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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  package org.apache.commons.lang.math;
18  
19  import java.io.Serializable;
20  
21  /**
22   * <p><code>FloatRange</code> represents an inclusive range of <code>float</code>s.</p>
23   *
24   * @author Stephen Colebourne
25   * @since 2.0
26   * @version $Id: FloatRange.java 437554 2006-08-28 06:21:41Z bayard $
27   */
28  public final class FloatRange extends Range implements Serializable {
29      
30      /**
31       * Required for serialization support.
32       * 
33       * @see java.io.Serializable
34       */
35      private static final long serialVersionUID = 71849363892750L;
36  
37      /**
38       * The minimum number in this range (inclusive).
39       */
40      private final float min;
41      /**
42       * The maximum number in this range (inclusive).
43       */
44      private final float max;
45      
46      /**
47       * Cached output minObject (class is immutable).
48       */
49      private transient Float minObject = null;
50      /**
51       * Cached output maxObject (class is immutable).
52       */
53      private transient Float maxObject = null;
54      /**
55       * Cached output hashCode (class is immutable).
56       */
57      private transient int hashCode = 0;
58      /**
59       * Cached output toString (class is immutable).
60       */
61      private transient String toString = null;
62      
63      /**
64       * <p>Constructs a new <code>FloatRange</code> using the specified
65       * number as both the minimum and maximum in this range.</p>
66       *
67       * @param number  the number to use for this range
68       * @throws IllegalArgumentException if the number is <code>NaN</code>
69       */
70      public FloatRange(float number) {
71          super();
72          if (Float.isNaN(number)) {
73              throw new IllegalArgumentException("The number must not be NaN");
74          }
75          this.min = number;
76          this.max = number;
77      }
78  
79      /**
80       * <p>Constructs a new <code>FloatRange</code> using the specified
81       * number as both the minimum and maximum in this range.</p>
82       *
83       * @param number  the number to use for this range, must not
84       *  be <code>null</code>
85       * @throws IllegalArgumentException if the number is <code>null</code>
86       * @throws IllegalArgumentException if the number is <code>NaN</code>
87       */
88      public FloatRange(Number number) {
89          super();
90          if (number == null) {
91              throw new IllegalArgumentException("The number must not be null");
92          }
93          this.min = number.floatValue();
94          this.max = number.floatValue();
95          if (Float.isNaN(min) || Float.isNaN(max)) {
96              throw new IllegalArgumentException("The number must not be NaN");
97          }
98          if (number instanceof Float) {
99              this.minObject = (Float) number;
100             this.maxObject = (Float) number;
101         }
102     }
103 
104     /**
105      * <p>Constructs a new <code>FloatRange</code> with the specified
106      * minimum and maximum numbers (both inclusive).</p>
107      * 
108      * <p>The arguments may be passed in the order (min,max) or (max,min). The
109      * getMinimum and getMaximum methods will return the correct values.</p>
110      * 
111      * @param number1  first number that defines the edge of the range, inclusive
112      * @param number2  second number that defines the edge of the range, inclusive
113      * @throws IllegalArgumentException if either number is <code>NaN</code>
114      */
115     public FloatRange(float number1, float number2) {
116         super();
117         if (Float.isNaN(number1) || Float.isNaN(number2)) {
118             throw new IllegalArgumentException("The numbers must not be NaN");
119         }
120         if (number2 < number1) {
121             this.min = number2;
122             this.max = number1;
123         } else {
124             this.min = number1;
125             this.max = number2;
126         }
127     }
128 
129     /**
130      * <p>Constructs a new <code>FloatRange</code> with the specified
131      * minimum and maximum numbers (both inclusive).</p>
132      * 
133      * <p>The arguments may be passed in the order (min,max) or (max,min). The
134      * getMinimum and getMaximum methods will return the correct values.</p>
135      *
136      * @param number1  first number that defines the edge of the range, inclusive
137      * @param number2  second number that defines the edge of the range, inclusive
138      * @throws IllegalArgumentException if either number is <code>null</code>
