1 /*
2 * Copyright 1996-2005 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any 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.LocaleServiceProviderPool;
54
55 /**
56 * DateFormat is an abstract class for date/time formatting subclasses which
57 * formats and parses dates or time in a language-independent manner.
58 * The date/time formatting subclass, such as SimpleDateFormat, allows for
59 * formatting (i.e., date -> text), parsing (text -> date), and
60 * normalization. The date is represented as a <code>Date</code> object or
61 * as the milliseconds since January 1, 1970, 00:00:00 GMT.
62 *
63 * <p>DateFormat provides many class methods for obtaining default date/time
64 * formatters based on the default or a given locale and a number of formatting
65 * styles. The formatting styles include FULL, LONG, MEDIUM, and SHORT. More
66 * detail and examples of using these styles are provided in the method
67 * descriptions.
68 *
69 * <p>DateFormat helps you to format and parse dates for any locale.
70 * Your code can be completely independent of the locale conventions for
71 * months, days of the week, or even the calendar format: lunar vs. solar.
72 *
73 * <p>To format a date for the current Locale, use one of the
74 * static factory methods:
75 * <pre>
76 * myString = DateFormat.getDateInstance().format(myDate);
77 * </pre>
78 * <p>If you are formatting multiple dates, it is
79 * more efficient to get the format and use it multiple times so that
80 * the system doesn't have to fetch the information about the local
81 * language and country conventions multiple times.
82 * <pre>
83 * DateFormat df = DateFormat.getDateInstance();
84 * for (int i = 0; i < myDate.length; ++i) {
85 * output.println(df.format(myDate[i]) + "; ");
86 * }
87 * </pre>
88 * <p>To format a date for a different Locale, specify it in the
89 * call to getDateInstance().
90 * <pre>
91 * DateFormat df = DateFormat.getDateInstance(DateFormat.LONG, Locale.FRANCE);
92 * </pre>
93 * <p>You can use a DateFormat to parse also.
94 * <pre>
95 * myDate = df.parse(myString);
96 * </pre>
97 * <p>Use getDateInstance to get the normal date format for that country.
98 * There are other static factory methods available.
99 * Use getTimeInstance to get the time format for that country.
100 * Use getDateTimeInstance to get a date and time format. You can pass in
101 * different options to these factory methods to control the length of the
102 * result; from SHORT to MEDIUM to LONG to FULL. The exact result depends
103 * on the locale, but generally:
104 * <ul><li>SHORT is completely numeric, such as 12.13.52 or 3:30pm
105 * <li>MEDIUM is longer, such as Jan 12, 1952
106 * <li>LONG is longer, such as January 12, 1952 or 3:30:32pm
107 * <li>FULL is pretty completely specified, such as
108 * Tuesday, April 12, 1952 AD or 3:30:42pm PST.
109 * </ul>
110 *
111 * <p>You can also set the time zone on the format if you wish.
112 * If you want even more control over the format or parsing,
113 * (or want to give your users more control),
114 * you can try casting the DateFormat you get from the factory methods
115 * to a SimpleDateFormat. This will work for the majority
116 * of countries; just remember to put it in a try block in case you
117 * encounter an unusual one.
118 *
119 * <p>You can also use forms of the parse and format methods with
120 * ParsePosition and FieldPosition to
121 * allow you to
122 * <ul><li>progressively parse through pieces of a string.
123 * <li>align any particular field, or find out where it is for selection
124 * on the screen.
125 * </ul>
126 *
127 * <h4><a name="synchronization">Synchronization</a></h4>
128 *
129 * <p>
130 * Date formats are not synchronized.
131 * It is recommended to create separate format instances for each thread.
132 * If multiple threads access a format concurrently, it must be synchronized
133 * externally.
134 *
135 * @see Format
136 * @see NumberFormat
137 * @see SimpleDateFormat
138 * @see java.util.Calendar
139 * @see java.util.GregorianCalendar
140 * @see java.util.TimeZone
141 * @author Mark Davis, Chen-Lieh Huang, Alan Liu
142 */
143 public abstract class DateFormat extends Format {
144
145 /**
146 * The calendar that <code>DateFormat</code> uses to produce the time field
147 * values needed to implement date and time formatting. Subclasses should
148 * initialize this to a calendar appropriate for the locale associated with
149 * this <code>DateFormat</code>.
