IntRange


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>IntRange</code> represents an inclusive range of <code>int</code>s.</p>
22   *
23   * @author Stephen Colebourne
24   * @since 2.0
25   * @version $Id: IntRange.java 161243 2005-04-14 04:30:28Z ggregory $
26   */
27  public final class IntRange extends Range implements Serializable   {
28      
29      private static final long serialVersionUID = 71849363892730L;
30  
31      /**
32       * The minimum number in this range (inclusive).
33       */
34      private final int min;
35      /**
36       * The maximum number in this range (inclusive).
37       */
38      private final int max;
39      
40      /**
41       * Cached output minObject (class is immutable).
42       */
43      private transient Integer   minObject = null;
44      /**
45       * Cached output maxObject (class is immutable).
46       */
47      private transient Integer   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>IntRange</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       */
63      public IntRange(int number) {
64          super();
65          this.min = number;
66          this.max = number;
67      }
68  
69      /**
70       * <p>Constructs a new <code>IntRange</code> using the specified
71       * number as both the minimum and maximum in this range.</p>
72       *
73       * @param number  the number to use for this range, must not be <code>null</code>
74       * @throws IllegalArgumentException if the number is <code>null</code>
75       */
76      public IntRange(Number   number) {
77          super();
78          if (number == null) {
79              throw new IllegalArgumentException  ("The number must not be null");
80          }
81          this.min = number.intValue();
82          this.max = number.intValue();
83          if (number instanceof Integer  ) {
84              this.minObject = (Integer  ) number;
85              this.maxObject = (Integer  ) number;
86          }
87      }
88  
89      /**
90       * <p>Constructs a new <code>IntRange</code> with the specified
91       * minimum and maximum numbers (both inclusive).</p>
92       * 
93       * <p>The arguments may be passed in the order (min,max) or (max,min). The
94       * getMinimum and getMaximum methods will return the correct values.</p>
95       * 
96       * @param number1  first number that defines the edge of the range, inclusive
97       * @param number2  second number that defines the edge of the range, inclusive
98       */
99      public IntRange(int number1, int number2) {
100         super();
101         if (number2 < number1) {
102             this.min = number2;
103             this.max = number1;
104         } else {
105             this.min = number1;
106             this.max = number2;
107         }
108     }
109 
110     /**
111      * <p>Constructs a new <code>IntRange</code> with the specified
112      * minimum and maximum numbers (both inclusive).</p>
113      * 
114      * <p>The arguments may be passed in the order (min,max) or (max,min). The
115      * getMinimum and getMaximum methods will return the correct values.</p>
116      *
117      * @param number1  first number that defines the edge of the range, inclusive
118      * @param number2  second number that defines the edge of the range, inclusive
119      * @throws IllegalArgumentException if either number is <code>null</code>
120      */
121     public IntRange(Number   number1, Number   number2) {
122         super();
123         if (number1 == null || number2 == null) {
124             throw new IllegalArgumentException  ("The numbers must not be null");
125         }
126         int number1val = number1.intValue();
127         int number2val = number2.intValue();
128         if (number2val < number1val) {
129             this.min = number2val;
130             this.max = number1val;
131             if (number2 instanceof Integer  ) {
132                 this.minObject = (Integer  ) number2;
133             }
134             if (number1 instanceof Integer  ) {
135                 this.maxObject = (Integer  ) number1;
136             }
137         } else {
138             this.min = number1val;
139             this.max = number2val;
140             if (number1 instanceof Integer  ) {
141                 this.minObject = (Integer  ) number1;
142             }
143             if (number2 instanceof Integer  ) {
144                 this.maxObject = (Integer  ) number2;
145             }
146         }
147     }
148 
149     // Accessors
150     //--------------------------------------------------------------------
151 
152     /**
153      * <p>Returns the minimum number in this range.</p>
154      *
155      * @return the minimum number in this range
156      */
157     public Number   getMinimumNumber() {
158         if (minObject == null) {
159             minObject = new Integer  (min);            
160         }
161         return minObject;
162     }
163 
164     /**
165      * <p>Gets the minimum number in this range as a <code>long</code>.</p>
166      *
167      * @return the minimum number in this range
168      */
169     public long getMinimumLong() {
170         return min;
171     }
172 
173     /**
174      * <p>Gets the minimum number in this range as a <code>int</code>.</p>
175      *
176      * @return the minimum number in this range
177      */
178     public int getMinimumInteger() {
179         return min;
180     }
181 
182     /**
183      * <p>Gets the minimum number in this range as a <code>double</code>.</p>
184      *
185      * @return the minimum number in this range
186      */
187     public double getMinimumDouble() {
188         return min;
189     }
190 
191     /**
192      * <p>Gets the minimum number in this range as a <code>float</code>.</p>
193      *
194      * @return the minimum number in this range
195      */
196     public float getMinimumFloat() {
197         return min;
198     }
199 
200     /**
201      * <p>Returns the maximum number in this range.</p>
202      *
203      * @return the maximum number in this range
