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 020package 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 */ 026public 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}