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 chars 028 * 029 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 030 */ 031public class CharComparator implements Comparator<Character> 032{ 033 /** A static instance of a CharComparator */ 034 public static final CharComparator INSTANCE = new CharComparator(); 035 036 /** 037 * A private constructor of the CharComparator class 038 */ 039 private CharComparator() 040 { 041 } 042 043 044 /** 045 * Compare two chars. 046 * 047 * @param char1 First char 048 * @param char2 Second char 049 * @return 1 if char1 > char2, 0 if char1 == char2, -1 if char1 < char2 050 */ 051 public int compare( Character char1, Character char2 ) 052 { 053 if ( char1 == char2 ) 054 { 055 return 0; 056 } 057 058 if ( char1 == null ) 059 { 060 if ( char2 == null ) 061 { 062 return 0; 063 } 064 else 065 { 066 return -1; 067 } 068 } 069 else 070 { 071 if ( char2 == null ) 072 { 073 return 1; 074 } 075 else 076 { 077 if ( char1 < char2 ) 078 { 079 return -1; 080 } 081 else if ( char1 > char2 ) 082 { 083 return 1; 084 } 085 else 086 { 087 return 0; 088 } 089 } 090 } 091 } 092}