1 /*
2 * Copyright (c) 1996, 2005, 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.LocaleServiceProviderPool;
54
55 /**
56 * {@code 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 {@link 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>{@code 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 {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, and {@link #SHORT}. More
66 * detail and examples of using these styles are provided in the method
67 * descriptions.
68 *
69 * <p>{@code 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 {@link #getDateInstance(int, Locale) 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 {@code getDateInstance} to get the normal date format for that country.
98 * There are other static factory methods available.
99 * Use {@code getTimeInstance} to get the time format for that country.
100 * Use {@code 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 {@link #SHORT} to {@link #MEDIUM} to {@link #LONG} to {@link #FULL}. The exact result depends
103 * on the locale, but generally:
104 * <ul><li>{@link #SHORT} is completely numeric, such as {@code 12.13.52} or {@code 3:30pm}
105 * <li>{@link #MEDIUM} is longer, such as {@code Jan 12, 1952}
106 * <li>{@link #LONG} is longer, such as {@code January 12, 1952} or {@code 3:30:32pm}
107 * <li>{@link #FULL} is pretty completely specified, such as
108 * {@code 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 {@code DateFormat} you get from the factory methods
115 * to a {@link SimpleDateFormat}. This will work for the majority
116 * of countries; just remember to put it in a {@code 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 * {@link ParsePosition} and {@link 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 {@link Calendar} instance used for calculating the date-time fields
147 * and the instant of time. This field is used for both formatting and
148 * parsing.
149 *
150 * <p>Subclasses should initialize this field to a {@link Calendar}
151 * appropriate for the {@link Locale} associated with this
152 * <code>DateFormat</code>.
153 * @serial
154 */
155 protected Calendar calendar;
156
157 /**
158 * The number formatter that <code>DateFormat</code> uses to format numbers
159 * in dates and times. Subclasses should initialize this to a number format
160 * appropriate for the locale associated with this <code>DateFormat</code>.
161 * @serial
162 */
163 protected NumberFormat numberFormat;
164
165 /**
166 * Useful constant for ERA field alignment.
167 * Used in FieldPosition of date/time formatting.
168 */
169 public final static int ERA_FIELD = 0;
170 /**
171 * Useful constant for YEAR field alignment.
172 * Used in FieldPosition of date/time formatting.
173 */
174 public final static int YEAR_FIELD = 1;
175 /**
176 * Useful constant for MONTH field alignment.
177 * Used in FieldPosition of date/time formatting.
178 */
179 public final static int MONTH_FIELD = 2;
180 /**
181 * Useful constant for DATE field alignment.
182 * Used in FieldPosition of date/time formatting.
183 */
184 public final static int DATE_FIELD = 3;
185 /**
186 * Useful constant for one-based HOUR_OF_DAY field alignment.
187 * Used in FieldPosition of date/time formatting.
188 * HOUR_OF_DAY1_FIELD is used for the one-based 24-hour clock.
189 * For example, 23:59 + 01:00 results in 24:59.
190 */
191 public final static int HOUR_OF_DAY1_FIELD = 4;
192 /**
193 * Useful constant for zero-based HOUR_OF_DAY field alignment.
194 * Used in FieldPosition of date/time formatting.
195 * HOUR_OF_DAY0_FIELD is used for the zero-based 24-hour clock.
196 * For example, 23:59 + 01:00 results in 00:59.
197 */
198 public final static int HOUR_OF_DAY0_FIELD = 5;
199 /**
200 * Useful constant for MINUTE field alignment.
201 * Used in FieldPosition of date/time formatting.
202 */
203 public final static int MINUTE_FIELD = 6;
204 /**
205 * Useful constant for SECOND field alignment.
206 * Used in FieldPosition of date/time formatting.
207 */
208 public final static int SECOND_FIELD = 7;
209 /**
210 * Useful constant for MILLISECOND field alignment.
211 * Used in FieldPosition of date/time formatting.
212 */
213 public final static int MILLISECOND_FIELD = 8;
214 /**
215 * Useful constant for DAY_OF_WEEK field alignment.
216 * Used in FieldPosition of date/time formatting.
217 */
218 public final static int DAY_OF_WEEK_FIELD = 9;
219 /**
220 * Useful constant for DAY_OF_YEAR field alignment.
