FloatRange


1   /*
2    * Copyright 2002-2005 The Apache Software Foundation.
3    * 
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    * 
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    * 
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  package org.apache.commons.lang.math;
17  
18  import java.io.Serializable  ;
19  
20  /**
21   * <p><code>FloatRange</code> represents an inclusive range of <code>float</code>s.</p>
22   *
23   * @author Stephen Colebourne
24   * @since 2.0
25   * @version $Id: FloatRange.java 161243 2005-04-14 04:30:28Z ggregory $
26   */
27  public final class FloatRange extends Range implements Serializable   {
28      
29      private static final long serialVersionUID = 71849363892750L;
30  
31      /**
32       * The minimum number in this range (inclusive).
33       */
34      private final float min;
35      /**
36       * The maximum number in this range (inclusive).
37       */
38      private final float max;
39      
40      /**
41       * Cached output minObject (class is immutable).
42       */
43      private transient Float   minObject = null;
44      /**
45       * Cached output maxObject (class is immutable).
46       */
47      private transient Float   maxObject = null;
48      /**
49       * Cached output hashCode (class is immutable).
50       */
51      private transient int hashCode = 0;
52      /**
53       * Cached output toString (class is immutable).
54       */
55      private transient String   toString = null;
56      
57      /**
58       * <p>Constructs a new <code>FloatRange</code> using the specified
59       * number as both the minimum and maximum in this range.</p>
60       *
61       * @param number  the number to use for this range
62       * @throws IllegalArgumentException if the number is <code>NaN</code>
63       */
64      public FloatRange(float number) {
65          super();
66          if (Float.isNaN(number)) {
67              throw new IllegalArgumentException  ("The number must not be NaN");
68          }
69          this.min = number;
70          this.max = number;
71      }
72  
73      /**
74       * <p>Constructs a new <code>FloatRange</code> using the specified
75       * number as both the minimum and maximum in this range.</p>
76       *
77       * @param number  the number to use for this range, must not
78       *  be <code>null</code>
79       * @throws IllegalArgumentException if the number is <code>null</code>
80       * @throws IllegalArgumentException if the number is <code>NaN</code>
81       */
82      public FloatRange(Number   number) {
83          super();
84          if (number == null) {
85              throw new IllegalArgumentException  ("The number must not be null");
86          }
87          this.min = number.floatValue();
88          this.max = number.floatValue();
89          if (Float.isNaN(min) || Float.isNaN(max)) {
90              throw new IllegalArgumentException  ("The number must not be NaN");
91          }
92          if (number instanceof Float  ) {
93              this.minObject = (Float  ) number;
94              this.maxObject = (Float  ) number;
95          }
96      }
97  
98      /**
99       * <p>Constructs a new <code>FloatRange</code> with the specified
100      * minimum and maximum numbers (both inclusive).</p>
101      * 
102      * <p>The arguments may be passed in the order (min,max) or (max,min). The
103      * getMinimum and getMaximum methods will return the correct values.</p>
104      * 
105      * @param number1  first number that defines the edge of the range, inclusive
106      * @param number2  second number that defines the edge of the range, inclusive
107      * @throws IllegalArgumentException if either number is <code>NaN</code>
108      */
109     public FloatRange(float number1, float number2) {
110         super();
111         if (Float.isNaN(number1) || Float.isNaN(number2)) {
112             throw new IllegalArgumentException  ("The numbers must not be NaN");
113         }
114         if (number2 < number1) {
115             this.min = number2;
116             this.max = number1;
117         } else {
118             this.min = number1;
119             this.max = number2;
120         }
121     }
122 
123     /**
124      * <p>Constructs a new <code>FloatRange</code> with the specified
125      * minimum and maximum numbers (both inclusive).</p>
126      * 
127      * <p>The arguments may be passed in the order (min,max) or (max,min). The
128      * getMinimum and getMaximum methods will return the correct values.</p>
129      *
130      * @param number1  first number that defines the edge of the range, inclusive
131      * @param number2  second number that defines the edge of the range, inclusive
132      * @throws IllegalArgumentException if either number is <code>null</code>
