1 /*
2 * Copyright (c) 1996, 2011, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
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).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 /*
27 * (C) Copyright Taligent, Inc. 1996-1998 - All Rights Reserved
28 * (C) Copyright IBM Corp. 1996-1998 - All Rights Reserved
29 *
30 * The original version of this source code and documentation is copyrighted
31 * and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
32 * materials are provided under terms of a License Agreement between Taligent
33 * and Sun. This technology is protected by multiple US and International
34 * patents. This notice and attribution to Taligent may not be removed.
35 * Taligent is a registered trademark of Taligent, Inc.
36 *
37 */
38
39 package java.util;
40
41 import java.io.IOException;
42 import java.io.ObjectInputStream;
43 import java.io.ObjectOutputStream;
44 import java.io.OptionalDataException;
45 import java.io.Serializable;
46 import java.security.AccessControlContext;
47 import java.security.AccessController;
48 import java.security.PermissionCollection;
49 import java.security.PrivilegedActionException;
50 import java.security.PrivilegedExceptionAction;
51 import java.security.ProtectionDomain;
52 import java.text.DateFormat;
53 import java.text.DateFormatSymbols;
54 import java.util.concurrent.ConcurrentHashMap;
55 import java.util.concurrent.ConcurrentMap;
56 import sun.util.BuddhistCalendar;
57 import sun.util.calendar.ZoneInfo;
58 import sun.util.resources.LocaleData;
59
60 /**
61 * The <code>Calendar</code> class is an abstract class that provides methods
62 * for converting between a specific instant in time and a set of {@link
63 * #fields calendar fields} such as <code>YEAR</code>, <code>MONTH</code>,
64 * <code>DAY_OF_MONTH</code>, <code>HOUR</code>, and so on, and for
65 * manipulating the calendar fields, such as getting the date of the next
66 * week. An instant in time can be represented by a millisecond value that is
67 * an offset from the <a name="Epoch"><em>Epoch</em></a>, January 1, 1970
68 * 00:00:00.000 GMT (Gregorian).
69 *
70 * <p>The class also provides additional fields and methods for
71 * implementing a concrete calendar system outside the package. Those
72 * fields and methods are defined as <code>protected</code>.
73 *
74 * <p>
75 * Like other locale-sensitive classes, <code>Calendar</code> provides a
76 * class method, <code>getInstance</code>, for getting a generally useful
77 * object of this type. <code>Calendar</code>'s <code>getInstance</code> method
78 * returns a <code>Calendar</code> object whose
79 * calendar fields have been initialized with the current date and time:
80 * <blockquote>
81 * <pre>
82 * Calendar rightNow = Calendar.getInstance();
83 * </pre>
84 * </blockquote>
85 *
86 * <p>A <code>Calendar</code> object can produce all the calendar field values
87 * needed to implement the date-time formatting for a particular language and
88 * calendar style (for example, Japanese-Gregorian, Japanese-Traditional).
89 * <code>Calendar</code> defines the range of values returned by
90 * certain calendar fields, as well as their meaning. For example,
91 * the first month of the calendar system has value <code>MONTH ==
92 * JANUARY</code> for all calendars. Other values are defined by the
93 * concrete subclass, such as <code>ERA</code>. See individual field
94 * documentation and subclass documentation for details.
95 *
96 * <h4>Getting and Setting Calendar Field Values</h4>
97 *
98 * <p>The calendar field values can be set by calling the <code>set</code>
99 * methods. Any field values set in a <code>Calendar</code> will not be
100 * interpreted until it needs to calculate its time value (milliseconds from
101 * the Epoch) or values of the calendar fields. Calling the
102 * <code>get</code>, <code>getTimeInMillis</code>, <code>getTime</code>,
103 * <code>add</code> and <code>roll</code> involves such calculation.
104 *
105 * <h4>Leniency</h4>
106 *
107 * <p><code>Calendar</code> has two modes for interpreting the calendar
108 * fields, <em>lenient</em> and <em>non-lenient</em>. When a
109 * <code>Calendar</code> is in lenient mode, it accepts a wider range of
110 * calendar field values than it produces. When a <code>Calendar</code>
111 * recomputes calendar field values for return by <code>get()</code>, all of
112 * the calendar fields are normalized. For example, a lenient
113 * <code>GregorianCalendar</code> interprets <code>MONTH == JANUARY</code>,
114 * <code>DAY_OF_MONTH == 32</code> as February 1.
115
116 * <p>When a <code>Calendar</code> is in non-lenient mode, it throws an
117 * exception if there is any inconsistency in its calendar fields. For
118 * example, a <code>GregorianCalendar</code> always produces
119 * <code>DAY_OF_MONTH</code> values between 1 and the length of the month. A
120 * non-lenient <code>GregorianCalendar</code> throws an exception upon
121 * calculating its time or calendar field values if any out-of-range field
122 * value has been set.
123 *
124 * <h4><a name="first_week">First Week</a></h4>
125 *
126 * <code>Calendar</code> defines a locale-specific seven day week using two
127 * parameters: the first day of the week and the minimal days in first week
128 * (from 1 to 7). These numbers are taken from the locale resource data when a
129 * <code>Calendar</code> is constructed. They may also be specified explicitly
130 * through the methods for setting their values.
131 *
132 * <p>When setting or getting the <code>WEEK_OF_MONTH</code> or
133 * <code>WEEK_OF_YEAR</code> fields, <code>Calendar</code> must determine the
134 * first week of the month or year as a reference point. The first week of a
135 * month or year is defined as the earliest seven day period beginning on
136 * <code>getFirstDayOfWeek()</code> and containing at least
137 * <code>getMinimalDaysInFirstWeek()</code> days of that month or year. Weeks
138 * numbered ..., -1, 0 precede the first week; weeks numbered 2, 3,... follow
139 * it. Note that the normalized numbering returned by <code>get()</code> may be
140 * different. For example, a specific <code>Calendar</code> subclass may
141 * designate the week before week 1 of a year as week <code><i>n</i></code> of
142 * the previous year.
143 *
144 * <h4>Calendar Fields Resolution</h4>
145 *
146 * When computing a date and time from the calendar fields, there
147 * may be insufficient information for the computation (such as only
148 * year and month with no day of month), or there may be inconsistent
149 * information (such as Tuesday, July 15, 1996 (Gregorian) -- July 15,
150 * 1996 is actually a Monday). <code>Calendar</code> will resolve
151 * calendar field values to determine the date and time in the
152 * following way.
153 *
154 * <p>If there is any conflict in calendar field values,
155 * <code>Calendar</code> gives priorities to calendar fields that have been set
156 * more recently. The following are the default combinations of the
157 * calendar fields. The most recent combination, as determined by the
158 * most recently set single field, will be used.
159 *
160 * <p><a name="date_resolution">For the date fields</a>:
161 * <blockquote>
162 * <pre>
163 * YEAR + MONTH + DAY_OF_MONTH
164 * YEAR + MONTH + WEEK_OF_MONTH + DAY_OF_WEEK
165 * YEAR + MONTH + DAY_OF_WEEK_IN_MONTH + DAY_OF_WEEK
166 * YEAR + DAY_OF_YEAR
167 * YEAR + DAY_OF_WEEK + WEEK_OF_YEAR
168 * </pre></blockquote>
169 *
170 * <a name="time_resolution">For the time of day fields</a>:
171 * <blockquote>
172 * <pre>
173 * HOUR_OF_DAY
174 * AM_PM + HOUR
175 * </pre></blockquote>
176 *
177 * <p>If there are any calendar fields whose values haven't been set in the selected
178 * field combination, <code>Calendar</code> uses their default values. The default
179 * value of each field may vary by concrete calendar systems. For example, in
180 * <code>GregorianCalendar</code>, the default of a field is the same as that
181 * of the start of the Epoch: i.e., <code>YEAR = 1970</code>, <code>MONTH =
182 * JANUARY</code>, <code>DAY_OF_MONTH = 1</code>, etc.
183 *
184 * <p>
185 * <strong>Note:</strong> There are certain possible ambiguities in
186 * interpretation of certain singular times, which are resolved in the
187 * following ways:
188 * <ol>
189 * <li> 23:59 is the last minute of the day and 00:00 is the first
190 * minute of the next day. Thus, 23:59 on Dec 31, 1999 < 00:00 on
191 * Jan 1, 2000 < 00:01 on Jan 1, 2000.
192 *
193 * <li> Although historically not precise, midnight also belongs to "am",
194 * and noon belongs to "pm", so on the same day,
195 * 12:00 am (midnight) < 12:01 am, and 12:00 pm (noon) < 12:01 pm
196 * </ol>
197 *
198 * <p>
199 * The date or time format strings are not part of the definition of a
200 * calendar, as those must be modifiable or overridable by the user at
201 * runtime. Use {@link DateFormat}
202 * to format dates.
203 *
204 * <h4>Field Manipulation</h4>
205 *
206 * The calendar fields can be changed using three methods:
207 * <code>set()</code>, <code>add()</code>, and <code>roll()</code>.</p>
208 *
209 * <p><strong><code>set(f, value)</code></strong> changes calendar field
210 * <code>f</code> to <code>value</code>. In addition, it sets an
211 * internal member variable to indicate that calendar field <code>f</code> has
212 * been changed. Although calendar field <code>f</code> is changed immediately,
213 * the calendar's time value in milliseconds is not recomputed until the next call to
214 * <code>get()</code>, <code>getTime()</code>, <code>getTimeInMillis()</code>,
215 * <code>add()</code>, or <code>roll()</code> is made. Thus, multiple calls to
216 * <code>set()</code> do not trigger multiple, unnecessary
217 * computations. As a result of changing a calendar field using
218 * <code>set()</code>, other calendar fields may also change, depending on the
219 * calendar field, the calendar field value, and the calendar system. In addition,
220 * <code>get(f)</code> will not necessarily return <code>value</code> set by
221 * the call to the <code>set</code> method
222 * after the calendar fields have been recomputed. The specifics are determined by
223 * the concrete calendar class.</p>
224 *
225 * <p><em>Example</em>: Consider a <code>GregorianCalendar</code>
226 * originally set to August 31, 1999. Calling <code>set(Calendar.MONTH,
227 * Calendar.SEPTEMBER)</code> sets the date to September 31,
228 * 1999. This is a temporary internal representation that resolves to
229 * October 1, 1999 if <code>getTime()</code>is then called. However, a
230 * call to <code>set(Calendar.DAY_OF_MONTH, 30)</code> before the call to
231 * <code>getTime()</code> sets the date to September 30, 1999, since
232 * no recomputation occurs after <code>set()</code> itself.</p>
233 *
234 * <p><strong><code>add(f, delta)</code></strong> adds <code>delta</code>
235 * to field <code>f</code>. This is equivalent to calling <code>set(f,
236 * get(f) + delta)</code> with two adjustments:</p>
237 *
238 * <blockquote>
239 * <p><strong>Add rule 1</strong>. The value of field <code>f</code>
240 * after the call minus the value of field <code>f</code> before the
241 * call is <code>delta</code>, modulo any overflow that has occurred in
242 * field <code>f</code>. Overflow occurs when a field value exceeds its
243 * range and, as a result, the next larger field is incremented or
244 * decremented and the field value is adjusted back into its range.</p>
245 *
246 * <p><strong>Add rule 2</strong>. If a smaller field is expected to be
247 * invariant, but it is impossible for it to be equal to its
248 * prior value because of changes in its minimum or maximum after field
249 * <code>f</code> is changed or other constraints, such as time zone
250 * offset changes, then its value is adjusted to be as close
251 * as possible to its expected value. A smaller field represents a
252 * smaller unit of time. <code>HOUR</code> is a smaller field than
253 * <code>DAY_OF_MONTH</code>. No adjustment is made to smaller fields
254 * that are not expected to be invariant. The calendar system
255 * determines what fields are expected to be invariant.</p>
256 * </blockquote>
257 *
258 * <p>In addition, unlike <code>set()</code>, <code>add()</code> forces
259 * an immediate recomputation of the calendar's milliseconds and all
260 * fields.</p>
261 *
262 * <p><em>Example</em>: Consider a <code>GregorianCalendar</code>
263 * originally set to August 31, 1999. Calling <code>add(Calendar.MONTH,
264 * 13)</code> sets the calendar to September 30, 2000. <strong>Add rule
265 * 1</strong> sets the <code>MONTH</code> field to September, since
266 * adding 13 months to August gives September of the next year. Since
267 * <code>DAY_OF_MONTH</code> cannot be 31 in September in a
268 * <code>GregorianCalendar</code>, <strong>add rule 2</strong> sets the
269 * <code>DAY_OF_MONTH</code> to 30, the closest possible value. Although
270 * it is a smaller field, <code>DAY_OF_WEEK</code> is not adjusted by
271 * rule 2, since it is expected to change when the month changes in a
272 * <code>GregorianCalendar</code>.</p>
273 *
274 * <p><strong><code>roll(f, delta)</code></strong> adds
275 * <code>delta</code> to field <code>f</code> without changing larger
276 * fields. This is equivalent to calling <code>add(f, delta)</code> with
277 * the following adjustment:</p>
278 *
279 * <blockquote>
280 * <p><strong>Roll rule</strong>. Larger fields are unchanged after the
281 * call. A larger field represents a larger unit of
282 * time. <code>DAY_OF_MONTH</code> is a larger field than
283 * <code>HOUR</code>.</p>
284 * </blockquote>
285 *
286 * <p><em>Example</em>: See {@link java.util.GregorianCalendar#roll(int, int)}.