139      * @throws IllegalArgumentException if either number is <code>NaN</code>
140      */
141     public FloatRange(Number number1, Number number2) {
142         super();
143         if (number1 == null || number2 == null) {
144             throw new IllegalArgumentException("The numbers must not be null");
145         }
146         float number1val = number1.floatValue();
147         float number2val = number2.floatValue();
148         if (Float.isNaN(number1val) || Float.isNaN(number2val)) {
149             throw new IllegalArgumentException("The numbers must not be NaN");
150         }
151         if (number2val < number1val) {
152             this.min = number2val;
153             this.max = number1val;
154             if (number2 instanceof Float) {
155                 this.minObject = (Float) number2;
156             }
157             if (number1 instanceof Float) {
158                 this.maxObject = (Float) number1;
159             }
160         } else {
161             this.min = number1val;
162             this.max = number2val;
163             if (number1 instanceof Float) {
164                 this.minObject = (Float) number1;
165             }
166             if (number2 instanceof Float) {
167                 this.maxObject = (Float) number2;
168             }
169         }
170     }
171 
172     // Accessors
173     //--------------------------------------------------------------------
174 
175     /**
176      * <p>Returns the minimum number in this range.</p>
177      *
178      * @return the minimum number in this range
179      */
180     public Number getMinimumNumber() {
181         if (minObject == null) {
182             minObject = new Float(min);            
183         }
184         return minObject;
185     }
186 
187     /**
188      * <p>Gets the minimum number in this range as a <code>long</code>.</p>
189      * 
190      * <p>This conversion can lose information for large values or decimals.</p>
191      *
192      * @return the minimum number in this range
193      */
194     public long getMinimumLong() {
195         return (long) min;
196     }
197 
198     /**
199      * <p>Gets the minimum number in this range as a <code>int</code>.</p>
200      * 
201      * <p>This conversion can lose information for large values or decimals.</p>
202      *
203      * @return the minimum number in this range
204      */
205     public int getMinimumInteger() {
206         return (int) min;
207     }
208 
209     /**
210      * <p>Gets the minimum number in this range as a <code>double</code>.</p>
211      *
212      * @return the minimum number in this range
213      */
214     public double getMinimumDouble() {
215         return min;
216     }
217 
218     /**
219      * <p>Gets the minimum number in this range as a <code>float</code>.</p>
220      *
221      * @return the minimum number in this range
222      */
223     public float getMinimumFloat() {
224         return min;
225     }
226 
227     /**
228      * <p>Returns the maximum number in this range.</p>
229      *
230      * @return the maximum number in this range
231      */
232     public Number getMaximumNumber() {
233         if (maxObject == null) {
234             maxObject = new Float(max);            
235         }
236         return maxObject;
237     }
238 
239     /**
240      * <p>Gets the maximum number in this range as a <code>long</code>.</p>
241      * 
242      * <p>This conversion can lose information for large values or decimals.</p>
243      *
244      * @return the maximum number in this range
245      */
246     public long getMaximumLong() {
247         return (long) max;
248     }
249 
250     /**
251      * <p>Gets the maximum number in this range as a <code>int</code>.</p>
252      * 
253      * <p>This conversion can lose information for large values or decimals.</p>
254      *
255      * @return the maximum number in this range
256      */
257     public int getMaximumInteger() {
258         return (int) max;
259     }
260 
261     /**
262      * <p>Gets the maximum number in this range as a <code>double</code>.</p>
263      *
264      * @return the maximum number in this range
265      */
266     public double getMaximumDouble() {
267         return max;
268     }
269 
270     /**
271      * <p>Gets the maximum number in this range as a <code>float</code>.</p>
272      *
273      * @return the maximum number in this range
274      */
275     public float getMaximumFloat() {
276         return max;
277     }
278 
279     // Tests
280     //--------------------------------------------------------------------
281     
282     /**
283      * <p>Tests whether the specified <code>number</code> occurs within
