| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.apache.felix.framework.util; |
| |
| import java.util.Comparator; |
| |
| public class StringComparator implements Comparator<String> |
| { |
| |
| public static final StringComparator COMPARATOR = new StringComparator(); |
| |
| public int compare(String s1, String s2) |
| { |
| int n1 = s1.length(); |
| int n2 = s2.length(); |
| int min = n1 < n2 ? n1 : n2; |
| for ( int i = 0; i < min; i++ ) |
| { |
| char c1 = s1.charAt( i ); |
| char c2 = s2.charAt( i ); |
| if ( c1 != c2 ) |
| { |
| // Fast check for simple ascii codes |
| if ( c1 <= 128 && c2 <= 128 ) |
| { |
| c1 = toLowerCaseFast(c1); |
| c2 = toLowerCaseFast(c2); |
| if ( c1 != c2 ) |
| { |
| return c1 - c2; |
| } |
| } |
| else |
| { |
| c1 = Character.toUpperCase( c1 ); |
| c2 = Character.toUpperCase( c2 ); |
| if ( c1 != c2 ) |
| { |
| c1 = Character.toLowerCase( c1 ); |
| c2 = Character.toLowerCase( c2 ); |
| if ( c1 != c2 ) |
| { |
| // No overflow because of numeric promotion |
| return c1 - c2; |
| } |
| } |
| } |
| } |
| } |
| return n1 - n2; |
| } |
| |
| private static char toLowerCaseFast( char ch ) |
| { |
| return ( ch >= 'A' && ch <= 'Z' ) ? ( char ) ( ch + 'a' - 'A' ) : ch; |
| } |
| } |