LangUtils.java revision 069490a5ca2fd1988d29daf45d892f47ad665115 
1/*
2 * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk/module-main/src/main/java/org/apache/http/util/LangUtils.java $
3 * $Revision: 503413 $
4 * $Date: 2007-02-04 06:22:14 -0800 (Sun, 04 Feb 2007) $
5 *
6 * ====================================================================
7 * Licensed to the Apache Software Foundation (ASF) under one
8 * or more contributor license agreements.  See the NOTICE file
9 * distributed with this work for additional information
10 * regarding copyright ownership.  The ASF licenses this file
11 * to you under the Apache License, Version 2.0 (the
12 * "License"); you may not use this file except in compliance
13 * with the License.  You may obtain a copy of the License at
14 *
15 *   http://www.apache.org/licenses/LICENSE-2.0
16 *
17 * Unless required by applicable law or agreed to in writing,
18 * software distributed under the License is distributed on an
19 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
20 * KIND, either express or implied.  See the License for the
21 * specific language governing permissions and limitations
22 * under the License.
23 * ====================================================================
24 *
25 * This software consists of voluntary contributions made by many
26 * individuals on behalf of the Apache Software Foundation.  For more
27 * information on the Apache Software Foundation, please see
28 * <http://www.apache.org/>.
29 *
30 */
31
32package org.apache.http.util;
33
34/**
35 * A set of utility methods to help produce consistent
36 * {@link Object#equals equals} and {@link Object#hashCode hashCode} methods.
37 *
38 * @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
39 *
40 * @since 4.0
41 */
42public final class LangUtils {
43
44    public static final int HASH_SEED = 17;
45    public static final int HASH_OFFSET = 37;
46
47    /** Disabled default constructor. */
48    private LangUtils() {
49    }
50
51    public static int hashCode(final int seed, final int hashcode) {
52        return seed * HASH_OFFSET + hashcode;
53    }
54
55    public static int hashCode(final int seed, final boolean b) {
56        return hashCode(seed, b ? 1 : 0);
57    }
58
59    public static int hashCode(final int seed, final Object obj) {
60        return hashCode(seed, obj != null ? obj.hashCode() : 0);
61    }
62
63    public static boolean equals(final Object obj1, final Object obj2) {
64        return obj1 == null ? obj2 == null : obj1.equals(obj2);
65    }
66
67    public static boolean equals(final Object[] a1, final Object[] a2) {
68        if (a1 == null) {
69            if (a2 == null) {
70                return true;
71            } else {
72                return false;
73            }
74        } else {
75            if (a2 != null && a1.length == a2.length) {
76                for (int i = 0; i < a1.length; i++) {
77                    if (!equals(a1[i], a2[i])) {
78                        return false;
79                    }
80                }
81                return true;
82            } else {
83                return false;
84            }
85        }
86    }
87
88}
89