Package org.apache.commons.collections.iterators

Class ArrayIterator

java.lang.Object
org.apache.commons.collections.iterators.ArrayIterator
All Implemented Interfaces:
Iterator, ResettableIterator
Direct Known Subclasses:
ArrayListIterator
public class ArrayIterator extends Object implements ResettableIterator
Implements an Iterator over any array.

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

The iterator implements a reset() method, allowing the reset of the iterator back to the start if required.

Since:
Commons Collections 1.0
Version:
$Revision: 647116 $ $Date: 2008-04-11 13:23:08 +0200 (Fri, 11 Apr 2008) $
Author:
James Strachan, Mauricio S. Moura, Michael A. Smith, Neil O'Toole, Stephen Colebourne

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected Object
    array
    The array to iterate over
    protected int
    endIndex
    The end index to loop to
    protected int
    index
    The current iterator index
    protected int
    startIndex
    The start index to loop from

  • Constructor Summary

    Constructors
    Constructor
    Description
    ArrayIterator()
    Constructor for use with setArray.
    ArrayIterator(Object array)
    Constructs an ArrayIterator that will iterate over the values in the specified array.
    ArrayIterator(Object array, int startIndex)
    Constructs an ArrayIterator that will iterate over the values in the specified array from a specific start index.
    ArrayIterator(Object array, int startIndex, int endIndex)
    Construct an ArrayIterator that will iterate over a range of values in the specified array.

  • Method Summary

    Modifier and Type
    Method
    Description
    protected void
    checkBound(int bound, String type)
    Checks whether the index is valid or not.
    Object
    getArray()
    Gets the array that this iterator is iterating over.
    boolean
    hasNext()
    Returns true if there are more elements to return from the array.
    Object
    next()
    Returns the next element in the array.
    void
    remove()
    Throws UnsupportedOperationException.
    void
    reset()
    Resets the iterator back to the start index.
    void
    setArray(Object array)
    Sets the array that the ArrayIterator should iterate over.

    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

  • Field Details

    • array

      protected Object array
      The array to iterate over

    • startIndex

      protected int startIndex
      The start index to loop from

    • endIndex

      protected int endIndex
      The end index to loop to

    • index

      protected int index
      The current iterator index

  • Constructor Details

    • ArrayIterator

      public ArrayIterator()
      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.

    • ArrayIterator

      public ArrayIterator(Object array)
      Constructs an ArrayIterator 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

    • ArrayIterator

      public ArrayIterator(Object array, int startIndex)
      Constructs an ArrayIterator 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 index is invalid

    • ArrayIterator

      public ArrayIterator(Object array, int startIndex, int endIndex)
      Construct an ArrayIterator 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 to finish iterating at.
      Throws:
      IllegalArgumentException - if array is not an array.
      NullPointerException - if array is null
      IndexOutOfBoundsException - if either index is invalid

  • Method Details

    • checkBound

      protected void checkBound(int bound, String type)
      Checks whether the index is valid or not.
      Parameters:
      bound - the index to check
      type - the index type (for error messages)
      Throws:
      IndexOutOfBoundsException - if the index is invalid

    • hasNext

      public boolean hasNext()
      Returns true if there are more elements to return from the array.
      Specified by:
      hasNext in interface Iterator
      Returns:
      true if there is a next element to return

    • next

      public Object next()
      Returns the next element in the array.
      Specified by:
      next in interface Iterator
      Returns:
      the next element in the array
      Throws:
      NoSuchElementException - if all the elements in the array have already been returned

    • remove

      public void remove()
      Throws UnsupportedOperationException.
      Specified by:
      remove in interface Iterator
      Throws:
      UnsupportedOperationException - always

    • getArray

      public Object getArray()
      Gets the array that this iterator is iterating over.
      Returns:
      the array this iterator iterates over, or null if the no-arg constructor was used and setArray(Object) has never been called with a valid array.

    • setArray

      public void setArray(Object array)
      Sets the array that the ArrayIterator should iterate over.

      If an array has previously been set (using the single-arg constructor or this method) then that array is discarded in favour of this one. Iteration is restarted at the start of the new array. Although this can be used to reset iteration, the reset() method is a more effective choice.

      Parameters:
      array - the array that the iterator should iterate over.
      Throws:
      IllegalArgumentException - if array is not an array.
      NullPointerException - if array is null

    • reset

      public void reset()
      Resets the iterator back to the start index.
      Specified by:
      reset in interface ResettableIterator