150 * @serial
151 */
152 protected Calendar calendar;
153
154 /**
155 * The number formatter that <code>DateFormat</code> uses to format numbers
156 * in dates and times. Subclasses should initialize this to a number format
157 * appropriate for the locale associated with this <code>DateFormat</code>.
158 * @serial
159 */
160 protected NumberFormat numberFormat;
161
162 /**
163 * Useful constant for ERA field alignment.
164 * Used in FieldPosition of date/time formatting.
165 */
166 public final static int ERA_FIELD = 0;
167 /**
168 * Useful constant for YEAR field alignment.
169 * Used in FieldPosition of date/time formatting.
170 */
171 public final static int YEAR_FIELD = 1;
172 /**
173 * Useful constant for MONTH field alignment.
174 * Used in FieldPosition of date/time formatting.
175 */
176 public final static int MONTH_FIELD = 2;
177 /**
178 * Useful constant for DATE field alignment.
179 * Used in FieldPosition of date/time formatting.
180 */
181 public final static int DATE_FIELD = 3;
182 /**
183 * Useful constant for one-based HOUR_OF_DAY field alignment.
184 * Used in FieldPosition of date/time formatting.
185 * HOUR_OF_DAY1_FIELD is used for the one-based 24-hour clock.
186 * For example, 23:59 + 01:00 results in 24:59.
187 */
188 public final static int HOUR_OF_DAY1_FIELD = 4;
189 /**
190 * Useful constant for zero-based HOUR_OF_DAY field alignment.
191 * Used in FieldPosition of date/time formatting.
192 * HOUR_OF_DAY0_FIELD is used for the zero-based 24-hour clock.
193 * For example, 23:59 + 01:00 results in 00:59.
194 */
195 public final static int HOUR_OF_DAY0_FIELD = 5;
196 /**
197 * Useful constant for MINUTE field alignment.
198 * Used in FieldPosition of date/time formatting.
199 */
200 public final static int MINUTE_FIELD = 6;
201 /**
202 * Useful constant for SECOND field alignment.
203 * Used in FieldPosition of date/time formatting.
204 */
205 public final static int SECOND_FIELD = 7;
206 /**
207 * Useful constant for MILLISECOND field alignment.
208 * Used in FieldPosition of date/time formatting.
209 */
210 public final static int MILLISECOND_FIELD = 8;
211 /**
212 * Useful constant for DAY_OF_WEEK field alignment.
213 * Used in FieldPosition of date/time formatting.
214 */
215 public final static int DAY_OF_WEEK_FIELD = 9;
216 /**
217 * Useful constant for DAY_OF_YEAR field alignment.
218 * Used in FieldPosition of date/time formatting.
219 */
220 public final static int DAY_OF_YEAR_FIELD = 10;
221 /**
222 * Useful constant for DAY_OF_WEEK_IN_MONTH field alignment.
223 * Used in FieldPosition of date/time formatting.
224 */
225 public final static int DAY_OF_WEEK_IN_MONTH_FIELD = 11;
226 /**
227 * Useful constant for WEEK_OF_YEAR field alignment.
228 * Used in FieldPosition of date/time formatting.
229 */
230 public final static int WEEK_OF_YEAR_FIELD = 12;
231 /**
232 * Useful constant for WEEK_OF_MONTH field alignment.
233 * Used in FieldPosition of date/time formatting.
234 */
235 public final static int WEEK_OF_MONTH_FIELD = 13;
236 /**
237 * Useful constant for AM_PM field alignment.
238 * Used in FieldPosition of date/time formatting.
239 */
240 public final static int AM_PM_FIELD = 14;
241 /**
242 * Useful constant for one-based HOUR field alignment.
243 * Used in FieldPosition of date/time formatting.
244 * HOUR1_FIELD is used for the one-based 12-hour clock.
245 * For example, 11:30 PM + 1 hour results in 12:30 AM.
246 */
247 public final static int HOUR1_FIELD = 15;
248 /**
249 * Useful constant for zero-based HOUR field alignment.
