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