Class ArrayIterator<E>

java.lang.Object
org.apache.commons.collections4.iterators.ArrayIterator<E>
Type Parameters:
E - the type of elements returned by this iterator
All Implemented Interfaces:
Iterator<E>, ResettableIterator<E>
Direct Known Subclasses:
ArrayListIterator

public class ArrayIterator<E> extends Object implements ResettableIterator<E>
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:
1.0
  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    (package private) final Object
    The array to iterate over
    (package private) final int
    The end index to loop to
    (package private) int
    The current iterator index
    (package private) final int
    The start index to loop from
  • Constructor Summary

    Constructors
    Constructor
    Description
    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, int len, String type)
    Checks whether the index is valid or not.
    Gets the array that this iterator is iterating over.
    int
    Gets the end index to loop to.
    int
    Gets the start index to loop from.
    boolean
    Returns true if there are more elements to return from the array.
    Returns the next element in the array.
    void
    void
    Resets the iterator back to the start index.

    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

      final Object array
      The array to iterate over
    • startIndex

      final int startIndex
      The start index to loop from
    • endIndex

      final int endIndex
      The end index to loop to
    • index

      int index
      The current iterator index
  • Constructor Details

    • 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, int len, String type)
      Checks whether the index is valid or not.
      Parameters:
      bound - the index to check
      len - the length of the array
      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<E>
      Returns:
      true if there is a next element to return
    • next

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

      public void remove()
      Specified by:
      remove in interface Iterator<E>
      Throws:
      UnsupportedOperationException - always
    • getArray

      public Object getArray()
      Gets the array that this iterator is iterating over.
      Returns:
      the array this iterator iterates over.
    • getStartIndex

      public int getStartIndex()
      Gets the start index to loop from.
      Returns:
      the start index
      Since:
      4.0
    • getEndIndex

      public int getEndIndex()
      Gets the end index to loop to.
      Returns:
      the end index
      Since:
      4.0
    • reset

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