250 * Used in FieldPosition of date/time formatting.
251 * HOUR0_FIELD is used for the zero-based 12-hour clock.
252 * For example, 11:30 PM + 1 hour results in 00:30 AM.
253 */
254 public final static int HOUR0_FIELD = 16;
255 /**
256 * Useful constant for TIMEZONE field alignment.
257 * Used in FieldPosition of date/time formatting.
258 */
259 public final static int TIMEZONE_FIELD = 17;
260
261 // Proclaim serial compatibility with 1.1 FCS
262 private static final long serialVersionUID = 7218322306649953788L;
263
264 /**
265 * Overrides Format.
266 * Formats a time object into a time string. Examples of time objects
267 * are a time value expressed in milliseconds and a Date object.
268 * @param obj must be a Number or a Date.
269 * @param toAppendTo the string buffer for the returning time string.
270 * @return the string buffer passed in as toAppendTo, with formatted text appended.
271 * @param fieldPosition keeps track of the position of the field
272 * within the returned string.
273 * On input: an alignment field,
274 * if desired. On output: the offsets of the alignment field. For
275 * example, given a time text "1996.07.10 AD at 15:08:56 PDT",
276 * if the given fieldPosition is DateFormat.YEAR_FIELD, the
277 * begin index and end index of fieldPosition will be set to
278 * 0 and 4, respectively.
279 * Notice that if the same time field appears
280 * more than once in a pattern, the fieldPosition will be set for the first
281 * occurrence of that time field. For instance, formatting a Date to
282 * the time string "1 PM PDT (Pacific Daylight Time)" using the pattern
283 * "h a z (zzzz)" and the alignment field DateFormat.TIMEZONE_FIELD,
284 * the begin index and end index of fieldPosition will be set to
285 * 5 and 8, respectively, for the first occurrence of the timezone
286 * pattern character 'z'.
287 * @see java.text.Format
288 */
289 public final StringBuffer format(Object obj, StringBuffer toAppendTo,
290 FieldPosition fieldPosition)
291 {
292 if (obj instanceof Date)
293 return format( (Date)obj, toAppendTo, fieldPosition );
294 else if (obj instanceof Number)
295 return format( new Date(((Number)obj).longValue()),
296 toAppendTo, fieldPosition );
297 else
298 throw new IllegalArgumentException("Cannot format given Object as a Date");
299 }
300
301 /**
302 * Formats a Date into a date/time string.
303 * @param date a Date to be formatted into a date/time string.
304 * @param toAppendTo the string buffer for the returning date/time string.
305 * @param fieldPosition keeps track of the position of the field
306 * within the returned string.
307 * On input: an alignment field,
308 * if desired. On output: the offsets of the alignment field. For
309 * example, given a time text "1996.07.10 AD at 15:08:56 PDT",
310 * if the given fieldPosition is DateFormat.YEAR_FIELD, the
311 * begin index and end index of fieldPosition will be set to
312 * 0 and 4, respectively.
313 * Notice that if the same time field appears
314 * more than once in a pattern, the fieldPosition will be set for the first
315 * occurrence of that time field. For instance, formatting a Date to
316 * the time string "1 PM PDT (Pacific Daylight Time)" using the pattern
317 * "h a z (zzzz)" and the alignment field DateFormat.TIMEZONE_FIELD,
318 * the begin index and end index of fieldPosition will be set to
319 * 5 and 8, respectively, for the first occurrence of the timezone
320 * pattern character 'z'.
321 * @return the string buffer passed in as toAppendTo, with formatted text appended.
322 */
323 public abstract StringBuffer format(Date date, StringBuffer toAppendTo,
324 FieldPosition fieldPosition);
325
326 /**
327 * Formats a Date into a date/time string.
328 * @param date the time value to be formatted into a time string.
329 * @return the formatted time string.
330 */
331 public final String format(Date date)
332 {
333 return format(date, new StringBuffer(),
334 DontCareFieldPosition.INSTANCE).toString();
335 }
336
337 /**
338 * Parses text from the beginning of the given string to produce a date.
339 * The method may not use the entire text of the given string.
340 * <p>
341 * See the {@link #parse(String, ParsePosition)} method for more information
342 * on date parsing.