287 *
288 * <p><strong>Usage model</strong>. To motivate the behavior of
289 * <code>add()</code> and <code>roll()</code>, consider a user interface
290 * component with increment and decrement buttons for the month, day, and
291 * year, and an underlying <code>GregorianCalendar</code>. If the
292 * interface reads January 31, 1999 and the user presses the month
293 * increment button, what should it read? If the underlying
294 * implementation uses <code>set()</code>, it might read March 3, 1999. A
295 * better result would be February 28, 1999. Furthermore, if the user
296 * presses the month increment button again, it should read March 31,
297 * 1999, not March 28, 1999. By saving the original date and using either
298 * <code>add()</code> or <code>roll()</code>, depending on whether larger
299 * fields should be affected, the user interface can behave as most users
300 * will intuitively expect.</p>
301 *
302 * @see java.lang.System#currentTimeMillis()
303 * @see Date
304 * @see GregorianCalendar
305 * @see TimeZone
306 * @see java.text.DateFormat
307 * @author Mark Davis, David Goldsmith, Chen-Lieh Huang, Alan Liu
308 * @since JDK1.1
309 */
310 public abstract class Calendar implements Serializable, Cloneable, Comparable<Calendar> {
311
312 // Data flow in Calendar
313 // ---------------------
314
315 // The current time is represented in two ways by Calendar: as UTC
316 // milliseconds from the epoch (1 January 1970 0:00 UTC), and as local
317 // fields such as MONTH, HOUR, AM_PM, etc. It is possible to compute the
318 // millis from the fields, and vice versa. The data needed to do this
319 // conversion is encapsulated by a TimeZone object owned by the Calendar.
320 // The data provided by the TimeZone object may also be overridden if the
321 // user sets the ZONE_OFFSET and/or DST_OFFSET fields directly. The class
322 // keeps track of what information was most recently set by the caller, and
323 // uses that to compute any other information as needed.
324
325 // If the user sets the fields using set(), the data flow is as follows.
326 // This is implemented by the Calendar subclass's computeTime() method.
327 // During this process, certain fields may be ignored. The disambiguation
328 // algorithm for resolving which fields to pay attention to is described
329 // in the class documentation.
330
331 // local fields (YEAR, MONTH, DATE, HOUR, MINUTE, etc.)
332 // |
333 // | Using Calendar-specific algorithm
334 // V
335 // local standard millis
336 // |
337 // | Using TimeZone or user-set ZONE_OFFSET / DST_OFFSET
338 // V
339 // UTC millis (in time data member)
340
341 // If the user sets the UTC millis using setTime() or setTimeInMillis(),
342 // the data flow is as follows. This is implemented by the Calendar
343 // subclass's computeFields() method.
344
345 // UTC millis (in time data member)
346 // |
347 // | Using TimeZone getOffset()
348 // V
349 // local standard millis
350 // |
351 // | Using Calendar-specific algorithm
352 // V
353 // local fields (YEAR, MONTH, DATE, HOUR, MINUTE, etc.)
354
355 // In general, a round trip from fields, through local and UTC millis, and
356 // back out to fields is made when necessary. This is implemented by the
357 // complete() method. Resolving a partial set of fields into a UTC millis
358 // value allows all remaining fields to be generated from that value. If
359 // the Calendar is lenient, the fields are also renormalized to standard
360 // ranges when they are regenerated.
361
362 /**
363 * Field number for <code>get</code> and <code>set</code> indicating the
364 * era, e.g., AD or BC in the Julian calendar. This is a calendar-specific
365 * value; see subclass documentation.
366 *
367 * @see GregorianCalendar#AD
368 * @see GregorianCalendar#BC
369 */
370 public final static int ERA = 0;
371
372 /**
373 * Field number for <code>get</code> and <code>set</code> indicating the
374 * year. This is a calendar-specific value; see subclass documentation.
375 */
376 public final static int YEAR = 1;
377
378 /**
379 * Field number for <code>get</code> and <code>set</code> indicating the
380 * month. This is a calendar-specific value. The first month of
381 * the year in the Gregorian and Julian calendars is
382 * <code>JANUARY</code> which is 0; the last depends on the number
383 * of months in a year.
384 *
385 * @see #JANUARY
386 * @see #FEBRUARY
387 * @see #MARCH
388 * @see #APRIL
389 * @see #MAY
390 * @see #JUNE
391 * @see #JULY
392 * @see #AUGUST
393 * @see #SEPTEMBER
394 * @see #OCTOBER
395 * @see #NOVEMBER
396 * @see #DECEMBER
397 * @see #UNDECIMBER
398 */
399 public final static int MONTH = 2;
400
401 /**
402 * Field number for <code>get</code> and <code>set</code> indicating the
403 * week number within the current year. The first week of the year, as
404 * defined by <code>getFirstDayOfWeek()</code> and
405 * <code>getMinimalDaysInFirstWeek()</code>, has value 1. Subclasses define
406 * the value of <code>WEEK_OF_YEAR</code> for days before the first week of
407 * the year.
408 *
409 * @see #getFirstDayOfWeek
410 * @see #getMinimalDaysInFirstWeek
411 */
412 public final static int WEEK_OF_YEAR = 3;
413
414 /**
415 * Field number for <code>get</code> and <code>set</code> indicating the
416 * week number within the current month. The first week of the month, as
417 * defined by <code>getFirstDayOfWeek()</code> and
418 * <code>getMinimalDaysInFirstWeek()</code>, has value 1. Subclasses define
419 * the value of <code>WEEK_OF_MONTH</code> for days before the first week of
420 * the month.
421 *
422 * @see #getFirstDayOfWeek
423 * @see #getMinimalDaysInFirstWeek
424 */
425 public final static int WEEK_OF_MONTH = 4;
426
427 /**
428 * Field number for <code>get</code> and <code>set</code> indicating the
429 * day of the month. This is a synonym for <code>DAY_OF_MONTH</code>.
430 * The first day of the month has value 1.
431 *
432 * @see #DAY_OF_MONTH
433 */
434 public final static int DATE = 5;
435
436 /**
437 * Field number for <code>get</code> and <code>set</code> indicating the
438 * day of the month. This is a synonym for <code>DATE</code>.
439 * The first day of the month has value 1.
440 *
441 * @see #DATE
442 */
443 public final static int DAY_OF_MONTH = 5;
444
445 /**
446 * Field number for <code>get</code> and <code>set</code> indicating the day
447 * number within the current year. The first day of the year has value 1.
448 */
449 public final static int DAY_OF_YEAR = 6;
450
451 /**
452 * Field number for <code>get</code> and <code>set</code> indicating the day
453 * of the week. This field takes values <code>SUNDAY</code>,
454 * <code>MONDAY</code>, <code>TUESDAY</code>, <code>WEDNESDAY</code>,
455 * <code>THURSDAY</code>, <code>FRIDAY</code>, and <code>SATURDAY</code>.
456 *
457 * @see #SUNDAY
458 * @see #MONDAY
459 * @see #TUESDAY
460 * @see #WEDNESDAY
461 * @see #THURSDAY
462 * @see #FRIDAY
463 * @see #SATURDAY
464 */
465 public final static int DAY_OF_WEEK = 7;
466
467 /**
468 * Field number for <code>get</code> and <code>set</code> indicating the
469 * ordinal number of the day of the week within the current month. Together
470 * with the <code>DAY_OF_WEEK</code> field, this uniquely specifies a day
471 * within a month. Unlike <code>WEEK_OF_MONTH</code> and
472 * <code>WEEK_OF_YEAR</code>, this field's value does <em>not</em> depend on
473 * <code>getFirstDayOfWeek()</code> or
474 * <code>getMinimalDaysInFirstWeek()</code>. <code>DAY_OF_MONTH 1</code>
475 * through <code>7</code> always correspond to <code>DAY_OF_WEEK_IN_MONTH
476 * 1</code>; <code>8</code> through <code>14</code> correspond to
477 * <code>DAY_OF_WEEK_IN_MONTH 2</code>, and so on.
478 * <code>DAY_OF_WEEK_IN_MONTH 0</code> indicates the week before
479 * <code>DAY_OF_WEEK_IN_MONTH 1</code>. Negative values count back from the
480 * end of the month, so the last Sunday of a month is specified as
481 * <code>DAY_OF_WEEK = SUNDAY, DAY_OF_WEEK_IN_MONTH = -1</code>. Because
482 * negative values count backward they will usually be aligned differently
483 * within the month than positive values. For example, if a month has 31
484 * days, <code>DAY_OF_WEEK_IN_MONTH -1</code> will overlap
485 * <code>DAY_OF_WEEK_IN_MONTH 5</code> and the end of <code>4</code>.
486 *
487 * @see #DAY_OF_WEEK
488 * @see #WEEK_OF_MONTH
489 */
490 public final static int DAY_OF_WEEK_IN_MONTH = 8;
491
492 /**
493 * Field number for <code>get</code> and <code>set</code> indicating
494 * whether the <code>HOUR</code> is before or after noon.
495 * E.g., at 10:04:15.250 PM the <code>AM_PM</code> is <code>PM</code>.
496 *
497 * @see #AM
498 * @see #PM
499 * @see #HOUR
500 */
501 public final static int AM_PM = 9;
502
503 /**
504 * Field number for <code>get</code> and <code>set</code> indicating the
505 * hour of the morning or afternoon. <code>HOUR</code> is used for the
506 * 12-hour clock (0 - 11). Noon and midnight are represented by 0, not by 12.
507 * E.g., at 10:04:15.250 PM the <code>HOUR</code> is 10.
508 *
509 * @see #AM_PM
510 * @see #HOUR_OF_DAY
511 */
512 public final static int HOUR = 10;
513
514 /**
515 * Field number for <code>get</code> and <code>set</code> indicating the
516 * hour of the day. <code>HOUR_OF_DAY</code> is used for the 24-hour clock.
517 * E.g., at 10:04:15.250 PM the <code>HOUR_OF_DAY</code> is 22.
518 *
519 * @see #HOUR
520 */
521 public final static int HOUR_OF_DAY = 11;
522
523 /**
524 * Field number for <code>get</code> and <code>set</code> indicating the
525 * minute within the hour.
526 * E.g., at 10:04:15.250 PM the <code>MINUTE</code> is 4.
527 */
528 public final static int MINUTE = 12;
529
530 /**
531 * Field number for <code>get</code> and <code>set</code> indicating the
532 * second within the minute.
533 * E.g., at 10:04:15.250 PM the <code>SECOND</code> is 15.
534 */
535 public final static int SECOND = 13;
536
537 /**
538 * Field number for <code>get</code> and <code>set</code> indicating the
539 * millisecond within the second.
540 * E.g., at 10:04:15.250 PM the <code>MILLISECOND</code> is 250.
541 */
542 public final static int MILLISECOND = 14;
543
544 /**
545 * Field number for <code>get</code> and <code>set</code>
546 * indicating the raw offset from GMT in milliseconds.
547 * <p>
548 * This field reflects the correct GMT offset value of the time
549 * zone of this <code>Calendar</code> if the
550 * <code>TimeZone</code> implementation subclass supports
551 * historical GMT offset changes.
552 */
553 public final static int ZONE_OFFSET = 15;
554
555 /**
556 * Field number for <code>get</code> and <code>set</code> indicating the
557 * daylight saving offset in milliseconds.
558 * <p>
559 * This field reflects the correct daylight saving offset value of
560 * the time zone of this <code>Calendar</code> if the
561 * <code>TimeZone</code> implementation subclass supports
562 * historical Daylight Saving Time schedule changes.
563 */
564 public final static int DST_OFFSET = 16;
565
566 /**
567 * The number of distinct fields recognized by <code>get</code> and <code>set</code>.
568 * Field numbers range from <code>0..FIELD_COUNT-1</code>.
569 */
570 public final static int FIELD_COUNT = 17;
571
572 /**
573 * Value of the {@link #DAY_OF_WEEK} field indicating
574 * Sunday.
575 */
576 public final static int SUNDAY = 1;
577
578 /**
579 * Value of the {@link #DAY_OF_WEEK} field indicating
580 * Monday.
581 */
582 public final static int MONDAY = 2;
583
584 /**
585 * Value of the {@link #DAY_OF_WEEK} field indicating
586 * Tuesday.
587 */
588 public final static int TUESDAY = 3;
589
590 /**
591 * Value of the {@link #DAY_OF_WEEK} field indicating
592 * Wednesday.
593 */
594 public final static int WEDNESDAY = 4;
595
596 /**
597 * Value of the {@link #DAY_OF_WEEK} field indicating
598 * Thursday.
599 */
600 public final static int THURSDAY = 5;
601
602 /**
603 * Value of the {@link #DAY_OF_WEEK} field indicating
604 * Friday.
605 */
606 public final static int FRIDAY = 6;
607
608 /**
609 * Value of the {@link #DAY_OF_WEEK} field indicating
610 * Saturday.
611 */
612 public final static int SATURDAY = 7;
613
614 /**
615 * Value of the {@link #MONTH} field indicating the
616 * first month of the year in the Gregorian and Julian calendars.
617 */
618 public final static int JANUARY = 0;
619
620 /**
621 * Value of the {@link #MONTH} field indicating the
622 * second month of the year in the Gregorian and Julian calendars.
623 */
624 public final static int FEBRUARY = 1;
625
626 /**
627 * Value of the {@link #MONTH} field indicating the
628 * third month of the year in the Gregorian and Julian calendars.
629 */
630 public final static int MARCH = 2;
631
632 /**
633 * Value of the {@link #MONTH} field indicating the
634 * fourth month of the year in the Gregorian and Julian calendars.
635 */
636 public final static int APRIL = 3;
637
638 /**
639 * Value of the {@link #MONTH} field indicating the
640 * fifth month of the year in the Gregorian and Julian calendars.
641 */
642 public final static int MAY = 4;
643
644 /**
645 * Value of the {@link #MONTH} field indicating the
646 * sixth month of the year in the Gregorian and Julian calendars.
647 */
648 public final static int JUNE = 5;
649
650 /**
651 * Value of the {@link #MONTH} field indicating the
652 * seventh month of the year in the Gregorian and Julian calendars.
653 */
654 public final static int JULY = 6;
655
656 /**
657 * Value of the {@link #MONTH} field indicating the
658 * eighth month of the year in the Gregorian and Julian calendars.
659 */
660 public final static int AUGUST = 7;
661
662 /**
663 * Value of the {@link #MONTH} field indicating the
664 * ninth month of the year in the Gregorian and Julian calendars.
