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.BinaryProcedure;
22 import org.apache.commons.functor.Procedure;
23
24 /**
25 * Adapts a
26 * {@link BinaryProcedure BinaryProcedure}
27 * to the
28 * {@link Procedure Procedure} interface
29 * using a constant left-side argument.
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 objects are. Attempts to serialize
35 * an instance whose delegates are not
36 * <code>Serializable</code> will result in an exception.
37 *
38 * @version $Revision: 1156320 $ $Date: 2011-08-10 21:14:50 +0200 (Wed, 10 Aug 2011) $
39 * @author Matt Benson
40 */
41 public final class FullyBoundProcedure implements Procedure, Serializable {
42 /**
43 * serialVersionUID declaration.
44 */
45 private static final long serialVersionUID = -904891610081737737L;
46 /** The {@link BinaryProcedure BinaryProcedure} I'm wrapping. */
47 private final BinaryProcedure<Object, Object> procedure;
48 /** The left parameter to pass to {@code procedure}. */
49 private final Object left;
50 /** The right parameter to pass to {@code procedure}. */
51 private final Object right;
52
53 /**
54 * Create a new FullyBoundProcedure instance.
55 * @param <L> left type
56 * @param <R> right type
57 * @param procedure the procedure to adapt
58 * @param left the left argument to use
59 * @param right the right argument to use
60 */
61 @SuppressWarnings("unchecked")
62 public <L, R> FullyBoundProcedure(BinaryProcedure<? super L, ? super R> procedure, L left, R right) {
63 if (procedure == null) {
64 throw new IllegalArgumentException("BinaryProcedure argument was null");
65 }
66 this.procedure = (BinaryProcedure<Object, Object>) procedure;
67 this.left = left;
68 this.right = right;
69 }
70
71 /**
72 * {@inheritDoc}
73 */
74 public void run() {
75 procedure.run(left, right);
76 }
77
78 /**
79 * {@inheritDoc}
80 */
81 public boolean equals(Object that) {
82 return that == this || (that instanceof FullyBoundProcedure && equals((FullyBoundProcedure) that));
83 }
84
85 /**
86 * Learn whether another FullyBoundProcedure is equal to this.
87 * @param that FullyBoundProcedure to test
88 * @return boolean
89 */
90 public boolean equals(FullyBoundProcedure that) {
91 return null != that && (null == procedure ? null == that.procedure : procedure.equals(that.procedure))
92 && (null == left ? null == that.left : left.equals(that.left))
93 && (null == right ? null == that.right : right.equals(that.right));
94 }
95
96 /**
97 * {@inheritDoc}
98 */
99 public int hashCode() {
100 int hash = "FullyBoundProcedure".hashCode();
101 if (null != procedure) {
102 hash <<= 2;
103 hash ^= procedure.hashCode();
104 }
105 hash <<= 2;
106 if (null != left) {
107 hash ^= left.hashCode();
108 }
109 hash <<= 2;
110 if (null != right) {
111 hash ^= right.hashCode();
112 }
113 return hash;
114 }
115
116 /**
117 * {@inheritDoc}
118 */
119 public String toString() {
120 return "FullyBoundProcedure<" + procedure + "(" + left + ", " + right + ")>";
121 }
122
123 /**
124 * Adapt a BinaryProcedure to the Procedure interface.
125 * @param <L> left type
126 * @param <R> right type
127 * @param procedure to adapt
128 * @param left left side argument
129 * @param right right side argument
130 * @return FullyBoundProcedure
131 */
132 public static <L, R> FullyBoundProcedure bind(BinaryProcedure<? super L, ? super R> procedure, L left, R right) {
133 return null == procedure ? null : new FullyBoundProcedure(procedure, left, right);
134 }
135
136 }