Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
UnaryFunctionUnaryPredicate |
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| 2.142857142857143;2.143 |
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.adapter; | |
18 | ||
19 | import java.io.Serializable; | |
20 | ||
21 | import org.apache.commons.functor.UnaryFunction; | |
22 | import org.apache.commons.functor.UnaryPredicate; | |
23 | ||
24 | /** | |
25 | * Adapts a <code>Boolean</code>-valued | |
26 | * {@link UnaryFunction UnaryFunction} | |
27 | * to the {@link UnaryPredicate UnaryPredicate} | |
28 | * interface. | |
29 | * <p/> | |
30 | * Note that although this class implements | |
31 | * {@link Serializable}, a given instance will | |
32 | * only be truly <code>Serializable</code> if the | |
33 | * underlying function is. Attempts to serialize | |
34 | * an instance whose delegate is not | |
35 | * <code>Serializable</code> will result in an exception. | |
36 | * | |
37 | * @param <A> the argument type. | |
38 | * @version $Revision: 1157648 $ $Date: 2011-08-14 22:22:47 +0200 (Sun, 14 Aug 2011) $ | |
39 | * @author Rodney Waldhoff | |
40 | */ | |
41 | public final class UnaryFunctionUnaryPredicate<A> implements UnaryPredicate<A>, Serializable { | |
42 | /** | |
43 | * serialVersionUID declaration. | |
44 | */ | |
45 | private static final long serialVersionUID = -9211927278252224707L; | |
46 | /** The {@link UnaryFunction UnaryFunction} I'm wrapping. */ | |
47 | private final UnaryFunction<? super A, Boolean> function; | |
48 | ||
49 | /** | |
50 | * Create an {@link UnaryPredicate UnaryPredicate} wrapping | |
51 | * the given {@link UnaryFunction UnaryFunction}. | |
52 | * @param function the {@link UnaryFunction UnaryFunction} to wrap | |
53 | */ | |
54 | 36 | public UnaryFunctionUnaryPredicate(UnaryFunction<? super A, Boolean> function) { |
55 | 36 | if (function == null) { |
56 | 0 | throw new IllegalArgumentException("UnaryFunction argument was null"); |
57 | } | |
58 | 36 | this.function = function; |
59 | 36 | } |
60 | ||
61 | /** | |
62 | * {@inheritDoc} | |
63 | * Returns the <code>boolean</code> value of the non-<code>null</code> | |
64 | * <code>Boolean</code> returned by the {@link UnaryFunction#evaluate evaluate} | |
65 | * method of my underlying function. | |
66 | */ | |
67 | public boolean test(A obj) { | |
68 | 16 | return function.evaluate(obj); |
69 | } | |
70 | ||
71 | /** | |
72 | * {@inheritDoc} | |
73 | */ | |
74 | public boolean equals(Object that) { | |
75 | 34 | return that == this |
76 | || (that instanceof UnaryFunctionUnaryPredicate<?> && equals((UnaryFunctionUnaryPredicate<?>) that)); | |
77 | } | |
78 | ||
79 | /** | |
80 | * Learn whether another UnaryFunctionUnaryPredicate is equal to this. | |
81 | * @param that UnaryFunctionUnaryPredicate to test | |
82 | * @return boolean | |
83 | */ | |
84 | public boolean equals(UnaryFunctionUnaryPredicate<?> that) { | |
85 | 22 | return null != that && (null == function ? null == that.function : function.equals(that.function)); |
86 | } | |
87 | ||
88 | /** | |
89 | * {@inheritDoc} | |
90 | */ | |
91 | public int hashCode() { | |
92 | 44 | int hash = "UnaryFunctionUnaryPredicate".hashCode(); |
93 | 44 | if (null != function) { |
94 | 44 | hash ^= function.hashCode(); |
95 | } | |
96 | 44 | return hash; |
97 | } | |
98 | ||
99 | /** | |
100 | * {@inheritDoc} | |
101 | */ | |
102 | public String toString() { | |
103 | 36 | return "UnaryFunctionUnaryPredicate<" + function + ">"; |
104 | } | |
105 | ||
106 | /** | |
107 | * Adapt the given, possibly-<code>null</code>, | |
108 | * {@link UnaryFunction UnaryFunction} to the | |
109 | * {@link UnaryPredicate UnaryPredicate} interface. | |
110 | * When the given <code>UnaryFunction</code> is <code>null</code>, | |
111 | * returns <code>null</code>. | |
112 | * | |
113 | * @param <A> the argument type. | |
114 | * @param function the possibly-<code>null</code> | |
115 | * {@link UnaryFunction UnaryFunction} to adapt | |
116 | * @return a {@link UnaryPredicate UnaryPredicate} wrapping the given | |
117 | * {@link UnaryFunction UnaryFunction}, or <code>null</code> | |
118 | * if the given <code>UnaryFunction</code> is <code>null</code> | |
119 | */ | |
120 | public static <A> UnaryFunctionUnaryPredicate<A> adapt(UnaryFunction<? super A, Boolean> function) { | |
121 | 6 | return null == function ? null : new UnaryFunctionUnaryPredicate<A>(function); |
122 | } | |
123 | ||
124 | } |