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 char arrays 028 * 029 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 030 */ 031public class CharArrayComparator implements Comparator<char[]> 032{ 033 /** A static instance of a CharArrayComparator */ 034 public static final CharArrayComparator INSTANCE = new CharArrayComparator(); 035 036 /** 037 * A private constructor of the CharArrayComparator class 038 */ 039 private CharArrayComparator() 040 { 041 } 042 043 044 /** 045 * Compare two char arrays. 046 * 047 * @param charArray1 First char array 048 * @param charArray2 Second char array 049 * @return 1 if charArray1 > charArray2, 0 if charArray1 == charArray2, -1 if charArray1 < charArray2 050 */ 051 public int compare( char[] charArray1, char[] charArray2 ) 052 { 053 if ( charArray1 == charArray2 ) 054 { 055 return 0; 056 } 057 058 if ( charArray1 == null ) 059 { 060 if ( charArray2 == null ) 061 { 062 return 0; 063 } 064 else 065 { 066 return -1; 067 } 068 } 069 else 070 { 071 if ( charArray2 == null ) 072 { 073 return 1; 074 } 075 else 076 { 077 if ( charArray1.length < charArray2.length ) 078 { 079 int pos = 0; 080 081 for ( char char1 : charArray1 ) 082 { 083 char char2 = charArray2[pos]; 084 085 if ( char1 == char2 ) 086 { 087 pos++; 088 } 089 else if ( char1 < char2 ) 090 { 091 return -1; 092 } 093 else 094 { 095 return 1; 096 } 097 } 098 099 return -1; 100 } 101 else 102 { 103 int pos = 0; 104 105 for ( char char2 : charArray2 ) 106 { 107 char char1 = charArray1[pos]; 108 109 if ( char1 == char2 ) 110 { 111 pos++; 112 } 113 else if ( char1 < char2 ) 114 { 115 return -1; 116 } 117 else 118 { 119 return 1; 120 } 121 } 122 123 if ( pos < charArray1.length ) 124 { 125 return 1; 126 } 127 else 128 { 129 return 0; 130 } 131 } 132 } 133 } 134 135 } 136}