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.BinaryProcedure;
23 import org.apache.commons.lang3.Validate;
24
25 /**
26 * Adapts a {@link BinaryFunction BinaryFunction}
27 * to the {@link BinaryProcedure BinaryProcedure}
28 * interface by ignoring the value returned
29 * by the function.
30 * <p/>
31 * Note that although this class implements
32 * {@link Serializable}, a given instance will
33 * only be truly <code>Serializable</code> if the
34 * underlying function is. Attempts to serialize
35 * an instance whose delegate is not
36 * <code>Serializable</code> will result in an exception.
37 *
38 * @param <L> the left argument type.
39 * @param <R> the right argument type.
40 * @version $Revision: 1365377 $ $Date: 2012-07-24 21:59:23 -0300 (Tue, 24 Jul 2012) $
41 */
42 public final class BinaryFunctionBinaryProcedure<L, R> implements BinaryProcedure<L, R>, Serializable {
43
44 /**
45 * serialVersionUID declaration.
46 */
47 private static final long serialVersionUID = 4498276997127058865L;
48 /** The {@link BinaryFunction BinaryFunction} I'm wrapping. */
49 private final BinaryFunction<? super L, ? super R, ?> function;
50
51 /**
52 * Create an {@link BinaryProcedure BinaryProcedure} wrapping
53 * the given {@link BinaryFunction BinaryFunction}.
54 * @param function the {@link BinaryFunction BinaryFunction} to wrap
55 */
56 public BinaryFunctionBinaryProcedure(BinaryFunction<? super L, ? super R, ?> function) {
57 this.function = Validate.notNull(function, "BinaryFunction argument was null");
58 }
59
60 /**
61 * {@link BinaryFunction#evaluate Evaluate} my function, but
62 * ignore its returned value.
63 * {@inheritDoc}
64 */
65 public void run(L left, R right) {
66 function.evaluate(left, right);
67 }
68
69 /**
70 * {@inheritDoc}
71 */
72 @Override
73 public boolean equals(Object that) {
74 return that == this
75 || (that instanceof BinaryFunctionBinaryProcedure<?, ?>
76 && equals((BinaryFunctionBinaryProcedure<?, ?>) that));
77 }
78
79 /**
80 * Learn whether a given BinaryFunctionBinaryPredicate is equal to this.
81 * @param that BinaryFunctionBinaryPredicate to compare
82 * @return boolean
83 */
84 public boolean equals(BinaryFunctionBinaryProcedure<?, ?> that) {
85 return null != that && function.equals(that.function);
86 }
87
88 /**
89 * {@inheritDoc}
90 */
91 @Override
92 public int hashCode() {
93 int hash = "BinaryFunctionBinaryProcedure".hashCode();
94 hash ^= function.hashCode();
95 return hash;
96 }
97
98 /**
99 * {@inheritDoc}
100 */
101 @Override
102 public String toString() {
103 return "BinaryFunctionBinaryProcedure<" + function + ">";
104 }
105
106 /**
107 * Adapt the given, possibly-<code>null</code>,
108 * {@link BinaryFunction BinaryFunction} to the
109 * {@link BinaryProcedure BinaryProcedure} interface.
110 * When the given <code>BinaryFunction</code> is <code>null</code>,
111 * returns <code>null</code>.
112 *
113 * @param <L> left type
114 * @param <R> right type
115 * @param function the possibly-<code>null</code>
116 * {@link BinaryFunction BinaryFunction} to adapt
117 * @return a <code>BinaryFunctionBinaryProcedure</code> wrapping the given
118 * {@link BinaryFunction BinaryFunction}, or <code>null</code>
119 * if the given <code>BinaryFunction</code> is <code>null</code>
120 */
121 public static <L, R> BinaryFunctionBinaryProcedure<L, R> adapt(BinaryFunction<? super L, ? super R, ?> function) {
122 return null == function ? null : new BinaryFunctionBinaryProcedure<L, R>(function);
123 }
124
125 }