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3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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11   * This code is distributed in the hope that it will be useful, but WITHOUT
12   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14   * version 2 for more details (a copy is included in the LICENSE file that
15   * accompanied this code).
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25  
26  /*
27   * This file is available under and governed by the GNU General Public
28   * License version 2 only, as published by the Free Software Foundation.
29   * However, the following notice accompanied the original version of this
30   * file:
31   *
32   * Copyright (c) 2011-2012, Stephen Colebourne & Michael Nascimento Santos
33   *
34   * All rights reserved.
35   *
36   * Redistribution and use in source and binary forms, with or without
37   * modification, are permitted provided that the following conditions are met:
38   *
39   *  * Redistributions of source code must retain the above copyright notice,
40   *    this list of conditions and the following disclaimer.
41   *
42   *  * Redistributions in binary form must reproduce the above copyright notice,
43   *    this list of conditions and the following disclaimer in the documentation
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45   *
46   *  * Neither the name of JSR-310 nor the names of its contributors
47   *    may be used to endorse or promote products derived from this software
48   *    without specific prior written permission.
49   *
50   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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56   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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61   */
62  package java.time.temporal;
63  
64  import java.io.IOException;
65  import java.io.InvalidObjectException;
66  import java.io.ObjectInputStream;
67  import java.io.Serializable;
68  import java.time.DateTimeException;
69  
70  /**
71   * The range of valid values for a date-time field.
72   * <p>
73   * All {@link TemporalField} instances have a valid range of values.
74   * For example, the ISO day-of-month runs from 1 to somewhere between 28 and 31.
75   * This class captures that valid range.
76   * <p>
77   * It is important to be aware of the limitations of this class.
78   * Only the minimum and maximum values are provided.
79   * It is possible for there to be invalid values within the outer range.
80   * For example, a weird field may have valid values of 1, 2, 4, 6, 7, thus
81   * have a range of '1 - 7', despite that fact that values 3 and 5 are invalid.
82   * <p>
83   * Instances of this class are not tied to a specific field.
84   *
85   * @implSpec
86   * This class is immutable and thread-safe.
87   *
88   * @since 1.8
89   */
90  public final class ValueRange implements Serializable {
91  
92      /**
93       * Serialization version.
94       */
95      private static final long serialVersionUID = -7317881728594519368L;
96  
97      /**
98       * The smallest minimum value.
99       */
100     private final long minSmallest;
101     /**
102      * The largest minimum value.
103      */
104     private final long minLargest;
105     /**
106      * The smallest maximum value.
107      */
108     private final long maxSmallest;
109     /**
110      * The largest maximum value.
111      */
112     private final long maxLargest;
113 
114     /**
115      * Obtains a fixed value range.
116      * <p>
117      * This factory obtains a range where the minimum and maximum values are fixed.
118      * For example, the ISO month-of-year always runs from 1 to 12.
119      *
120      * @param min  the minimum value
121      * @param max  the maximum value
122      * @return the ValueRange for min, max, not null
123      * @throws IllegalArgumentException if the minimum is greater than the maximum
124      */
125     public static ValueRange of(long min, long max) {
126         if (min > max) {
127             throw new IllegalArgumentException("Minimum value must be less than maximum value");
128         }
129         return new ValueRange(min, min, max, max);
130     }
131 
132     /**
133      * Obtains a variable value range.
134      * <p>
135      * This factory obtains a range where the minimum value is fixed and the maximum value may vary.
136      * For example, the ISO day-of-month always starts at 1, but ends between 28 and 31.
137      *
138      * @param min  the minimum value
139      * @param maxSmallest  the smallest maximum value
140      * @param maxLargest  the largest maximum value
141      * @return the ValueRange for min, smallest max, largest max, not null
142      * @throws IllegalArgumentException if
143      *     the minimum is greater than the smallest maximum,
144      *  or the smallest maximum is greater than the largest maximum
145      */
146     public static ValueRange of(long min, long maxSmallest, long maxLargest) {
147         return of(min, min, maxSmallest, maxLargest);
148     }
149 
150     /**
151      * Obtains a fully variable value range.
152      * <p>
153      * This factory obtains a range where both the minimum and maximum value may vary.
