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 integers 028 * 029 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 030 */ 031public class IntComparator implements Comparator<Integer> 032{ 033 /** A static instance of a IntComparator */ 034 public static final IntComparator INSTANCE = new IntComparator(); 035 036 /** 037 * A private constructor of the IntComparator class 038 */ 039 private IntComparator() 040 { 041 } 042 043 044 /** 045 * Compare two integers. 046 * 047 * @param integer1 First integer 048 * @param integer2 Second integer 049 * @return 1 if integer1 > integer2, 0 if integer1 == integer2, -1 if integer1 < integer2 050 */ 051 public int compare( Integer integer1, Integer integer2 ) 052 { 053 if ( integer1 == integer2 ) 054 { 055 return 0; 056 } 057 058 if ( integer1 == null ) 059 { 060 if ( integer2 == null ) 061 { 062 return 0; 063 } 064 else 065 { 066 return -1; 067 } 068 } 069 else 070 { 071 if ( integer2 == null ) 072 { 073 return 1; 074 } 075 else 076 { 077 return integer1.compareTo( integer2 ); 078 } 079 } 080 } 081}