001    /*
002     * CDDL HEADER START
003     *
004     * The contents of this file are subject to the terms of the
005     * Common Development and Distribution License, Version 1.0 only
006     * (the "License").  You may not use this file except in compliance
007     * with the License.
008     *
009     * You can obtain a copy of the license at
010     * trunk/opends/resource/legal-notices/OpenDS.LICENSE
011     * or https://OpenDS.dev.java.net/OpenDS.LICENSE.
012     * See the License for the specific language governing permissions
013     * and limitations under the License.
014     *
015     * When distributing Covered Code, include this CDDL HEADER in each
016     * file and include the License file at
017     * trunk/opends/resource/legal-notices/OpenDS.LICENSE.  If applicable,
018     * add the following below this CDDL HEADER, with the fields enclosed
019     * by brackets "[]" replaced with your own identifying information:
020     *      Portions Copyright [yyyy] [name of copyright owner]
021     *
022     * CDDL HEADER END
023     *
024     *
025     *      Copyright 2006-2008 Sun Microsystems, Inc.
026     */
027    package org.opends.server.backends.jeb;
028    
029    import java.util.Iterator;
030    import java.util.NoSuchElementException;
031    
032    /**
033     * Implements an iterator over a range of entry IDs.
034     */
035    public class IndexIteratorRange implements Iterator<EntryID>
036    {
037      /**
038       * The upper bound of the range.
039       */
040      private long highID;
041    
042      /**
043       * The current position of the iterator in the range.
044       */
045      private long currentID;
046    
047    
048    
049      /**
050       * Constructs a range iterator from lower and upper bounds.
051       *
052       * @param lowID  The lower bound.
053       * @param highID The upper bound.
054       */
055      public IndexIteratorRange(long lowID, long highID)
056      {
057        this.currentID = lowID;
058        this.highID = highID;
059      }
060    
061    
062    
063      /**
064       * Returns <tt>true</tt> if the iteration has more elements. (In other words,
065       * returns <tt>true</tt> if <tt>next</tt> would return an element rather than
066       * throwing an exception.)
067       *
068       * @return <tt>true</tt> if the iterator has more elements.
069       */
070      public boolean hasNext()
071      {
072        return currentID <= highID;
073      }
074    
075    
076    
077      /**
078       * Returns the next element in the iteration.  Calling this method repeatedly
079       * until the {@link #hasNext()} method returns false will return each element
080       * in the underlying collection exactly once.
081       *
082       * @return the next element in the iteration.
083       * @throws java.util.NoSuchElementException
084       *          iteration has no more elements.
085       */
086      public EntryID next() throws NoSuchElementException
087      {
088        if (currentID <= highID)
089        {
090          return new EntryID(currentID++);
091        }
092        else
093        {
094          throw new NoSuchElementException();
095        }
096      }
097    
098    
099    
100      /**
101       * Removes from the underlying collection the last element returned by the
102       * iterator (optional operation).  This method can be called only once per
103       * call to <tt>next</tt>.  The behavior of an iterator is unspecified if the
104       * underlying collection is modified while the iteration is in progress in any
105       * way other than by calling this method.
106       *
107       * @throws UnsupportedOperationException if the <tt>remove</tt> operation is
108       *                                       not supported by this Iterator.
109       */
110      public void remove() throws UnsupportedOperationException
111      {
112        throw new UnsupportedOperationException();
113      }
114    }