665 */
666 public final static int SEPTEMBER = 8;
667
668 /**
669 * Value of the {@link #MONTH} field indicating the
670 * tenth month of the year in the Gregorian and Julian calendars.
671 */
672 public final static int OCTOBER = 9;
673
674 /**
675 * Value of the {@link #MONTH} field indicating the
676 * eleventh month of the year in the Gregorian and Julian calendars.
677 */
678 public final static int NOVEMBER = 10;
679
680 /**
681 * Value of the {@link #MONTH} field indicating the
682 * twelfth month of the year in the Gregorian and Julian calendars.
683 */
684 public final static int DECEMBER = 11;
685
686 /**
687 * Value of the {@link #MONTH} field indicating the
688 * thirteenth month of the year. Although <code>GregorianCalendar</code>
689 * does not use this value, lunar calendars do.
690 */
691 public final static int UNDECIMBER = 12;
692
693 /**
694 * Value of the {@link #AM_PM} field indicating the
695 * period of the day from midnight to just before noon.
696 */
697 public final static int AM = 0;
698
699 /**
700 * Value of the {@link #AM_PM} field indicating the
701 * period of the day from noon to just before midnight.
702 */
703 public final static int PM = 1;
704
705 /**
706 * A style specifier for {@link #getDisplayNames(int, int, Locale)
707 * getDisplayNames} indicating names in all styles, such as
708 * "January" and "Jan".
709 *
710 * @see #SHORT
711 * @see #LONG
712 * @since 1.6
713 */
714 public static final int ALL_STYLES = 0;
715
716 /**
717 * A style specifier for {@link #getDisplayName(int, int, Locale)
718 * getDisplayName} and {@link #getDisplayNames(int, int, Locale)
719 * getDisplayNames} indicating a short name, such as "Jan".
720 *
721 * @see #LONG
722 * @since 1.6
723 */
724 public static final int SHORT = 1;
725
726 /**
727 * A style specifier for {@link #getDisplayName(int, int, Locale)
728 * getDisplayName} and {@link #getDisplayNames(int, int, Locale)
729 * getDisplayNames} indicating a long name, such as "January".
730 *
731 * @see #SHORT
732 * @since 1.6
733 */
734 public static final int LONG = 2;
735
736 // Internal notes:
737 // Calendar contains two kinds of time representations: current "time" in
738 // milliseconds, and a set of calendar "fields" representing the current time.
739 // The two representations are usually in sync, but can get out of sync
740 // as follows.
741 // 1. Initially, no fields are set, and the time is invalid.
742 // 2. If the time is set, all fields are computed and in sync.
743 // 3. If a single field is set, the time is invalid.
744 // Recomputation of the time and fields happens when the object needs
745 // to return a result to the user, or use a result for a computation.
746
747 /**
748 * The calendar field values for the currently set time for this calendar.
749 * This is an array of <code>FIELD_COUNT</code> integers, with index values
750 * <code>ERA</code> through <code>DST_OFFSET</code>.
751 * @serial
752 */
753 protected int fields[];
754
755 /**
756 * The flags which tell if a specified calendar field for the calendar is set.
757 * A new object has no fields set. After the first call to a method
758 * which generates the fields, they all remain set after that.
759 * This is an array of <code>FIELD_COUNT</code> booleans, with index values
760 * <code>ERA</code> through <code>DST_OFFSET</code>.
761 * @serial
762 */
763 protected boolean isSet[];
764
765 /**
766 * Pseudo-time-stamps which specify when each field was set. There
767 * are two special values, UNSET and COMPUTED. Values from
768 * MINIMUM_USER_SET to Integer.MAX_VALUE are legal user set values.
769 */
770 transient private int stamp[];
771
772 /**
773 * The currently set time for this calendar, expressed in milliseconds after
774 * January 1, 1970, 0:00:00 GMT.
775 * @see #isTimeSet
776 * @serial
777 */
778 protected long time;
779
780 /**
781 * True if then the value of <code>time</code> is valid.
782 * The time is made invalid by a change to an item of <code>field[]</code>.
783 * @see #time
784 * @serial
785 */
786 protected boolean isTimeSet;
787
788 /**
789 * True if <code>fields[]</code> are in sync with the currently set time.
790 * If false, then the next attempt to get the value of a field will
791 * force a recomputation of all fields from the current value of
792 * <code>time</code>.
793 * @serial
794 */
795 protected boolean areFieldsSet;
796
797 /**
798 * True if all fields have been set.
799 * @serial
800 */
801 transient boolean areAllFieldsSet;
802
803 /**
804 * <code>True</code> if this calendar allows out-of-range field values during computation
805 * of <code>time</code> from <code>fields[]</code>.
806 * @see #setLenient
807 * @see #isLenient
808 * @serial
809 */
810 private boolean lenient = true;
811
812 /**
813 * The <code>TimeZone</code> used by this calendar. <code>Calendar</code>
814 * uses the time zone data to translate between locale and GMT time.
815 * @serial
816 */
817 private TimeZone zone;
818
819 /**
820 * <code>True</code> if zone references to a shared TimeZone object.
821 */
822 transient private boolean sharedZone = false;
823
824 /**
825 * The first day of the week, with possible values <code>SUNDAY</code>,
826 * <code>MONDAY</code>, etc. This is a locale-dependent value.
827 * @serial
828 */
829 private int firstDayOfWeek;
830
831 /**
832 * The number of days required for the first week in a month or year,
833 * with possible values from 1 to 7. This is a locale-dependent value.
834 * @serial
835 */
836 private int minimalDaysInFirstWeek;
837
838 /**
839 * Cache to hold the firstDayOfWeek and minimalDaysInFirstWeek
840 * of a Locale.
841 */
842 private static final ConcurrentMap<Locale, int[]> cachedLocaleData
843 = new ConcurrentHashMap<>(3);
844
845 // Special values of stamp[]
846 /**
847 * The corresponding fields[] has no value.
848 */
849 private static final int UNSET = 0;
850
851 /**
852 * The value of the corresponding fields[] has been calculated internally.
853 */
854 private static final int COMPUTED = 1;
855
856 /**
857 * The value of the corresponding fields[] has been set externally. Stamp
858 * values which are greater than 1 represents the (pseudo) time when the
859 * corresponding fields[] value was set.
860 */
861 private static final int MINIMUM_USER_STAMP = 2;
862
863 /**
864 * The mask value that represents all of the fields.
865 */
866 static final int ALL_FIELDS = (1 << FIELD_COUNT) - 1;
867
868 /**
869 * The next available value for <code>stamp[]</code>, an internal array.
870 * This actually should not be written out to the stream, and will probably
871 * be removed from the stream in the near future. In the meantime,
872 * a value of <code>MINIMUM_USER_STAMP</code> should be used.
873 * @serial
874 */
875 private int nextStamp = MINIMUM_USER_STAMP;
876
877 // the internal serial version which says which version was written
878 // - 0 (default) for version up to JDK 1.1.5
879 // - 1 for version from JDK 1.1.6, which writes a correct 'time' value
880 // as well as compatible values for other fields. This is a
881 // transitional format.
882 // - 2 (not implemented yet) a future version, in which fields[],
883 // areFieldsSet, and isTimeSet become transient, and isSet[] is
884 // removed. In JDK 1.1.6 we write a format compatible with version 2.
885 static final int currentSerialVersion = 1;
886
887 /**
888 * The version of the serialized data on the stream. Possible values:
889 * <dl>
890 * <dt><b>0</b> or not present on stream</dt>
891 * <dd>
892 * JDK 1.1.5 or earlier.
893 * </dd>
894 * <dt><b>1</b></dt>
895 * <dd>
896 * JDK 1.1.6 or later. Writes a correct 'time' value
897 * as well as compatible values for other fields. This is a
898 * transitional format.
899 * </dd>
900 * </dl>
901 * When streaming out this class, the most recent format
902 * and the highest allowable <code>serialVersionOnStream</code>
903 * is written.
904 * @serial
905 * @since JDK1.1.6
906 */
907 private int serialVersionOnStream = currentSerialVersion;
908
909 // Proclaim serialization compatibility with JDK 1.1
910 static final long serialVersionUID = -1807547505821590642L;
911
912 // Mask values for calendar fields
913 final static int ERA_MASK = (1 << ERA);
914 final static int YEAR_MASK = (1 << YEAR);
915 final static int MONTH_MASK = (1 << MONTH);
916 final static int WEEK_OF_YEAR_MASK = (1 << WEEK_OF_YEAR);
917 final static int WEEK_OF_MONTH_MASK = (1 << WEEK_OF_MONTH);
918 final static int DAY_OF_MONTH_MASK = (1 << DAY_OF_MONTH);
919 final static int DATE_MASK = DAY_OF_MONTH_MASK;
920 final static int DAY_OF_YEAR_MASK = (1 << DAY_OF_YEAR);
921 final static int DAY_OF_WEEK_MASK = (1 << DAY_OF_WEEK);
922 final static int DAY_OF_WEEK_IN_MONTH_MASK = (1 << DAY_OF_WEEK_IN_MONTH);
923 final static int AM_PM_MASK = (1 << AM_PM);
924 final static int HOUR_MASK = (1 << HOUR);
925 final static int HOUR_OF_DAY_MASK = (1 << HOUR_OF_DAY);
926 final static int MINUTE_MASK = (1 << MINUTE);
927 final static int SECOND_MASK = (1 << SECOND);
928 final static int MILLISECOND_MASK = (1 << MILLISECOND);
929 final static int ZONE_OFFSET_MASK = (1 << ZONE_OFFSET);
930 final static int DST_OFFSET_MASK = (1 << DST_OFFSET);
931
932 /**
933 * Constructs a Calendar with the default time zone
934 * and locale.
935 * @see TimeZone#getDefault
936 */
937 protected Calendar()
938 {
939 this(TimeZone.getDefaultRef(), Locale.getDefault(Locale.Category.FORMAT));
940 sharedZone = true;
941 }
942
943 /**
944 * Constructs a calendar with the specified time zone and locale.
945 *
946 * @param zone the time zone to use
947 * @param aLocale the locale for the week data
948 */
949 protected Calendar(TimeZone zone, Locale aLocale)
950 {
951 fields = new int[FIELD_COUNT];
952 isSet = new boolean[FIELD_COUNT];
953 stamp = new int[FIELD_COUNT];
954
955 this.zone = zone;
956 setWeekCountData(aLocale);
957 }
958
959 /**
960 * Gets a calendar using the default time zone and locale. The
961 * <code>Calendar</code> returned is based on the current time
962 * in the default time zone with the default locale.
963 *
964 * @return a Calendar.
965 */
966 public static Calendar getInstance()
967 {
968 Calendar cal = createCalendar(TimeZone.getDefaultRef(), Locale.getDefault(Locale.Category.FORMAT));
969 cal.sharedZone = true;
970 return cal;
971 }
972
973 /**
974 * Gets a calendar using the specified time zone and default locale.
975 * The <code>Calendar</code> returned is based on the current time
976 * in the given time zone with the default locale.
977 *
978 * @param zone the time zone to use
979 * @return a Calendar.
980 */
981 public static Calendar getInstance(TimeZone zone)
982 {
983 return createCalendar(zone, Locale.getDefault(Locale.Category.FORMAT));
984 }
985
986 /**
987 * Gets a calendar using the default time zone and specified locale.
988 * The <code>Calendar</code> returned is based on the current time
989 * in the default time zone with the given locale.
990 *
991 * @param aLocale the locale for the week data
992 * @return a Calendar.
993 */
994 public static Calendar getInstance(Locale aLocale)
995 {
996 Calendar cal = createCalendar(TimeZone.getDefaultRef(), aLocale);
997 cal.sharedZone = true;
998 return cal;
999 }
1000
1001 /**
1002 * Gets a calendar with the specified time zone and locale.
1003 * The <code>Calendar</code> returned is based on the current time
1004 * in the given time zone with the given locale.
1005 *
1006 * @param zone the time zone to use
1007 * @param aLocale the locale for the week data
1008 * @return a Calendar.
1009 */
1010 public static Calendar getInstance(TimeZone zone,
1011 Locale aLocale)
1012 {
1013 return createCalendar(zone, aLocale);
1014 }
1015
1016 private static Calendar createCalendar(TimeZone zone,
1017 Locale aLocale)
1018 {
1019 Calendar cal = null;
1020
1021 String caltype = aLocale.getUnicodeLocaleType("ca");
1022 if (caltype == null) {
1023 // Calendar type is not specified.
1024 // If the specified locale is a Thai locale,
1025 // returns a BuddhistCalendar instance.
1026 if ("th".equals(aLocale.getLanguage())
1027 && ("TH".equals(aLocale.getCountry()))) {
1028 cal = new BuddhistCalendar(zone, aLocale);
1029 } else {
1030 cal = new GregorianCalendar(zone, aLocale);
1031 }
1032 } else if (caltype.equals("japanese")) {
1033 cal = new JapaneseImperialCalendar(zone, aLocale);
1034 } else if (caltype.equals("buddhist")) {
1035 cal = new BuddhistCalendar(zone, aLocale);
1036 } else {
1037 // Unsupported calendar type.
1038 // Use Gregorian calendar as a fallback.
1039 cal = new GregorianCalendar(zone, aLocale);
1040 }
1041
1042 return cal;
1043 }
1044
1045 /**
1046 * Returns an array of all locales for which the <code>getInstance</code>
1047 * methods of this class can return localized instances.
1048 * The array returned must contain at least a <code>Locale</code>
1049 * instance equal to {@link java.util.Locale#US Locale.US}.
1050 *
1051 * @return An array of locales for which localized
1052 * <code>Calendar</code> instances are available.
1053 */
1054 public static synchronized Locale[] getAvailableLocales()
1055 {
1056 return DateFormat.getAvailableLocales();
1057 }
1058
1059 /**
1060 * Converts the current calendar field values in {@link #fields fields[]}
1061 * to the millisecond time value
1062 * {@link #time}.