154      *
155      * @param minSmallest  the smallest minimum value
156      * @param minLargest  the largest minimum value
157      * @param maxSmallest  the smallest maximum value
158      * @param maxLargest  the largest maximum value
159      * @return the ValueRange for smallest min, largest min, smallest max, largest max, not null
160      * @throws IllegalArgumentException if
161      *     the smallest minimum is greater than the smallest maximum,
162      *  or the smallest maximum is greater than the largest maximum
163      *  or the largest minimum is greater than the largest maximum
164      */
165     public static ValueRange of(long minSmallest, long minLargest, long maxSmallest, long maxLargest) {
166         if (minSmallest > minLargest) {
167             throw new IllegalArgumentException("Smallest minimum value must be less than largest minimum value");
168         }
169         if (maxSmallest > maxLargest) {
170             throw new IllegalArgumentException("Smallest maximum value must be less than largest maximum value");
171         }
172         if (minLargest > maxLargest) {
173             throw new IllegalArgumentException("Minimum value must be less than maximum value");
174         }
175         return new ValueRange(minSmallest, minLargest, maxSmallest, maxLargest);
176     }
177 
178     /**
179      * Restrictive constructor.
180      *
181      * @param minSmallest  the smallest minimum value
182      * @param minLargest  the largest minimum value
183      * @param maxSmallest  the smallest minimum value
184      * @param maxLargest  the largest minimum value
185      */
186     private ValueRange(long minSmallest, long minLargest, long maxSmallest, long maxLargest) {
187         this.minSmallest = minSmallest;
188         this.minLargest = minLargest;
189         this.maxSmallest = maxSmallest;
190         this.maxLargest = maxLargest;
191     }
192 
193     //-----------------------------------------------------------------------
194     /**
195      * Is the value range fixed and fully known.
196      * <p>
197      * For example, the ISO day-of-month runs from 1 to between 28 and 31.
198      * Since there is uncertainty about the maximum value, the range is not fixed.
199      * However, for the month of January, the range is always 1 to 31, thus it is fixed.
200      *
201      * @return true if the set of values is fixed
202      */
203     public boolean isFixed() {
204         return minSmallest == minLargest && maxSmallest == maxLargest;
205     }
206 
207     //-----------------------------------------------------------------------
208     /**
209      * Gets the minimum value that the field can take.
210      * <p>
211      * For example, the ISO day-of-month always starts at 1.
212      * The minimum is therefore 1.
213      *
214      * @return the minimum value for this field
215      */
216     public long getMinimum() {
217         return minSmallest;
218     }
219 
220     /**
221      * Gets the largest possible minimum value that the field can take.
222      * <p>
223      * For example, the ISO day-of-month always starts at 1.
224      * The largest minimum is therefore 1.
225      *
226      * @return the largest possible minimum value for this field
227      */
228     public long getLargestMinimum() {
229         return minLargest;
230     }
231 
232     /**
233      * Gets the smallest possible maximum value that the field can take.
234      * <p>
235      * For example, the ISO day-of-month runs to between 28 and 31 days.
236      * The smallest maximum is therefore 28.
237      *
238      * @return the smallest possible maximum value for this field
239      */
240     public long getSmallestMaximum() {
241         return maxSmallest;
242     }
243 
244     /**
245      * Gets the maximum value that the field can take.
246      * <p>
247      * For example, the ISO day-of-month runs to between 28 and 31 days.
248      * The maximum is therefore 31.
249      *
250      * @return the maximum value for this field
251      */
252     public long getMaximum() {
253         return maxLargest;
254     }
255 
256     //-----------------------------------------------------------------------
257     /**
258      * Checks if all values in the range fit in an {@code int}.
259      * <p>
260      * This checks that all valid values are within the bounds of an {@code int}.
261      * <p>
262      * For example, the ISO month-of-year has values from 1 to 12, which fits in an {@code int}.
263      * By comparison, ISO nano-of-day runs from 1 to 86,400,000,000,000 which does not fit in an {@code int}.
264      * <p>
265      * This implementation uses {@link #getMinimum()} and {@link #getMaximum()}.
266      *
267      * @return true if a valid value always fits in an {@code int}
268      */
269     public boolean isIntValue() {
270         return getMinimum() >= Integer.MIN_VALUE && getMaximum() <= Integer.MAX_VALUE;
271     }
272 
273     /**
274      * Checks if the value is within the valid range.
275      * <p>
276      * This checks that the value is within the stored range of values.
277      *
278      * @param value  the value to check
279      * @return true if the value is valid
280      */
281     public boolean isValidValue(long value) {
282         return (value >= getMinimum() && value <= getMaximum());
283     }
284 
285     /**
286      * Checks if the value is within the valid range and that all values
287      * in the range fit in an {@code int}.
288      * <p>
289      * This method combines {@link #isIntValue()} and {@link #isValidValue(long)}.
