001 /****************************************************************
002 * Licensed to the Apache Software Foundation (ASF) under one *
003 * or more contributor license agreements. See the NOTICE file *
004 * distributed with this work for additional information *
005 * regarding copyright ownership. The ASF licenses this file *
006 * to you under the Apache License, Version 2.0 (the *
007 * "License"); you may not use this file except in compliance *
008 * with the License. You may obtain a copy of the License at *
009 * *
010 * http://www.apache.org/licenses/LICENSE-2.0 *
011 * *
012 * Unless required by applicable law or agreed to in writing, *
013 * software distributed under the License is distributed on an *
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY *
015 * KIND, either express or implied. See the License for the *
016 * specific language governing permissions and limitations *
017 * under the License. *
018 ****************************************************************/
019
020 package org.apache.james.mime4j.util;
021
022 /**
023 * A set of utility methods to help produce consistent
024 * {@link Object#equals equals} and {@link Object#hashCode hashCode} methods.
025 */
026 public final class LangUtils {
027
028 public static final int HASH_SEED = 17;
029 public static final int HASH_OFFSET = 37;
030
031 /** Disabled default constructor. */
032 private LangUtils() {
033 }
034
035 public static int hashCode(final int seed, final int hashcode) {
036 return seed * HASH_OFFSET + hashcode;
037 }
038
039 public static int hashCode(final int seed, final boolean b) {
040 return hashCode(seed, b ? 1 : 0);
041 }
042
043 public static int hashCode(final int seed, final Object obj) {
044 return hashCode(seed, obj != null ? obj.hashCode() : 0);
045 }
046
047 /**
048 * Check if two objects are equal.
049 *
050 * @param obj1 first object to compare, may be {@code null}
051 * @param obj2 second object to compare, may be {@code null}
052 * @return {@code true} if the objects are equal or both null
053 */
054 public static boolean equals(final Object obj1, final Object obj2) {
055 return obj1 == null ? obj2 == null : obj1.equals(obj2);
056 }
057
058 /**
059 * Check if two strings are equal, ignoring case considerations.
060 *
061 * @param s1 first string to compare, may be {@code null}
062 * @param s2 second string to compare, may be {@code null}
063 * @return {@code true} if the objects are equal or both null
064 */
065 public static boolean equalsIgnoreCase(final String s1, final String s2) {
066 return s1 == null ? s2 == null : s1.equalsIgnoreCase(s2);
067 }
068
069 }