View Javadoc
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   * @version $Id: MutableBoolean.java 1669791 2015-03-28 15:22:59Z britter $
32   */
33  public class MutableBoolean implements Mutable<Boolean>, Serializable, Comparable<MutableBoolean> {
34  
35      /**
36       * Required for serialization support.
37       * 
38       * @see java.io.Serializable
39       */
40      private static final long serialVersionUID = -4830728138360036487L;
41  
42      /** The mutable value. */
43      private boolean value;
44  
45      /**
46       * Constructs a new MutableBoolean with the default value of false.
47       */
48      public MutableBoolean() {
49          super();
50      }
51  
52      /**
53       * Constructs a new MutableBoolean with the specified value.
54       * 
55       * @param value  the initial value to store
56       */
57      public MutableBoolean(final boolean value) {
58          super();
59          this.value = value;
60      }
61  
62      /**
63       * Constructs a new MutableBoolean with the specified value.
64       * 
65       * @param value  the initial value to store, not null
66       * @throws NullPointerException if the object is null
67       */
68      public MutableBoolean(final Boolean value) {
69          super();
70          this.value = value.booleanValue();
71      }
72  
73      //-----------------------------------------------------------------------
74      /**
75       * Gets the value as a Boolean instance.
76       * 
77       * @return the value as a Boolean, never null
78       */
79      @Override
80      public Boolean getValue() {
81          return Boolean.valueOf(this.value);
82      }
83  
84      /**
85       * Sets the value.
86       * 
87       * @param value  the value to set
88       */
89      public void setValue(final boolean value) {
90          this.value = value;
91      }
92  
93      /**
94       * Sets the value to true.
95       * 
96       * @since 3.3
97       */
98      public void setFalse() {
99          this.value = false;
100     }
101 
102     /**
103      * Sets the value to false.
104      * 
105      * @since 3.3
106      */
107     public void setTrue() {
108         this.value = true;
109     }
110 
111     /**
112      * Sets the value from any Boolean instance.
113      * 
114      * @param value  the value to set, not null
115      * @throws NullPointerException if the object is null
116      */
117     @Override
118     public void setValue(final Boolean value) {
119         this.value = value.booleanValue();
120     }
121 
122     //-----------------------------------------------------------------------
123     /**
124      * Checks if the current value is <code>true</code>.
125      * 
126      * @return <code>true</code> if the current value is <code>true</code>
127      * @since 2.5
128      */
129     public boolean isTrue() {
130         return value == true;
131     }
132 
133     /**
134      * Checks if the current value is <code>false</code>.
135      * 
136      * @return <code>true</code> if the current value is <code>false</code>
137      * @since 2.5
138      */
139     public boolean isFalse() {
140         return value == false;
141     }
142 
143     //-----------------------------------------------------------------------
144     /**
145      * Returns the value of this MutableBoolean as a boolean.
146      * 
147      * @return the boolean value represented by this object.
148      */
149     public boolean booleanValue() {
150         return value;
151     }
152 
153     //-----------------------------------------------------------------------
154     /**
155      * Gets this mutable as an instance of Boolean.
156      *
157      * @return a Boolean instance containing the value from this mutable, never null
158      * @since 2.5
159      */
160     public Boolean toBoolean() {
161         return Boolean.valueOf(booleanValue());
162     }
163 
164     //-----------------------------------------------------------------------
165     /**
166      * Compares this object to the specified object. The result is <code>true</code> if and only if the argument is
167      * not <code>null</code> and is an <code>MutableBoolean</code> object that contains the same
168      * <code>boolean</code> value as this object.
169      * 
170      * @param obj  the object to compare with, null returns false
171      * @return <code>true</code> if the objects are the same; <code>false</code> otherwise.
172      */
173     @Override
174     public boolean equals(final Object obj) {
175         if (obj instanceof MutableBoolean) {
176             return value == ((MutableBoolean) obj).booleanValue();
177         }
178         return false;
179     }
180 
181     /**
182      * Returns a suitable hash code for this mutable.
183      * 
184      * @return the hash code returned by <code>Boolean.TRUE</code> or <code>Boolean.FALSE</code>
185      */
186     @Override
187     public int hashCode() {
188         return value ? Boolean.TRUE.hashCode() : Boolean.FALSE.hashCode();
189     }
190 
191     //-----------------------------------------------------------------------
192     /**
193      * Compares this mutable to another in ascending order.
194      * 
195      * @param other  the other mutable to compare to, not null
196      * @return negative if this is less, zero if equal, positive if greater
197      *  where false is less than true
198      */
199     @Override
200     public int compareTo(final MutableBoolean other) {
201         return BooleanUtils.compare(this.value, other.value);
202     }
203 
204     //-----------------------------------------------------------------------
205     /**
206      * Returns the String value of this mutable.
207      * 
208      * @return the mutable value as a string
209      */
210     @Override
211     public String toString() {
212         return String.valueOf(value);
213     }
214 
215 }