284      * this range using <code>float</code> comparison.</p>
285      * 
286      * <p><code>null</code> is handled and returns <code>false</code>.</p>
287      *
288      * @param number  the number to test, may be <code>null</code>
289      * @return <code>true</code> if the specified number occurs within this range
290      */
291     public boolean containsNumber(Number number) {
292         if (number == null) {
293             return false;
294         }
295         return containsFloat(number.floatValue());
296     }
297 
298     /**
299      * <p>Tests whether the specified <code>float</code> occurs within
300      * this range using <code>float</code> comparison.</p>
301      * 
302      * <p>This implementation overrides the superclass for performance as it is
303      * the most common case.</p>
304      * 
305      * @param value  the float to test
306      * @return <code>true</code> if the specified number occurs within this
307      *  range by <code>float</code> comparison
308      */
309     public boolean containsFloat(float value) {
310         return value >= min && value <= max;
311     }
312 
313     // Range tests
314     //--------------------------------------------------------------------
315 
316     /**
317      * <p>Tests whether the specified range occurs entirely within this range
318      * using <code>float</code> comparison.</p>
319      * 
320      * <p><code>null</code> is handled and returns <code>false</code>.</p>
321      *
322      * @param range  the range to test, may be <code>null</code>
323      * @return <code>true</code> if the specified range occurs entirely within this range
324      * @throws IllegalArgumentException if the range is not of this type
325      */
326     public boolean containsRange(Range range) {
327         if (range == null) {
328             return false;
329         }
330         return containsFloat(range.getMinimumFloat()) &&
331                containsFloat(range.getMaximumFloat());
332     }
333 
334     /**
335      * <p>Tests whether the specified range overlaps with this range
336      * using <code>float</code> comparison.</p>
337      * 
338      * <p><code>null</code> is handled and returns <code>false</code>.</p>
339      *
340      * @param range  the range to test, may be <code>null</code>
341      * @return <code>true</code> if the specified range overlaps with this range
342      */
343     public boolean overlapsRange(Range range) {
344         if (range == null) {
345             return false;
346         }
347         return range.containsFloat(min) ||
348                range.containsFloat(max) || 
349                containsFloat(range.getMinimumFloat());
350     }
351 
352     // Basics
353     //--------------------------------------------------------------------
354 
355     /**
356      * <p>Compares this range to another object to test if they are equal.</p>.
357      * 
358      * <p>To be equal, the class, minimum and maximum must be equal.</p>
359      *
360      * @param obj the reference object with which to compare
361      * @return <code>true</code> if this object is equal
362      */
363     public boolean equals(Object obj) {
364         if (obj == this) {
365             return true;
366         }
367         if (obj instanceof FloatRange == false) {
368             return false;
369         }
370         FloatRange range = (FloatRange) obj;
371         return (Float.floatToIntBits(min) == Float.floatToIntBits(range.min) &&
372                 Float.floatToIntBits(max) == Float.floatToIntBits(range.max));
373     }
374 
375     /**
376      * <p>Gets a hashCode for the range.</p>
377      *
378      * @return a hash code value for this object
379      */
380     public int hashCode() {
381         if (hashCode == 0) {
382             hashCode = 17;
383             hashCode = 37 * hashCode + getClass().hashCode();
384             hashCode = 37 * hashCode + Float.floatToIntBits(min);
385             hashCode = 37 * hashCode + Float.floatToIntBits(max);
386         }
387         return hashCode;
388     }
389 
390     /**
391      * <p>Gets the range as a <code>String</code>.</p>
392      *
393      * <p>The format of the String is 'Range[<i>min</i>,<i>max</i>]'.</p>
394      *
395      * @return the <code>String</code> representation of this range
396      */
397     public String toString() {
398         if (toString == null) {
399             StringBuffer buf = new StringBuffer(32);
400             buf.append("Range[");
401             buf.append(min);
402             buf.append(',');
403             buf.append(max);
404             buf.append(']');
405             toString = buf.toString();
406         }
407         return toString;
408     }
409 
410 }