343 *
344 * @param source A <code>String</code> whose beginning should be parsed.
345 * @return A <code>Date</code> parsed from the string.
346 * @exception ParseException if the beginning of the specified string
347 * cannot be parsed.
348 */
349 public Date parse(String source) throws ParseException
350 {
351 ParsePosition pos = new ParsePosition(0);
352 Date result = parse(source, pos);
353 if (pos.index == 0)
354 throw new ParseException("Unparseable date: \"" + source + "\"" ,
355 pos.errorIndex);
356 return result;
357 }
358
359 /**
360 * Parse a date/time string according to the given parse position. For
361 * example, a time text "07/10/96 4:5 PM, PDT" will be parsed into a Date
362 * that is equivalent to Date(837039928046).
363 *
364 * <p> By default, parsing is lenient: If the input is not in the form used
365 * by this object's format method but can still be parsed as a date, then
366 * the parse succeeds. Clients may insist on strict adherence to the
367 * format by calling setLenient(false).
368 *
369 * @see java.text.DateFormat#setLenient(boolean)
370 *
371 * @param source The date/time string to be parsed
372 *
373 * @param pos On input, the position at which to start parsing; on
374 * output, the position at which parsing terminated, or the
375 * start position if the parse failed.
376 *
377 * @return A Date, or null if the input could not be parsed
378 */
379 public abstract Date parse(String source, ParsePosition pos);
380
381 /**
382 * Parses text from a string to produce a <code>Date</code>.
383 * <p>
384 * The method attempts to parse text starting at the index given by
385 * <code>pos</code>.
386 * If parsing succeeds, then the index of <code>pos</code> is updated
387 * to the index after the last character used (parsing does not necessarily
388 * use all characters up to the end of the string), and the parsed
389 * date is returned. The updated <code>pos</code> can be used to
390 * indicate the starting point for the next call to this method.
391 * If an error occurs, then the index of <code>pos</code> is not
392 * changed, the error index of <code>pos</code> is set to the index of
393 * the character where the error occurred, and null is returned.
394 * <p>
395 * See the {@link #parse(String, ParsePosition)} method for more information
396 * on date parsing.
397 *
398 * @param source A <code>String</code>, part of which should be parsed.
399 * @param pos A <code>ParsePosition</code> object with index and error
400 * index information as described above.
401 * @return A <code>Date</code> parsed from the string. In case of
402 * error, returns null.
403 * @exception NullPointerException if <code>pos</code> is null.
404 */
405 public Object parseObject(String source, ParsePosition pos) {
406 return parse(source, pos);
407 }
408
409 /**
410 * Constant for full style pattern.
411 */
412 public static final int FULL = 0;
413 /**
414 * Constant for long style pattern.
415 */
416 public static final int LONG = 1;
417 /**
418 * Constant for medium style pattern.
419 */
420 public static final int MEDIUM = 2;
421 /**
422 * Constant for short style pattern.
423 */
424 public static final int SHORT = 3;
425 /**
426 * Constant for default style pattern. Its value is MEDIUM.
427 */
428 public static final int DEFAULT = MEDIUM;
429
430 /**
431 * Gets the time formatter with the default formatting style
432 * for the default locale.
433 * @return a time formatter.
434 */
435 public final static DateFormat getTimeInstance()
436 {
437 return get(DEFAULT, 0, 1, Locale.getDefault());
438 }
439
440 /**
441 * Gets the time formatter with the given formatting style
442 * for the default locale.
443 * @param style the given formatting style. For example,
444 * SHORT for "h:mm a" in the US locale.
445 * @return a time formatter.
446 */
447 public final static DateFormat getTimeInstance(int style)
448 {
449 return get(style, 0, 1, Locale.getDefault());
450 }
451
452 /**
453 * Gets the time formatter with the given formatting style
454 * for the given locale.
455 * @param style the given formatting style. For example,
456 * SHORT for "h:mm a" in the US locale.
457 * @param aLocale the given locale.
458 * @return a time formatter.
459 */
460 public final static DateFormat getTimeInstance(int style,
461 Locale aLocale)
462 {
463 return get(style, 0, 1, aLocale);
464 }
465
466 /**
467 * Gets the date formatter with the default formatting style
468 * for the default locale.