1063 *
1064 * @see #complete()
1065 * @see #computeFields()
1066 */
1067 protected abstract void computeTime();
1068
1069 /**
1070 * Converts the current millisecond time value {@link #time}
1071 * to calendar field values in {@link #fields fields[]}.
1072 * This allows you to sync up the calendar field values with
1073 * a new time that is set for the calendar. The time is <em>not</em>
1074 * recomputed first; to recompute the time, then the fields, call the
1075 * {@link #complete()} method.
1076 *
1077 * @see #computeTime()
1078 */
1079 protected abstract void computeFields();
1080
1081 /**
1082 * Returns a <code>Date</code> object representing this
1083 * <code>Calendar</code>'s time value (millisecond offset from the <a
1084 * href="#Epoch">Epoch</a>").
1085 *
1086 * @return a <code>Date</code> representing the time value.
1087 * @see #setTime(Date)
1088 * @see #getTimeInMillis()
1089 */
1090 public final Date getTime() {
1091 return new Date(getTimeInMillis());
1092 }
1093
1094 /**
1095 * Sets this Calendar's time with the given <code>Date</code>.
1096 * <p>
1097 * Note: Calling <code>setTime()</code> with
1098 * <code>Date(Long.MAX_VALUE)</code> or <code>Date(Long.MIN_VALUE)</code>
1099 * may yield incorrect field values from <code>get()</code>.
1100 *
1101 * @param date the given Date.
1102 * @see #getTime()
1103 * @see #setTimeInMillis(long)
1104 */
1105 public final void setTime(Date date) {
1106 setTimeInMillis(date.getTime());
1107 }
1108
1109 /**
1110 * Returns this Calendar's time value in milliseconds.
1111 *
1112 * @return the current time as UTC milliseconds from the epoch.
1113 * @see #getTime()
1114 * @see #setTimeInMillis(long)
1115 */
1116 public long getTimeInMillis() {
1117 if (!isTimeSet) {
1118 updateTime();
1119 }
1120 return time;
1121 }
1122
1123 /**
1124 * Sets this Calendar's current time from the given long value.
1125 *
1126 * @param millis the new time in UTC milliseconds from the epoch.
1127 * @see #setTime(Date)
1128 * @see #getTimeInMillis()
1129 */
1130 public void setTimeInMillis(long millis) {
1131 // If we don't need to recalculate the calendar field values,
1132 // do nothing.
1133 if (time == millis && isTimeSet && areFieldsSet && areAllFieldsSet
1134 && (zone instanceof ZoneInfo) && !((ZoneInfo)zone).isDirty()) {
1135 return;
1136 }
1137 time = millis;
1138 isTimeSet = true;
1139 areFieldsSet = false;
1140 computeFields();
1141 areAllFieldsSet = areFieldsSet = true;
1142 }
1143
1144 /**
1145 * Returns the value of the given calendar field. In lenient mode,
1146 * all calendar fields are normalized. In non-lenient mode, all
1147 * calendar fields are validated and this method throws an
1148 * exception if any calendar fields have out-of-range values. The
1149 * normalization and validation are handled by the
1150 * {@link #complete()} method, which process is calendar
1151 * system dependent.
1152 *
1153 * @param field the given calendar field.
1154 * @return the value for the given calendar field.
1155 * @throws ArrayIndexOutOfBoundsException if the specified field is out of range
1156 * (<code>field < 0 || field >= FIELD_COUNT</code>).
1157 * @see #set(int,int)
1158 * @see #complete()
1159 */
1160 public int get(int field)
1161 {
1162 complete();
1163 return internalGet(field);
1164 }
1165
1166 /**
1167 * Returns the value of the given calendar field. This method does
1168 * not involve normalization or validation of the field value.
1169 *
1170 * @param field the given calendar field.
1171 * @return the value for the given calendar field.
1172 * @see #get(int)
1173 */
1174 protected final int internalGet(int field)
1175 {
1176 return fields[field];
1177 }
1178
1179 /**
1180 * Sets the value of the given calendar field. This method does
1181 * not affect any setting state of the field in this
1182 * <code>Calendar</code> instance.
1183 *
1184 * @throws IndexOutOfBoundsException if the specified field is out of range
1185 * (<code>field < 0 || field >= FIELD_COUNT</code>).
1186 * @see #areFieldsSet
1187 * @see #isTimeSet
1188 * @see #areAllFieldsSet
1189 * @see #set(int,int)
1190 */
1191 final void internalSet(int field, int value)
1192 {
1193 fields[field] = value;
1194 }
1195
1196 /**
1197 * Sets the given calendar field to the given value. The value is not
1198 * interpreted by this method regardless of the leniency mode.
1199 *
1200 * @param field the given calendar field.
1201 * @param value the value to be set for the given calendar field.
1202 * @throws ArrayIndexOutOfBoundsException if the specified field is out of range
1203 * (<code>field < 0 || field >= FIELD_COUNT</code>).
1204 * in non-lenient mode.
1205 * @see #set(int,int,int)
1206 * @see #set(int,int,int,int,int)
1207 * @see #set(int,int,int,int,int,int)
1208 * @see #get(int)
1209 */
1210 public void set(int field, int value)
1211 {
1212 // If the fields are partially normalized, calculate all the
1213 // fields before changing any fields.
1214 if (areFieldsSet && !areAllFieldsSet) {
1215 computeFields();
1216 }
1217 internalSet(field, value);
1218 isTimeSet = false;
1219 areFieldsSet = false;
1220 isSet[field] = true;
1221 stamp[field] = nextStamp++;
1222 if (nextStamp == Integer.MAX_VALUE) {
1223 adjustStamp();
1224 }
1225 }
1226
1227 /**
1228 * Sets the values for the calendar fields <code>YEAR</code>,
1229 * <code>MONTH</code>, and <code>DAY_OF_MONTH</code>.
1230 * Previous values of other calendar fields are retained. If this is not desired,
1231 * call {@link #clear()} first.
1232 *
1233 * @param year the value used to set the <code>YEAR</code> calendar field.
1234 * @param month the value used to set the <code>MONTH</code> calendar field.
1235 * Month value is 0-based. e.g., 0 for January.
1236 * @param date the value used to set the <code>DAY_OF_MONTH</code> calendar field.
1237 * @see #set(int,int)
1238 * @see #set(int,int,int,int,int)
1239 * @see #set(int,int,int,int,int,int)
1240 */
1241 public final void set(int year, int month, int date)
1242 {
1243 set(YEAR, year);
1244 set(MONTH, month);
1245 set(DATE, date);
1246 }
1247
1248 /**
1249 * Sets the values for the calendar fields <code>YEAR</code>,
1250 * <code>MONTH</code>, <code>DAY_OF_MONTH</code>,
1251 * <code>HOUR_OF_DAY</code>, and <code>MINUTE</code>.
1252 * Previous values of other fields are retained. If this is not desired,
1253 * call {@link #clear()} first.
1254 *
1255 * @param year the value used to set the <code>YEAR</code> calendar field.
1256 * @param month the value used to set the <code>MONTH</code> calendar field.
1257 * Month value is 0-based. e.g., 0 for January.
1258 * @param date the value used to set the <code>DAY_OF_MONTH</code> calendar field.
1259 * @param hourOfDay the value used to set the <code>HOUR_OF_DAY</code> calendar field.
1260 * @param minute the value used to set the <code>MINUTE</code> calendar field.
1261 * @see #set(int,int)
1262 * @see #set(int,int,int)
1263 * @see #set(int,int,int,int,int,int)
1264 */
1265 public final void set(int year, int month, int date, int hourOfDay, int minute)
1266 {
1267 set(YEAR, year);
1268 set(MONTH, month);
1269 set(DATE, date);
1270 set(HOUR_OF_DAY, hourOfDay);
1271 set(MINUTE, minute);
1272 }
1273
1274 /**
1275 * Sets the values for the fields <code>YEAR</code>, <code>MONTH</code>,
1276 * <code>DAY_OF_MONTH</code>, <code>HOUR</code>, <code>MINUTE</code>, and
1277 * <code>SECOND</code>.
1278 * Previous values of other fields are retained. If this is not desired,
1279 * call {@link #clear()} first.
1280 *
1281 * @param year the value used to set the <code>YEAR</code> calendar field.
1282 * @param month the value used to set the <code>MONTH</code> calendar field.
1283 * Month value is 0-based. e.g., 0 for January.
1284 * @param date the value used to set the <code>DAY_OF_MONTH</code> calendar field.
1285 * @param hourOfDay the value used to set the <code>HOUR_OF_DAY</code> calendar field.
1286 * @param minute the value used to set the <code>MINUTE</code> calendar field.
1287 * @param second the value used to set the <code>SECOND</code> calendar field.
1288 * @see #set(int,int)
1289 * @see #set(int,int,int)
1290 * @see #set(int,int,int,int,int)
1291 */
1292 public final void set(int year, int month, int date, int hourOfDay, int minute,
1293 int second)
1294 {
1295 set(YEAR, year);
1296 set(MONTH, month);
1297 set(DATE, date);
1298 set(HOUR_OF_DAY, hourOfDay);
1299 set(MINUTE, minute);
1300 set(SECOND, second);
1301 }
1302
1303 /**
1304 * Sets all the calendar field values and the time value
1305 * (millisecond offset from the <a href="#Epoch">Epoch</a>) of
1306 * this <code>Calendar</code> undefined. This means that {@link
1307 * #isSet(int) isSet()} will return <code>false</code> for all the
1308 * calendar fields, and the date and time calculations will treat
1309 * the fields as if they had never been set. A
1310 * <code>Calendar</code> implementation class may use its specific
1311 * default field values for date/time calculations. For example,
1312 * <code>GregorianCalendar</code> uses 1970 if the
1313 * <code>YEAR</code> field value is undefined.
1314 *
1315 * @see #clear(int)
1316 */
1317 public final void clear()
1318 {
1319 for (int i = 0; i < fields.length; ) {
1320 stamp[i] = fields[i] = 0; // UNSET == 0
1321 isSet[i++] = false;
1322 }
1323 areAllFieldsSet = areFieldsSet = false;
1324 isTimeSet = false;
1325 }
1326
1327 /**
1328 * Sets the given calendar field value and the time value
1329 * (millisecond offset from the <a href="#Epoch">Epoch</a>) of
1330 * this <code>Calendar</code> undefined. This means that {@link
1331 * #isSet(int) isSet(field)} will return <code>false</code>, and
1332 * the date and time calculations will treat the field as if it
1333 * had never been set. A <code>Calendar</code> implementation
1334 * class may use the field's specific default value for date and
1335 * time calculations.
1336 *
1337 * <p>The {@link #HOUR_OF_DAY}, {@link #HOUR} and {@link #AM_PM}
1338 * fields are handled independently and the <a
1339 * href="#time_resolution">the resolution rule for the time of
1340 * day</a> is applied. Clearing one of the fields doesn't reset
1341 * the hour of day value of this <code>Calendar</code>. Use {@link
1342 * #set(int,int) set(Calendar.HOUR_OF_DAY, 0)} to reset the hour
1343 * value.
1344 *
1345 * @param field the calendar field to be cleared.
1346 * @see #clear()
1347 */
1348 public final void clear(int field)
1349 {
1350 fields[field] = 0;
1351 stamp[field] = UNSET;
1352 isSet[field] = false;
1353
1354 areAllFieldsSet = areFieldsSet = false;
1355 isTimeSet = false;
1356 }
1357
1358 /**
1359 * Determines if the given calendar field has a value set,
1360 * including cases that the value has been set by internal fields
1361 * calculations triggered by a <code>get</code> method call.
1362 *
1363 * @return <code>true</code> if the given calendar field has a value set;
1364 * <code>false</code> otherwise.
1365 */
1366 public final boolean isSet(int field)
1367 {
1368 return stamp[field] != UNSET;
1369 }
1370
1371 /**
1372 * Returns the string representation of the calendar
1373 * <code>field</code> value in the given <code>style</code> and
1374 * <code>locale</code>. If no string representation is
1375 * applicable, <code>null</code> is returned. This method calls
1376 * {@link Calendar#get(int) get(field)} to get the calendar
1377 * <code>field</code> value if the string representation is
1378 * applicable to the given calendar <code>field</code>.
1379 *
1380 * <p>For example, if this <code>Calendar</code> is a
1381 * <code>GregorianCalendar</code> and its date is 2005-01-01, then
1382 * the string representation of the {@link #MONTH} field would be
1383 * "January" in the long style in an English locale or "Jan" in
1384 * the short style. However, no string representation would be
1385 * available for the {@link #DAY_OF_MONTH} field, and this method
1386 * would return <code>null</code>.
1387 *
1388 * <p>The default implementation supports the calendar fields for
1389 * which a {@link DateFormatSymbols} has names in the given
1390 * <code>locale</code>.
1391 *
1392 * @param field
1393 * the calendar field for which the string representation
1394 * is returned
1395 * @param style
1396 * the style applied to the string representation; one of
1397 * {@link #SHORT} or {@link #LONG}.
1398 * @param locale
1399 * the locale for the string representation
1400 * @return the string representation of the given
1401 * <code>field</code> in the given <code>style</code>, or
1402 * <code>null</code> if no string representation is
1403 * applicable.
1404 * @exception IllegalArgumentException
1405 * if <code>field</code> or <code>style</code> is invalid,
1406 * or if this <code>Calendar</code> is non-lenient and any
1407 * of the calendar fields have invalid values
1408 * @exception NullPointerException
1409 * if <code>locale</code> is null
1410 * @since 1.6
1411 */
1412 public String getDisplayName(int field, int style, Locale locale) {
1413 if (!checkDisplayNameParams(field, style, ALL_STYLES, LONG, locale,
1414 ERA_MASK|MONTH_MASK|DAY_OF_WEEK_MASK|AM_PM_MASK)) {
1415 return null;
1416 }
1417
1418 DateFormatSymbols symbols = DateFormatSymbols.getInstance(locale);
1419 String[] strings = getFieldStrings(field, style, symbols);
1420 if (strings != null) {
1421 int fieldValue = get(field);
1422 if (fieldValue < strings.length) {
1423 return strings[fieldValue];
1424 }
1425 }
1426 return null;
1427 }
1428
1429 /**
1430 * Returns a <code>Map</code> containing all names of the calendar
1431 * <code>field</code> in the given <code>style</code> and
1432 * <code>locale</code> and their corresponding field values. For
1433 * example, if this <code>Calendar</code> is a {@link
1434 * GregorianCalendar}, the returned map would contain "Jan" to
1435 * {@link #JANUARY}, "Feb" to {@link #FEBRUARY}, and so on, in the
1436 * {@linkplain #SHORT short} style in an English locale.