133      * @throws IllegalArgumentException if either number is <code>NaN</code>
134      */
135     public FloatRange(Number   number1, Number   number2) {
136         super();
137         if (number1 == null || number2 == null) {
138             throw new IllegalArgumentException  ("The numbers must not be null");
139         }
140         float number1val = number1.floatValue();
141         float number2val = number2.floatValue();
142         if (Float.isNaN(number1val) || Float.isNaN(number2val)) {
143             throw new IllegalArgumentException  ("The numbers must not be NaN");
144         }
145         if (number2val < number1val) {
146             this.min = number2val;
147             this.max = number1val;
148             if (number2 instanceof Float  ) {
149                 this.minObject = (Float  ) number2;
150             }
151             if (number1 instanceof Float  ) {
152                 this.maxObject = (Float  ) number1;
153             }
154         } else {
155             this.min = number1val;
156             this.max = number2val;
157             if (number1 instanceof Float  ) {
158                 this.minObject = (Float  ) number1;
159             }
160             if (number2 instanceof Float  ) {
161                 this.maxObject = (Float  ) number2;
162             }
163         }
164     }
165 
166     // Accessors
167     //--------------------------------------------------------------------
168 
169     /**
170      * <p>Returns the minimum number in this range.</p>
171      *
172      * @return the minimum number in this range
173      */
174     public Number   getMinimumNumber() {
175         if (minObject == null) {
176             minObject = new Float  (min);            
177         }
178         return minObject;
179     }
180 
181     /**
182      * <p>Gets the minimum number in this range as a <code>long</code>.</p>
183      * 
184      * <p>This conversion can lose information for large values or decimals.</p>
185      *
186      * @return the minimum number in this range
187      */
188     public long getMinimumLong() {
189         return (long) min;
190     }
191 
192     /**
193      * <p>Gets the minimum number in this range as a <code>int</code>.</p>
194      * 
195      * <p>This conversion can lose information for large values or decimals.</p>
196      *
197      * @return the minimum number in this range
198      */
199     public int getMinimumInteger() {
200         return (int) min;
201     }
202 
203     /**
204      * <p>Gets the minimum number in this range as a <code>double</code>.</p>
205      *
206      * @return the minimum number in this range
207      */
208     public double getMinimumDouble() {
209         return min;
210     }
211 
212     /**
213      * <p>Gets the minimum number in this range as a <code>float</code>.</p>
214      *
215      * @return the minimum number in this range
216      */
217     public float getMinimumFloat() {
218         return min;
219     }
220 
221     /**
222      * <p>Returns the maximum number in this range.</p>
223      *
224      * @return the maximum number in this range
225      */
226     public Number   getMaximumNumber() {
227         if (maxObject == null) {
228             maxObject = new Float  (max);            
229         }
230         return maxObject;
231     }
232 
233     /**
234      * <p>Gets the maximum number in this range as a <code>long</code>.</p>
235      * 
236      * <p>This conversion can lose information for large values or decimals.</p>
237      *
238      * @return the maximum number in this range
239      */
240     public long getMaximumLong() {
241         return (long) max;
242     }
243 
244     /**
245      * <p>Gets the maximum number in this range as a <code>int</code>.</p>
246      * 
247      * <p>This conversion can lose information for large values or decimals.</p>
248      *
249      * @return the maximum number in this range
250      */
251     public int getMaximumInteger() {
252         return (int) max;
253     }
254 
255     /**
256      * <p>Gets the maximum number in this range as a <code>double</code>.</p>
257      *
258      * @return the maximum number in this range
259      */
260     public double getMaximumDouble() {
261         return max;
262     }
263 
264     /**
265      * <p>Gets the maximum number in this range as a <code>float</code>.</p>
266      *
267      * @return the maximum number in this range
268      */
269     public float getMaximumFloat() {
270         return max;
271     }
272 
273     // Tests
274     //--------------------------------------------------------------------
275     
276     /**
277      * <p>Tests whether the specified <code>number</code> occurs within