469 * @return a date formatter.
470 */
471 public final static DateFormat getDateInstance()
472 {
473 return get(0, DEFAULT, 2, Locale.getDefault());
474 }
475
476 /**
477 * Gets the date formatter with the given formatting style
478 * for the default locale.
479 * @param style the given formatting style. For example,
480 * SHORT for "M/d/yy" in the US locale.
481 * @return a date formatter.
482 */
483 public final static DateFormat getDateInstance(int style)
484 {
485 return get(0, style, 2, Locale.getDefault());
486 }
487
488 /**
489 * Gets the date formatter with the given formatting style
490 * for the given locale.
491 * @param style the given formatting style. For example,
492 * SHORT for "M/d/yy" in the US locale.
493 * @param aLocale the given locale.
494 * @return a date formatter.
495 */
496 public final static DateFormat getDateInstance(int style,
497 Locale aLocale)
498 {
499 return get(0, style, 2, aLocale);
500 }
501
502 /**
503 * Gets the date/time formatter with the default formatting style
504 * for the default locale.
505 * @return a date/time formatter.
506 */
507 public final static DateFormat getDateTimeInstance()
508 {
509 return get(DEFAULT, DEFAULT, 3, Locale.getDefault());
510 }
511
512 /**
513 * Gets the date/time formatter with the given date and time
514 * formatting styles for the default locale.
515 * @param dateStyle the given date formatting style. For example,
516 * SHORT for "M/d/yy" in the US locale.
517 * @param timeStyle the given time formatting style. For example,
518 * SHORT for "h:mm a" in the US locale.
519 * @return a date/time formatter.
520 */
521 public final static DateFormat getDateTimeInstance(int dateStyle,
522 int timeStyle)
523 {
524 return get(timeStyle, dateStyle, 3, Locale.getDefault());
525 }
526
527 /**
528 * Gets the date/time formatter with the given formatting styles
529 * for the given locale.
530 * @param dateStyle the given date formatting style.
531 * @param timeStyle the given time formatting style.
532 * @param aLocale the given locale.
533 * @return a date/time formatter.
534 */
535 public final static DateFormat
536 getDateTimeInstance(int dateStyle, int timeStyle, Locale aLocale)
537 {
538 return get(timeStyle, dateStyle, 3, aLocale);
539 }
540
541 /**
542 * Get a default date/time formatter that uses the SHORT style for both the
543 * date and the time.
544 */
545 public final static DateFormat getInstance() {
546 return getDateTimeInstance(SHORT, SHORT);
547 }
548
549 /**
550 * Returns an array of all locales for which the
551 * <code>get*Instance</code> methods of this class can return
552 * localized instances.
553 * The returned array represents the union of locales supported by the Java
554 * runtime and by installed
555 * {@link java.text.spi.DateFormatProvider DateFormatProvider} implementations.
556 * It must contain at least a <code>Locale</code> instance equal to
557 * {@link java.util.Locale#US Locale.US}.
558 *
559 * @return An array of locales for which localized
560 * <code>DateFormat</code> instances are available.
561 */
562 public static Locale[] getAvailableLocales()
563 {
564 LocaleServiceProviderPool pool =
565 LocaleServiceProviderPool.getPool(DateFormatProvider.class);
566 return pool.getAvailableLocales();
567 }
568
569 /**
570 * Set the calendar to be used by this date format. Initially, the default
571 * calendar for the specified or default locale is used.
572 * @param newCalendar the new Calendar to be used by the date format
573 */
574 public void setCalendar(Calendar newCalendar)
575 {
576 this.calendar = newCalendar;
577 }
578
579 /**
580 * Gets the calendar associated with this date/time formatter.
581 * @return the calendar associated with this date/time formatter.
582 */
583 public Calendar getCalendar()
584 {
585 return calendar;
586 }
587
588 /**
589 * Allows you to set the number formatter.
590 * @param newNumberFormat the given new NumberFormat.
591 */
592 public void setNumberFormat(NumberFormat newNumberFormat)
593 {
594 this.numberFormat = newNumberFormat;
595 }
596
597 /**
598 * Gets the number formatter which this date/time formatter uses to
599 * format and parse a time.
