Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
BinaryFunctionBinaryPredicate |
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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.BinaryFunction; | |
22 | import org.apache.commons.functor.BinaryPredicate; | |
23 | ||
24 | /** | |
25 | * Adapts a <code>Boolean</code>-valued {@link BinaryFunction BinaryFunction} to | |
26 | * the {@link BinaryPredicate BinaryPredicate} interface. <p> Note that although | |
27 | * this class implements {@link Serializable}, a given instance will only be | |
28 | * truly <code>Serializable</code> if the underlying functor is. Attempts to | |
29 | * serialize an instance whose delegate is not <code>Serializable</code> will | |
30 | * result in an exception. </p> | |
31 | * @param <L> the left argument type. | |
32 | * @param <R> the right argument type. | |
33 | * @version $Revision: 1156745 $ $Date: 2011-08-11 21:08:49 +0200 (Thu, 11 Aug 2011) $ | |
34 | * @author Rodney Waldhoff | |
35 | */ | |
36 | public final class BinaryFunctionBinaryPredicate<L, R> implements BinaryPredicate<L, R>, Serializable { | |
37 | /** | |
38 | * serialVersionUID declaration. | |
39 | */ | |
40 | private static final long serialVersionUID = -5150315320718936186L; | |
41 | /** The {@link BinaryFunction BinaryFunction} I'm wrapping. */ | |
42 | private final BinaryFunction<? super L, ? super R, Boolean> function; | |
43 | ||
44 | /** | |
45 | * Create an {@link BinaryPredicate BinaryPredicate} wrapping the given | |
46 | * {@link BinaryFunction BinaryFunction}. | |
47 | * @param function the {@link BinaryFunction BinaryFunction} to wrap | |
48 | */ | |
49 | 32 | public BinaryFunctionBinaryPredicate(final BinaryFunction<? super L, ? super R, Boolean> function) { |
50 | 32 | if (function == null) { |
51 | 0 | throw new IllegalArgumentException("BinaryFunction argument must not be null"); |
52 | } | |
53 | 32 | this.function = function; |
54 | 32 | } |
55 | ||
56 | /** | |
57 | * {@inheritDoc} Returns the <code>boolean</code> value of the | |
58 | * non-<code>null</code> <code>Boolean</code> returned by the | |
59 | * {@link BinaryFunction#evaluate evaluate} method of my underlying | |
60 | * function. | |
61 | * | |
62 | * The mehod throws NullPointerException if the underlying function returns | |
63 | * <code>null</code>, and | |
64 | * ClassCastException if the underlying function returns a | |
65 | * non-<code>Boolean</code> | |
66 | */ | |
67 | public boolean test(final L left, final R right) { | |
68 | 44 | return function.evaluate(left, right); |
69 | } | |
70 | ||
71 | /** | |
72 | * {@inheritDoc} | |
73 | */ | |
74 | public boolean equals(final Object that) { | |
75 | 56 | return that == this |
76 | || (that instanceof BinaryFunctionBinaryPredicate<?, ?> | |
77 | && equals((BinaryFunctionBinaryPredicate<?, ?>) that)); | |
78 | } | |
79 | ||
80 | /** | |
81 | * Learn whether another BinaryFunctionBinaryPredicate is equal to this. | |
82 | * @param that BinaryFunctionBinaryPredicate to test | |
83 | * @return boolean | |
84 | */ | |
85 | public boolean equals(final BinaryFunctionBinaryPredicate<?, ?> that) { | |
86 | 20 | return null != that && (null == function ? null == that.function : function.equals(that.function)); |
87 | } | |
88 | ||
89 | /** | |
90 | * {@inheritDoc} | |
91 | */ | |
92 | public int hashCode() { | |
93 | 66 | int hash = "BinaryFunctionBinaryPredicate".hashCode(); |
94 | 66 | if (null != function) { |
95 | 66 | hash ^= function.hashCode(); |
96 | } | |
97 | 66 | return hash; |
98 | } | |
99 | ||
100 | /** | |
101 | * {@inheritDoc} | |
102 | */ | |
103 | public String toString() { | |
104 | 50 | return "BinaryFunctionBinaryPredicate<" + function + ">"; |
105 | } | |
106 | ||
107 | /** | |
108 | * Adapt the given, possibly-<code>null</code>, {@link BinaryFunction | |
109 | * BinaryFunction} to the {@link BinaryPredicate BinaryPredicate} interface. | |
110 | * When the given <code>BinaryFunction</code> is <code>null</code>, returns | |
111 | * <code>null</code>. | |
112 | * | |
113 | * @param <L> left type | |
114 | * @param <R> right type | |
115 | * @param <T> result type | |
116 | * @param function the possibly-<code>null</code> {@link BinaryFunction | |
117 | * BinaryFunction} to adapt | |
118 | * @return a <code>BinaryFunctionBinaryPredicate</code> wrapping the given | |
119 | * {@link BinaryFunction BinaryFunction}, or <code>null</code> if the given | |
120 | * <code>BinaryFunction</code> is <code>null</code> | |
121 | */ | |
122 | public static <L, R, T> BinaryFunctionBinaryPredicate<L, R> adapt( | |
123 | final BinaryFunction<? super L, ? super R, Boolean> function) { | |
124 | 12 | return null == function ? null : new BinaryFunctionBinaryPredicate<L, R>(function); |
125 | } | |
126 | ||
127 | } |