toys/data-structures/avl-tree/ArrayIterator.java

/**
 * ArrayIterator represents an iterator over the elements of an array.
 * 
 * @author Dr. Lewis
 * @author Dr. Chase
 * @version 1.0, 8/19/08
 */

import java.util.*;

public class ArrayIterator<T> implements Iterator
{
   private int count;    // the number of elements in the collection
   private int current;  // the current position in the iteration 
   private T[] items; 

   /**
    * Sets up this iterator using the specified items.
    * 
    * @param collection  the collection for which the iterator will be created
    * @param size        the size of the collection
    */
   public ArrayIterator (T[] collection, int size)
   {
      items = collection;
      count = size;
      current = 0;
   }

   /**
    * Returns true if this iterator has at least one more element
    * to deliver in the iteraion.
    *
    * @return  true if this iterator has at least one more element to deliver
    */
   public boolean hasNext()
   {
      return (current < count);
   }

   /**
    * Returns the next element in the iteration. If there are no
    * more elements in this itertion, a NoSuchElementException is
    * thrown.
    *
    * @return  the next element in the iteration
    * @throws NoSuchElementException  if a no such element exception occurs
    */
   public T next()
   {
      if (! hasNext())
         throw new NoSuchElementException();

 	  current++;
 	  
      return items[current - 1]; 
   }

   /**
    * The remove operation is not supported in this collection.
    *
    * @throws UnsupportedOperationException  if an unsupported operation
    *                                        exception occurs
    */
   public void remove() throws UnsupportedOperationException
   {
      throw new UnsupportedOperationException();
   }
}