1 /*
2 * Copyright (c) 1996, 2019, 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 - All Rights Reserved
28 * (C) Copyright IBM Corp. 1996 - 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.text;
40
41 import java.io.InvalidObjectException;
42 import java.text.spi.DateFormatProvider;
43 import java.util.Calendar;
44 import java.util.Date;
45 import java.util.GregorianCalendar;
46 import java.util.HashMap;
47 import java.util.Locale;
48 import java.util.Map;
49 import java.util.MissingResourceException;
50 import java.util.ResourceBundle;
51 import java.util.TimeZone;
52 import java.util.spi.LocaleServiceProvider;
53 import sun.util.locale.provider.LocaleProviderAdapter;
54 import sun.util.locale.provider.LocaleServiceProviderPool;
55
56 /**
57 * {@code DateFormat} is an abstract class for date/time formatting subclasses which
58 * formats and parses dates or time in a language-independent manner.
59 * The date/time formatting subclass, such as {@link SimpleDateFormat}, allows for
60 * formatting (i.e., date → text), parsing (text → date), and
61 * normalization. The date is represented as a <code>Date</code> object or
62 * as the milliseconds since January 1, 1970, 00:00:00 GMT.
63 *
64 * <p>{@code DateFormat} provides many class methods for obtaining default date/time
65 * formatters based on the default or a given locale and a number of formatting
66 * styles. The formatting styles include {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, and {@link #SHORT}. More
67 * detail and examples of using these styles are provided in the method
68 * descriptions.
69 *
70 * <p>{@code DateFormat} helps you to format and parse dates for any locale.
71 * Your code can be completely independent of the locale conventions for
72 * months, days of the week, or even the calendar format: lunar vs. solar.
73 *
74 * <p>To format a date for the current Locale, use one of the
75 * static factory methods:
76 * <blockquote>
77 * <pre>{@code
78 * myString = DateFormat.getDateInstance().format(myDate);
79 * }</pre>
80 * </blockquote>
81 * <p>If you are formatting multiple dates, it is
82 * more efficient to get the format and use it multiple times so that
83 * the system doesn't have to fetch the information about the local
84 * language and country conventions multiple times.
85 * <blockquote>
86 * <pre>{@code
87 * DateFormat df = DateFormat.getDateInstance();
88 * for (int i = 0; i < myDate.length; ++i) {
89 * output.println(df.format(myDate[i]) + "; ");
90 * }
91 * }</pre>
92 * </blockquote>
93 * <p>To format a date for a different Locale, specify it in the
94 * call to {@link #getDateInstance(int, Locale) getDateInstance()}.
95 * <blockquote>
96 * <pre>{@code
97 * DateFormat df = DateFormat.getDateInstance(DateFormat.LONG, Locale.FRANCE);
98 * }</pre>
99 * </blockquote>
100 *
101 * <p>If the specified locale contains "ca" (calendar), "rg" (region override),
102 * and/or "tz" (timezone) <a href="../util/Locale.html#def_locale_extension">Unicode
103 * extensions</a>, the calendar, the country and/or the time zone for formatting
104 * are overridden. If both "ca" and "rg" are specified, the calendar from the "ca"
105 * extension supersedes the implicit one from the "rg" extension.
106 *
107 * <p>You can use a DateFormat to parse also.
108 * <blockquote>
109 * <pre>{@code
110 * myDate = df.parse(myString);
111 * }</pre>
112 * </blockquote>
113 * <p>Use {@code getDateInstance} to get the normal date format for that country.
114 * There are other static factory methods available.
115 * Use {@code getTimeInstance} to get the time format for that country.
116 * Use {@code getDateTimeInstance} to get a date and time format. You can pass in
117 * different options to these factory methods to control the length of the
118 * result; from {@link #SHORT} to {@link #MEDIUM} to {@link #LONG} to {@link #FULL}. The exact result depends
119 * on the locale, but generally:
120 * <ul><li>{@link #SHORT} is completely numeric, such as {@code 12.13.52} or {@code 3:30pm}
121 * <li>{@link #MEDIUM} is longer, such as {@code Jan 12, 1952}
122 * <li>{@link #LONG} is longer, such as {@code January 12, 1952} or {@code 3:30:32pm}
123 * <li>{@link #FULL} is pretty completely specified, such as
124 * {@code Tuesday, April 12, 1952 AD or 3:30:42pm PST}.
125 * </ul>
126 *
127 * <p>You can also set the time zone on the format if you wish.
128 * If you want even more control over the format or parsing,
129 * (or want to give your users more control),
130 * you can try casting the {@code DateFormat} you get from the factory methods
131 * to a {@link SimpleDateFormat}. This will work for the majority
132 * of countries; just remember to put it in a {@code try} block in case you
133 * encounter an unusual one.
134 *
135 * <p>You can also use forms of the parse and format methods with
136 * {@link ParsePosition} and {@link FieldPosition} to
137 * allow you to
138 * <ul><li>progressively parse through pieces of a string.
139 * <li>align any particular field, or find out where it is for selection
140 * on the screen.