1437 *
1438 * <p>The values of other calendar fields may be taken into
1439 * account to determine a set of display names. For example, if
1440 * this <code>Calendar</code> is a lunisolar calendar system and
1441 * the year value given by the {@link #YEAR} field has a leap
1442 * month, this method would return month names containing the leap
1443 * month name, and month names are mapped to their values specific
1444 * for the year.
1445 *
1446 * <p>The default implementation supports display names contained in
1447 * a {@link DateFormatSymbols}. For example, if <code>field</code>
1448 * is {@link #MONTH} and <code>style</code> is {@link
1449 * #ALL_STYLES}, this method returns a <code>Map</code> containing
1450 * all strings returned by {@link DateFormatSymbols#getShortMonths()}
1451 * and {@link DateFormatSymbols#getMonths()}.
1452 *
1453 * @param field
1454 * the calendar field for which the display names are returned
1455 * @param style
1456 * the style applied to the display names; one of {@link
1457 * #SHORT}, {@link #LONG}, or {@link #ALL_STYLES}.
1458 * @param locale
1459 * the locale for the display names
1460 * @return a <code>Map</code> containing all display names in
1461 * <code>style</code> and <code>locale</code> and their
1462 * field values, or <code>null</code> if no display names
1463 * are defined for <code>field</code>
1464 * @exception IllegalArgumentException
1465 * if <code>field</code> or <code>style</code> is invalid,
1466 * or if this <code>Calendar</code> is non-lenient and any
1467 * of the calendar fields have invalid values
1468 * @exception NullPointerException
1469 * if <code>locale</code> is null
1470 * @since 1.6
1471 */
1472 public Map<String, Integer> getDisplayNames(int field, int style, Locale locale) {
1473 if (!checkDisplayNameParams(field, style, ALL_STYLES, LONG, locale,
1474 ERA_MASK|MONTH_MASK|DAY_OF_WEEK_MASK|AM_PM_MASK)) {
1475 return null;
1476 }
1477
1478 // ALL_STYLES
1479 if (style == ALL_STYLES) {
1480 Map<String,Integer> shortNames = getDisplayNamesImpl(field, SHORT, locale);
1481 if (field == ERA || field == AM_PM) {
1482 return shortNames;
1483 }
1484 Map<String,Integer> longNames = getDisplayNamesImpl(field, LONG, locale);
1485 if (shortNames == null) {
1486 return longNames;
1487 }
1488 if (longNames != null) {
1489 shortNames.putAll(longNames);
1490 }
1491 return shortNames;
1492 }
1493
1494 // SHORT or LONG
1495 return getDisplayNamesImpl(field, style, locale);
1496 }
1497
1498 private Map<String,Integer> getDisplayNamesImpl(int field, int style, Locale locale) {
1499 DateFormatSymbols symbols = DateFormatSymbols.getInstance(locale);
1500 String[] strings = getFieldStrings(field, style, symbols);
1501 if (strings != null) {
1502 Map<String,Integer> names = new HashMap<>();
1503 for (int i = 0; i < strings.length; i++) {
1504 if (strings[i].length() == 0) {
1505 continue;
1506 }
1507 names.put(strings[i], i);
1508 }
1509 return names;
1510 }
1511 return null;
1512 }
1513
1514 boolean checkDisplayNameParams(int field, int style, int minStyle, int maxStyle,
1515 Locale locale, int fieldMask) {
1516 if (field < 0 || field >= fields.length ||
1517 style < minStyle || style > maxStyle) {
1518 throw new IllegalArgumentException();
1519 }
1520 if (locale == null) {
1521 throw new NullPointerException();
1522 }
1523 return isFieldSet(fieldMask, field);
1524 }
1525
1526 private String[] getFieldStrings(int field, int style, DateFormatSymbols symbols) {
1527 String[] strings = null;
1528 switch (field) {
1529 case ERA:
1530 strings = symbols.getEras();
1531 break;
1532
1533 case MONTH:
1534 strings = (style == LONG) ? symbols.getMonths() : symbols.getShortMonths();
1535 break;
1536
1537 case DAY_OF_WEEK:
1538 strings = (style == LONG) ? symbols.getWeekdays() : symbols.getShortWeekdays();
1539 break;
1540
1541 case AM_PM:
1542 strings = symbols.getAmPmStrings();
1543 break;
1544 }
1545 return strings;
1546 }
1547
1548 /**
1549 * Fills in any unset fields in the calendar fields. First, the {@link
1550 * #computeTime()} method is called if the time value (millisecond offset
1551 * from the <a href="#Epoch">Epoch</a>) has not been calculated from
1552 * calendar field values. Then, the {@link #computeFields()} method is
1553 * called to calculate all calendar field values.
1554 */
1555 protected void complete()
1556 {
1557 if (!isTimeSet)
1558 updateTime();
1559 if (!areFieldsSet || !areAllFieldsSet) {
1560 computeFields(); // fills in unset fields
1561 areAllFieldsSet = areFieldsSet = true;
1562 }
1563 }
1564
1565 /**
1566 * Returns whether the value of the specified calendar field has been set
1567 * externally by calling one of the setter methods rather than by the
1568 * internal time calculation.
1569 *
1570 * @return <code>true</code> if the field has been set externally,
1571 * <code>false</code> otherwise.
1572 * @exception IndexOutOfBoundsException if the specified
1573 * <code>field</code> is out of range
1574 * (<code>field < 0 || field >= FIELD_COUNT</code>).
1575 * @see #selectFields()
1576 * @see #setFieldsComputed(int)
1577 */
1578 final boolean isExternallySet(int field) {
1579 return stamp[field] >= MINIMUM_USER_STAMP;
1580 }
1581
1582 /**
1583 * Returns a field mask (bit mask) indicating all calendar fields that
1584 * have the state of externally or internally set.
1585 *
1586 * @return a bit mask indicating set state fields
1587 */
1588 final int getSetStateFields() {
1589 int mask = 0;
1590 for (int i = 0; i < fields.length; i++) {
1591 if (stamp[i] != UNSET) {
1592 mask |= 1 << i;
1593 }
1594 }
1595 return mask;
1596 }
1597
1598 /**
1599 * Sets the state of the specified calendar fields to
1600 * <em>computed</em>. This state means that the specified calendar fields
1601 * have valid values that have been set by internal time calculation
1602 * rather than by calling one of the setter methods.
1603 *
1604 * @param fieldMask the field to be marked as computed.
1605 * @exception IndexOutOfBoundsException if the specified
1606 * <code>field</code> is out of range
1607 * (<code>field < 0 || field >= FIELD_COUNT</code>).
1608 * @see #isExternallySet(int)
1609 * @see #selectFields()
1610 */
1611 final void setFieldsComputed(int fieldMask) {
1612 if (fieldMask == ALL_FIELDS) {
1613 for (int i = 0; i < fields.length; i++) {
1614 stamp[i] = COMPUTED;
1615 isSet[i] = true;
1616 }
1617 areFieldsSet = areAllFieldsSet = true;
1618 } else {
1619 for (int i = 0; i < fields.length; i++) {
1620 if ((fieldMask & 1) == 1) {
1621 stamp[i] = COMPUTED;
1622 isSet[i] = true;
1623 } else {
1624 if (areAllFieldsSet && !isSet[i]) {
1625 areAllFieldsSet = false;
1626 }
1627 }
1628 fieldMask >>>= 1;
1629 }
1630 }
1631 }
1632
1633 /**
1634 * Sets the state of the calendar fields that are <em>not</em> specified
1635 * by <code>fieldMask</code> to <em>unset</em>. If <code>fieldMask</code>
1636 * specifies all the calendar fields, then the state of this
1637 * <code>Calendar</code> becomes that all the calendar fields are in sync
1638 * with the time value (millisecond offset from the Epoch).
1639 *
1640 * @param fieldMask the field mask indicating which calendar fields are in
1641 * sync with the time value.
1642 * @exception IndexOutOfBoundsException if the specified
1643 * <code>field</code> is out of range
1644 * (<code>field < 0 || field >= FIELD_COUNT</code>).
1645 * @see #isExternallySet(int)
1646 * @see #selectFields()
1647 */
1648 final void setFieldsNormalized(int fieldMask) {
1649 if (fieldMask != ALL_FIELDS) {
1650 for (int i = 0; i < fields.length; i++) {
1651 if ((fieldMask & 1) == 0) {
1652 stamp[i] = fields[i] = 0; // UNSET == 0
1653 isSet[i] = false;
1654 }
1655 fieldMask >>= 1;
1656 }
1657 }
1658
1659 // Some or all of the fields are in sync with the
1660 // milliseconds, but the stamp values are not normalized yet.
1661 areFieldsSet = true;
1662 areAllFieldsSet = false;
1663 }
1664
1665 /**
1666 * Returns whether the calendar fields are partially in sync with the time
1667 * value or fully in sync but not stamp values are not normalized yet.
1668 */
1669 final boolean isPartiallyNormalized() {
1670 return areFieldsSet && !areAllFieldsSet;
1671 }
1672
1673 /**
1674 * Returns whether the calendar fields are fully in sync with the time
1675 * value.
1676 */
1677 final boolean isFullyNormalized() {
1678 return areFieldsSet && areAllFieldsSet;
1679 }
1680
1681 /**
1682 * Marks this Calendar as not sync'd.
1683 */
1684 final void setUnnormalized() {
1685 areFieldsSet = areAllFieldsSet = false;
1686 }
1687
1688 /**
1689 * Returns whether the specified <code>field</code> is on in the
1690 * <code>fieldMask</code>.
1691 */
1692 static final boolean isFieldSet(int fieldMask, int field) {
1693 return (fieldMask & (1 << field)) != 0;
1694 }
1695
1696 /**
1697 * Returns a field mask indicating which calendar field values
1698 * to be used to calculate the time value. The calendar fields are
1699 * returned as a bit mask, each bit of which corresponds to a field, i.e.,
1700 * the mask value of <code>field</code> is <code>(1 <<
1701 * field)</code>. For example, 0x26 represents the <code>YEAR</code>,
1702 * <code>MONTH</code>, and <code>DAY_OF_MONTH</code> fields (i.e., 0x26 is
1703 * equal to
1704 * <code>(1<<YEAR)|(1<<MONTH)|(1<<DAY_OF_MONTH))</code>.
1705 *
1706 * <p>This method supports the calendar fields resolution as described in
1707 * the class description. If the bit mask for a given field is on and its
1708 * field has not been set (i.e., <code>isSet(field)</code> is
1709 * <code>false</code>), then the default value of the field has to be
1710 * used, which case means that the field has been selected because the
1711 * selected combination involves the field.
1712 *
1713 * @return a bit mask of selected fields
1714 * @see #isExternallySet(int)
1715 * @see #setInternallySetState(int)
1716 */
1717 final int selectFields() {
1718 // This implementation has been taken from the GregorianCalendar class.
1719
1720 // The YEAR field must always be used regardless of its SET
1721 // state because YEAR is a mandatory field to determine the date
1722 // and the default value (EPOCH_YEAR) may change through the
1723 // normalization process.
1724 int fieldMask = YEAR_MASK;
1725
1726 if (stamp[ERA] != UNSET) {
1727 fieldMask |= ERA_MASK;
1728 }
1729 // Find the most recent group of fields specifying the day within
1730 // the year. These may be any of the following combinations:
1731 // MONTH + DAY_OF_MONTH
1732 // MONTH + WEEK_OF_MONTH + DAY_OF_WEEK
1733 // MONTH + DAY_OF_WEEK_IN_MONTH + DAY_OF_WEEK
1734 // DAY_OF_YEAR
1735 // WEEK_OF_YEAR + DAY_OF_WEEK
1736 // We look for the most recent of the fields in each group to determine
1737 // the age of the group. For groups involving a week-related field such
1738 // as WEEK_OF_MONTH, DAY_OF_WEEK_IN_MONTH, or WEEK_OF_YEAR, both the
1739 // week-related field and the DAY_OF_WEEK must be set for the group as a
1740 // whole to be considered. (See bug 4153860 - liu 7/24/98.)
1741 int dowStamp = stamp[DAY_OF_WEEK];
1742 int monthStamp = stamp[MONTH];
1743 int domStamp = stamp[DAY_OF_MONTH];
1744 int womStamp = aggregateStamp(stamp[WEEK_OF_MONTH], dowStamp);
1745 int dowimStamp = aggregateStamp(stamp[DAY_OF_WEEK_IN_MONTH], dowStamp);
1746 int doyStamp = stamp[DAY_OF_YEAR];
1747 int woyStamp = aggregateStamp(stamp[WEEK_OF_YEAR], dowStamp);
1748
1749 int bestStamp = domStamp;
1750 if (womStamp > bestStamp) {
1751 bestStamp = womStamp;
1752 }
1753 if (dowimStamp > bestStamp) {
1754 bestStamp = dowimStamp;
1755 }
1756 if (doyStamp > bestStamp) {
1757 bestStamp = doyStamp;
1758 }
1759 if (woyStamp > bestStamp) {
1760 bestStamp = woyStamp;
1761 }
1762
1763 /* No complete combination exists. Look for WEEK_OF_MONTH,
1764 * DAY_OF_WEEK_IN_MONTH, or WEEK_OF_YEAR alone. Treat DAY_OF_WEEK alone
1765 * as DAY_OF_WEEK_IN_MONTH.
