1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.functor.core;
18
19 import java.io.Serializable;
20
21 import org.apache.commons.functor.BinaryPredicate;
22 import org.apache.commons.functor.UnaryPredicate;
23 import org.apache.commons.functor.adapter.RightBoundPredicate;
24
25 /**
26 * {@link #test Tests}
27 * <code>true</code> iff its arguments are
28 * not {@link Object#equals equal} or both
29 * <code>null</code>.
30 * <p>
31 * This relation is symmetric but irreflexive
32 * and not transitive.
33 * </p>
34 * @param <L> the left argument type.
35 * @param <R> the right argument type.
36 * @version $Revision: 1345136 $ $Date: 2012-06-01 09:47:06 -0300 (Fri, 01 Jun 2012) $
37 */
38 public final class IsNotEqual<L, R> implements BinaryPredicate<L, R>, Serializable {
39 // static attributes
40 // ------------------------------------------------------------------------
41 /**
42 * Basic IsNotEqual<Object, Object> instance.
43 */
44 public static final IsNotEqual<Object, Object> INSTANCE = IsNotEqual.<Object, Object>instance();
45 /**
46 * serialVersionUID declaration.
47 */
48 private static final long serialVersionUID = -7303588338955281317L;
49
50 // constructor
51 // ------------------------------------------------------------------------
52 /**
53 * Create a new IsNotEqual.
54 */
55 public IsNotEqual() {
56 }
57
58 // predicate interface
59 // ------------------------------------------------------------------------
60 /**
61 * {@inheritDoc}
62 */
63 public boolean test(L left, R right) {
64 return (null == left ? null != right : !left.equals(right));
65 }
66
67 /**
68 * {@inheritDoc}
69 */
70 @Override
71 public boolean equals(Object that) {
72 return that instanceof IsNotEqual<?, ?>;
73 }
74
75 /**
76 * {@inheritDoc}
77 */
78 @Override
79 public int hashCode() {
80 return "IsNotEqual".hashCode();
81 }
82
83 /**
84 * {@inheritDoc}
85 */
86 @Override
87 public String toString() {
88 return "IsNotEqual";
89 }
90
91 // static methods
92 // ------------------------------------------------------------------------
93
94 /**
95 * Get an IsNotEqual instance.
96 * @param <L> the left argument type.
97 * @param <R> the right argument type.
98 * @return IsNotEqual<L, R>
99 */
100 public static <L, R> IsNotEqual<L, R> instance() {
101 return new IsNotEqual<L, R>();
102 }
103
104 /**
105 * Get an IsNotEqual UnaryPredicate.
106 * @param <L> the left argument type.
107 * @param <R> the right argument type.
108 * @param object bound comparison object
109 * @return UnaryPredicate<L>
110 */
111 public static <L, R> UnaryPredicate<L> to(R object) {
112 return new RightBoundPredicate<L>(new IsNotEqual<L, R>(), object);
113 }
114 }