141 * </ul>
142 *
143 * <h2><a id="synchronization">Synchronization</a></h2>
144 *
145 * <p>
146 * Date formats are not synchronized.
147 * It is recommended to create separate format instances for each thread.
148 * If multiple threads access a format concurrently, it must be synchronized
149 * externally.
150 *
151 * @implSpec
152 * <ul><li>The {@link #format(Date, StringBuffer, FieldPosition)} and
153 * {@link #parse(String, ParsePosition)} methods may throw
154 * {@code NullPointerException}, if any of their parameter is {@code null}.
155 * The subclass may provide its own implementation and specification about
156 * {@code NullPointerException}.</li>
157 * <li>The {@link #setCalendar(Calendar)}, {@link
158 * #setNumberFormat(NumberFormat)} and {@link #setTimeZone(TimeZone)} methods
159 * do not throw {@code NullPointerException} when their parameter is
160 * {@code null}, but any subsequent operations on the same instance may throw
161 * {@code NullPointerException}.</li>
162 * <li>The {@link #getCalendar()}, {@link #getNumberFormat()} and
163 * {@link getTimeZone()} methods may return {@code null}, if the respective
164 * values of this instance is set to {@code null} through the corresponding
165 * setter methods. For Example: {@link #getTimeZone()} may return {@code null},
166 * if the {@code TimeZone} value of this instance is set as
167 * {@link #setTimeZone(java.util.TimeZone) setTimeZone(null)}.</li>
168 * </ul>
169 *
170 * @see Format
171 * @see NumberFormat
172 * @see SimpleDateFormat
173 * @see java.util.Calendar
174 * @see java.util.GregorianCalendar
175 * @see java.util.TimeZone
176 * @author Mark Davis, Chen-Lieh Huang, Alan Liu
177 * @since 1.1
178 */
179 public abstract class DateFormat extends Format {
180
181 /**
182 * The {@link Calendar} instance used for calculating the date-time fields
183 * and the instant of time. This field is used for both formatting and
184 * parsing.
185 *
186 * <p>Subclasses should initialize this field to a {@link Calendar}
187 * appropriate for the {@link Locale} associated with this
188 * <code>DateFormat</code>.
189 * @serial
190 */
191 protected Calendar calendar;
192
193 /**
194 * The number formatter that <code>DateFormat</code> uses to format numbers
195 * in dates and times. Subclasses should initialize this to a number format
196 * appropriate for the locale associated with this <code>DateFormat</code>.
197 * @serial
198 */
199 protected NumberFormat numberFormat;
200
201 /**
202 * Useful constant for ERA field alignment.
203 * Used in FieldPosition of date/time formatting.
204 */
205 public static final int ERA_FIELD = 0;
206 /**
207 * Useful constant for YEAR field alignment.
208 * Used in FieldPosition of date/time formatting.
209 */
210 public static final int YEAR_FIELD = 1;
211 /**
212 * Useful constant for MONTH field alignment.
213 * Used in FieldPosition of date/time formatting.
214 */
215 public static final int MONTH_FIELD = 2;
216 /**
217 * Useful constant for DATE field alignment.
218 * Used in FieldPosition of date/time formatting.
219 */
220 public static final int DATE_FIELD = 3;
221 /**
222 * Useful constant for one-based HOUR_OF_DAY field alignment.
223 * Used in FieldPosition of date/time formatting.
224 * HOUR_OF_DAY1_FIELD is used for the one-based 24-hour clock.
225 * For example, 23:59 + 01:00 results in 24:59.
226 */
227 public static final int HOUR_OF_DAY1_FIELD = 4;
228 /**
229 * Useful constant for zero-based HOUR_OF_DAY field alignment.
230 * Used in FieldPosition of date/time formatting.
231 * HOUR_OF_DAY0_FIELD is used for the zero-based 24-hour clock.
232 * For example, 23:59 + 01:00 results in 00:59.
233 */
234 public static final int HOUR_OF_DAY0_FIELD = 5;
235 /**
236 * Useful constant for MINUTE field alignment.
237 * Used in FieldPosition of date/time formatting.
238 */
239 public static final int MINUTE_FIELD = 6;
240 /**
241 * Useful constant for SECOND field alignment.
242 * Used in FieldPosition of date/time formatting.
243 */
244 public static final int SECOND_FIELD = 7;
245 /**
246 * Useful constant for MILLISECOND field alignment.
247 * Used in FieldPosition of date/time formatting.
248 */
249 public static final int MILLISECOND_FIELD = 8;
250 /**
251 * Useful constant for DAY_OF_WEEK field alignment.
252 * Used in FieldPosition of date/time formatting.
253 */
254 public static final int DAY_OF_WEEK_FIELD = 9;
255 /**
256 * Useful constant for DAY_OF_YEAR field alignment.
257 * Used in FieldPosition of date/time formatting.
258 */
259 public static final int DAY_OF_YEAR_FIELD = 10;
260 /**
261 * Useful constant for DAY_OF_WEEK_IN_MONTH field alignment.
262 * Used in FieldPosition of date/time formatting.