1766 */
1767 if (bestStamp == UNSET) {
1768 womStamp = stamp[WEEK_OF_MONTH];
1769 dowimStamp = Math.max(stamp[DAY_OF_WEEK_IN_MONTH], dowStamp);
1770 woyStamp = stamp[WEEK_OF_YEAR];
1771 bestStamp = Math.max(Math.max(womStamp, dowimStamp), woyStamp);
1772
1773 /* Treat MONTH alone or no fields at all as DAY_OF_MONTH. This may
1774 * result in bestStamp = domStamp = UNSET if no fields are set,
1775 * which indicates DAY_OF_MONTH.
1776 */
1777 if (bestStamp == UNSET) {
1778 bestStamp = domStamp = monthStamp;
1779 }
1780 }
1781
1782 if (bestStamp == domStamp ||
1783 (bestStamp == womStamp && stamp[WEEK_OF_MONTH] >= stamp[WEEK_OF_YEAR]) ||
1784 (bestStamp == dowimStamp && stamp[DAY_OF_WEEK_IN_MONTH] >= stamp[WEEK_OF_YEAR])) {
1785 fieldMask |= MONTH_MASK;
1786 if (bestStamp == domStamp) {
1787 fieldMask |= DAY_OF_MONTH_MASK;
1788 } else {
1789 assert (bestStamp == womStamp || bestStamp == dowimStamp);
1790 if (dowStamp != UNSET) {
1791 fieldMask |= DAY_OF_WEEK_MASK;
1792 }
1793 if (womStamp == dowimStamp) {
1794 // When they are equal, give the priority to
1795 // WEEK_OF_MONTH for compatibility.
1796 if (stamp[WEEK_OF_MONTH] >= stamp[DAY_OF_WEEK_IN_MONTH]) {
1797 fieldMask |= WEEK_OF_MONTH_MASK;
1798 } else {
1799 fieldMask |= DAY_OF_WEEK_IN_MONTH_MASK;
1800 }
1801 } else {
1802 if (bestStamp == womStamp) {
1803 fieldMask |= WEEK_OF_MONTH_MASK;
1804 } else {
1805 assert (bestStamp == dowimStamp);
1806 if (stamp[DAY_OF_WEEK_IN_MONTH] != UNSET) {
1807 fieldMask |= DAY_OF_WEEK_IN_MONTH_MASK;
1808 }
1809 }
1810 }
1811 }
1812 } else {
1813 assert (bestStamp == doyStamp || bestStamp == woyStamp ||
1814 bestStamp == UNSET);
1815 if (bestStamp == doyStamp) {
1816 fieldMask |= DAY_OF_YEAR_MASK;
1817 } else {
1818 assert (bestStamp == woyStamp);
1819 if (dowStamp != UNSET) {
1820 fieldMask |= DAY_OF_WEEK_MASK;
1821 }
1822 fieldMask |= WEEK_OF_YEAR_MASK;
1823 }
1824 }
1825
1826 // Find the best set of fields specifying the time of day. There
1827 // are only two possibilities here; the HOUR_OF_DAY or the
1828 // AM_PM and the HOUR.
1829 int hourOfDayStamp = stamp[HOUR_OF_DAY];
1830 int hourStamp = aggregateStamp(stamp[HOUR], stamp[AM_PM]);
1831 bestStamp = (hourStamp > hourOfDayStamp) ? hourStamp : hourOfDayStamp;
1832
1833 // if bestStamp is still UNSET, then take HOUR or AM_PM. (See 4846659)
1834 if (bestStamp == UNSET) {
1835 bestStamp = Math.max(stamp[HOUR], stamp[AM_PM]);
1836 }
1837
1838 // Hours
1839 if (bestStamp != UNSET) {
1840 if (bestStamp == hourOfDayStamp) {
1841 fieldMask |= HOUR_OF_DAY_MASK;
1842 } else {
1843 fieldMask |= HOUR_MASK;
1844 if (stamp[AM_PM] != UNSET) {
1845 fieldMask |= AM_PM_MASK;
1846 }
1847 }
1848 }
1849 if (stamp[MINUTE] != UNSET) {
1850 fieldMask |= MINUTE_MASK;
1851 }
1852 if (stamp[SECOND] != UNSET) {
1853 fieldMask |= SECOND_MASK;
1854 }
1855 if (stamp[MILLISECOND] != UNSET) {
1856 fieldMask |= MILLISECOND_MASK;
1857 }
1858 if (stamp[ZONE_OFFSET] >= MINIMUM_USER_STAMP) {
1859 fieldMask |= ZONE_OFFSET_MASK;
1860 }
1861 if (stamp[DST_OFFSET] >= MINIMUM_USER_STAMP) {
1862 fieldMask |= DST_OFFSET_MASK;
1863 }
1864
1865 return fieldMask;
1866 }
1867
1868 /**
1869 * Returns the pseudo-time-stamp for two fields, given their
1870 * individual pseudo-time-stamps. If either of the fields
1871 * is unset, then the aggregate is unset. Otherwise, the
1872 * aggregate is the later of the two stamps.
1873 */
1874 private static final int aggregateStamp(int stamp_a, int stamp_b) {
1875 if (stamp_a == UNSET || stamp_b == UNSET) {
1876 return UNSET;
1877 }
1878 return (stamp_a > stamp_b) ? stamp_a : stamp_b;
1879 }
1880
1881 /**
1882 * Compares this <code>Calendar</code> to the specified
1883 * <code>Object</code>. The result is <code>true</code> if and only if
1884 * the argument is a <code>Calendar</code> object of the same calendar
1885 * system that represents the same time value (millisecond offset from the
1886 * <a href="#Epoch">Epoch</a>) under the same
1887 * <code>Calendar</code> parameters as this object.
1888 *
1889 * <p>The <code>Calendar</code> parameters are the values represented
1890 * by the <code>isLenient</code>, <code>getFirstDayOfWeek</code>,
1891 * <code>getMinimalDaysInFirstWeek</code> and <code>getTimeZone</code>
1892 * methods. If there is any difference in those parameters
1893 * between the two <code>Calendar</code>s, this method returns
1894 * <code>false</code>.
1895 *
1896 * <p>Use the {@link #compareTo(Calendar) compareTo} method to
1897 * compare only the time values.
1898 *
1899 * @param obj the object to compare with.
1900 * @return <code>true</code> if this object is equal to <code>obj</code>;
1901 * <code>false</code> otherwise.
1902 */
1903 public boolean equals(Object obj) {
1904 if (this == obj)
1905 return true;
1906 try {
1907 Calendar that = (Calendar)obj;
1908 return compareTo(getMillisOf(that)) == 0 &&
1909 lenient == that.lenient &&
1910 firstDayOfWeek == that.firstDayOfWeek &&
1911 minimalDaysInFirstWeek == that.minimalDaysInFirstWeek &&
1912 zone.equals(that.zone);
1913 } catch (Exception e) {
1914 // Note: GregorianCalendar.computeTime throws
1915 // IllegalArgumentException if the ERA value is invalid
1916 // even it's in lenient mode.
1917 }
1918 return false;
1919 }
1920
1921 /**
1922 * Returns a hash code for this calendar.
1923 *
1924 * @return a hash code value for this object.
1925 * @since 1.2
1926 */
1927 public int hashCode() {
1928 // 'otheritems' represents the hash code for the previous versions.
1929 int otheritems = (lenient ? 1 : 0)
1930 | (firstDayOfWeek << 1)
1931 | (minimalDaysInFirstWeek << 4)
1932 | (zone.hashCode() << 7);
1933 long t = getMillisOf(this);
1934 return (int) t ^ (int)(t >> 32) ^ otheritems;
1935 }
1936
1937 /**
1938 * Returns whether this <code>Calendar</code> represents a time
1939 * before the time represented by the specified
1940 * <code>Object</code>. This method is equivalent to:
1941 * <pre><blockquote>
1942 * compareTo(when) < 0
1943 * </blockquote></pre>
1944 * if and only if <code>when</code> is a <code>Calendar</code>
1945 * instance. Otherwise, the method returns <code>false</code>.
1946 *
1947 * @param when the <code>Object</code> to be compared
1948 * @return <code>true</code> if the time of this
1949 * <code>Calendar</code> is before the time represented by
1950 * <code>when</code>; <code>false</code> otherwise.
1951 * @see #compareTo(Calendar)
1952 */
1953 public boolean before(Object when) {
1954 return when instanceof Calendar
1955 && compareTo((Calendar)when) < 0;
1956 }
1957
1958 /**
1959 * Returns whether this <code>Calendar</code> represents a time
1960 * after the time represented by the specified
1961 * <code>Object</code>. This method is equivalent to:
1962 * <pre><blockquote>
1963 * compareTo(when) > 0
1964 * </blockquote></pre>
1965 * if and only if <code>when</code> is a <code>Calendar</code>
1966 * instance. Otherwise, the method returns <code>false</code>.
1967 *
1968 * @param when the <code>Object</code> to be compared
1969 * @return <code>true</code> if the time of this <code>Calendar</code> is
1970 * after the time represented by <code>when</code>; <code>false</code>
1971 * otherwise.
1972 * @see #compareTo(Calendar)
1973 */
1974 public boolean after(Object when) {
1975 return when instanceof Calendar
1976 && compareTo((Calendar)when) > 0;
1977 }
1978
1979 /**
1980 * Compares the time values (millisecond offsets from the <a
1981 * href="#Epoch">Epoch</a>) represented by two
1982 * <code>Calendar</code> objects.
1983 *
1984 * @param anotherCalendar the <code>Calendar</code> to be compared.
1985 * @return the value <code>0</code> if the time represented by the argument
1986 * is equal to the time represented by this <code>Calendar</code>; a value
1987 * less than <code>0</code> if the time of this <code>Calendar</code> is
1988 * before the time represented by the argument; and a value greater than
1989 * <code>0</code> if the time of this <code>Calendar</code> is after the
1990 * time represented by the argument.
1991 * @exception NullPointerException if the specified <code>Calendar</code> is
1992 * <code>null</code>.
1993 * @exception IllegalArgumentException if the time value of the
1994 * specified <code>Calendar</code> object can't be obtained due to
1995 * any invalid calendar values.
1996 * @since 1.5
1997 */
1998 public int compareTo(Calendar anotherCalendar) {
1999 return compareTo(getMillisOf(anotherCalendar));
2000 }
2001
2002 /**
2003 * Adds or subtracts the specified amount of time to the given calendar field,
2004 * based on the calendar's rules. For example, to subtract 5 days from
2005 * the current time of the calendar, you can achieve it by calling:
2006 * <p><code>add(Calendar.DAY_OF_MONTH, -5)</code>.
2007 *
2008 * @param field the calendar field.
2009 * @param amount the amount of date or time to be added to the field.
2010 * @see #roll(int,int)
2011 * @see #set(int,int)
2012 */
2013 abstract public void add(int field, int amount);
2014
2015 /**
2016 * Adds or subtracts (up/down) a single unit of time on the given time
2017 * field without changing larger fields. For example, to roll the current
2018 * date up by one day, you can achieve it by calling:
2019 * <p>roll(Calendar.DATE, true).
2020 * When rolling on the year or Calendar.YEAR field, it will roll the year
2021 * value in the range between 1 and the value returned by calling
2022 * <code>getMaximum(Calendar.YEAR)</code>.
2023 * When rolling on the month or Calendar.MONTH field, other fields like
2024 * date might conflict and, need to be changed. For instance,
2025 * rolling the month on the date 01/31/96 will result in 02/29/96.
2026 * When rolling on the hour-in-day or Calendar.HOUR_OF_DAY field, it will
2027 * roll the hour value in the range between 0 and 23, which is zero-based.
2028 *
2029 * @param field the time field.
2030 * @param up indicates if the value of the specified time field is to be
2031 * rolled up or rolled down. Use true if rolling up, false otherwise.
2032 * @see Calendar#add(int,int)
2033 * @see Calendar#set(int,int)
2034 */
2035 abstract public void roll(int field, boolean up);
2036
2037 /**
2038 * Adds the specified (signed) amount to the specified calendar field
2039 * without changing larger fields. A negative amount means to roll
2040 * down.
2041 *
2042 * <p>NOTE: This default implementation on <code>Calendar</code> just repeatedly calls the
2043 * version of {@link #roll(int,boolean) roll()} that rolls by one unit. This may not
2044 * always do the right thing. For example, if the <code>DAY_OF_MONTH</code> field is 31,
2045 * rolling through February will leave it set to 28. The <code>GregorianCalendar</code>
2046 * version of this function takes care of this problem. Other subclasses
2047 * should also provide overrides of this function that do the right thing.
2048 *
2049 * @param field the calendar field.
2050 * @param amount the signed amount to add to the calendar <code>field</code>.
2051 * @since 1.2
2052 * @see #roll(int,boolean)
2053 * @see #add(int,int)
2054 * @see #set(int,int)
2055 */
2056 public void roll(int field, int amount)
2057 {
2058 while (amount > 0) {
2059 roll(field, true);
2060 amount--;
2061 }
2062 while (amount < 0) {
2063 roll(field, false);
2064 amount++;
2065 }
2066 }
2067
2068 /**
2069 * Sets the time zone with the given time zone value.
2070 *
2071 * @param value the given time zone.
2072 */
2073 public void setTimeZone(TimeZone value)
2074 {
2075 zone = value;
2076 sharedZone = false;
2077 /* Recompute the fields from the time using the new zone. This also
2078 * works if isTimeSet is false (after a call to set()). In that case
2079 * the time will be computed from the fields using the new zone, then
2080 * the fields will get recomputed from that. Consider the sequence of
2081 * calls: cal.setTimeZone(EST); cal.set(HOUR, 1); cal.setTimeZone(PST).
2082 * Is cal set to 1 o'clock EST or 1 o'clock PST? Answer: PST. More
2083 * generally, a call to setTimeZone() affects calls to set() BEFORE AND
2084 * AFTER it up to the next call to complete().