600 * @return the number formatter which this date/time formatter uses.
601 */
602 public NumberFormat getNumberFormat()
603 {
604 return numberFormat;
605 }
606
607 /**
608 * Sets the time zone for the calendar of this DateFormat object.
609 * @param zone the given new time zone.
610 */
611 public void setTimeZone(TimeZone zone)
612 {
613 calendar.setTimeZone(zone);
614 }
615
616 /**
617 * Gets the time zone.
618 * @return the time zone associated with the calendar of DateFormat.
619 */
620 public TimeZone getTimeZone()
621 {
622 return calendar.getTimeZone();
623 }
624
625 /**
626 * Specify whether or not date/time parsing is to be lenient. With
627 * lenient parsing, the parser may use heuristics to interpret inputs that
628 * do not precisely match this object's format. With strict parsing,
629 * inputs must match this object's format.
630 * @param lenient when true, parsing is lenient
631 * @see java.util.Calendar#setLenient
632 */
633 public void setLenient(boolean lenient)
634 {
635 calendar.setLenient(lenient);
636 }
637
638 /**
639 * Tell whether date/time parsing is to be lenient.
640 */
641 public boolean isLenient()
642 {
643 return calendar.isLenient();
644 }
645
646 /**
647 * Overrides hashCode
648 */
649 public int hashCode() {
650 return numberFormat.hashCode();
651 // just enough fields for a reasonable distribution
652 }
653
654 /**
655 * Overrides equals
656 */
657 public boolean equals(Object obj) {
658 if (this == obj) return true;
659 if (obj == null || getClass() != obj.getClass()) return false;
660 DateFormat other = (DateFormat) obj;
661 return (// calendar.equivalentTo(other.calendar) // THIS API DOESN'T EXIST YET!
662 calendar.getFirstDayOfWeek() == other.calendar.getFirstDayOfWeek() &&
663 calendar.getMinimalDaysInFirstWeek() == other.calendar.getMinimalDaysInFirstWeek() &&
664 calendar.isLenient() == other.calendar.isLenient() &&
665 calendar.getTimeZone().equals(other.calendar.getTimeZone()) &&
666 numberFormat.equals(other.numberFormat));
667 }
668
669 /**
670 * Overrides Cloneable
671 */
672 public Object clone()
673 {
674 DateFormat other = (DateFormat) super.clone();
675 other.calendar = (Calendar) calendar.clone();
676 other.numberFormat = (NumberFormat) numberFormat.clone();
677 return other;
678 }
679
680 /**
681 * Creates a DateFormat with the given time and/or date style in the given
682 * locale.
683 * @param timeStyle a value from 0 to 3 indicating the time format,
684 * ignored if flags is 2
685 * @param dateStyle a value from 0 to 3 indicating the time format,
686 * ignored if flags is 1
687 * @param flags either 1 for a time format, 2 for a date format,
688 * or 3 for a date/time format
689 * @param loc the locale for the format
690 */
691 private static DateFormat get(int timeStyle, int dateStyle,
692 int flags, Locale loc) {
693 if ((flags & 1) != 0) {
694 if (timeStyle < 0 || timeStyle > 3) {
695 throw new IllegalArgumentException("Illegal time style " + timeStyle);
696 }
697 } else {
698 timeStyle = -1;
699 }
700 if ((flags & 2) != 0) {
701 if (dateStyle < 0 || dateStyle > 3) {
702 throw new IllegalArgumentException("Illegal date style " + dateStyle);
703 }
704 } else {
705 dateStyle = -1;
706 }
707 try {
708 // Check whether a provider can provide an implementation that's closer
709 // to the requested locale than what the Java runtime itself can provide.
710 LocaleServiceProviderPool pool =
711 LocaleServiceProviderPool.getPool(DateFormatProvider.class);
712 if (pool.hasProviders()) {
713 DateFormat providersInstance = pool.getLocalizedObject(
714 DateFormatGetter.INSTANCE,
715 loc,
716 timeStyle,
717 dateStyle,
718 flags);
719 if (providersInstance != null) {
720 return providersInstance;
721 }
722 }
723
724 return new SimpleDateFormat(timeStyle, dateStyle, loc);
725 } catch (MissingResourceException e) {
726 return new SimpleDateFormat("M/d/yy h:mm a");
727 }
728 }
729
730 /**
731 * Create a new date format.
