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
28 package org.apache.hc.core5.util;
29
30 import java.util.Objects;
31
32 /**
33 * A set of utility methods to help produce consistent
34 * {@link Object#equals equals} and {@link Object#hashCode hashCode} methods.
35 *
36 *
37 * @since 4.0
38 */
39 public final class LangUtils {
40
41 public static final int HASH_SEED = 17;
42 public static final int HASH_OFFSET = 37;
43
44 /** Disabled default constructor. */
45 private LangUtils() {
46 }
47
48 public static int hashCode(final int seed, final int hashcode) {
49 return seed * HASH_OFFSET + hashcode;
50 }
51
52 public static int hashCode(final int seed, final boolean b) {
53 return hashCode(seed, b ? 1 : 0);
54 }
55
56 public static int hashCode(final int seed, final Object obj) {
57 return hashCode(seed, obj != null ? obj.hashCode() : 0);
58 }
59
60 /**
61 * Check if two objects are equal.
62 *
63 * @param obj1 first object to compare, may be {@code null}
64 * @param obj2 second object to compare, may be {@code null}
65 * @return {@code true} if the objects are equal or both null
66 */
67 public static boolean equals(final Object obj1, final Object obj2) {
68 return Objects.equals(obj1, obj2);
69 }
70
71 /**
72 * Check if two object arrays are equal.
73 * <ul>
74 * <li>If both parameters are null, return {@code true}</li>
75 * <li>If one parameter is null, return {@code false}</li>
76 * <li>If the array lengths are different, return {@code false}</li>
77 * <li>Compare array elements using .equals(); return {@code false} if any comparisons fail.</li>
78 * <li>Return {@code true}</li>
79 * </ul>
80 *
81 * @param a1 first array to compare, may be {@code null}
82 * @param a2 second array to compare, may be {@code null}
83 * @return {@code true} if the arrays are equal or both null
84 */
85 public static boolean equals(final Object[] a1, final Object[] a2) {
86 if (a1 == null) {
87 return a2 == null;
88 }
89 if (a2 != null && a1.length == a2.length) {
90 for (int i = 0; i < a1.length; i++) {
91 if (!equals(a1[i], a2[i])) {
92 return false;
93 }
94 }
95 return true;
96 }
97 return false;
98 }
99
100 }