/lib/src/org/apache/http/util/LangUtils.java

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