263 */
264 public static final int DAY_OF_WEEK_IN_MONTH_FIELD = 11;
265 /**
266 * Useful constant for WEEK_OF_YEAR field alignment.
267 * Used in FieldPosition of date/time formatting.
268 */
269 public static final int WEEK_OF_YEAR_FIELD = 12;
270 /**
271 * Useful constant for WEEK_OF_MONTH field alignment.
272 * Used in FieldPosition of date/time formatting.
273 */
274 public static final int WEEK_OF_MONTH_FIELD = 13;
275 /**
276 * Useful constant for AM_PM field alignment.
277 * Used in FieldPosition of date/time formatting.
278 */
279 public static final int AM_PM_FIELD = 14;
280 /**
281 * Useful constant for one-based HOUR field alignment.
282 * Used in FieldPosition of date/time formatting.
283 * HOUR1_FIELD is used for the one-based 12-hour clock.
284 * For example, 11:30 PM + 1 hour results in 12:30 AM.
285 */
286 public static final int HOUR1_FIELD = 15;
287 /**
288 * Useful constant for zero-based HOUR field alignment.
289 * Used in FieldPosition of date/time formatting.
290 * HOUR0_FIELD is used for the zero-based 12-hour clock.
291 * For example, 11:30 PM + 1 hour results in 00:30 AM.
292 */
293 public static final int HOUR0_FIELD = 16;
294 /**
295 * Useful constant for TIMEZONE field alignment.
296 * Used in FieldPosition of date/time formatting.
297 */
298 public static final int TIMEZONE_FIELD = 17;
299
300 // Proclaim serial compatibility with 1.1 FCS
301 @java.io.Serial
302 private static final long serialVersionUID = 7218322306649953788L;
303
304 /**
305 * Formats the given {@code Object} into a date-time string. The formatted
306 * string is appended to the given {@code StringBuffer}.
307 *
308 * @param obj Must be a {@code Date} or a {@code Number} representing a
309 * millisecond offset from the <a href="../util/Calendar.html#Epoch">Epoch</a>.
310 * @param toAppendTo The string buffer for the returning date-time string.
311 * @param fieldPosition keeps track on the position of the field within
312 * the returned string. For example, given a date-time text
313 * {@code "1996.07.10 AD at 15:08:56 PDT"}, if the given {@code fieldPosition}
314 * is {@link DateFormat#YEAR_FIELD}, the begin index and end index of
315 * {@code fieldPosition} will be set to 0 and 4, respectively.
316 * Notice that if the same date-time field appears more than once in a
317 * pattern, the {@code fieldPosition} will be set for the first occurrence
318 * of that date-time field. For instance, formatting a {@code Date} to the
319 * date-time string {@code "1 PM PDT (Pacific Daylight Time)"} using the
320 * pattern {@code "h a z (zzzz)"} and the alignment field
321 * {@link DateFormat#TIMEZONE_FIELD}, the begin index and end index of
322 * {@code fieldPosition} will be set to 5 and 8, respectively, for the
323 * first occurrence of the timezone pattern character {@code 'z'}.
324 * @return the string buffer passed in as {@code toAppendTo},
325 * with formatted text appended.
326 * @throws IllegalArgumentException if the {@code Format} cannot format
327 * the given {@code obj}.
328 * @see java.text.Format
329 */
330 public final StringBuffer format(Object obj, StringBuffer toAppendTo,
331 FieldPosition fieldPosition)
332 {
333 if (obj instanceof Date)
334 return format( (Date)obj, toAppendTo, fieldPosition );
335 else if (obj instanceof Number)
336 return format( new Date(((Number)obj).longValue()),
337 toAppendTo, fieldPosition );
338 else
339 throw new IllegalArgumentException("Cannot format given Object as a Date");
340 }
341
342 /**
343 * Formats a {@link Date} into a date-time string. The formatted
344 * string is appended to the given {@code StringBuffer}.
345 *
346 * @param date a Date to be formatted into a date-time string.
347 * @param toAppendTo the string buffer for the returning date-time string.
348 * @param fieldPosition keeps track on the position of the field within
349 * the returned string. For example, given a date-time text
350 * {@code "1996.07.10 AD at 15:08:56 PDT"}, if the given {@code fieldPosition}
351 * is {@link DateFormat#YEAR_FIELD}, the begin index and end index of
352 * {@code fieldPosition} will be set to 0 and 4, respectively.
353 * Notice that if the same date-time field appears more than once in a
354 * pattern, the {@code fieldPosition} will be set for the first occurrence
355 * of that date-time field. For instance, formatting a {@code Date} to the
356 * date-time string {@code "1 PM PDT (Pacific Daylight Time)"} using the
357 * pattern {@code "h a z (zzzz)"} and the alignment field
358 * {@link DateFormat#TIMEZONE_FIELD}, the begin index and end index of
359 * {@code fieldPosition} will be set to 5 and 8, respectively, for the
360 * first occurrence of the timezone pattern character {@code 'z'}.
361 * @return the string buffer passed in as {@code toAppendTo}, with formatted
362 * text appended.