278      * this range using <code>float</code> comparison.</p>
279      * 
280      * <p><code>null</code> is handled and returns <code>false</code>.</p>
281      *
282      * @param number  the number to test, may be <code>null</code>
283      * @return <code>true</code> if the specified number occurs within this range
284      */
285     public boolean containsNumber(Number   number) {
286         if (number == null) {
287             return false;
288         }
289         return containsFloat(number.floatValue());
290     }
291 
292     /**
293      * <p>Tests whether the specified <code>float</code> occurs within
294      * this range using <code>float</code> comparison.</p>
295      * 
296      * <p>This implementation overrides the superclass for performance as it is
297      * the most common case.</p>
298      * 
299      * @param value  the float to test
300      * @return <code>true</code> if the specified number occurs within this
301      *  range by <code>float</code> comparison
302      */
303     public boolean containsFloat(float value) {
304         return value >= min && value <= max;
305     }
306 
307     // Range tests
308     //--------------------------------------------------------------------
309 
310     /**
311      * <p>Tests whether the specified range occurs entirely within this range
312      * using <code>float</code> comparison.</p>
313      * 
314      * <p><code>null</code> is handled and returns <code>false</code>.</p>
315      *
316      * @param range  the range to test, may be <code>null</code>
317      * @return <code>true</code> if the specified range occurs entirely within this range
318      * @throws IllegalArgumentException if the range is not of this type
319      */
320     public boolean containsRange(Range range) {
321         if (range == null) {
322             return false;
323         }
324         return containsFloat(range.getMinimumFloat()) &&
325                containsFloat(range.getMaximumFloat());
326     }
327 
328     /**
329      * <p>Tests whether the specified range overlaps with this range
330      * using <code>float</code> comparison.</p>
331      * 
332      * <p><code>null</code> is handled and returns <code>false</code>.</p>
333      *
334      * @param range  the range to test, may be <code>null</code>
335      * @return <code>true</code> if the specified range overlaps with this range
336      */
337     public boolean overlapsRange(Range range) {
338         if (range == null) {
339             return false;
340         }
341         return range.containsFloat(min) ||
342                range.containsFloat(max) || 
343                containsFloat(range.getMinimumFloat());
344     }
345 
346     // Basics
347     //--------------------------------------------------------------------
348 
349     /**
350      * <p>Compares this range to another object to test if they are equal.</p>.
351      * 
352      * <p>To be equal, the class, minimum and maximum must be equal.</p>
353      *
354      * @param obj the reference object with which to compare
355      * @return <code>true</code> if this object is equal
356      */
357     public boolean equals(Object   obj) {
358         if (obj == this) {
359             return true;
360         }
361         if (obj instanceof FloatRange == false) {
362             return false;
363         }
364         FloatRange range = (FloatRange) obj;
365         return (Float.floatToIntBits(min) == Float.floatToIntBits(range.min) &&
366                 Float.floatToIntBits(max) == Float.floatToIntBits(range.max));
367     }
368 
369     /**
370      * <p>Gets a hashCode for the range.</p>
371      *
372      * @return a hash code value for this object
373      */
374     public int hashCode() {
375         if (hashCode == 0) {
376             hashCode = 17;
377             hashCode = 37 * hashCode + getClass().hashCode();
378             hashCode = 37 * hashCode + Float.floatToIntBits(min);
379             hashCode = 37 * hashCode + Float.floatToIntBits(max);
380         }
381         return hashCode;
382     }
383 
384     /**
385      * <p>Gets the range as a <code>String</code>.</p>
386      *
387      * <p>The format of the String is 'Range[<i>min</i>,<i>max</i>]'.</p>
388      *
389      * @return the <code>String</code> representation of this range
390      */
391     public String   toString() {
392         if (toString == null) {
393             StringBuffer   buf = new StringBuffer  (32);
394             buf.append("Range[");
395             buf.append(min);
396             buf.append(',');
397             buf.append(max);
398             buf.append(']');
399             toString = buf.toString();
400         }
401         return toString;
402     }
403 
404 }
405
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