732 */
733 protected DateFormat() {}
734
735 /**
736 * Defines constants that are used as attribute keys in the
737 * <code>AttributedCharacterIterator</code> returned
738 * from <code>DateFormat.formatToCharacterIterator</code> and as
739 * field identifiers in <code>FieldPosition</code>.
740 * <p>
741 * The class also provides two methods to map
742 * between its constants and the corresponding Calendar constants.
743 *
744 * @since 1.4
745 * @see java.util.Calendar
746 */
747 public static class Field extends Format.Field {
748
749 // Proclaim serial compatibility with 1.4 FCS
750 private static final long serialVersionUID = 7441350119349544720L;
751
752 // table of all instances in this class, used by readResolve
753 private static final Map instanceMap = new HashMap(18);
754 // Maps from Calendar constant (such as Calendar.ERA) to Field
755 // constant (such as Field.ERA).
756 private static final Field[] calendarToFieldMapping =
757 new Field[Calendar.FIELD_COUNT];
758
759 /** Calendar field. */
760 private int calendarField;
761
762 /**
763 * Returns the <code>Field</code> constant that corresponds to
764 * the <code>Calendar</code> constant <code>calendarField</code>.
765 * If there is no direct mapping between the <code>Calendar</code>
766 * constant and a <code>Field</code>, null is returned.
767 *
768 * @throws IllegalArgumentException if <code>calendarField</code> is
769 * not the value of a <code>Calendar</code> field constant.
770 * @param calendarField Calendar field constant
771 * @return Field instance representing calendarField.
772 * @see java.util.Calendar
773 */
774 public static Field ofCalendarField(int calendarField) {
775 if (calendarField < 0 || calendarField >=
776 calendarToFieldMapping.length) {
777 throw new IllegalArgumentException("Unknown Calendar constant "
778 + calendarField);
779 }
780 return calendarToFieldMapping[calendarField];
781 }
782
783 /**
784 * Creates a <code>Field</code>.
785 *
786 * @param name the name of the <code>Field</code>
787 * @param calendarField the <code>Calendar</code> constant this
788 * <code>Field</code> corresponds to; any value, even one
789 * outside the range of legal <code>Calendar</code> values may
790 * be used, but <code>-1</code> should be used for values
791 * that don't correspond to legal <code>Calendar</code> values
792 */
793 protected Field(String name, int calendarField) {
794 super(name);
795 this.calendarField = calendarField;
796 if (this.getClass() == DateFormat.Field.class) {
797 instanceMap.put(name, this);
798 if (calendarField >= 0) {
799 // assert(calendarField < Calendar.FIELD_COUNT);
800 calendarToFieldMapping[calendarField] = this;
801 }
802 }
803 }
804
805 /**
806 * Returns the <code>Calendar</code> field associated with this
807 * attribute. For example, if this represents the hours field of
808 * a <code>Calendar</code>, this would return
809 * <code>Calendar.HOUR</code>. If there is no corresponding
810 * <code>Calendar</code> constant, this will return -1.
811 *
812 * @return Calendar constant for this field
813 * @see java.util.Calendar
814 */
815 public int getCalendarField() {
816 return calendarField;
817 }
818
819 /**
820 * Resolves instances being deserialized to the predefined constants.
821 *
822 * @throws InvalidObjectException if the constant could not be
823 * resolved.
824 * @return resolved DateFormat.Field constant
825 */
826 protected Object readResolve() throws InvalidObjectException {
827 if (this.getClass() != DateFormat.Field.class) {
828 throw new InvalidObjectException("subclass didn't correctly implement readResolve");
829 }
830
831 Object instance = instanceMap.get(getName());
832 if (instance != null) {
833 return instance;
834 } else {
835 throw new InvalidObjectException("unknown attribute name");
836 }
837 }
838
839 //
840 // The constants
841 //
842
843 /**
844 * Constant identifying the era field.
845 */
846 public final static Field ERA = new Field("era", Calendar.ERA);
847
848 /**
849 * Constant identifying the year field.