221 * Used in FieldPosition of date/time formatting.
222 */
223 public final static int DAY_OF_YEAR_FIELD = 10;
224 /**
225 * Useful constant for DAY_OF_WEEK_IN_MONTH field alignment.
226 * Used in FieldPosition of date/time formatting.
227 */
228 public final static int DAY_OF_WEEK_IN_MONTH_FIELD = 11;
229 /**
230 * Useful constant for WEEK_OF_YEAR field alignment.
231 * Used in FieldPosition of date/time formatting.
232 */
233 public final static int WEEK_OF_YEAR_FIELD = 12;
234 /**
235 * Useful constant for WEEK_OF_MONTH field alignment.
236 * Used in FieldPosition of date/time formatting.
237 */
238 public final static int WEEK_OF_MONTH_FIELD = 13;
239 /**
240 * Useful constant for AM_PM field alignment.
241 * Used in FieldPosition of date/time formatting.
242 */
243 public final static int AM_PM_FIELD = 14;
244 /**
245 * Useful constant for one-based HOUR field alignment.
246 * Used in FieldPosition of date/time formatting.
247 * HOUR1_FIELD is used for the one-based 12-hour clock.
248 * For example, 11:30 PM + 1 hour results in 12:30 AM.
249 */
250 public final static int HOUR1_FIELD = 15;
251 /**
252 * Useful constant for zero-based HOUR field alignment.
253 * Used in FieldPosition of date/time formatting.
254 * HOUR0_FIELD is used for the zero-based 12-hour clock.
255 * For example, 11:30 PM + 1 hour results in 00:30 AM.
256 */
257 public final static int HOUR0_FIELD = 16;
258 /**
259 * Useful constant for TIMEZONE field alignment.
260 * Used in FieldPosition of date/time formatting.
261 */
262 public final static int TIMEZONE_FIELD = 17;
263
264 // Proclaim serial compatibility with 1.1 FCS
265 private static final long serialVersionUID = 7218322306649953788L;
266
267 /**
268 * Overrides Format.
269 * Formats a time object into a time string. Examples of time objects
270 * are a time value expressed in milliseconds and a Date object.
271 * @param obj must be a Number or a Date.
272 * @param toAppendTo the string buffer for the returning time string.
273 * @return the string buffer passed in as toAppendTo, with formatted text appended.
274 * @param fieldPosition keeps track of the position of the field
275 * within the returned string.
276 * On input: an alignment field,
277 * if desired. On output: the offsets of the alignment field. For
278 * example, given a time text "1996.07.10 AD at 15:08:56 PDT",
279 * if the given fieldPosition is DateFormat.YEAR_FIELD, the
280 * begin index and end index of fieldPosition will be set to
281 * 0 and 4, respectively.
282 * Notice that if the same time field appears
283 * more than once in a pattern, the fieldPosition will be set for the first
284 * occurrence of that time field. For instance, formatting a Date to
285 * the time string "1 PM PDT (Pacific Daylight Time)" using the pattern
286 * "h a z (zzzz)" and the alignment field DateFormat.TIMEZONE_FIELD,
287 * the begin index and end index of fieldPosition will be set to
288 * 5 and 8, respectively, for the first occurrence of the timezone
289 * pattern character 'z'.
290 * @see java.text.Format
291 */
292 public final StringBuffer format(Object obj, StringBuffer toAppendTo,
293 FieldPosition fieldPosition)
294 {
295 if (obj instanceof Date)
296 return format( (Date)obj, toAppendTo, fieldPosition );
297 else if (obj instanceof Number)
298 return format( new Date(((Number)obj).longValue()),
299 toAppendTo, fieldPosition );
300 else
301 throw new IllegalArgumentException("Cannot format given Object as a Date");
302 }
303
304 /**
305 * Formats a Date into a date/time string.
306 * @param date a Date to be formatted into a date/time string.
307 * @param toAppendTo the string buffer for the returning date/time string.
308 * @param fieldPosition keeps track of the position of the field
309 * within the returned string.
310 * On input: an alignment field,
311 * if desired. On output: the offsets of the alignment field. For
312 * example, given a time text "1996.07.10 AD at 15:08:56 PDT",
313 * if the given fieldPosition is DateFormat.YEAR_FIELD, the
314 * begin index and end index of fieldPosition will be set to
315 * 0 and 4, respectively.