363 */
364 public abstract StringBuffer format(Date date, StringBuffer toAppendTo,
365 FieldPosition fieldPosition);
366
367 /**
368 * Formats a {@link Date} into a date-time string.
369 *
370 * @param date the time value to be formatted into a date-time string.
371 * @return the formatted date-time string.
372 */
373 public final String format(Date date)
374 {
375 return format(date, new StringBuffer(),
376 DontCareFieldPosition.INSTANCE).toString();
377 }
378
379 /**
380 * Parses text from the beginning of the given string to produce a date.
381 * The method may not use the entire text of the given string.
382 * <p>
383 * See the {@link #parse(String, ParsePosition)} method for more information
384 * on date parsing.
385 *
386 * @param source A <code>String</code> whose beginning should be parsed.
387 * @return A <code>Date</code> parsed from the string.
388 * @throws ParseException if the beginning of the specified string
389 * cannot be parsed.
390 */
391 public Date parse(String source) throws ParseException
392 {
393 ParsePosition pos = new ParsePosition(0);
394 Date result = parse(source, pos);
395 if (pos.index == 0)
396 throw new ParseException("Unparseable date: \"" + source + "\"" ,
397 pos.errorIndex);
398 return result;
399 }
400
401 /**
402 * Parse a date/time string according to the given parse position. For
403 * example, a time text {@code "07/10/96 4:5 PM, PDT"} will be parsed into a {@code Date}
404 * that is equivalent to {@code Date(837039900000L)}.
405 *
406 * <p> By default, parsing is lenient: If the input is not in the form used
407 * by this object's format method but can still be parsed as a date, then
408 * the parse succeeds. Clients may insist on strict adherence to the
409 * format by calling {@link #setLenient(boolean) setLenient(false)}.
410 *
411 * <p>This parsing operation uses the {@link #calendar} to produce
412 * a {@code Date}. As a result, the {@code calendar}'s date-time
413 * fields and the {@code TimeZone} value may have been
414 * overwritten, depending on subclass implementations. Any {@code
415 * TimeZone} value that has previously been set by a call to
416 * {@link #setTimeZone(java.util.TimeZone) setTimeZone} may need
417 * to be restored for further operations.
418 *
419 * @param source The date/time string to be parsed
420 *
421 * @param pos On input, the position at which to start parsing; on
422 * output, the position at which parsing terminated, or the
423 * start position if the parse failed.
424 *
425 * @return A {@code Date}, or {@code null} if the input could not be parsed
426 */
427 public abstract Date parse(String source, ParsePosition pos);
428
429 /**
430 * Parses text from a string to produce a <code>Date</code>.
431 * <p>
432 * The method attempts to parse text starting at the index given by
433 * <code>pos</code>.
434 * If parsing succeeds, then the index of <code>pos</code> is updated
435 * to the index after the last character used (parsing does not necessarily
436 * use all characters up to the end of the string), and the parsed
437 * date is returned. The updated <code>pos</code> can be used to
438 * indicate the starting point for the next call to this method.
439 * If an error occurs, then the index of <code>pos</code> is not
440 * changed, the error index of <code>pos</code> is set to the index of
441 * the character where the error occurred, and null is returned.
442 * <p>
443 * See the {@link #parse(String, ParsePosition)} method for more information
444 * on date parsing.
445 *
446 * @param source A <code>String</code>, part of which should be parsed.
447 * @param pos A <code>ParsePosition</code> object with index and error
448 * index information as described above.
449 * @return A <code>Date</code> parsed from the string. In case of
450 * error, returns null.
451 * @throws NullPointerException if {@code source} or {@code pos} is null.
452 */
453 public Object parseObject(String source, ParsePosition pos) {
454 return parse(source, pos);
455 }
456
457 /**
458 * Constant for full style pattern.
459 */
460 public static final int FULL = 0;
461 /**
462 * Constant for long style pattern.
463 */
464 public static final int LONG = 1;
465 /**
466 * Constant for medium style pattern.
467 */
468 public static final int MEDIUM = 2;
469 /**
470 * Constant for short style pattern.
471 */
472 public static final int SHORT = 3;
473 /**
474 * Constant for default style pattern. Its value is MEDIUM.
475 */
476 public static final int DEFAULT = MEDIUM;
477
478 /**
479 * Gets the time formatter with the default formatting style
480 * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.
481 * <p>This is equivalent to calling
482 * {@link #getTimeInstance(int, Locale) getTimeInstance(DEFAULT,
483 * Locale.getDefault(Locale.Category.FORMAT))}.
484 * @see java.util.Locale#getDefault(java.util.Locale.Category)
485 * @see java.util.Locale.Category#FORMAT
486 * @return a time formatter.
487 */
488 public static final DateFormat getTimeInstance()
489 {
490 return get(DEFAULT, 0, 1, Locale.getDefault(Locale.Category.FORMAT));
491 }
492
493 /**
494 * Gets the time formatter with the given formatting style
495 * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.
