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 package org.apache.commons.lang3.mutable;
018
019 /**
020 * A mutable <code>float</code> wrapper.
021 *
022 * @see Float
023 * @since 2.1
024 * @version $Id: MutableFloat.java 1096472 2011-04-25 13:28:06Z mbenson $
025 */
026 public class MutableFloat extends Number implements Comparable<MutableFloat>, Mutable<Number> {
027
028 /**
029 * Required for serialization support.
030 *
031 * @see java.io.Serializable
032 */
033 private static final long serialVersionUID = 5787169186L;
034
035 /** The mutable value. */
036 private float value;
037
038 /**
039 * Constructs a new MutableFloat with the default value of zero.
040 */
041 public MutableFloat() {
042 super();
043 }
044
045 /**
046 * Constructs a new MutableFloat with the specified value.
047 *
048 * @param value the initial value to store
049 */
050 public MutableFloat(float value) {
051 super();
052 this.value = value;
053 }
054
055 /**
056 * Constructs a new MutableFloat with the specified value.
057 *
058 * @param value the initial value to store, not null
059 * @throws NullPointerException if the object is null
060 */
061 public MutableFloat(Number value) {
062 super();
063 this.value = value.floatValue();
064 }
065
066 /**
067 * Constructs a new MutableFloat parsing the given string.
068 *
069 * @param value the string to parse, not null
070 * @throws NumberFormatException if the string cannot be parsed into a float
071 * @since 2.5
072 */
073 public MutableFloat(String value) throws NumberFormatException {
074 super();
075 this.value = Float.parseFloat(value);
076 }
077
078 //-----------------------------------------------------------------------
079 /**
080 * Gets the value as a Float instance.
081 *
082 * @return the value as a Float, never null
083 */
084 public Float getValue() {
085 return new Float(this.value);
086 }
087
088 /**
089 * Sets the value.
090 *
091 * @param value the value to set
092 */
093 public void setValue(float value) {
094 this.value = value;
095 }
096
097 /**
098 * Sets the value from any Number instance.
099 *
100 * @param value the value to set, not null
101 * @throws NullPointerException if the object is null
102 */
103 public void setValue(Number value) {
104 this.value = value.floatValue();
105 }
106
107 //-----------------------------------------------------------------------
108 /**
109 * Checks whether the float value is the special NaN value.
110 *
111 * @return true if NaN
112 */
113 public boolean isNaN() {
114 return Float.isNaN(value);
115 }
116
117 /**
118 * Checks whether the float value is infinite.
119 *
120 * @return true if infinite
121 */
122 public boolean isInfinite() {
123 return Float.isInfinite(value);
124 }
125
126 //-----------------------------------------------------------------------
127 /**
128 * Increments the value.
129 *
130 * @since Commons Lang 2.2
131 */
132 public void increment() {
133 value++;
134 }
135
136 /**
137 * Decrements the value.
138 *
139 * @since Commons Lang 2.2
140 */
141 public void decrement() {
142 value--;
143 }
144
145 //-----------------------------------------------------------------------
146 /**
147 * Adds a value to the value of this instance.
148 *
149 * @param operand the value to add, not null
150 * @since Commons Lang 2.2
151 */
152 public void add(float operand) {
153 this.value += operand;
154 }
155
156 /**
157 * Adds a value to the value of this instance.
158 *
159 * @param operand the value to add, not null
160 * @throws NullPointerException if the object is null
161 * @since Commons Lang 2.2
162 */
163 public void add(Number operand) {
164 this.value += operand.floatValue();
165 }
166
167 /**
168 * Subtracts a value from the value of this instance.
169 *
170 * @param operand the value to subtract
171 * @since Commons Lang 2.2
172 */
173 public void subtract(float operand) {
174 this.value -= operand;
175 }
176
177 /**
178 * Subtracts a value from the value of this instance.
179 *
180 * @param operand the value to subtract, not null
181 * @throws NullPointerException if the object is null
182 * @since Commons Lang 2.2
183 */
184 public void subtract(Number operand) {
185 this.value -= operand.floatValue();
186 }
187
188 //-----------------------------------------------------------------------
189 // shortValue and byteValue rely on Number implementation
190 /**
191 * Returns the value of this MutableFloat as an int.