316 * Notice that if the same time field appears
317 * more than once in a pattern, the fieldPosition will be set for the first
318 * occurrence of that time field. For instance, formatting a Date to
319 * the time string "1 PM PDT (Pacific Daylight Time)" using the pattern
320 * "h a z (zzzz)" and the alignment field DateFormat.TIMEZONE_FIELD,
321 * the begin index and end index of fieldPosition will be set to
322 * 5 and 8, respectively, for the first occurrence of the timezone
323 * pattern character 'z'.
324 * @return the string buffer passed in as toAppendTo, with formatted text appended.
325 */
326 public abstract StringBuffer format(Date date, StringBuffer toAppendTo,
327 FieldPosition fieldPosition);
328
329 /**
330 * Formats a Date into a date/time string.
331 * @param date the time value to be formatted into a time string.
332 * @return the formatted time string.
333 */
334 public final String format(Date date)
335 {
336 return format(date, new StringBuffer(),
337 DontCareFieldPosition.INSTANCE).toString();
338 }
339
340 /**
341 * Parses text from the beginning of the given string to produce a date.
342 * The method may not use the entire text of the given string.
343 * <p>
344 * See the {@link #parse(String, ParsePosition)} method for more information
345 * on date parsing.
346 *
347 * @param source A <code>String</code> whose beginning should be parsed.
348 * @return A <code>Date</code> parsed from the string.
349 * @exception ParseException if the beginning of the specified string
350 * cannot be parsed.
351 */
352 public Date parse(String source) throws ParseException
353 {
354 ParsePosition pos = new ParsePosition(0);
355 Date result = parse(source, pos);
356 if (pos.index == 0)
357 throw new ParseException("Unparseable date: \"" + source + "\"" ,
358 pos.errorIndex);
359 return result;
360 }
361
362 /**
363 * Parse a date/time string according to the given parse position. For
364 * example, a time text {@code "07/10/96 4:5 PM, PDT"} will be parsed into a {@code Date}
365 * that is equivalent to {@code Date(837039900000L)}.
366 *
367 * <p> By default, parsing is lenient: If the input is not in the form used
368 * by this object's format method but can still be parsed as a date, then
369 * the parse succeeds. Clients may insist on strict adherence to the
370 * format by calling {@link #setLenient(boolean) setLenient(false)}.
371 *
372 * <p>This parsing operation uses the {@link #calendar} to produce
373 * a {@code Date}. As a result, the {@code calendar}'s date-time
374 * fields and the {@code TimeZone} value may have been
375 * overwritten, depending on subclass implementations. Any {@code
376 * TimeZone} value that has previously been set by a call to
377 * {@link #setTimeZone(java.util.TimeZone) setTimeZone} may need
378 * to be restored for further operations.
379 *
380 * @param source The date/time string to be parsed
381 *
382 * @param pos On input, the position at which to start parsing; on
383 * output, the position at which parsing terminated, or the
384 * start position if the parse failed.
385 *
386 * @return A {@code Date}, or {@code null} if the input could not be parsed
387 */
388 public abstract Date parse(String source, ParsePosition pos);
389
390 /**
391 * Parses text from a string to produce a <code>Date</code>.
392 * <p>
393 * The method attempts to parse text starting at the index given by
394 * <code>pos</code>.
395 * If parsing succeeds, then the index of <code>pos</code> is updated
396 * to the index after the last character used (parsing does not necessarily
397 * use all characters up to the end of the string), and the parsed
398 * date is returned. The updated <code>pos</code> can be used to
399 * indicate the starting point for the next call to this method.
400 * If an error occurs, then the index of <code>pos</code> is not
401 * changed, the error index of <code>pos</code> is set to the index of
402 * the character where the error occurred, and null is returned.
403 * <p>
404 * See the {@link #parse(String, ParsePosition)} method for more information
405 * on date parsing.
406 *
407 * @param source A <code>String</code>, part of which should be parsed.
408 * @param pos A <code>ParsePosition</code> object with index and error
409 * index information as described above.
410 * @return A <code>Date</code> parsed from the string. In case of
411 * error, returns null.
