Package org.apache.commons.collections.iterators

Class SingletonListIterator

java.lang.Object
org.apache.commons.collections.iterators.SingletonListIterator
All Implemented Interfaces:
Iterator, ListIterator, ResettableIterator, ResettableListIterator
public class SingletonListIterator extends Object implements ListIterator, ResettableListIterator
SingletonIterator is an ListIterator over a single object instance.
Since:
Commons Collections 2.1
Version:
$Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
Author:
Stephen Colebourne, Rodney Waldhoff

  • Constructor Details

    • SingletonListIterator

      public SingletonListIterator(Object object)
      Constructs a new SingletonListIterator.
      Parameters:
      object - the single object to return from the iterator

  • Method Details

    • hasNext

      public boolean hasNext()
      Is another object available from the iterator?

      This returns true if the single object hasn't been returned yet.

      Specified by:
      hasNext in interface Iterator
      Specified by:
      hasNext in interface ListIterator
      Returns:
      true if the single object hasn't been returned yet

    • hasPrevious

      public boolean hasPrevious()
      Is a previous object available from the iterator?

      This returns true if the single object has been returned.

      Specified by:
      hasPrevious in interface ListIterator
      Returns:
      true if the single object has been returned

    • nextIndex

      public int nextIndex()
      Returns the index of the element that would be returned by a subsequent call to next.
      Specified by:
      nextIndex in interface ListIterator
      Returns:
      0 or 1 depending on current state.

    • previousIndex

      public int previousIndex()
      Returns the index of the element that would be returned by a subsequent call to previous. A return value of -1 indicates that the iterator is currently at the start.
      Specified by:
      previousIndex in interface ListIterator
      Returns:
      0 or -1 depending on current state.

    • next

      public Object next()
      Get the next object from the iterator.

      This returns the single object if it hasn't been returned yet.

      Specified by:
      next in interface Iterator
      Specified by:
      next in interface ListIterator
      Returns:
      the single object
      Throws:
      NoSuchElementException - if the single object has already been returned

    • previous

      public Object previous()
      Get the previous object from the iterator.

      This returns the single object if it has been returned.

      Specified by:
      previous in interface ListIterator
      Returns:
      the single object
      Throws:
      NoSuchElementException - if the single object has not already been returned

    • remove

      public void remove()
      Remove the object from this iterator.
      Specified by:
      remove in interface Iterator
      Specified by:
      remove in interface ListIterator
      Throws:
      IllegalStateException - if the next or previous method has not yet been called, or the remove method has already been called after the last call to next or previous.

    • add

      public void add(Object obj)
      Add always throws UnsupportedOperationException.
      Specified by:
      add in interface ListIterator
      Throws:
      UnsupportedOperationException - always

    • set

      public void set(Object obj)
      Set sets the value of the singleton.
      Specified by:
      set in interface ListIterator
      Parameters:
      obj - the object to set
      Throws:
      IllegalStateException - if next has not been called or the object has been removed

    • reset

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