496 * <p>This is equivalent to calling
497 * {@link #getTimeInstance(int, Locale) getTimeInstance(style,
498 * Locale.getDefault(Locale.Category.FORMAT))}.
499 * @see java.util.Locale#getDefault(java.util.Locale.Category)
500 * @see java.util.Locale.Category#FORMAT
501 * @param style the given formatting style. For example,
502 * SHORT for "h:mm a" in the US locale.
503 * @return a time formatter.
504 */
505 public static final DateFormat getTimeInstance(int style)
506 {
507 return get(style, 0, 1, Locale.getDefault(Locale.Category.FORMAT));
508 }
509
510 /**
511 * Gets the time formatter with the given formatting style
512 * for the given locale.
513 * @param style the given formatting style. For example,
514 * SHORT for "h:mm a" in the US locale.
515 * @param aLocale the given locale.
516 * @return a time formatter.
517 */
518 public static final DateFormat getTimeInstance(int style,
519 Locale aLocale)
520 {
521 return get(style, 0, 1, aLocale);
522 }
523
524 /**
525 * Gets the date formatter with the default formatting style
526 * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.
527 * <p>This is equivalent to calling
528 * {@link #getDateInstance(int, Locale) getDateInstance(DEFAULT,
529 * Locale.getDefault(Locale.Category.FORMAT))}.
530 * @see java.util.Locale#getDefault(java.util.Locale.Category)
531 * @see java.util.Locale.Category#FORMAT
532 * @return a date formatter.
533 */
534 public static final DateFormat getDateInstance()
535 {
536 return get(0, DEFAULT, 2, Locale.getDefault(Locale.Category.FORMAT));
537 }
538
539 /**
540 * Gets the date formatter with the given formatting style
541 * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.
542 * <p>This is equivalent to calling
543 * {@link #getDateInstance(int, Locale) getDateInstance(style,
544 * Locale.getDefault(Locale.Category.FORMAT))}.
545 * @see java.util.Locale#getDefault(java.util.Locale.Category)
546 * @see java.util.Locale.Category#FORMAT
547 * @param style the given formatting style. For example,
548 * SHORT for "M/d/yy" in the US locale.
549 * @return a date formatter.
550 */
551 public static final DateFormat getDateInstance(int style)
552 {
553 return get(0, style, 2, Locale.getDefault(Locale.Category.FORMAT));
554 }
555
556 /**
557 * Gets the date formatter with the given formatting style
558 * for the given locale.
559 * @param style the given formatting style. For example,
560 * SHORT for "M/d/yy" in the US locale.
561 * @param aLocale the given locale.
562 * @return a date formatter.
563 */
564 public static final DateFormat getDateInstance(int style,
565 Locale aLocale)
566 {
567 return get(0, style, 2, aLocale);
568 }
569
570 /**
571 * Gets the date/time formatter with the default formatting style
572 * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.
573 * <p>This is equivalent to calling
574 * {@link #getDateTimeInstance(int, int, Locale) getDateTimeInstance(DEFAULT,
575 * DEFAULT, Locale.getDefault(Locale.Category.FORMAT))}.
576 * @see java.util.Locale#getDefault(java.util.Locale.Category)
577 * @see java.util.Locale.Category#FORMAT
578 * @return a date/time formatter.
579 */
580 public static final DateFormat getDateTimeInstance()
581 {
582 return get(DEFAULT, DEFAULT, 3, Locale.getDefault(Locale.Category.FORMAT));
583 }
584
585 /**
586 * Gets the date/time formatter with the given date and time
587 * formatting styles for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.
588 * <p>This is equivalent to calling
589 * {@link #getDateTimeInstance(int, int, Locale) getDateTimeInstance(dateStyle,
590 * timeStyle, Locale.getDefault(Locale.Category.FORMAT))}.
591 * @see java.util.Locale#getDefault(java.util.Locale.Category)
592 * @see java.util.Locale.Category#FORMAT
593 * @param dateStyle the given date formatting style. For example,
594 * SHORT for "M/d/yy" in the US locale.
595 * @param timeStyle the given time formatting style. For example,
596 * SHORT for "h:mm a" in the US locale.
597 * @return a date/time formatter.
598 */
599 public static final DateFormat getDateTimeInstance(int dateStyle,
600 int timeStyle)
601 {
602 return get(timeStyle, dateStyle, 3, Locale.getDefault(Locale.Category.FORMAT));
603 }
604
605 /**
606 * Gets the date/time formatter with the given formatting styles
607 * for the given locale.
608 * @param dateStyle the given date formatting style.
609 * @param timeStyle the given time formatting style.
610 * @param aLocale the given locale.
611 * @return a date/time formatter.
612 */
613 public static final DateFormat
614 getDateTimeInstance(int dateStyle, int timeStyle, Locale aLocale)
615 {
616 return get(timeStyle, dateStyle, 3, aLocale);
617 }
618
619 /**
620 * Get a default date/time formatter that uses the SHORT style for both the
621 * date and the time.
