Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
Identity |
|
| 1.0;1 |
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.UnaryFunction; | |
22 | import org.apache.commons.functor.UnaryPredicate; | |
23 | ||
24 | /** | |
25 | * {@link #evaluate Evaluates} to its input argument. | |
26 | * | |
27 | * {@link #test Tests} to the <code>boolean</code> | |
28 | * value of the <code>Boolean</code>-valued parameter. | |
29 | * The {@link #test} method throws an exception if | |
30 | * the parameter isn't a non-<code>null</code> | |
31 | * <code>Boolean</code>. | |
32 | * | |
33 | * @param <T> the returned value type. | |
34 | * @version $Revision: 1160385 $ $Date: 2011-08-22 21:28:37 +0200 (Mon, 22 Aug 2011) $ | |
35 | * @author Rodney Waldhoff | |
36 | */ | |
37 | public final class Identity<T> implements UnaryFunction<T, T>, UnaryPredicate<T>, Serializable { | |
38 | // static attributes | |
39 | // ------------------------------------------------------------------------ | |
40 | /** | |
41 | * A generic {@code Identity<Object>} instance. | |
42 | */ | |
43 | 2 | public static final Identity<Object> INSTANCE = new Identity<Object>(); |
44 | ||
45 | /** | |
46 | * serialVersionUID declaration. | |
47 | */ | |
48 | private static final long serialVersionUID = 4145504259013789494L; | |
49 | ||
50 | // constructor | |
51 | // ------------------------------------------------------------------------ | |
52 | ||
53 | /** | |
54 | * Create a new Identity. | |
55 | */ | |
56 | 154 | public Identity() { |
57 | 154 | } |
58 | ||
59 | // function interface | |
60 | // ------------------------------------------------------------------------ | |
61 | ||
62 | /** | |
63 | * {@inheritDoc} | |
64 | */ | |
65 | public T evaluate(T obj) { | |
66 | 340 | return obj; |
67 | } | |
68 | ||
69 | /** | |
70 | * {@inheritDoc} | |
71 | */ | |
72 | public boolean test(Object obj) { | |
73 | 22 | return test((Boolean) obj); |
74 | } | |
75 | ||
76 | /** | |
77 | * Test a Boolean object by returning its <code>booleanValue</code>. | |
78 | * @param bool Boolean | |
79 | * @return boolean | |
80 | */ | |
81 | public boolean test(Boolean bool) { | |
82 | 20 | return bool.booleanValue(); |
83 | } | |
84 | ||
85 | /** | |
86 | * {@inheritDoc} | |
87 | */ | |
88 | public boolean equals(Object that) { | |
89 | 138 | return (that instanceof Identity<?>); |
90 | } | |
91 | ||
92 | /** | |
93 | * {@inheritDoc} | |
94 | */ | |
95 | public int hashCode() { | |
96 | 436 | return "Identity".hashCode(); |
97 | } | |
98 | ||
99 | /** | |
100 | * {@inheritDoc} | |
101 | */ | |
102 | public String toString() { | |
103 | 324 | return "Identity"; |
104 | } | |
105 | ||
106 | // static methods | |
107 | // ------------------------------------------------------------------------ | |
108 | ||
109 | /** | |
110 | * Get an Identity instance. | |
111 | * @param <T> the identity returned value type. | |
112 | * @return Identity | |
113 | */ | |
114 | public static <T> Identity<T> instance() { | |
115 | 66 | return new Identity<T>(); |
116 | } | |
117 | ||
118 | } |