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.lang3.mutable;
019    
020    import java.io.Serializable;
021    
022    /**
023     * A mutable <code>boolean</code> wrapper.
024     * <p>
025     * Note that as MutableBoolean does not extend Boolean, it is not treated by String.format as a Boolean parameter. 
026     * 
027     * @see Boolean
028     * @since 2.2
029     * @version $Id: MutableBoolean.java 1160571 2011-08-23 07:36:08Z bayard $
030     */
031    public class MutableBoolean implements Mutable<Boolean>, Serializable, Comparable<MutableBoolean> {
032    
033        /**
034         * Required for serialization support.
035         * 
036         * @see java.io.Serializable
037         */
038        private static final long serialVersionUID = -4830728138360036487L;
039    
040        /** The mutable value. */
041        private boolean value;
042    
043        /**
044         * Constructs a new MutableBoolean with the default value of false.
045         */
046        public MutableBoolean() {
047            super();
048        }
049    
050        /**
051         * Constructs a new MutableBoolean with the specified value.
052         * 
053         * @param value  the initial value to store
054         */
055        public MutableBoolean(boolean value) {
056            super();
057            this.value = value;
058        }
059    
060        /**
061         * Constructs a new MutableBoolean with the specified value.
062         * 
063         * @param value  the initial value to store, not null
064         * @throws NullPointerException if the object is null
065         */
066        public MutableBoolean(Boolean value) {
067            super();
068            this.value = value.booleanValue();
069        }
070    
071        //-----------------------------------------------------------------------
072        /**
073         * Gets the value as a Boolean instance.
074         * 
075         * @return the value as a Boolean, never null
076         */
077        public Boolean getValue() {
078            return Boolean.valueOf(this.value);
079        }
080    
081        /**
082         * Sets the value.
083         * 
084         * @param value  the value to set
085         */
086        public void setValue(boolean value) {
087            this.value = value;
088        }
089    
090        /**
091         * Sets the value from any Boolean instance.
092         * 
093         * @param value  the value to set, not null
094         * @throws NullPointerException if the object is null
095         */
096        public void setValue(Boolean value) {
097            this.value = value.booleanValue();
098        }
099    
100        //-----------------------------------------------------------------------
101        /**
102         * Checks if the current value is <code>true</code>.
103         * 
104         * @return <code>true</code> if the current value is <code>true</code>
105         * @since 2.5
106         */
107        public boolean isTrue() {
108            return value == true;
109        }
110    
111        /**
112         * Checks if the current value is <code>false</code>.
113         * 
114         * @return <code>true</code> if the current value is <code>false</code>
115         * @since 2.5
116         */
117        public boolean isFalse() {
118            return value == false;
119        }
120    
121        //-----------------------------------------------------------------------
122        /**
123         * Returns the value of this MutableBoolean as a boolean.
124         * 
125         * @return the boolean value represented by this object.
126         */
127        public boolean booleanValue() {
128            return value;
129        }
130    
131        //-----------------------------------------------------------------------
132        /**
133         * Gets this mutable as an instance of Boolean.
134         *
135         * @return a Boolean instance containing the value from this mutable, never null
136         * @since 2.5
137         */
138        public Boolean toBoolean() {
139            return Boolean.valueOf(booleanValue());
140        }
141    
142        //-----------------------------------------------------------------------
143        /**
144         * Compares this object to the specified object. The result is <code>true</code> if and only if the argument is
145         * not <code>null</code> and is an <code>MutableBoolean</code> object that contains the same
146         * <code>boolean</code> value as this object.
147         * 
148         * @param obj  the object to compare with, null returns false
149         * @return <code>true</code> if the objects are the same; <code>false</code> otherwise.
150         */
151        @Override
152        public boolean equals(Object obj) {
153            if (obj instanceof MutableBoolean) {
154                return value == ((MutableBoolean) obj).booleanValue();
155            }
156            return false;
157        }
158    
159        /**
160         * Returns a suitable hash code for this mutable.
161         * 
162         * @return the hash code returned by <code>Boolean.TRUE</code> or <code>Boolean.FALSE</code>
163         */
164        @Override
165        public int hashCode() {
166            return value ? Boolean.TRUE.hashCode() : Boolean.FALSE.hashCode();
167        }
168    
169        //-----------------------------------------------------------------------
170        /**
171         * Compares this mutable to another in ascending order.
172         * 
173         * @param other  the other mutable to compare to, not null
174         * @return negative if this is less, zero if equal, positive if greater
175         *  where false is less than true
176         */
177        public int compareTo(MutableBoolean other) {
178            boolean anotherVal = other.value;
179            return value == anotherVal ? 0 : (value ? 1 : -1);
180        }
181    
182        //-----------------------------------------------------------------------
183        /**
184         * Returns the String value of this mutable.
185         * 
186         * @return the mutable value as a string
187         */
188        @Override
189        public String toString() {
190            return String.valueOf(value);
191        }
192    
193    }