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.core.composite;
18
19 import org.apache.commons.functor.Predicate;
20 import org.apache.commons.functor.Procedure;
21 import org.apache.commons.lang3.Validate;
22
23 import java.io.Serializable;
24
25 /**
26 * Abstract base class for {@link WhileDoProcedure} and {@link DoWhileProcedure}
27 * used to implement loop procedures.
28 * <p>
29 * @version $Revision: 1365329 $ $Date: 2012-07-24 19:34:23 -0300 (Tue, 24 Jul 2012) $
30 */
31 public abstract class AbstractLoopProcedure implements Procedure, Serializable {
32 /**
33 * serialVersionUID declaration.
34 */
35 private static final long serialVersionUID = -5903381842630236070L;
36
37 /** Base hash integer used to shift hash. */
38 private static final int HASH_SHIFT = 4;
39
40 /**
41 * The condition has to be verified that while true,
42 * forces the action repetition.
43 */
44 private final Predicate condition;
45
46 /**
47 * The action to be repeated until the condition is true.
48 */
49 private final Procedure action;
50
51 /**
52 * Create a new AbstractLoopProcedure.
53 * @param condition while true, repeat
54 * @param action loop body
55 */
56 protected AbstractLoopProcedure(Predicate condition, Procedure action) {
57 this.condition = Validate.notNull(condition, "Predicate argument must not be null");
58 this.action = Validate.notNull(action, "Predicate argument must not be null");
59 }
60
61 /**
62 * {@inheritDoc}
63 */
64 @Override
65 public final boolean equals(Object object) {
66 if (object == this) {
67 return true;
68 }
69 if (!(object instanceof AbstractLoopProcedure)) {
70 return false;
71 }
72 AbstractLoopProcedure that = (AbstractLoopProcedure) object;
73 return (getCondition().equals(that.getCondition())
74 && (getAction().equals(that.getAction())));
75 }
76
77 /**
78 * {@inheritDoc}
79 */
80 @Override
81 public int hashCode() {
82 return hashCode("AbstractLoopProcedure".hashCode());
83 }
84
85 /**
86 * {@inheritDoc}
87 */
88 @Override
89 public String toString() {
90 return getClass().getName() + "<" + getCondition() + "," + getAction() + ">";
91 }
92
93 /**
94 * Create a hashCode by manipulating an input hashCode and factoring in instance state.
95 * @param hash incoming hashCode
96 * @return int
97 */
98 protected int hashCode(int hash) {
99 hash <<= HASH_SHIFT;
100 hash ^= getAction().hashCode();
101 hash <<= HASH_SHIFT;
102 hash ^= getCondition().hashCode();
103 return hash;
104 }
105
106 /**
107 * Get the condition.
108 * @return Predicate
109 */
110 protected final Predicate getCondition() {
111 return condition;
112 }
113
114 /**
115 * Get the action.
116 * @return Procedure
117 */
118 protected final Procedure getAction() {
119 return action;
120 }
121
122 }