DoubleRange


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>DoubleRange</code> represents an inclusive range of <code>double</code>s.</p>
22   *
23   * @author Stephen Colebourne
24   * @since 2.0
25   * @version $Id: DoubleRange.java 161243 2005-04-14 04:30:28Z ggregory $
26   */
27  public final class DoubleRange extends Range implements Serializable   {
28      
29      private static final long serialVersionUID = 71849363892740L;
30  
31      /**
32       * The minimum number in this range (inclusive).
33       */
34      private final double min;
35      /**
36       * The maximum number in this range (inclusive).
37       */
38      private final double max;
39      
40      /**
41       * Cached output minObject (class is immutable).
42       */
43      private transient Double   minObject = null;
44      /**
45       * Cached output maxObject (class is immutable).
46       */
47      private transient Double   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>DoubleRange</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 DoubleRange(double number) {
65          super();
66          if (Double.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>DoubleRange</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 DoubleRange(Number   number) {
83          super();
84          if (number == null) {
85              throw new IllegalArgumentException  ("The number must not be null");
86          }
87          this.min = number.doubleValue();
88          this.max = number.doubleValue();
89          if (Double.isNaN(min) || Double.isNaN(max)) {
90              throw new IllegalArgumentException  ("The number must not be NaN");
91          }
92          if (number instanceof Double  ) {
93              this.minObject = (Double  ) number;
94              this.maxObject = (Double  ) number;
95          }
96      }
97  
98      /**
99       * <p>Constructs a new <code>DoubleRange</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 DoubleRange(double number1, double number2) {
110         super();
111         if (Double.isNaN(number1) || Double.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>DoubleRange</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 DoubleRange(Number   number1, Number   number2) {
136         super();
137         if (number1 == null || number2 == null) {
138             throw new IllegalArgumentException  ("The numbers must not be null");
139         }
140         double number1val = number1.doubleValue();
141         double number2val = number2.doubleValue();
142         if (Double.isNaN(number1val) || Double.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 Double  ) {
149                 this.minObject = (Double  ) number2;
150             }
151             if (number1 instanceof Double  ) {
152                 this.maxObject = (Double  ) number1;
153             }
154         } else {
155             this.min = number1val;
156             this.max = number2val;
157             if (number1 instanceof Double  ) {
158                 this.minObject = (Double  ) number1;
159             }
160             if (number2 instanceof Double  ) {
161                 this.maxObject = (Double  ) 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 Double  (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      * <p>This conversion can lose information for large values.</p>
216      *
217      * @return the minimum number in this range
218      */
219     public float getMinimumFloat() {
220         return (float) min;
221     }
222 
223     /**
224      * <p>Returns the maximum number in this range.</p>
225      *
226      * @return the maximum number in this range
227      */
228     public Number   getMaximumNumber() {
229         if (maxObject == null) {
230             maxObject = new Double  (max);            
231         }
232         return maxObject;
233     }
234 
235     /**
236      * <p>Gets the maximum number in this range as a <code>long</code>.</p>
237      * 
238      * <p>This conversion can lose information for large values or decimals.</p>
239      *
240      * @return the maximum number in this range
241      */
242     public long getMaximumLong() {
243         return (long) max;
244     }
245 
246     /**
247      * <p>Gets the maximum number in this range as a <code>int</code>.</p>
248      * 
249      * <p>This conversion can lose information for large values or decimals.</p>
250      *
251      * @return the maximum number in this range
252      */
253     public int getMaximumInteger() {
254         return (int) max;
255     }
256 
257     /**
258      * <p>Gets the maximum number in this range as a <code>double</code>.</p>
259      *
260      * @return the maximum number in this range
261      */
262     public double getMaximumDouble() {
263         return max;
264     }
265 
266     /**
267      * <p>Gets the maximum number in this range as a <code>float</code>.</p>
268      * 
269      * <p>This conversion can lose information for large values.</p>
270      *
271      * @return the maximum number in this range
272      */
273     public float getMaximumFloat() {
274         return (float) max;
275     }
276 
277     // Tests
278     //--------------------------------------------------------------------
279     
280     /**
281      * <p>Tests whether the specified <code>number</code> occurs within
282      * this range using <code>double</code> comparison.</p>
283      * 
284      * <p><code>null</code> is handled and returns <code>false</code>.</p>
285      *
286      * @param number  the number to test, may be <code>null</code>
287      * @return <code>true</code> if the specified number occurs within this range
288      */
289     public boolean containsNumber(Number   number) {
290         if (number == null) {
291             return false;
292         }
293         return containsDouble(number.doubleValue());
294     }
295 
296     /**
297      * <p>Tests whether the specified <code>double</code> occurs within
298      * this range using <code>double</code> comparison.</p>
299      * 
300      * <p>This implementation overrides the superclass for performance as it is
301      * the most common case.</p>
302      * 
303      * @param value  the double to test
304      * @return <code>true</code> if the specified number occurs within this
305      *  range by <code>double</code> comparison
306      */
307     public boolean containsDouble(double value) {
308         return value >= min && value <= max;
309     }
310 
311     // Range tests
312     //--------------------------------------------------------------------
313 
314     /**
315      * <p>Tests whether the specified range occurs entirely within this range
316      * using <code>double</code> comparison.</p>
317      * 
318      * <p><code>null</code> is handled and returns <code>false</code>.</p>
319      *
320      * @param range  the range to test, may be <code>null</code>
321      * @return <code>true</code> if the specified range occurs entirely within this range
322      * @throws IllegalArgumentException if the range is not of this type
323      */
324     public boolean containsRange(Range range) {
325         if (range == null) {
326             return false;
327         }
328         return containsDouble(range.getMinimumDouble())
329             && containsDouble(range.getMaximumDouble());
330     }
331 
332     /**
333      * <p>Tests whether the specified range overlaps with this range
334      * using <code>double</code> comparison.</p>
335      * 
336      * <p><code>null</code> is handled and returns <code>false</code>.</p>
337      *
338      * @param range  the range to test, may be <code>null</code>
339      * @return <code>true</code> if the specified range overlaps with this range
340      */
341     public boolean overlapsRange(Range range) {
342         if (range == null) {
343             return false;
344         }
345         return range.containsDouble(min)
346             || range.containsDouble(max)
347             || containsDouble(range.getMinimumDouble());
348     }
349 
350     // Basics
351     //--------------------------------------------------------------------
352 
353     /**
354      * <p>Compares this range to another object to test if they are equal.</p>.
355      * 
356      * <p>To be equal, the class, minimum and maximum must be equal.</p>
357      *
358      * @param obj the reference object with which to compare
359      * @return <code>true</code> if this object is equal
360      */
361     public boolean equals(Object   obj) {
362         if (obj == this) {
363             return true;
364         }
365         if (obj instanceof DoubleRange == false) {
366             return false;
367         }
368         DoubleRange range = (DoubleRange) obj;
369         return (Double.doubleToLongBits(min) == Double.doubleToLongBits(range.min) &&
370                 Double.doubleToLongBits(max) == Double.doubleToLongBits(range.max));
371     }
372 
373     /**
374      * <p>Gets a hashCode for the range.</p>
375      *
376      * @return a hash code value for this object
377      */
378     public int hashCode() {
379         if (hashCode == 0) {
380             hashCode = 17;
381             hashCode = 37 * hashCode + getClass().hashCode();
382             long lng = Double.doubleToLongBits(min);
383             hashCode = 37 * hashCode + ((int) (lng ^ (lng >> 32)));
384             lng = Double.doubleToLongBits(max);
385             hashCode = 37 * hashCode + ((int) (lng ^ (lng >> 32)));
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 }
411
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