2085 */
2086 areAllFieldsSet = areFieldsSet = false;
2087 }
2088
2089 /**
2090 * Gets the time zone.
2091 *
2092 * @return the time zone object associated with this calendar.
2093 */
2094 public TimeZone getTimeZone()
2095 {
2096 // If the TimeZone object is shared by other Calendar instances, then
2097 // create a clone.
2098 if (sharedZone) {
2099 zone = (TimeZone) zone.clone();
2100 sharedZone = false;
2101 }
2102 return zone;
2103 }
2104
2105 /**
2106 * Returns the time zone (without cloning).
2107 */
2108 TimeZone getZone() {
2109 return zone;
2110 }
2111
2112 /**
2113 * Sets the sharedZone flag to <code>shared</code>.
2114 */
2115 void setZoneShared(boolean shared) {
2116 sharedZone = shared;
2117 }
2118
2119 /**
2120 * Specifies whether or not date/time interpretation is to be lenient. With
2121 * lenient interpretation, a date such as "February 942, 1996" will be
2122 * treated as being equivalent to the 941st day after February 1, 1996.
2123 * With strict (non-lenient) interpretation, such dates will cause an exception to be
2124 * thrown. The default is lenient.
2125 *
2126 * @param lenient <code>true</code> if the lenient mode is to be turned
2127 * on; <code>false</code> if it is to be turned off.
2128 * @see #isLenient()
2129 * @see java.text.DateFormat#setLenient
2130 */
2131 public void setLenient(boolean lenient)
2132 {
2133 this.lenient = lenient;
2134 }
2135
2136 /**
2137 * Tells whether date/time interpretation is to be lenient.
2138 *
2139 * @return <code>true</code> if the interpretation mode of this calendar is lenient;
2140 * <code>false</code> otherwise.
2141 * @see #setLenient(boolean)
2142 */
2143 public boolean isLenient()
2144 {
2145 return lenient;
2146 }
2147
2148 /**
2149 * Sets what the first day of the week is; e.g., <code>SUNDAY</code> in the U.S.,
2150 * <code>MONDAY</code> in France.
2151 *
2152 * @param value the given first day of the week.
2153 * @see #getFirstDayOfWeek()
2154 * @see #getMinimalDaysInFirstWeek()
2155 */
2156 public void setFirstDayOfWeek(int value)
2157 {
2158 if (firstDayOfWeek == value) {
2159 return;
2160 }
2161 firstDayOfWeek = value;
2162 invalidateWeekFields();
2163 }
2164
2165 /**
2166 * Gets what the first day of the week is; e.g., <code>SUNDAY</code> in the U.S.,
2167 * <code>MONDAY</code> in France.
2168 *
2169 * @return the first day of the week.
2170 * @see #setFirstDayOfWeek(int)
2171 * @see #getMinimalDaysInFirstWeek()
2172 */
2173 public int getFirstDayOfWeek()
2174 {
2175 return firstDayOfWeek;
2176 }
2177
2178 /**
2179 * Sets what the minimal days required in the first week of the year are;
2180 * For example, if the first week is defined as one that contains the first
2181 * day of the first month of a year, call this method with value 1. If it
2182 * must be a full week, use value 7.
2183 *
2184 * @param value the given minimal days required in the first week
2185 * of the year.
2186 * @see #getMinimalDaysInFirstWeek()
2187 */
2188 public void setMinimalDaysInFirstWeek(int value)
2189 {
2190 if (minimalDaysInFirstWeek == value) {
2191 return;
2192 }
2193 minimalDaysInFirstWeek = value;
2194 invalidateWeekFields();
2195 }
2196
2197 /**
2198 * Gets what the minimal days required in the first week of the year are;
2199 * e.g., if the first week is defined as one that contains the first day
2200 * of the first month of a year, this method returns 1. If
2201 * the minimal days required must be a full week, this method
2202 * returns 7.
2203 *
2204 * @return the minimal days required in the first week of the year.
2205 * @see #setMinimalDaysInFirstWeek(int)
2206 */
2207 public int getMinimalDaysInFirstWeek()
2208 {
2209 return minimalDaysInFirstWeek;
2210 }
2211
2212 /**
2213 * Returns whether this {@code Calendar} supports week dates.
2214 *
2215 * <p>The default implementation of this method returns {@code false}.
2216 *
2217 * @return {@code true} if this {@code Calendar} supports week dates;
2218 * {@code false} otherwise.
2219 * @see #getWeekYear()
2220 * @see #setWeekDate(int,int,int)
2221 * @see #getWeeksInWeekYear()
2222 * @since 1.7
2223 */
2224 public boolean isWeekDateSupported() {
2225 return false;
2226 }
2227
2228 /**
2229 * Returns the week year represented by this {@code Calendar}. The
2230 * week year is in sync with the week cycle. The {@linkplain
2231 * #getFirstDayOfWeek() first day of the first week} is the first
2232 * day of the week year.
2233 *
2234 * <p>The default implementation of this method throws an
2235 * {@link UnsupportedOperationException}.
2236 *
2237 * @return the week year of this {@code Calendar}
2238 * @exception UnsupportedOperationException
2239 * if any week year numbering isn't supported
2240 * in this {@code Calendar}.
2241 * @see #isWeekDateSupported()
2242 * @see #getFirstDayOfWeek()
2243 * @see #getMinimalDaysInFirstWeek()
2244 * @since 1.7
2245 */
2246 public int getWeekYear() {
2247 throw new UnsupportedOperationException();
2248 }
2249
2250 /**
2251 * Sets the date of this {@code Calendar} with the the given date
2252 * specifiers - week year, week of year, and day of week.
2253 *
2254 * <p>Unlike the {@code set} method, all of the calendar fields
2255 * and {@code time} values are calculated upon return.
2256 *
2257 * <p>If {@code weekOfYear} is out of the valid week-of-year range
2258 * in {@code weekYear}, the {@code weekYear} and {@code
2259 * weekOfYear} values are adjusted in lenient mode, or an {@code
2260 * IllegalArgumentException} is thrown in non-lenient mode.
2261 *
2262 * <p>The default implementation of this method throws an
2263 * {@code UnsupportedOperationException}.
2264 *
2265 * @param weekYear the week year
2266 * @param weekOfYear the week number based on {@code weekYear}
2267 * @param dayOfWeek the day of week value: one of the constants
2268 * for the {@link #DAY_OF_WEEK} field: {@link
2269 * #SUNDAY}, ..., {@link #SATURDAY}.
2270 * @exception IllegalArgumentException
2271 * if any of the given date specifiers is invalid
2272 * or any of the calendar fields are inconsistent
2273 * with the given date specifiers in non-lenient mode
2274 * @exception UnsupportedOperationException
2275 * if any week year numbering isn't supported in this
2276 * {@code Calendar}.
2277 * @see #isWeekDateSupported()
2278 * @see #getFirstDayOfWeek()
2279 * @see #getMinimalDaysInFirstWeek()
2280 * @since 1.7
2281 */
2282 public void setWeekDate(int weekYear, int weekOfYear, int dayOfWeek) {
2283 throw new UnsupportedOperationException();
2284 }
2285
2286 /**
2287 * Returns the number of weeks in the week year represented by this
2288 * {@code Calendar}.
2289 *
2290 * <p>The default implementation of this method throws an
2291 * {@code UnsupportedOperationException}.
2292 *
2293 * @return the number of weeks in the week year.
2294 * @exception UnsupportedOperationException
2295 * if any week year numbering isn't supported in this
2296 * {@code Calendar}.
2297 * @see #WEEK_OF_YEAR
2298 * @see #isWeekDateSupported()
2299 * @see #getWeekYear()
2300 * @see #getActualMaximum(int)
2301 * @since 1.7
2302 */
2303 public int getWeeksInWeekYear() {
2304 throw new UnsupportedOperationException();
2305 }
2306
2307 /**
2308 * Returns the minimum value for the given calendar field of this
2309 * <code>Calendar</code> instance. The minimum value is defined as
2310 * the smallest value returned by the {@link #get(int) get} method
2311 * for any possible time value. The minimum value depends on
2312 * calendar system specific parameters of the instance.
2313 *
2314 * @param field the calendar field.
2315 * @return the minimum value for the given calendar field.
2316 * @see #getMaximum(int)
2317 * @see #getGreatestMinimum(int)
2318 * @see #getLeastMaximum(int)
2319 * @see #getActualMinimum(int)
2320 * @see #getActualMaximum(int)
2321 */
2322 abstract public int getMinimum(int field);
2323
2324 /**
2325 * Returns the maximum value for the given calendar field of this
2326 * <code>Calendar</code> instance. The maximum value is defined as
2327 * the largest value returned by the {@link #get(int) get} method
2328 * for any possible time value. The maximum value depends on
2329 * calendar system specific parameters of the instance.
2330 *
2331 * @param field the calendar field.
2332 * @return the maximum value for the given calendar field.
2333 * @see #getMinimum(int)
2334 * @see #getGreatestMinimum(int)
2335 * @see #getLeastMaximum(int)
2336 * @see #getActualMinimum(int)
2337 * @see #getActualMaximum(int)
2338 */
2339 abstract public int getMaximum(int field);
2340
2341 /**
2342 * Returns the highest minimum value for the given calendar field
2343 * of this <code>Calendar</code> instance. The highest minimum
2344 * value is defined as the largest value returned by {@link
2345 * #getActualMinimum(int)} for any possible time value. The
2346 * greatest minimum value depends on calendar system specific
2347 * parameters of the instance.
2348 *
2349 * @param field the calendar field.
2350 * @return the highest minimum value for the given calendar field.
2351 * @see #getMinimum(int)
2352 * @see #getMaximum(int)
2353 * @see #getLeastMaximum(int)
2354 * @see #getActualMinimum(int)
2355 * @see #getActualMaximum(int)
2356 */
2357 abstract public int getGreatestMinimum(int field);
2358
2359 /**
2360 * Returns the lowest maximum value for the given calendar field
2361 * of this <code>Calendar</code> instance. The lowest maximum
2362 * value is defined as the smallest value returned by {@link
2363 * #getActualMaximum(int)} for any possible time value. The least
2364 * maximum value depends on calendar system specific parameters of
2365 * the instance. For example, a <code>Calendar</code> for the
2366 * Gregorian calendar system returns 28 for the
2367 * <code>DAY_OF_MONTH</code> field, because the 28th is the last
2368 * day of the shortest month of this calendar, February in a
2369 * common year.
2370 *
2371 * @param field the calendar field.
2372 * @return the lowest maximum value for the given calendar field.
2373 * @see #getMinimum(int)
2374 * @see #getMaximum(int)
2375 * @see #getGreatestMinimum(int)
2376 * @see #getActualMinimum(int)
2377 * @see #getActualMaximum(int)
2378 */
2379 abstract public int getLeastMaximum(int field);
2380
2381 /**
2382 * Returns the minimum value that the specified calendar field
2383 * could have, given the time value of this <code>Calendar</code>.
2384 *
2385 * <p>The default implementation of this method uses an iterative
2386 * algorithm to determine the actual minimum value for the
2387 * calendar field. Subclasses should, if possible, override this
2388 * with a more efficient implementation - in many cases, they can
2389 * simply return <code>getMinimum()</code>.
2390 *
2391 * @param field the calendar field
2392 * @return the minimum of the given calendar field for the time
2393 * value of this <code>Calendar</code>
2394 * @see #getMinimum(int)
2395 * @see #getMaximum(int)
2396 * @see #getGreatestMinimum(int)
2397 * @see #getLeastMaximum(int)
2398 * @see #getActualMaximum(int)
2399 * @since 1.2
2400 */
2401 public int getActualMinimum(int field) {
2402 int fieldValue = getGreatestMinimum(field);
2403 int endValue = getMinimum(field);
2404
2405 // if we know that the minimum value is always the same, just return it
2406 if (fieldValue == endValue) {
2407 return fieldValue;
2408 }
2409
2410 // clone the calendar so we don't mess with the real one, and set it to
2411 // accept anything for the field values
2412 Calendar work = (Calendar)this.clone();
2413 work.setLenient(true);
2414
2415 // now try each value from getLeastMaximum() to getMaximum() one by one until
2416 // we get a value that normalizes to another value. The last value that
2417 // normalizes to itself is the actual minimum for the current date
2418 int result = fieldValue;
2419
2420 do {
2421 work.set(field, fieldValue);
2422 if (work.get(field) != fieldValue) {
2423 break;
2424 } else {
2425 result = fieldValue;
2426 fieldValue--;
2427 }
2428 } while (fieldValue >= endValue);
2429
2430 return result;
2431 }
2432
2433 /**
2434 * Returns the maximum value that the specified calendar field
2435 * could have, given the time value of this
2436 * <code>Calendar</code>. For example, the actual maximum value of
2437 * the <code>MONTH</code> field is 12 in some years, and 13 in
2438 * other years in the Hebrew calendar system.
2439 *
2440 * <p>The default implementation of this method uses an iterative
2441 * algorithm to determine the actual maximum value for the
2442 * calendar field. Subclasses should, if possible, override this
2443 * with a more efficient implementation.
2444 *
2445 * @param field the calendar field
2446 * @return the maximum of the given calendar field for the time
2447 * value of this <code>Calendar</code>
2448 * @see #getMinimum(int)
2449 * @see #getMaximum(int)
2450 * @see #getGreatestMinimum(int)
2451 * @see #getLeastMaximum(int)
2452 * @see #getActualMinimum(int)
2453 * @since 1.2
2454 */
2455 public int getActualMaximum(int field) {
2456 int fieldValue = getLeastMaximum(field);
2457 int endValue = getMaximum(field);
2458
2459 // if we know that the maximum value is always the same, just return it.
2460 if (fieldValue == endValue) {
2461 return fieldValue;
2462 }
2463
2464 // clone the calendar so we don't mess with the real one, and set it to
2465 // accept anything for the field values.