204      */
205     public Number   getMaximumNumber() {
206         if (maxObject == null) {
207             maxObject = new Integer  (max);            
208         }
209         return maxObject;
210     }
211 
212     /**
213      * <p>Gets the maximum number in this range as a <code>long</code>.</p>
214      *
215      * @return the maximum number in this range
216      */
217     public long getMaximumLong() {
218         return max;
219     }
220 
221     /**
222      * <p>Gets the maximum number in this range as a <code>int</code>.</p>
223      *
224      * @return the maximum number in this range
225      */
226     public int getMaximumInteger() {
227         return max;
228     }
229 
230     /**
231      * <p>Gets the maximum number in this range as a <code>double</code>.</p>
232      *
233      * @return the maximum number in this range
234      */
235     public double getMaximumDouble() {
236         return max;
237     }
238 
239     /**
240      * <p>Gets the maximum number in this range as a <code>float</code>.</p>
241      *
242      * @return the maximum number in this range
243      */
244     public float getMaximumFloat() {
245         return max;
246     }
247 
248     // Tests
249     //--------------------------------------------------------------------
250     
251     /**
252      * <p>Tests whether the specified <code>number</code> occurs within
253      * this range using <code>int</code> comparison.</p>
254      * 
255      * <p><code>null</code> is handled and returns <code>false</code>.</p>
256      *
257      * @param number  the number to test, may be <code>null</code>
258      * @return <code>true</code> if the specified number occurs within this range
259      */
260     public boolean containsNumber(Number   number) {
261         if (number == null) {
262             return false;
263         }
264         return containsInteger(number.intValue());
265     }
266 
267     /**
268      * <p>Tests whether the specified <code>int</code> occurs within
269      * this range using <code>int</code> comparison.</p>
270      * 
271      * <p>This implementation overrides the superclass for performance as it is
272      * the most common case.</p>
273      * 
274      * @param value  the int to test
275      * @return <code>true</code> if the specified number occurs within this
276      *  range by <code>int</code> comparison
277      */
278     public boolean containsInteger(int value) {
279         return value >= min && value <= max;
280     }
281 
282     // Range tests
283     //--------------------------------------------------------------------
284 
285     /**
286      * <p>Tests whether the specified range occurs entirely within this range
287      * using <code>int</code> comparison.</p>
288      * 
289      * <p><code>null</code> is handled and returns <code>false</code>.</p>
290      *
291      * @param range  the range to test, may be <code>null</code>
292      * @return <code>true</code> if the specified range occurs entirely within this range
293      * @throws IllegalArgumentException if the range is not of this type
294      */
295     public boolean containsRange(Range range) {
296         if (range == null) {
297             return false;
298         }
299         return containsInteger(range.getMinimumInteger()) &&
300                containsInteger(range.getMaximumInteger());
301     }
302 
303     /**
304      * <p>Tests whether the specified range overlaps with this range
305      * using <code>int</code> comparison.</p>
306      * 
307      * <p><code>null</code> is handled and returns <code>false</code>.</p>
308      *
309      * @param range  the range to test, may be <code>null</code>
310      * @return <code>true</code> if the specified range overlaps with this range
311      */
312     public boolean overlapsRange(Range range) {
313         if (range == null) {
314             return false;
315         }
316         return range.containsInteger(min) ||
317                range.containsInteger(max) || 
318                containsInteger(range.getMinimumInteger());
319     }
320 
321     // Basics
322     //--------------------------------------------------------------------
323 
324     /**
325      * <p>Compares this range to another object to test if they are equal.</p>.
326      * 
327      * <p>To be equal, the class, minimum and maximum must be equal.</p>
328      *
329      * @param obj the reference object with which to compare
330      * @return <code>true</code> if this object is equal
331      */
332     public boolean equals(Object   obj) {
333         if (obj == this) {
334             return true;
335         }
336         if (obj instanceof IntRange == false) {
337             return false;
338         }
339         IntRange range = (IntRange) obj;
340         return min == range.min && max == range.max;
341     }
342 
343     /**
344      * <p>Gets a hashCode for the range.</p>
345      *
346      * @return a hash code value for this object
347      */
348     public int hashCode() {
349         if (hashCode == 0) {
350             hashCode = 17;
351             hashCode = 37 * hashCode + getClass().hashCode();
352             hashCode = 37 * hashCode + min;
353             hashCode = 37 * hashCode + max;
354         }
355         return hashCode;
356     }
357 
358     /**
359      * <p>Gets the range as a <code>String</code>.</p>
360      *
361      * <p>The format of the String is 'Range[<i>min</i>,<i>max</i>]'.</p>
362      *
363      * @return the <code>String</code> representation of this range
364      */
365     public String   toString() {
366         if (toString == null) {
367             StringBuffer   buf = new StringBuffer  (32);
368             buf.append("Range[");
369             buf.append(min);
370             buf.append(',');
371             buf.append(max);
372             buf.append(']');
373             toString = buf.toString();
374         }
375         return toString;
376     }
377 
378 }
379
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