412 * @exception NullPointerException if <code>pos</code> is null.
413 */
414 public Object parseObject(String source, ParsePosition pos) {
415 return parse(source, pos);
416 }
417
418 /**
419 * Constant for full style pattern.
420 */
421 public static final int FULL = 0;
422 /**
423 * Constant for long style pattern.
424 */
425 public static final int LONG = 1;
426 /**
427 * Constant for medium style pattern.
428 */
429 public static final int MEDIUM = 2;
430 /**
431 * Constant for short style pattern.
432 */
433 public static final int SHORT = 3;
434 /**
435 * Constant for default style pattern. Its value is MEDIUM.
436 */
437 public static final int DEFAULT = MEDIUM;
438
439 /**
440 * Gets the time formatter with the default formatting style
441 * for the default locale.
442 * @return a time formatter.
443 */
444 public final static DateFormat getTimeInstance()
445 {
446 return get(DEFAULT, 0, 1, Locale.getDefault(Locale.Category.FORMAT));
447 }
448
449 /**
450 * Gets the time formatter with the given formatting style
451 * for the default locale.
452 * @param style the given formatting style. For example,
453 * SHORT for "h:mm a" in the US locale.
454 * @return a time formatter.
455 */
456 public final static DateFormat getTimeInstance(int style)
457 {
458 return get(style, 0, 1, Locale.getDefault(Locale.Category.FORMAT));
459 }
460
461 /**
462 * Gets the time formatter with the given formatting style
463 * for the given locale.
464 * @param style the given formatting style. For example,
465 * SHORT for "h:mm a" in the US locale.
466 * @param aLocale the given locale.
467 * @return a time formatter.
468 */
469 public final static DateFormat getTimeInstance(int style,
470 Locale aLocale)
471 {
472 return get(style, 0, 1, aLocale);
473 }
474
475 /**
476 * Gets the date formatter with the default formatting style
477 * for the default locale.
478 * @return a date formatter.
479 */
480 public final static DateFormat getDateInstance()
481 {
482 return get(0, DEFAULT, 2, Locale.getDefault(Locale.Category.FORMAT));
483 }
484
485 /**
486 * Gets the date formatter with the given formatting style
487 * for the default locale.
488 * @param style the given formatting style. For example,
489 * SHORT for "M/d/yy" in the US locale.
490 * @return a date formatter.
491 */
492 public final static DateFormat getDateInstance(int style)
493 {
494 return get(0, style, 2, Locale.getDefault(Locale.Category.FORMAT));
495 }
496
497 /**
498 * Gets the date formatter with the given formatting style
499 * for the given locale.
500 * @param style the given formatting style. For example,
501 * SHORT for "M/d/yy" in the US locale.
502 * @param aLocale the given locale.
503 * @return a date formatter.
504 */
505 public final static DateFormat getDateInstance(int style,
506 Locale aLocale)
507 {
508 return get(0, style, 2, aLocale);
509 }
510
511 /**
512 * Gets the date/time formatter with the default formatting style
513 * for the default locale.
514 * @return a date/time formatter.
515 */
516 public final static DateFormat getDateTimeInstance()
517 {
518 return get(DEFAULT, DEFAULT, 3, Locale.getDefault(Locale.Category.FORMAT));
519 }
520
521 /**
522 * Gets the date/time formatter with the given date and time
523 * formatting styles for the default locale.
524 * @param dateStyle the given date formatting style. For example,
525 * SHORT for "M/d/yy" in the US locale.
526 * @param timeStyle the given time formatting style. For example,
527 * SHORT for "h:mm a" in the US locale.
528 * @return a date/time formatter.
529 */
530 public final static DateFormat getDateTimeInstance(int dateStyle,
531 int timeStyle)
532 {
533 return get(timeStyle, dateStyle, 3, Locale.getDefault(Locale.Category.FORMAT));
534 }
535
536 /**
537 * Gets the date/time formatter with the given formatting styles
538 * for the given locale.
539 * @param dateStyle the given date formatting style.
540 * @param timeStyle the given time formatting style.
541 * @param aLocale the given locale.
542 * @return a date/time formatter.