290      *
291      * @param value  the value to check
292      * @return true if the value is valid and fits in an {@code int}
293      */
294     public boolean isValidIntValue(long value) {
295         return isIntValue() && isValidValue(value);
296     }
297 
298     /**
299      * Checks that the specified value is valid.
300      * <p>
301      * This validates that the value is within the valid range of values.
302      * The field is only used to improve the error message.
303      *
304      * @param value  the value to check
305      * @param field  the field being checked, may be null
306      * @return the value that was passed in
307      * @see #isValidValue(long)
308      */
309     public long checkValidValue(long value, TemporalField field) {
310         if (isValidValue(value) == false) {
311             throw new DateTimeException(genInvalidFieldMessage(field, value));
312         }
313         return value;
314     }
315 
316     /**
317      * Checks that the specified value is valid and fits in an {@code int}.
318      * <p>
319      * This validates that the value is within the valid range of values and that
320      * all valid values are within the bounds of an {@code int}.
321      * The field is only used to improve the error message.
322      *
323      * @param value  the value to check
324      * @param field  the field being checked, may be null
325      * @return the value that was passed in
326      * @see #isValidIntValue(long)
327      */
328     public int checkValidIntValue(long value, TemporalField field) {
329         if (isValidIntValue(value) == false) {
330             throw new DateTimeException(genInvalidFieldMessage(field, value));
331         }
332         return (int) value;
333     }
334 
335     private String genInvalidFieldMessage(TemporalField field, long value) {
336         if (field != null) {
337             return "Invalid value for " + field + " (valid values " + this + "): " + value;
338         } else {
339             return "Invalid value (valid values " + this + "): " + value;
340         }
341     }
342 
343     //-----------------------------------------------------------------------
344     /**
345      * Restore the state of an ValueRange from the stream.
346      * Check that the values are valid.
347      * @throws InvalidObjectException if
348      *     the smallest minimum is greater than the smallest maximum,
349      *  or the smallest maximum is greater than the largest maximum
350      *  or the largest minimum is greater than the largest maximum
351      */
352     private void readObject(ObjectInputStream s)
353          throws IOException, ClassNotFoundException, InvalidObjectException
354     {
355         s.defaultReadObject();
356         if (minSmallest > minLargest) {
357             throw new InvalidObjectException("Smallest minimum value must be less than largest minimum value");
358         }
359         if (maxSmallest > maxLargest) {
360             throw new InvalidObjectException("Smallest maximum value must be less than largest maximum value");
361         }
362         if (minLargest > maxLargest) {
363             throw new InvalidObjectException("Minimum value must be less than maximum value");
364         }
365     }
366 
367     //-----------------------------------------------------------------------
368     /**
369      * Checks if this range is equal to another range.
370      * <p>
371      * The comparison is based on the four values, minimum, largest minimum,
372      * smallest maximum and maximum.
373      * Only objects of type {@code ValueRange} are compared, other types return false.
374      *
375      * @param obj  the object to check, null returns false
376      * @return true if this is equal to the other range
377      */
378     @Override
379     public boolean equals(Object obj) {
380         if (obj == this) {
381             return true;
382         }
383         if (obj instanceof ValueRange) {
384             ValueRange other = (ValueRange) obj;
385            return minSmallest == other.minSmallest && minLargest == other.minLargest &&
386                    maxSmallest == other.maxSmallest && maxLargest == other.maxLargest;
387         }
388         return false;
389     }
390 
391     /**
392      * A hash code for this range.
393      *
394      * @return a suitable hash code
395      */
396     @Override
397     public int hashCode() {
398         long hash = minSmallest + minLargest << 16 + minLargest >> 48 + maxSmallest << 32 +
399             maxSmallest >> 32 + maxLargest << 48 + maxLargest >> 16;
400         return (int) (hash ^ (hash >>> 32));
401     }
402 
403     //-----------------------------------------------------------------------
404     /**
405      * Outputs this range as a {@code String}.
406      * <p>
407      * The format will be '{min}/{largestMin} - {smallestMax}/{max}',
408      * where the largestMin or smallestMax sections may be omitted, together
409      * with associated slash, if they are the same as the min or max.
410      *
411      * @return a string representation of this range, not null
412      */
413     @Override
414     public String toString() {
415         StringBuilder buf = new StringBuilder();
416         buf.append(minSmallest);
417         if (minSmallest != minLargest) {
418             buf.append('/').append(minLargest);
419         }
420         buf.append(" - ").append(maxSmallest);
421         if (maxSmallest != maxLargest) {
422             buf.append('/').append(maxLargest);
423         }
424         return buf.toString();
425     }
426 
427 }