1/*
2 *  Licensed to the Apache Software Foundation (ASF) under one or more
3 *  contributor license agreements.  See the NOTICE file distributed with
4 *  this work for additional information regarding copyright ownership.
5 *  The ASF licenses this file to You under the Apache License, Version 2.0
6 *  (the "License"); you may not use this file except in compliance with
7 *  the License.  You may obtain a copy of the License at
8 *
9 *     http://www.apache.org/licenses/LICENSE-2.0
10 *
11 *  Unless required by applicable law or agreed to in writing, software
12 *  distributed under the License is distributed on an "AS IS" BASIS,
13 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 *  See the License for the specific language governing permissions and
15 *  limitations under the License.
16 */
17
18/**
19* @author Alexander V. Esin
20* @version $Revision$
21*/
22
23package org.apache.harmony.security.x501;
24
25import java.io.Serializable;
26import java.util.Comparator;
27import org.apache.harmony.security.utils.ObjectIdentifier;
28
29/**
30 * AttributeTypeAndValue comparator
31 *
32 */
33public class AttributeTypeAndValueComparator implements Comparator, Serializable {
34
35    private static final long serialVersionUID = -1286471842007103132L;
36
37    /**
38     * compares two AttributeTypeAndValues
39     *
40     * @param obj1
41     *            first AttributeTypeAndValue
42     * @param obj2
43     *            second AttributeTypeAndValue
44     * @return -1 of first AttributeTypeAndValue "less" than second
45     *         AttributeTypeAndValue 1 otherwise, 0 if they are equal
46     */
47    public int compare(Object obj1, Object obj2) {
48        if (obj1 == obj2) {
49            return 0;
50        }
51
52        AttributeTypeAndValue atav1 = (AttributeTypeAndValue) obj1;
53        AttributeTypeAndValue atav2 = (AttributeTypeAndValue) obj2;
54        String kw1 = atav1.getType().getName();
55        String kw2 = atav2.getType().getName();
56        if (kw1 != null && kw2 == null) {
57            return -1;
58        }
59        if (kw1 == null && kw2 != null) {
60            return 1;
61        }
62        if (kw1 != null && kw2 != null) {
63            return kw1.compareTo(kw2);
64        }
65
66        return compateOids(atav1.getType(), atav2.getType());
67    }
68
69    /**
70     * compares two Object identifiers
71     *
72     * @param oid1
73     *            first OID
74     * @param oid2
75     *            second OID
76     * @return -1 of first OID "less" than second OID 1 otherwise, 0 if they are
77     *         equal
78     */
79    private static int compateOids(ObjectIdentifier oid1, ObjectIdentifier oid2) {
80        if (oid1 == oid2) {
81            return 0;
82        }
83
84        int[] ioid1 = oid1.getOid();
85        int[] ioid2 = oid2.getOid();
86        int min = ioid1.length < ioid2.length ? ioid1.length : ioid2.length;
87        for (int i = 0; i < min; ++i) {
88            if (ioid1[i] < ioid2[i]) {
89                return -1;
90            }
91            if (ioid1[i] > ioid2[i]) {
92                return 1;
93            }
94            if ((i + 1) == ioid1.length && (i + 1) < ioid2.length) {
95                return -1;
96            }
97            if ((i + 1) < ioid1.length && (i + 1) == ioid2.length) {
98                return 1;
99            }
100        }
101        return 0;
102    }
103}
104