192 *
193 * @return the numeric value represented by this object after conversion to type int.
194 */
195 @Override
196 public int intValue() {
197 return (int) value;
198 }
199
200 /**
201 * Returns the value of this MutableFloat as a long.
202 *
203 * @return the numeric value represented by this object after conversion to type long.
204 */
205 @Override
206 public long longValue() {
207 return (long) value;
208 }
209
210 /**
211 * Returns the value of this MutableFloat as a float.
212 *
213 * @return the numeric value represented by this object after conversion to type float.
214 */
215 @Override
216 public float floatValue() {
217 return value;
218 }
219
220 /**
221 * Returns the value of this MutableFloat as a double.
222 *
223 * @return the numeric value represented by this object after conversion to type double.
224 */
225 @Override
226 public double doubleValue() {
227 return value;
228 }
229
230 //-----------------------------------------------------------------------
231 /**
232 * Gets this mutable as an instance of Float.
233 *
234 * @return a Float instance containing the value from this mutable, never null
235 */
236 public Float toFloat() {
237 return Float.valueOf(floatValue());
238 }
239
240 //-----------------------------------------------------------------------
241 /**
242 * Compares this object against some other object. The result is <code>true</code> if and only if the argument is
243 * not <code>null</code> and is a <code>Float</code> object that represents a <code>float</code> that has the
244 * identical bit pattern to the bit pattern of the <code>float</code> represented by this object. For this
245 * purpose, two float values are considered to be the same if and only if the method
246 * {@link Float#floatToIntBits(float)}returns the same int value when applied to each.
247 * <p>
248 * Note that in most cases, for two instances of class <code>Float</code>,<code>f1</code> and <code>f2</code>,
249 * the value of <code>f1.equals(f2)</code> is <code>true</code> if and only if <blockquote>
250 *
251 * <pre>
252 * f1.floatValue() == f2.floatValue()
253 * </pre>
254 *
255 * </blockquote>
256 * <p>
257 * also has the value <code>true</code>. However, there are two exceptions:
258 * <ul>
259 * <li>If <code>f1</code> and <code>f2</code> both represent <code>Float.NaN</code>, then the
260 * <code>equals</code> method returns <code>true</code>, even though <code>Float.NaN==Float.NaN</code> has
261 * the value <code>false</code>.
262 * <li>If <code>f1</code> represents <code>+0.0f</code> while <code>f2</code> represents <code>-0.0f</code>,
263 * or vice versa, the <code>equal</code> test has the value <code>false</code>, even though
264 * <code>0.0f==-0.0f</code> has the value <code>true</code>.
265 * </ul>
266 * This definition allows hashtables to operate properly.
267 *
268 * @param obj the object to compare with, null returns false
269 * @return <code>true</code> if the objects are the same; <code>false</code> otherwise.
270 * @see java.lang.Float#floatToIntBits(float)
271 */
272 @Override
273 public boolean equals(Object obj) {
274 return (obj instanceof MutableFloat)
275 && (Float.floatToIntBits(((MutableFloat) obj).value) == Float.floatToIntBits(value));
276 }
277
278 /**
279 * Returns a suitable hash code for this mutable.
280 *
281 * @return a suitable hash code
282 */
283 @Override
284 public int hashCode() {
285 return Float.floatToIntBits(value);
286 }
287
288 //-----------------------------------------------------------------------
289 /**
290 * Compares this mutable to another in ascending order.
291 *
292 * @param other the other mutable to compare to, not null
293 * @return negative if this is less, zero if equal, positive if greater
294 */
295 public int compareTo(MutableFloat other) {
296 float anotherVal = other.value;
297 return Float.compare(value, anotherVal);
298 }
299
300 //-----------------------------------------------------------------------
301 /**
302 * Returns the String value of this mutable.
303 *
304 * @return the mutable value as a string
305 */
306 @Override
307 public String toString() {
308 return String.valueOf(value);
309 }
310
311 }