws:
  
  UnsupportedOperationException - always thrown.
  
  See Also:
  
  ListIterator.set(E)
- set
  
  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.
  Specified by:
  
  set in interface ListIterator
  
  See Also:
  
  ListIterator.set(E)
- reset
  
  public void reset()
  
  Resets the iterator back to the start index.
  
  Specified by:
  
  reset in interface ResettableIterator
  
  Specified by:
  
  reset in interface ResettableListIterator
  
  Overrides:
  
  reset in class ArrayIterator

Class ArrayListIterator

Field Summary

Fields inherited from class org.apache.commons.collections.iterators.ArrayIterator

Constructor Summary

Method Summary

Methods inherited from class org.apache.commons.collections.iterators.ArrayIterator

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.Iterator

Methods inherited from interface java.util.ListIterator

Field Details

lastItemIndex

Constructor Details

ArrayListIterator

ArrayListIterator

ArrayListIterator

ArrayListIterator

Method Details

hasPrevious

previous

next

nextIndex

previousIndex

add

set

reset