content: /*
   * $Header$
   * $Revision$
   * $Date$
   *
   * ====================================================================
   *
   * Copyright 2000-2002 bob mcwhirter & James Strachan.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are
   * met:
   * 
   *   * Redistributions of source code must retain the above copyright
   *     notice, this list of conditions and the following disclaimer.
   * 
   *   * Redistributions in binary form must reproduce the above copyright
   *     notice, this list of conditions and the following disclaimer in the
   *     documentation and/or other materials provided with the distribution.
   * 
   *   * Neither the name of the Jaxen Project nor the names of its
   *     contributors may be used to endorse or promote products derived 
   *     from this software without specific prior written permission.
   * 
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
   * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
   * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
   * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
   * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
   * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
   * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   * ====================================================================
   * This software consists of voluntary contributions made by many 
   * individuals on behalf of the Jaxen Project and was originally 
   * created by bob mcwhirter <bob@werken.com> and 
   * James Strachan <jstrachan@apache.org>.  For more information on the 
   * Jaxen Project, please see <http://www.jaxen.org/>.
   * 
   * $Id$
   */
  
  
  package org.jaxen.util;
  
  import java.util.Iterator;
  import java.util.NoSuchElementException;
  
  /**
   * Simple utility class that wraps an iterator around one object.
   * This is a little more efficent than creating a one-object list.
   *
   */
  public class SingleObjectIterator implements Iterator
  {
      
      private Object  object;
      private boolean seen;
  
      /**
       * Creates a new single object iterator.
       * 
       * @param object the object to iterate over
       */
      public SingleObjectIterator(Object object)
      {
          this.object = object;
          this.seen   = false;
      }
  
  
      /**
       * Returns true if this iterator's element has not yet been seen; false if it has.
       * 
       * @return true if this iterator has another element; false if it doesn't
       * 
       * @see java.util.Iterator#hasNext()
       */
      public boolean hasNext()
      {
          return ! this.seen;
      }
  
      /**
       * Returns the single element in this iterator if it has not yet
       * been seen. 
       * 
       * @return the next element in this iterator
       * 
       * @throws NoSuchElementException if the element has already been seen
       * 
       * @see java.util.Iterator#next()
       */
      public Object next()
      {
          if ( hasNext() )
          {
              this.seen = true;
              return this.object;
          }
  
          throw new NoSuchElementException();
      }
  
      /**
       * This operation is not supported.
       * 
       * @throws UnsupportedOperationException always
       */
      public void remove()
      {
          throw new UnsupportedOperationException();
      }
      
  }
  