2466 Calendar work = (Calendar)this.clone();
2467 work.setLenient(true);
2468
2469 // if we're counting weeks, set the day of the week to Sunday. We know the
2470 // last week of a month or year will contain the first day of the week.
2471 if (field == WEEK_OF_YEAR || field == WEEK_OF_MONTH)
2472 work.set(DAY_OF_WEEK, firstDayOfWeek);
2473
2474 // now try each value from getLeastMaximum() to getMaximum() one by one until
2475 // we get a value that normalizes to another value. The last value that
2476 // normalizes to itself is the actual maximum for the current date
2477 int result = fieldValue;
2478
2479 do {
2480 work.set(field, fieldValue);
2481 if (work.get(field) != fieldValue) {
2482 break;
2483 } else {
2484 result = fieldValue;
2485 fieldValue++;
2486 }
2487 } while (fieldValue <= endValue);
2488
2489 return result;
2490 }
2491
2492 /**
2493 * Creates and returns a copy of this object.
2494 *
2495 * @return a copy of this object.
2496 */
2497 public Object clone()
2498 {
2499 try {
2500 Calendar other = (Calendar) super.clone();
2501
2502 other.fields = new int[FIELD_COUNT];
2503 other.isSet = new boolean[FIELD_COUNT];
2504 other.stamp = new int[FIELD_COUNT];
2505 for (int i = 0; i < FIELD_COUNT; i++) {
2506 other.fields[i] = fields[i];
2507 other.stamp[i] = stamp[i];
2508 other.isSet[i] = isSet[i];
2509 }
2510 other.zone = (TimeZone) zone.clone();
2511 return other;
2512 }
2513 catch (CloneNotSupportedException e) {
2514 // this shouldn't happen, since we are Cloneable
2515 throw new InternalError(e);
2516 }
2517 }
2518
2519 private static final String[] FIELD_NAME = {
2520 "ERA", "YEAR", "MONTH", "WEEK_OF_YEAR", "WEEK_OF_MONTH", "DAY_OF_MONTH",
2521 "DAY_OF_YEAR", "DAY_OF_WEEK", "DAY_OF_WEEK_IN_MONTH", "AM_PM", "HOUR",
2522 "HOUR_OF_DAY", "MINUTE", "SECOND", "MILLISECOND", "ZONE_OFFSET",
2523 "DST_OFFSET"
2524 };
2525
2526 /**
2527 * Returns the name of the specified calendar field.
2528 *
2529 * @param field the calendar field
2530 * @return the calendar field name
2531 * @exception IndexOutOfBoundsException if <code>field</code> is negative,
2532 * equal to or greater then <code>FIELD_COUNT</code>.
2533 */
2534 static final String getFieldName(int field) {
2535 return FIELD_NAME[field];
2536 }
2537
2538 /**
2539 * Return a string representation of this calendar. This method
2540 * is intended to be used only for debugging purposes, and the
2541 * format of the returned string may vary between implementations.
2542 * The returned string may be empty but may not be <code>null</code>.
2543 *
2544 * @return a string representation of this calendar.
2545 */
2546 public String toString() {
2547 // NOTE: BuddhistCalendar.toString() interprets the string
2548 // produced by this method so that the Gregorian year number
2549 // is substituted by its B.E. year value. It relies on
2550 // "...,YEAR=<year>,..." or "...,YEAR=?,...".
2551 StringBuilder buffer = new StringBuilder(800);
2552 buffer.append(getClass().getName()).append('[');
2553 appendValue(buffer, "time", isTimeSet, time);
2554 buffer.append(",areFieldsSet=").append(areFieldsSet);
2555 buffer.append(",areAllFieldsSet=").append(areAllFieldsSet);
2556 buffer.append(",lenient=").append(lenient);
2557 buffer.append(",zone=").append(zone);
2558 appendValue(buffer, ",firstDayOfWeek", true, (long) firstDayOfWeek);
2559 appendValue(buffer, ",minimalDaysInFirstWeek", true, (long) minimalDaysInFirstWeek);
2560 for (int i = 0; i < FIELD_COUNT; ++i) {
2561 buffer.append(',');
2562 appendValue(buffer, FIELD_NAME[i], isSet(i), (long) fields[i]);
2563 }
2564 buffer.append(']');
2565 return buffer.toString();
2566 }
2567
2568 // =======================privates===============================
2569
2570 private static final void appendValue(StringBuilder sb, String item, boolean valid, long value) {
2571 sb.append(item).append('=');
2572 if (valid) {
2573 sb.append(value);
2574 } else {
2575 sb.append('?');
2576 }
2577 }
2578
2579 /**
2580 * Both firstDayOfWeek and minimalDaysInFirstWeek are locale-dependent.
2581 * They are used to figure out the week count for a specific date for
2582 * a given locale. These must be set when a Calendar is constructed.
2583 * @param desiredLocale the given locale.
2584 */
2585 private void setWeekCountData(Locale desiredLocale)
2586 {
2587 /* try to get the Locale data from the cache */
2588 int[] data = cachedLocaleData.get(desiredLocale);
2589 if (data == null) { /* cache miss */
2590 ResourceBundle bundle = LocaleData.getCalendarData(desiredLocale);
2591 data = new int[2];
2592 data[0] = Integer.parseInt(bundle.getString("firstDayOfWeek"));
2593 data[1] = Integer.parseInt(bundle.getString("minimalDaysInFirstWeek"));
2594 cachedLocaleData.putIfAbsent(desiredLocale, data);
2595 }
2596 firstDayOfWeek = data[0];
2597 minimalDaysInFirstWeek = data[1];
2598 }
2599
2600 /**
2601 * Recomputes the time and updates the status fields isTimeSet
2602 * and areFieldsSet. Callers should check isTimeSet and only
2603 * call this method if isTimeSet is false.
2604 */
2605 private void updateTime() {
2606 computeTime();
2607 // The areFieldsSet and areAllFieldsSet values are no longer
2608 // controlled here (as of 1.5).
2609 isTimeSet = true;
2610 }
2611
2612 private int compareTo(long t) {
2613 long thisTime = getMillisOf(this);
2614 return (thisTime > t) ? 1 : (thisTime == t) ? 0 : -1;
2615 }
2616
2617 private static final long getMillisOf(Calendar calendar) {
2618 if (calendar.isTimeSet) {
2619 return calendar.time;
2620 }
2621 Calendar cal = (Calendar) calendar.clone();
2622 cal.setLenient(true);
2623 return cal.getTimeInMillis();
2624 }
2625
2626 /**
2627 * Adjusts the stamp[] values before nextStamp overflow. nextStamp
2628 * is set to the next stamp value upon the return.
2629 */
2630 private final void adjustStamp() {
2631 int max = MINIMUM_USER_STAMP;
2632 int newStamp = MINIMUM_USER_STAMP;
2633
2634 for (;;) {
2635 int min = Integer.MAX_VALUE;
2636 for (int i = 0; i < stamp.length; i++) {
2637 int v = stamp[i];
2638 if (v >= newStamp && min > v) {
2639 min = v;
2640 }
2641 if (max < v) {
2642 max = v;
2643 }
2644 }
2645 if (max != min && min == Integer.MAX_VALUE) {
2646 break;
2647 }
2648 for (int i = 0; i < stamp.length; i++) {
2649 if (stamp[i] == min) {
2650 stamp[i] = newStamp;
2651 }
2652 }
2653 newStamp++;
2654 if (min == max) {
2655 break;
2656 }
2657 }
2658 nextStamp = newStamp;
2659 }
2660
2661 /**
2662 * Sets the WEEK_OF_MONTH and WEEK_OF_YEAR fields to new values with the
2663 * new parameter value if they have been calculated internally.
2664 */
2665 private void invalidateWeekFields()
2666 {
2667 if (stamp[WEEK_OF_MONTH] != COMPUTED &&
2668 stamp[WEEK_OF_YEAR] != COMPUTED) {
2669 return;
2670 }
2671
2672 // We have to check the new values of these fields after changing
2673 // firstDayOfWeek and/or minimalDaysInFirstWeek. If the field values
2674 // have been changed, then set the new values. (4822110)
2675 Calendar cal = (Calendar) clone();
2676 cal.setLenient(true);
2677 cal.clear(WEEK_OF_MONTH);
2678 cal.clear(WEEK_OF_YEAR);
2679
2680 if (stamp[WEEK_OF_MONTH] == COMPUTED) {
2681 int weekOfMonth = cal.get(WEEK_OF_MONTH);
2682 if (fields[WEEK_OF_MONTH] != weekOfMonth) {
2683 fields[WEEK_OF_MONTH] = weekOfMonth;
2684 }
2685 }
2686
2687 if (stamp[WEEK_OF_YEAR] == COMPUTED) {
2688 int weekOfYear = cal.get(WEEK_OF_YEAR);
2689 if (fields[WEEK_OF_YEAR] != weekOfYear) {
2690 fields[WEEK_OF_YEAR] = weekOfYear;
2691 }
2692 }
2693 }
2694
2695 /**
2696 * Save the state of this object to a stream (i.e., serialize it).
2697 *
2698 * Ideally, <code>Calendar</code> would only write out its state data and
2699 * the current time, and not write any field data out, such as
2700 * <code>fields[]</code>, <code>isTimeSet</code>, <code>areFieldsSet</code>,
2701 * and <code>isSet[]</code>. <code>nextStamp</code> also should not be part
2702 * of the persistent state. Unfortunately, this didn't happen before JDK 1.1
2703 * shipped. To be compatible with JDK 1.1, we will always have to write out
2704 * the field values and state flags. However, <code>nextStamp</code> can be
2705 * removed from the serialization stream; this will probably happen in the
2706 * near future.
2707 */
2708 private synchronized void writeObject(ObjectOutputStream stream)
2709 throws IOException
2710 {
2711 // Try to compute the time correctly, for the future (stream
2712 // version 2) in which we don't write out fields[] or isSet[].
2713 if (!isTimeSet) {
2714 try {
2715 updateTime();
2716 }
2717 catch (IllegalArgumentException e) {}
2718 }
2719
2720 // If this Calendar has a ZoneInfo, save it and set a
2721 // SimpleTimeZone equivalent (as a single DST schedule) for
2722 // backward compatibility.
2723 TimeZone savedZone = null;
2724 if (zone instanceof ZoneInfo) {
2725 SimpleTimeZone stz = ((ZoneInfo)zone).getLastRuleInstance();
2726 if (stz == null) {
2727 stz = new SimpleTimeZone(zone.getRawOffset(), zone.getID());
2728 }
2729 savedZone = zone;
2730 zone = stz;
2731 }
2732
2733 // Write out the 1.1 FCS object.
2734 stream.defaultWriteObject();
2735
2736 // Write out the ZoneInfo object
2737 // 4802409: we write out even if it is null, a temporary workaround
2738 // the real fix for bug 4844924 in corba-iiop
2739 stream.writeObject(savedZone);
2740 if (savedZone != null) {
2741 zone = savedZone;
2742 }
2743 }
2744
2745 private static class CalendarAccessControlContext {
2746 private static final AccessControlContext INSTANCE;
2747 static {
2748 RuntimePermission perm = new RuntimePermission("accessClassInPackage.sun.util.calendar");
2749 PermissionCollection perms = perm.newPermissionCollection();
2750 perms.add(perm);
2751 INSTANCE = new AccessControlContext(new ProtectionDomain[] {
2752 new ProtectionDomain(null, perms)
2753 });
2754 }
2755 }
2756
2757 /**
2758 * Reconstitutes this object from a stream (i.e., deserialize it).
2759 */
2760 private void readObject(ObjectInputStream stream)
2761 throws IOException, ClassNotFoundException
2762 {
2763 final ObjectInputStream input = stream;
2764 input.defaultReadObject();
2765
2766 stamp = new int[FIELD_COUNT];
2767
2768 // Starting with version 2 (not implemented yet), we expect that
2769 // fields[], isSet[], isTimeSet, and areFieldsSet may not be
2770 // streamed out anymore. We expect 'time' to be correct.
2771 if (serialVersionOnStream >= 2)
2772 {
2773 isTimeSet = true;
2774 if (fields == null) fields = new int[FIELD_COUNT];
2775 if (isSet == null) isSet = new boolean[FIELD_COUNT];
2776 }
2777 else if (serialVersionOnStream >= 0)
2778 {
2779 for (int i=0; i<FIELD_COUNT; ++i)
2780 stamp[i] = isSet[i] ? COMPUTED : UNSET;
2781 }
2782
2783 serialVersionOnStream = currentSerialVersion;
2784
2785 // If there's a ZoneInfo object, use it for zone.
2786 ZoneInfo zi = null;
2787 try {
2788 zi = AccessController.doPrivileged(
2789 new PrivilegedExceptionAction<ZoneInfo>() {
2790 public ZoneInfo run() throws Exception {
2791 return (ZoneInfo) input.readObject();
2792 }
2793 },
2794 CalendarAccessControlContext.INSTANCE);
2795 } catch (PrivilegedActionException pae) {
2796 Exception e = pae.getException();
2797 if (!(e instanceof OptionalDataException)) {
2798 if (e instanceof RuntimeException) {
2799 throw (RuntimeException) e;
2800 } else if (e instanceof IOException) {
2801 throw (IOException) e;
2802 } else if (e instanceof ClassNotFoundException) {
2803 throw (ClassNotFoundException) e;
2804 }
2805 throw new RuntimeException(e);
2806 }
2807 }
2808 if (zi != null) {
2809 zone = zi;
2810 }
2811
2812 // If the deserialized object has a SimpleTimeZone, try to
2813 // replace it with a ZoneInfo equivalent (as of 1.4) in order
2814 // to be compatible with the SimpleTimeZone-based
2815 // implementation as much as possible.
2816 if (zone instanceof SimpleTimeZone) {
2817 String id = zone.getID();
2818 TimeZone tz = TimeZone.getTimeZone(id);
2819 if (tz != null && tz.hasSameRules(zone) && tz.getID().equals(id)) {
2820 zone = tz;
2821 }
2822 }
2823 }
2824 }