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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  
18  package org.apache.commons.lang3.mutable;
19  
20  import java.io.Serializable;
21  
22  /**
23   * A mutable <code>boolean</code> wrapper.
24   * <p>
25   * Note that as MutableBoolean does not extend Boolean, it is not treated by String.format as a Boolean parameter. 
26   * 
27   * @see Boolean
28   * @since 2.2
29   * @version $Id: MutableBoolean.java 1565915 2014-02-08 04:35:17Z ggregory $
30   */
31  public class MutableBoolean implements Mutable<Boolean>, Serializable, Comparable<MutableBoolean> {
32  
33      /**
34       * Required for serialization support.
35       * 
36       * @see java.io.Serializable
37       */
38      private static final long serialVersionUID = -4830728138360036487L;
39  
40      /** The mutable value. */
41      private boolean value;
42  
43      /**
44       * Constructs a new MutableBoolean with the default value of false.
45       */
46      public MutableBoolean() {
47          super();
48      }
49  
50      /**
51       * Constructs a new MutableBoolean with the specified value.
52       * 
53       * @param value  the initial value to store
54       */
55      public MutableBoolean(final boolean value) {
56          super();
57          this.value = value;
58      }
59  
60      /**
61       * Constructs a new MutableBoolean with the specified value.
62       * 
63       * @param value  the initial value to store, not null
64       * @throws NullPointerException if the object is null
65       */
66      public MutableBoolean(final Boolean value) {
67          super();
68          this.value = value.booleanValue();
69      }
70  
71      //-----------------------------------------------------------------------
72      /**
73       * Gets the value as a Boolean instance.
74       * 
75       * @return the value as a Boolean, never null
76       */
77      @Override
78      public Boolean getValue() {
79          return Boolean.valueOf(this.value);
80      }
81  
82      /**
83       * Sets the value.
84       * 
85       * @param value  the value to set
86       */
87      public void setValue(final boolean value) {
88          this.value = value;
89      }
90  
91      /**
92       * Sets the value to true.
93       * 
94       * @since 3.3
95       */
96      public void setFalse() {
97          this.value = false;
98      }
99  
100     /**
101      * Sets the value to false.
102      * 
103      * @since 3.3
104      */
105     public void setTrue() {
106         this.value = true;
107     }
108 
109     /**
110      * Sets the value from any Boolean instance.
111      * 
112      * @param value  the value to set, not null
113      * @throws NullPointerException if the object is null
114      */
115     @Override
116     public void setValue(final Boolean value) {
117         this.value = value.booleanValue();
118     }
119 
120     //-----------------------------------------------------------------------
121     /**
122      * Checks if the current value is <code>true</code>.
123      * 
124      * @return <code>true</code> if the current value is <code>true</code>
125      * @since 2.5
126      */
127     public boolean isTrue() {
128         return value == true;
129     }
130 
131     /**
132      * Checks if the current value is <code>false</code>.
133      * 
134      * @return <code>true</code> if the current value is <code>false</code>
135      * @since 2.5
136      */
137     public boolean isFalse() {
138         return value == false;
139     }
140 
141     //-----------------------------------------------------------------------
142     /**
143      * Returns the value of this MutableBoolean as a boolean.
144      * 
145      * @return the boolean value represented by this object.
146      */
147     public boolean booleanValue() {
148         return value;
149     }
150 
151     //-----------------------------------------------------------------------
152     /**
153      * Gets this mutable as an instance of Boolean.
154      *
155      * @return a Boolean instance containing the value from this mutable, never null
156      * @since 2.5
157      */
158     public Boolean toBoolean() {
159         return Boolean.valueOf(booleanValue());
160     }
161 
162     //-----------------------------------------------------------------------
163     /**
164      * Compares this object to the specified object. The result is <code>true</code> if and only if the argument is
165      * not <code>null</code> and is an <code>MutableBoolean</code> object that contains the same
166      * <code>boolean</code> value as this object.
167      * 
168      * @param obj  the object to compare with, null returns false
169      * @return <code>true</code> if the objects are the same; <code>false</code> otherwise.
170      */
171     @Override
172     public boolean equals(final Object obj) {
173         if (obj instanceof MutableBoolean) {
174             return value == ((MutableBoolean) obj).booleanValue();
175         }
176         return false;
177     }
178 
179     /**
180      * Returns a suitable hash code for this mutable.
181      * 
182      * @return the hash code returned by <code>Boolean.TRUE</code> or <code>Boolean.FALSE</code>
183      */
184     @Override
185     public int hashCode() {
186         return value ? Boolean.TRUE.hashCode() : Boolean.FALSE.hashCode();
187     }
188 
189     //-----------------------------------------------------------------------
190     /**
191      * Compares this mutable to another in ascending order.
192      * 
193      * @param other  the other mutable to compare to, not null
194      * @return negative if this is less, zero if equal, positive if greater
195      *  where false is less than true
196      */
197     @Override
198     public int compareTo(final MutableBoolean other) {
199         final boolean anotherVal = other.value;
200         return value == anotherVal ? 0 : (value ? 1 : -1);
201     }
202 
203     //-----------------------------------------------------------------------
204     /**
205      * Returns the String value of this mutable.
206      * 
207      * @return the mutable value as a string
208      */
209     @Override
210     public String toString() {
211         return String.valueOf(value);
212     }
213 
214 }