543 */
544 public final static DateFormat
545 getDateTimeInstance(int dateStyle, int timeStyle, Locale aLocale)
546 {
547 return get(timeStyle, dateStyle, 3, aLocale);
548 }
549
550 /**
551 * Get a default date/time formatter that uses the SHORT style for both the
552 * date and the time.
553 */
554 public final static DateFormat getInstance() {
555 return getDateTimeInstance(SHORT, SHORT);
556 }
557
558 /**
559 * Returns an array of all locales for which the
560 * <code>get*Instance</code> methods of this class can return
561 * localized instances.
562 * The returned array represents the union of locales supported by the Java
563 * runtime and by installed
564 * {@link java.text.spi.DateFormatProvider DateFormatProvider} implementations.
565 * It must contain at least a <code>Locale</code> instance equal to
566 * {@link java.util.Locale#US Locale.US}.
567 *
568 * @return An array of locales for which localized
569 * <code>DateFormat</code> instances are available.
570 */
571 public static Locale[] getAvailableLocales()
572 {
573 LocaleServiceProviderPool pool =
574 LocaleServiceProviderPool.getPool(DateFormatProvider.class);
575 return pool.getAvailableLocales();
576 }
577
578 /**
579 * Set the calendar to be used by this date format. Initially, the default
580 * calendar for the specified or default locale is used.
581 *
582 * <p>Any {@link java.util.TimeZone TimeZone} and {@linkplain
583 * #isLenient() leniency} values that have previously been set are
584 * overwritten by {@code newCalendar}'s values.
585 *
586 * @param newCalendar the new {@code Calendar} to be used by the date format
587 */
588 public void setCalendar(Calendar newCalendar)
589 {
590 this.calendar = newCalendar;
591 }
592
593 /**
594 * Gets the calendar associated with this date/time formatter.
595 *
596 * @return the calendar associated with this date/time formatter.
597 */
598 public Calendar getCalendar()
599 {
600 return calendar;
601 }
602
603 /**
604 * Allows you to set the number formatter.
605 * @param newNumberFormat the given new NumberFormat.
606 */
607 public void setNumberFormat(NumberFormat newNumberFormat)
608 {
609 this.numberFormat = newNumberFormat;
610 }
611
612 /**
613 * Gets the number formatter which this date/time formatter uses to
614 * format and parse a time.
615 * @return the number formatter which this date/time formatter uses.
616 */
617 public NumberFormat getNumberFormat()
618 {
619 return numberFormat;
620 }
621
622 /**
623 * Sets the time zone for the calendar of this {@code DateFormat} object.
624 * This method is equivalent to the following call.
625 * <blockquote><pre>
626 * getCalendar().setTimeZone(zone)
627 * </pre></blockquote>
628 *
629 * <p>The {@code TimeZone} set by this method is overwritten by a
630 * {@link #setCalendar(java.util.Calendar) setCalendar} call.
631 *
632 * <p>The {@code TimeZone} set by this method may be overwritten as
633 * a result of a call to the parse method.
634 *
635 * @param zone the given new time zone.
636 */
637 public void setTimeZone(TimeZone zone)
638 {
639 calendar.setTimeZone(zone);
640 }
641
642 /**
643 * Gets the time zone.
644 * This method is equivalent to the following call.
645 * <blockquote><pre>
646 * getCalendar().getTimeZone()
647 * </pre></blockquote>
648 *
649 * @return the time zone associated with the calendar of DateFormat.
650 */
651 public TimeZone getTimeZone()
652 {
653 return calendar.getTimeZone();
654 }
655
656 /**
657 * Specify whether or not date/time parsing is to be lenient. With
658 * lenient parsing, the parser may use heuristics to interpret inputs that
659 * do not precisely match this object's format. With strict parsing,
660 * inputs must match this object's format.
661 *
662 * <p>This method is equivalent to the following call.
663 * <blockquote><pre>
664 * getCalendar().setLenient(lenient)
665 * </pre></blockquote>
666 *
667 * <p>This leniency value is overwritten by a call to {@link
668 * #setCalendar(java.util.Calendar) setCalendar()}.
669 *
670 * @param lenient when {@code true}, parsing is lenient
671 * @see java.util.Calendar#setLenient(boolean)
672 */
673 public void setLenient(boolean lenient)
674 {
675 calendar.setLenient(lenient);
676 }
677
678 /**
679 * Tell whether date/time parsing is to be lenient.
