Package org.apache.commons.collections4.iterators

Class SingletonListIterator<E>

java.lang.Object
org.apache.commons.collections4.iterators.SingletonListIterator<E>
All Implemented Interfaces:
Iterator<E>, ListIterator<E>, OrderedIterator<E>, ResettableIterator<E>, ResettableListIterator<E>
public class SingletonListIterator<E> extends Object implements ResettableListIterator<E>
SingletonIterator is an ListIterator over a single object instance.
Since:
2.1

  • Constructor Summary

    Constructors
    Constructor
    Description
    SingletonListIterator(E object)
    Constructs a new SingletonListIterator.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    add(E obj)
    Add always throws UnsupportedOperationException.
    boolean
    hasNext()
    Is another object available from the iterator?
    boolean
    hasPrevious()
    Is a previous object available from the iterator?
    E
    next()
    Get the next object from the iterator.
    int
    nextIndex()
    Returns the index of the element that would be returned by a subsequent call to next.
    E
    previous()
    Get the previous object from the iterator.
    int
    previousIndex()
    Returns the index of the element that would be returned by a subsequent call to previous.
    void
    remove()
    Remove the object from this iterator.
    void
    reset()
    Reset the iterator back to the start.
    void
    set(E obj)
    Set sets the value of the singleton.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • SingletonListIterator

      public SingletonListIterator(E 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<E>
      Specified by:
      hasNext in interface ListIterator<E>
      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<E>
      Specified by:
      hasPrevious in interface OrderedIterator<E>
      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<E>
      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<E>
      Returns:
      0 or -1 depending on current state.

    • next

      public E 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<E>
      Specified by:
      next in interface ListIterator<E>
      Returns:
      the single object
      Throws:
      NoSuchElementException - if the single object has already been returned

    • previous

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

      This returns the single object if it has been returned.

      Specified by:
      previous in interface ListIterator<E>
      Specified by:
      previous in interface OrderedIterator<E>
      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<E>
      Specified by:
      remove in interface ListIterator<E>
      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(E obj)
      Add always throws UnsupportedOperationException.
      Specified by:
      add in interface ListIterator<E>
      Parameters:
      obj - the object to add
      Throws:
      UnsupportedOperationException - always

    • set

      public void set(E obj)
      Set sets the value of the singleton.
      Specified by:
      set in interface ListIterator<E>
      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<E>