850 */
851 public final static Field YEAR = new Field("year", Calendar.YEAR);
852
853 /**
854 * Constant identifying the month field.
855 */
856 public final static Field MONTH = new Field("month", Calendar.MONTH);
857
858 /**
859 * Constant identifying the day of month field.
860 */
861 public final static Field DAY_OF_MONTH = new
862 Field("day of month", Calendar.DAY_OF_MONTH);
863
864 /**
865 * Constant identifying the hour of day field, where the legal values
866 * are 1 to 24.
867 */
868 public final static Field HOUR_OF_DAY1 = new Field("hour of day 1",-1);
869
870 /**
871 * Constant identifying the hour of day field, where the legal values
872 * are 0 to 23.
873 */
874 public final static Field HOUR_OF_DAY0 = new
875 Field("hour of day", Calendar.HOUR_OF_DAY);
876
877 /**
878 * Constant identifying the minute field.
879 */
880 public final static Field MINUTE =new Field("minute", Calendar.MINUTE);
881
882 /**
883 * Constant identifying the second field.
884 */
885 public final static Field SECOND =new Field("second", Calendar.SECOND);
886
887 /**
888 * Constant identifying the millisecond field.
889 */
890 public final static Field MILLISECOND = new
891 Field("millisecond", Calendar.MILLISECOND);
892
893 /**
894 * Constant identifying the day of week field.
895 */
896 public final static Field DAY_OF_WEEK = new
897 Field("day of week", Calendar.DAY_OF_WEEK);
898
899 /**
900 * Constant identifying the day of year field.
901 */
902 public final static Field DAY_OF_YEAR = new
903 Field("day of year", Calendar.DAY_OF_YEAR);
904
905 /**
906 * Constant identifying the day of week field.
907 */
908 public final static Field DAY_OF_WEEK_IN_MONTH =
909 new Field("day of week in month",
910 Calendar.DAY_OF_WEEK_IN_MONTH);
911
912 /**
913 * Constant identifying the week of year field.
914 */
915 public final static Field WEEK_OF_YEAR = new
916 Field("week of year", Calendar.WEEK_OF_YEAR);
917
918 /**
919 * Constant identifying the week of month field.
920 */
921 public final static Field WEEK_OF_MONTH = new
922 Field("week of month", Calendar.WEEK_OF_MONTH);
923
924 /**
925 * Constant identifying the time of day indicator
926 * (e.g. "a.m." or "p.m.") field.
927 */
928 public final static Field AM_PM = new
929 Field("am pm", Calendar.AM_PM);
930
931 /**
932 * Constant identifying the hour field, where the legal values are
933 * 1 to 12.
934 */
935 public final static Field HOUR1 = new Field("hour 1", -1);
936
937 /**
938 * Constant identifying the hour field, where the legal values are
939 * 0 to 11.
940 */
941 public final static Field HOUR0 = new
942 Field("hour", Calendar.HOUR);
943
944 /**
945 * Constant identifying the time zone field.
946 */
947 public final static Field TIME_ZONE = new Field("time zone", -1);
948 }
949
950 /**
951 * Obtains a DateFormat instance from a DateFormatProvider
952 * implementation.
953 */
954 private static class DateFormatGetter
955 implements LocaleServiceProviderPool.LocalizedObjectGetter<DateFormatProvider, DateFormat> {
956 private static final DateFormatGetter INSTANCE = new DateFormatGetter();
957
958 public DateFormat getObject(DateFormatProvider dateFormatProvider,
959 Locale locale,
960 String key,
961 Object... params) {
962 assert params.length == 3;
963
964 int timeStyle = (Integer)params[0];
965 int dateStyle = (Integer)params[1];
966 int flags = (Integer)params[2];
967
968 switch (flags) {
969 case 1:
970 return dateFormatProvider.getTimeInstance(timeStyle, locale);
971 case 2:
972 return dateFormatProvider.getDateInstance(dateStyle, locale);
973 case 3:
974 return dateFormatProvider.getDateTimeInstance(dateStyle, timeStyle, locale);
975 default:
976 assert false : "should not happen";
977 }
978
979 return null;
980 }
981 }
982 }
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