622 *
623 * @return a date/time formatter
624 */
625 public static final DateFormat getInstance() {
626 return getDateTimeInstance(SHORT, SHORT);
627 }
628
629 /**
630 * Returns an array of all locales for which the
631 * <code>get*Instance</code> methods of this class can return
632 * localized instances.
633 * The returned array represents the union of locales supported by the Java
634 * runtime and by installed
635 * {@link java.text.spi.DateFormatProvider DateFormatProvider} implementations.
636 * It must contain at least a <code>Locale</code> instance equal to
637 * {@link java.util.Locale#US Locale.US}.
638 *
639 * @return An array of locales for which localized
640 * <code>DateFormat</code> instances are available.
641 */
642 public static Locale[] getAvailableLocales()
643 {
644 LocaleServiceProviderPool pool =
645 LocaleServiceProviderPool.getPool(DateFormatProvider.class);
646 return pool.getAvailableLocales();
647 }
648
649 /**
650 * Set the calendar to be used by this date format. Initially, the default
651 * calendar for the specified or default locale is used.
652 *
653 * <p>Any {@link java.util.TimeZone TimeZone} and {@linkplain
654 * #isLenient() leniency} values that have previously been set are
655 * overwritten by {@code newCalendar}'s values.
656 *
657 * @param newCalendar the new {@code Calendar} to be used by the date format
658 */
659 public void setCalendar(Calendar newCalendar)
660 {
661 this.calendar = newCalendar;
662 }
663
664 /**
665 * Gets the calendar associated with this date/time formatter.
666 *
667 * @return the calendar associated with this date/time formatter.
668 */
669 public Calendar getCalendar()
670 {
671 return calendar;
672 }
673
674 /**
675 * Allows you to set the number formatter.
676 * @param newNumberFormat the given new NumberFormat.
677 */
678 public void setNumberFormat(NumberFormat newNumberFormat)
679 {
680 this.numberFormat = newNumberFormat;
681 }
682
683 /**
684 * Gets the number formatter which this date/time formatter uses to
685 * format and parse a time.
686 * @return the number formatter which this date/time formatter uses.
687 */
688 public NumberFormat getNumberFormat()
689 {
690 return numberFormat;
691 }
692
693 /**
694 * Sets the time zone for the calendar of this {@code DateFormat} object.
695 * This method is equivalent to the following call.
696 * <blockquote><pre>{@code
697 * getCalendar().setTimeZone(zone)
698 * }</pre></blockquote>
699 *
700 * <p>The {@code TimeZone} set by this method is overwritten by a
701 * {@link #setCalendar(java.util.Calendar) setCalendar} call.
702 *
703 * <p>The {@code TimeZone} set by this method may be overwritten as
704 * a result of a call to the parse method.
705 *
706 * @param zone the given new time zone.
707 */
708 public void setTimeZone(TimeZone zone)
709 {
710 calendar.setTimeZone(zone);
711 }
712
713 /**
714 * Gets the time zone.
715 * This method is equivalent to the following call.
716 * <blockquote><pre>{@code
717 * getCalendar().getTimeZone()
718 * }</pre></blockquote>
719 *
720 * @return the time zone associated with the calendar of DateFormat.
721 */
722 public TimeZone getTimeZone()
723 {
724 return calendar.getTimeZone();
725 }
726
727 /**
728 * Specify whether or not date/time parsing is to be lenient. With
729 * lenient parsing, the parser may use heuristics to interpret inputs that
730 * do not precisely match this object's format. With strict parsing,
731 * inputs must match this object's format.
732 *
733 * <p>This method is equivalent to the following call.
734 * <blockquote><pre>{@code
735 * getCalendar().setLenient(lenient)
736 * }</pre></blockquote>
737 *
738 * <p>This leniency value is overwritten by a call to {@link
739 * #setCalendar(java.util.Calendar) setCalendar()}.
740 *
741 * @param lenient when {@code true}, parsing is lenient
742 * @see java.util.Calendar#setLenient(boolean)
743 */
744 public void setLenient(boolean lenient)
745 {
746 calendar.setLenient(lenient);
747 }
748
749 /**
750 * Tell whether date/time parsing is to be lenient.
751 * This method is equivalent to the following call.
752 * <blockquote><pre>{@code
753 * getCalendar().isLenient()
754 * }</pre></blockquote>
755 *
756 * @return {@code true} if the {@link #calendar} is lenient;
757 * {@code false} otherwise.
758 * @see java.util.Calendar#isLenient()
759 */
760 public boolean isLenient()
761 {
762 return calendar.isLenient();
763 }
764
765 /**
766 * Overrides hashCode
767 */
768 public int hashCode() {
769 return numberFormat.hashCode();
770 // just enough fields for a reasonable distribution
771 }
772
773 /**
774 * Overrides equals
775 */
776 public boolean equals(Object obj) {
777 if (this == obj) return true;
778 if (obj == null || getClass() != obj.getClass()) return false;
779 DateFormat other = (DateFormat) obj;
780 return (// calendar.equivalentTo(other.calendar) // THIS API DOESN'T EXIST YET!
