001/*
002 *  Licensed to the Apache Software Foundation (ASF) under one
003 *  or more contributor license agreements.  See the NOTICE file
004 *  distributed with this work for additional information
005 *  regarding copyright ownership.  The ASF licenses this file
006 *  to you under the Apache License, Version 2.0 (the
007 *  "License"); you may not use this file except in compliance
008 *  with the License.  You may obtain a copy of the License at
009 *
010 *    http://www.apache.org/licenses/LICENSE-2.0
011 *
012 *  Unless required by applicable law or agreed to in writing,
013 *  software distributed under the License is distributed on an
014 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 *  KIND, either express or implied.  See the License for the
016 *  specific language governing permissions and limitations
017 *  under the License.
018 *
019 */
020package org.apache.directory.mavibot.btree.comparator;
021
022
023import java.util.Comparator;
024
025
026/**
027 * Compares Longs
028 *
029 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
030 */
031public class LongComparator implements Comparator<Long>
032{
033    /** A static instance of a LongComparator */
034    public static final LongComparator INSTANCE = new LongComparator();
035
036    /**
037     * A private constructor of the BooleanArrayComparator class
038     */
039    private LongComparator()
040    {
041    }
042    /**
043     * Compare two longs.
044     *
045     * @param long1 First long
046     * @param long2 Second long
047     * @return 1 if long1 > long2, 0 if long1 == long2, -1 if long1 < long2
048     */
049    public int compare( Long long1, Long long2 )
050    {
051        if ( long1 == long2 )
052        {
053            return 0;
054        }
055
056        if ( long1 == null )
057        {
058            if ( long2 == null )
059            {
060                return 0;
061            }
062            else
063            {
064                return -1;
065            }
066        }
067        else
068        {
069            if ( long2 == null )
070            {
071                return 1;
072            }
073            else
074            {
075                if ( long1 < long2 )
076                {
077                    return -1;
078                }
079                else if ( long1 > long2 )
080                {
081                    return 1;
082                }
083                else
084                {
085                    return 0;
086                }
087            }
088        }
089    }
090}