001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.commons.functor.adapter;
018
019 import java.io.Serializable;
020
021 import org.apache.commons.functor.BinaryProcedure;
022 import org.apache.commons.functor.Procedure;
023
024 /**
025 * Adapts a
026 * {@link BinaryProcedure BinaryProcedure}
027 * to the
028 * {@link Procedure Procedure} interface
029 * using a constant left-side argument.
030 * <p/>
031 * Note that although this class implements
032 * {@link Serializable}, a given instance will
033 * only be truly <code>Serializable</code> if the
034 * underlying objects are. Attempts to serialize
035 * an instance whose delegates are not
036 * <code>Serializable</code> will result in an exception.
037 *
038 * @version $Revision: 1156320 $ $Date: 2011-08-10 21:14:50 +0200 (Wed, 10 Aug 2011) $
039 * @author Matt Benson
040 */
041 public final class FullyBoundProcedure implements Procedure, Serializable {
042 /**
043 * serialVersionUID declaration.
044 */
045 private static final long serialVersionUID = -904891610081737737L;
046 /** The {@link BinaryProcedure BinaryProcedure} I'm wrapping. */
047 private final BinaryProcedure<Object, Object> procedure;
048 /** The left parameter to pass to {@code procedure}. */
049 private final Object left;
050 /** The right parameter to pass to {@code procedure}. */
051 private final Object right;
052
053 /**
054 * Create a new FullyBoundProcedure instance.
055 * @param <L> left type
056 * @param <R> right type
057 * @param procedure the procedure to adapt
058 * @param left the left argument to use
059 * @param right the right argument to use
060 */
061 @SuppressWarnings("unchecked")
062 public <L, R> FullyBoundProcedure(BinaryProcedure<? super L, ? super R> procedure, L left, R right) {
063 if (procedure == null) {
064 throw new IllegalArgumentException("BinaryProcedure argument was null");
065 }
066 this.procedure = (BinaryProcedure<Object, Object>) procedure;
067 this.left = left;
068 this.right = right;
069 }
070
071 /**
072 * {@inheritDoc}
073 */
074 public void run() {
075 procedure.run(left, right);
076 }
077
078 /**
079 * {@inheritDoc}
080 */
081 public boolean equals(Object that) {
082 return that == this || (that instanceof FullyBoundProcedure && equals((FullyBoundProcedure) that));
083 }
084
085 /**
086 * Learn whether another FullyBoundProcedure is equal to this.
087 * @param that FullyBoundProcedure to test
088 * @return boolean
089 */
090 public boolean equals(FullyBoundProcedure that) {
091 return null != that && (null == procedure ? null == that.procedure : procedure.equals(that.procedure))
092 && (null == left ? null == that.left : left.equals(that.left))
093 && (null == right ? null == that.right : right.equals(that.right));
094 }
095
096 /**
097 * {@inheritDoc}
098 */
099 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 }