781 calendar.getFirstDayOfWeek() == other.calendar.getFirstDayOfWeek() &&
782 calendar.getMinimalDaysInFirstWeek() == other.calendar.getMinimalDaysInFirstWeek() &&
783 calendar.isLenient() == other.calendar.isLenient() &&
784 calendar.getTimeZone().equals(other.calendar.getTimeZone()) &&
785 numberFormat.equals(other.numberFormat));
786 }
787
788 /**
789 * Overrides Cloneable
790 */
791 public Object clone()
792 {
793 DateFormat other = (DateFormat) super.clone();
794 other.calendar = (Calendar) calendar.clone();
795 other.numberFormat = (NumberFormat) numberFormat.clone();
796 return other;
797 }
798
799 /**
800 * Creates a DateFormat with the given time and/or date style in the given
801 * locale.
802 * @param timeStyle a value from 0 to 3 indicating the time format,
803 * ignored if flags is 2
804 * @param dateStyle a value from 0 to 3 indicating the time format,
805 * ignored if flags is 1
806 * @param flags either 1 for a time format, 2 for a date format,
807 * or 3 for a date/time format
808 * @param loc the locale for the format
809 */
810 private static DateFormat get(int timeStyle, int dateStyle,
811 int flags, Locale loc) {
812 if ((flags & 1) != 0) {
813 if (timeStyle < 0 || timeStyle > 3) {
814 throw new IllegalArgumentException("Illegal time style " + timeStyle);
815 }
816 } else {
817 timeStyle = -1;
818 }
819 if ((flags & 2) != 0) {
820 if (dateStyle < 0 || dateStyle > 3) {
821 throw new IllegalArgumentException("Illegal date style " + dateStyle);
822 }
823 } else {
824 dateStyle = -1;
825 }
826
827 LocaleProviderAdapter adapter = LocaleProviderAdapter.getAdapter(DateFormatProvider.class, loc);
828 DateFormat dateFormat = get(adapter, timeStyle, dateStyle, loc);
829 if (dateFormat == null) {
830 dateFormat = get(LocaleProviderAdapter.forJRE(), timeStyle, dateStyle, loc);
831 }
832 return dateFormat;
833 }
834
835 private static DateFormat get(LocaleProviderAdapter adapter, int timeStyle, int dateStyle, Locale loc) {
836 DateFormatProvider provider = adapter.getDateFormatProvider();
837 DateFormat dateFormat;
838 if (timeStyle == -1) {
839 dateFormat = provider.getDateInstance(dateStyle, loc);
840 } else {
841 if (dateStyle == -1) {
842 dateFormat = provider.getTimeInstance(timeStyle, loc);
843 } else {
844 dateFormat = provider.getDateTimeInstance(dateStyle, timeStyle, loc);
845 }
846 }
847 return dateFormat;
848 }
849
850 /**
851 * Create a new date format.
852 */
853 protected DateFormat() {}
854
855 /**
856 * Defines constants that are used as attribute keys in the
857 * <code>AttributedCharacterIterator</code> returned
858 * from <code>DateFormat.formatToCharacterIterator</code> and as
859 * field identifiers in <code>FieldPosition</code>.
860 * <p>
861 * The class also provides two methods to map
862 * between its constants and the corresponding Calendar constants.
863 *
864 * @since 1.4
865 * @see java.util.Calendar
866 */
867 public static class Field extends Format.Field {
868
869 // Proclaim serial compatibility with 1.4 FCS
870 @java.io.Serial
871 private static final long serialVersionUID = 7441350119349544720L;
872
873 // table of all instances in this class, used by readResolve
874 private static final Map<String, Field> instanceMap = new HashMap<>(18);
875 // Maps from Calendar constant (such as Calendar.ERA) to Field
876 // constant (such as Field.ERA).
877 private static final Field[] calendarToFieldMapping =
878 new Field[Calendar.FIELD_COUNT];
879
880 /** Calendar field. */
881 private int calendarField;
882
883 /**
884 * Returns the <code>Field</code> constant that corresponds to
885 * the <code>Calendar</code> constant <code>calendarField</code>.
886 * If there is no direct mapping between the <code>Calendar</code>
887 * constant and a <code>Field</code>, null is returned.
888 *
889 * @throws IllegalArgumentException if <code>calendarField</code> is
890 * not the value of a <code>Calendar</code> field constant.
891 * @param calendarField Calendar field constant
892 * @return Field instance representing calendarField.
893 * @see java.util.Calendar
894 */
895 public static Field ofCalendarField(int calendarField) {
896 if (calendarField < 0 || calendarField >=
897 calendarToFieldMapping.length) {
898 throw new IllegalArgumentException("Unknown Calendar constant "
899 + calendarField);
900 }
901 return calendarToFieldMapping[calendarField];
902 }
903
904 /**
905 * Creates a <code>Field</code>.
