1/*
2 * Copyright (c) 1997, 2006, 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
27package sun.security.util;
28
29import java.util.Comparator;
30
31/**
32 * Compare two byte arrays in lexicographical order.
33 *
34 * @author D. N. Hoover
35 */
36public class ByteArrayLexOrder implements Comparator<byte[]> {
37
38    /**
39     * Perform lexicographical comparison of two byte arrays,
40     * regarding each byte as unsigned.  That is, compare array entries
41     * in order until they differ--the array with the smaller entry
42     * is "smaller". If array entries are
43     * equal till one array ends, then the longer array is "bigger".
44     *
45     * @param  bytes1 first byte array to compare.
46     * @param  bytes2 second byte array to compare.
47     * @return negative number if bytes1 < bytes2, 0 if bytes1 == bytes2,
48     * positive number if bytes1 > bytes2.
49     *
50     * @exception <code>ClassCastException</code>
51     * if either argument is not a byte array.
52     */
53    public final int compare( byte[] bytes1, byte[] bytes2) {
54        int diff;
55        for (int i = 0; i < bytes1.length && i < bytes2.length; i++) {
56            diff = (bytes1[i] & 0xFF) - (bytes2[i] & 0xFF);
57            if (diff != 0) {
58                return diff;
59            }
60        }
61        // if array entries are equal till the first ends, then the
62        // longer is "bigger"
63        return bytes1.length - bytes2.length;
64    }
65
66
67}
68