Showing the changes to java/pkg/sun/misc/ASCIICaseInsensitiveComparator.java (1 of 18352 files). Show all
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| 1 | +/* | |
| 2 | + * Copyright (c) 2002, 2004, Oracle and/or its affiliates. All rights reserved. | |
| 3 | + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
| 4 | + * | |
| 5 | + * This code is free software; you can redistribute it and/or modify it | |
| 6 | + * under the terms of the GNU General Public License version 2 only, as | |
| 7 | + * published by the Free Software Foundation. Oracle designates this | |
| 8 | + * particular file as subject to the "Classpath" exception as provided | |
| 9 | + * by Oracle in the LICENSE file that accompanied this code. | |
| 10 | + * | |
| 11 | + * This code is distributed in the hope that it will be useful, but WITHOUT | |
| 12 | + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 13 | + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 14 | + * version 2 for more details (a copy is included in the LICENSE file that | |
| 15 | + * accompanied this code). | |
| 16 | + * | |
| 17 | + * You should have received a copy of the GNU General Public License version | |
| 18 | + * 2 along with this work; if not, write to the Free Software Foundation, | |
| 19 | + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
| 20 | + * | |
| 21 | + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | |
| 22 | + * or visit www.oracle.com if you need additional information or have any | |
| 23 | + * questions. | |
| 24 | + */ | |
| 25 | + | |
| 26 | +package sun.misc; | |
| 27 | + | |
| 28 | +import java.util.Comparator; | |
| 29 | + | |
| 30 | +/** Implements a locale and case insensitive comparator suitable for | |
| 31 | + strings that are known to only contain ASCII characters. Some | |
| 32 | + tables internal to the JDK contain only ASCII data and are using | |
| 33 | + the "generalized" java.lang.String case-insensitive comparator | |
| 34 | + which converts each character to both upper and lower case. */ | |
| 35 | + | |
| 36 | +public class ASCIICaseInsensitiveComparator implements Comparator<String> { | |
| 37 | + public static final Comparator<String> CASE_INSENSITIVE_ORDER = | |
| 38 | + new ASCIICaseInsensitiveComparator(); | |
| 39 | + | |
| 40 | + public int compare(String s1, String s2) { | |
| 41 | + int n1=s1.length(), n2=s2.length(); | |
| 42 | + int minLen = n1 < n2 ? n1 : n2; | |
| 43 | + for (int i=0; i < minLen; i++) { | |
| 44 | + char c1 = s1.charAt(i); | |
| 45 | + char c2 = s2.charAt(i); | |
| 46 | + assert c1 <= '\u007F' && c2 <= '\u007F'; | |
| 47 | + if (c1 != c2) { | |
| 48 | + c1 = (char)toLower(c1); | |
| 49 | + c2 = (char)toLower(c2); | |
| 50 | + if (c1 != c2) { | |
| 51 | + return c1 - c2; | |
| 52 | + } | |
| 53 | + } | |
| 54 | + } | |
| 55 | + return n1 - n2; | |
| 56 | + } | |
| 57 | + | |
| 58 | + /** | |
| 59 | + * A case insensitive hash code method to go with the case insensitive | |
| 60 | + * compare() method. | |
| 61 | + * | |
| 62 | + * Returns a hash code for this ASCII string as if it were lower case. | |
| 63 | + * | |
| 64 | + * returns same answer as:<p> | |
| 65 | + * <code>s.toLowerCase(Locale.US).hashCode();</code><p> | |
| 66 | + * but does not allocate memory (it does NOT have the special | |
| 67 | + * case Turkish rules). | |
| 68 | + * | |
| 69 | + * @param s a String to compute the hashcode on. | |
| 70 | + * @return a hash code value for this object. | |
| 71 | + */ | |
| 72 | + public static int lowerCaseHashCode(String s) { | |
| 73 | + int h = 0; | |
| 74 | + int len = s.length(); | |
| 75 | + | |
| 76 | + for (int i = 0; i < len; i++) { | |
| 77 | + h = 31*h + toLower(s.charAt(i)); | |
| 78 | + } | |
| 79 | + | |
| 80 | + return h; | |
| 81 | + } | |
| 82 | + | |
| 83 | + /* If java.util.regex.ASCII ever becomes public or sun.*, use its code instead:*/ | |
| 84 | + static boolean isLower(int ch) { | |
| 85 | + return ((ch-'a')|('z'-ch)) >= 0; | |
| 86 | + } | |
| 87 | + | |
| 88 | + static boolean isUpper(int ch) { | |
| 89 | + return ((ch-'A')|('Z'-ch)) >= 0; | |
| 90 | + } | |
| 91 | + | |
| 92 | + static int toLower(int ch) { | |
| 93 | + return isUpper(ch) ? (ch + 0x20) : ch; | |
| 94 | + } | |
| 95 | + | |
| 96 | + static int toUpper(int ch) { | |
| 97 | + return isLower(ch) ? (ch - 0x20) : ch; | |
| 98 | + } | |
| 99 | +} | |