906 *
907 * @param name the name of the <code>Field</code>
908 * @param calendarField the <code>Calendar</code> constant this
909 * <code>Field</code> corresponds to; any value, even one
910 * outside the range of legal <code>Calendar</code> values may
911 * be used, but <code>-1</code> should be used for values
912 * that don't correspond to legal <code>Calendar</code> values
913 */
914 protected Field(String name, int calendarField) {
915 super(name);
916 this.calendarField = calendarField;
917 if (this.getClass() == DateFormat.Field.class) {
918 instanceMap.put(name, this);
919 if (calendarField >= 0) {
920 // assert(calendarField < Calendar.FIELD_COUNT);
921 calendarToFieldMapping[calendarField] = this;
922 }
923 }
924 }
925
926 /**
927 * Returns the <code>Calendar</code> field associated with this
928 * attribute. For example, if this represents the hours field of
929 * a <code>Calendar</code>, this would return
930 * <code>Calendar.HOUR</code>. If there is no corresponding
931 * <code>Calendar</code> constant, this will return -1.
932 *
933 * @return Calendar constant for this field
934 * @see java.util.Calendar
935 */
936 public int getCalendarField() {
937 return calendarField;
938 }
939
940 /**
941 * Resolves instances being deserialized to the predefined constants.
942 *
943 * @throws InvalidObjectException if the constant could not be
944 * resolved.
945 * @return resolved DateFormat.Field constant
946 */
947 @Override
948 @java.io.Serial
949 protected Object readResolve() throws InvalidObjectException {
950 if (this.getClass() != DateFormat.Field.class) {
951 throw new InvalidObjectException("subclass didn't correctly implement readResolve");
952 }
953
954 Object instance = instanceMap.get(getName());
955 if (instance != null) {
956 return instance;
957 } else {
958 throw new InvalidObjectException("unknown attribute name");
959 }
960 }
961
962 //
963 // The constants
964 //
965
966 /**
967 * Constant identifying the era field.
968 */
969 public static final Field ERA = new Field("era", Calendar.ERA);
970
971 /**
972 * Constant identifying the year field.
973 */
974 public static final Field YEAR = new Field("year", Calendar.YEAR);
975
976 /**
977 * Constant identifying the month field.
978 */
979 public static final Field MONTH = new Field("month", Calendar.MONTH);
980
981 /**
982 * Constant identifying the day of month field.
983 */
984 public static final Field DAY_OF_MONTH = new
985 Field("day of month", Calendar.DAY_OF_MONTH);
986
987 /**
988 * Constant identifying the hour of day field, where the legal values
989 * are 1 to 24.
990 */
991 public static final Field HOUR_OF_DAY1 = new Field("hour of day 1",-1);
992
993 /**
994 * Constant identifying the hour of day field, where the legal values
995 * are 0 to 23.
996 */
997 public static final Field HOUR_OF_DAY0 = new
998 Field("hour of day", Calendar.HOUR_OF_DAY);
999
1000 /**
1001 * Constant identifying the minute field.
1002 */
1003 public static final Field MINUTE =new Field("minute", Calendar.MINUTE);
1004
1005 /**
1006 * Constant identifying the second field.
1007 */
1008 public static final Field SECOND =new Field("second", Calendar.SECOND);
1009
1010 /**
1011 * Constant identifying the millisecond field.
1012 */
1013 public static final Field MILLISECOND = new
1014 Field("millisecond", Calendar.MILLISECOND);
1015
1016 /**
1017 * Constant identifying the day of week field.
1018 */
1019 public static final Field DAY_OF_WEEK = new
1020 Field("day of week", Calendar.DAY_OF_WEEK);
1021
1022 /**
1023 * Constant identifying the day of year field.
1024 */
1025 public static final Field DAY_OF_YEAR = new
1026 Field("day of year", Calendar.DAY_OF_YEAR);
1027
1028 /**
1029 * Constant identifying the day of week field.
1030 */
1031 public static final Field DAY_OF_WEEK_IN_MONTH =
1032 new Field("day of week in month",
1033 Calendar.DAY_OF_WEEK_IN_MONTH);
1034
1035 /**
1036 * Constant identifying the week of year field.
1037 */
1038 public static final Field WEEK_OF_YEAR = new
1039 Field("week of year", Calendar.WEEK_OF_YEAR);
1040
1041 /**
1042 * Constant identifying the week of month field.
1043 */
1044 public static final Field WEEK_OF_MONTH = new
1045 Field("week of month", Calendar.WEEK_OF_MONTH);
1046
1047 /**
1048 * Constant identifying the time of day indicator
1049 * (e.g. "a.m." or "p.m.") field.
1050 */
1051 public static final Field AM_PM = new
1052 Field("am pm", Calendar.AM_PM);
1053
1054 /**
1055 * Constant identifying the hour field, where the legal values are
1056 * 1 to 12.
1057 */
1058 public static final Field HOUR1 = new Field("hour 1", -1);
1059
1060 /**
1061 * Constant identifying the hour field, where the legal values are
1062 * 0 to 11.
1063 */
1064 public static final Field HOUR0 = new
1065 Field("hour", Calendar.HOUR);
1066
1067 /**
1068 * Constant identifying the time zone field.
1069 */
1070 public static final Field TIME_ZONE = new Field("time zone", -1);
1071 }
1072 }