001 /* This file is part of the project "Hilbert II" - http://www.qedeq.org
002 *
003 * Copyright 2000-2013, Michael Meyling <mime@qedeq.org>.
004 *
005 * "Hilbert II" is free software; you can redistribute
006 * it and/or modify it under the terms of the GNU General Public
007 * License as published by the Free Software Foundation; either
008 * version 2 of the License, or (at your option) any later version.
009 *
010 * This program is distributed in the hope that it will be useful,
011 * but WITHOUT ANY WARRANTY; without even the implied warranty of
012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
013 * GNU General Public License for more details.
014 */
015
016 package org.qedeq.base.utility;
017
018 import java.util.Arrays;
019
020
021 /**
022 * A collection of useful static methods for equality.
023 *
024 * @author Michael Meyling
025 */
026 public final class EqualsUtility {
027
028 /**
029 * Constructor, should never be called.
030 */
031 private EqualsUtility() {
032 // don't call me
033 }
034
035 /**
036 * Compare two objects, each of them could be <code>null</code>.
037 *
038 * @param a First parameter.
039 * @param b Second parameter.
040 * @return Are <code>a</code> and <code>b</code> equal?
041 */
042 public static boolean equals(final Object a, final Object b) {
043 if (a == null) {
044 if (b == null) {
045 return true;
046 }
047 return false;
048 }
049 return a.equals(b);
050 }
051
052 /**
053 * Compare two objects, each of them could be <code>null</code>.
054 *
055 * @param a First parameter.
056 * @param b Second parameter.
057 * @return Are <code>a</code> and <code>b</code> equal?
058 */
059 public static boolean equals(final Object[] a, final Object[] b) {
060 if (a == null) {
061 if (b == null) {
062 return true;
063 }
064 return false;
065 }
066 return Arrays.equals(a, b);
067 }
068
069 /**
070 * Compare two objects, each of them could be <code>null</code>.
071 *
072 * @param a First parameter.
073 * @param b Second parameter.
074 * @return Are <code>a</code> and <code>b</code> equal?
075 */
076 public static boolean equals(final byte[] a, final byte[] b) {
077 if (a == null) {
078 if (b == null) {
079 return true;
080 }
081 return false;
082 }
083 return Arrays.equals(a, b);
084 }
085
086 /**
087 * Compare two objects, each of them could be <code>null</code>.
088 *
089 * @param a First parameter.
090 * @param b Second parameter.
091 * @return Are <code>a</code> and <code>b</code> equal?
092 */
093 public static boolean equals(final int[] a, final int[] b) {
094 if (a == null) {
095 if (b == null) {
096 return true;
097 }
098 return false;
099 }
100 return Arrays.equals(a, b);
101 }
102
103 }
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