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
018 package org.apache.commons.lang.mutable;
019
020 import java.io.Serializable;
021
022 import org.apache.commons.lang.BooleanUtils;
023
024 /**
025 * A mutable <code>boolean</code> wrapper.
026 *
027 * @see Boolean
028 * @since 2.2
029 * @author Apache Software Foundation
030 * @version $Id: MutableBoolean.java 491052 2006-12-29 17:16:37Z scolebourne $
031 */
032 public class MutableBoolean implements Mutable, Serializable, Comparable {
033
034 /**
035 * Required for serialization support.
036 *
037 * @see java.io.Serializable
038 */
039 private static final long serialVersionUID = -4830728138360036487L;
040
041 /** The mutable value. */
042 private boolean value;
043
044 /**
045 * Constructs a new MutableBoolean with the default value of false.
046 */
047 public MutableBoolean() {
048 super();
049 }
050
051 /**
052 * Constructs a new MutableBoolean with the specified value.
053 *
054 * @param value
055 * a value.
056 */
057 public MutableBoolean(boolean value) {
058 super();
059 this.value = value;
060 }
061
062 /**
063 * Constructs a new MutableBoolean with the specified value.
064 *
065 * @param value
066 * a value.
067 * @throws NullPointerException
068 * if the object is null
069 */
070 public MutableBoolean(Boolean value) {
071 super();
072 this.value = value.booleanValue();
073 }
074
075 // -----------------------------------------------------------------------
076 /**
077 * Returns the value of this MutableBoolean as a boolean.
078 *
079 * @return the boolean value represented by this object.
080 */
081 public boolean booleanValue() {
082 return value;
083 }
084
085 /**
086 * Compares this mutable to another in ascending order.
087 *
088 * @param obj
089 * the mutable to compare to
090 * @return zero if this object represents the same boolean value as the argument; a positive value if this object
091 * represents true and the argument represents false; and a negative value if this object represents false
092 * and the argument represents true
093 * @throws ClassCastException
094 * if the argument is not a MutableInt
095 */
096 public int compareTo(Object obj) {
097 MutableBoolean other = (MutableBoolean) obj;
098 boolean anotherVal = other.value;
099 return value == anotherVal ? 0 : (value ? 1 : -1);
100 }
101
102 // -----------------------------------------------------------------------
103 /**
104 * Compares this object to the specified object. The result is <code>true</code> if and only if the argument is
105 * not <code>null</code> and is an <code>MutableBoolean</code> object that contains the same
106 * <code>boolean</code> value as this object.
107 *
108 * @param obj
109 * the object to compare with.
110 * @return <code>true</code> if the objects are the same; <code>false</code> otherwise.
111 */
112 public boolean equals(Object obj) {
113 if (obj instanceof MutableBoolean) {
114 return value == ((MutableBoolean) obj).booleanValue();
115 }
116 return false;
117 }
118
119 // -----------------------------------------------------------------------
120 /**
121 * Gets the value as a Boolean instance.
122 *
123 * @return the value as a Boolean
124 */
125 public Object getValue() {
126 return BooleanUtils.toBooleanObject(this.value);
127 }
128
129 /**
130 * Returns a suitable hashcode for this mutable.
131 *
132 * @return the integer <code>1231</code> if this object represents <code>true</code>; returns the integer
133 * <code>1237</code> if this object represents <code>false</code>.
134 */
135 public int hashCode() {
136 return value ? Boolean.TRUE.hashCode() : Boolean.FALSE.hashCode();
137 }
138
139 /**
140 * Sets the value.
141 *
142 * @param value
143 * the value to set
144 */
145 public void setValue(boolean value) {
146 this.value = value;
147 }
148
149 /**
150 * Sets the value from any Boolean instance.
151 *
152 * @param value
153 * the value to set
154 * @throws NullPointerException
155 * if the object is null
156 * @throws ClassCastException
157 * if the type is not a {@link Boolean}
158 */
159 public void setValue(Object value) {
160 setValue(((Boolean) value).booleanValue());
161 }
162
163 /**
164 * Returns the String value of this mutable.
165 *
166 * @return the mutable value as a string
167 */
168 public String toString() {
169 return String.valueOf(value);
170 }
171
172 }