680 * This method is equivalent to the following call.
681 * <blockquote><pre>
682 * getCalendar().isLenient()
683 * </pre></blockquote>
684 *
685 * @return {@code true} if the {@link #calendar} is lenient;
686 * {@code false} otherwise.
687 * @see java.util.Calendar#isLenient()
688 */
689 public boolean isLenient()
690 {
691 return calendar.isLenient();
692 }
693
694 /**
695 * Overrides hashCode
696 */
697 public int hashCode() {
698 return numberFormat.hashCode();
699 // just enough fields for a reasonable distribution
700 }
701
702 /**
703 * Overrides equals
704 */
705 public boolean equals(Object obj) {
706 if (this == obj) return true;
707 if (obj == null || getClass() != obj.getClass()) return false;
708 DateFormat other = (DateFormat) obj;
709 return (// calendar.equivalentTo(other.calendar) // THIS API DOESN'T EXIST YET!
710 calendar.getFirstDayOfWeek() == other.calendar.getFirstDayOfWeek() &&
711 calendar.getMinimalDaysInFirstWeek() == other.calendar.getMinimalDaysInFirstWeek() &&
712 calendar.isLenient() == other.calendar.isLenient() &&
713 calendar.getTimeZone().equals(other.calendar.getTimeZone()) &&
714 numberFormat.equals(other.numberFormat));
715 }
716
717 /**
718 * Overrides Cloneable
719 */
720 public Object clone()
721 {
722 DateFormat other = (DateFormat) super.clone();
723 other.calendar = (Calendar) calendar.clone();
724 other.numberFormat = (NumberFormat) numberFormat.clone();
725 return other;
726 }
727
728 /**
729 * Creates a DateFormat with the given time and/or date style in the given
730 * locale.
731 * @param timeStyle a value from 0 to 3 indicating the time format,
732 * ignored if flags is 2
733 * @param dateStyle a value from 0 to 3 indicating the time format,
734 * ignored if flags is 1
735 * @param flags either 1 for a time format, 2 for a date format,
736 * or 3 for a date/time format
737 * @param loc the locale for the format
738 */
739 private static DateFormat get(int timeStyle, int dateStyle,
740 int flags, Locale loc) {
741 if ((flags & 1) != 0) {
742 if (timeStyle < 0 || timeStyle > 3) {
743 throw new IllegalArgumentException("Illegal time style " + timeStyle);
744 }
745 } else {
746 timeStyle = -1;
747 }
748 if ((flags & 2) != 0) {
749 if (dateStyle < 0 || dateStyle > 3) {
750 throw new IllegalArgumentException("Illegal date style " + dateStyle);
751 }
752 } else {
753 dateStyle = -1;
754 }
755 try {
756 // Check whether a provider can provide an implementation that's closer
757 // to the requested locale than what the Java runtime itself can provide.
758 LocaleServiceProviderPool pool =
759 LocaleServiceProviderPool.getPool(DateFormatProvider.class);
760 if (pool.hasProviders()) {
761 DateFormat providersInstance = pool.getLocalizedObject(
762 DateFormatGetter.INSTANCE,
763 loc,
764 timeStyle,
765 dateStyle,
766 flags);
767 if (providersInstance != null) {
768 return providersInstance;
769 }
770 }
771
772 return new SimpleDateFormat(timeStyle, dateStyle, loc);
773 } catch (MissingResourceException e) {
774 return new SimpleDateFormat("M/d/yy h:mm a");
775 }
776 }
777
778 /**
779 * Create a new date format.
780 */
781 protected DateFormat() {}
782
783 /**
784 * Defines constants that are used as attribute keys in the
785 * <code>AttributedCharacterIterator</code> returned
786 * from <code>DateFormat.formatToCharacterIterator</code> and as
787 * field identifiers in <code>FieldPosition</code>.
788 * <p>
789 * The class also provides two methods to map
790 * between its constants and the corresponding Calendar constants.
791 *
792 * @since 1.4
793 * @see java.util.Calendar
794 */
795 public static class Field extends Format.Field {
796
797 // Proclaim serial compatibility with 1.4 FCS
798 private static final long serialVersionUID = 7441350119349544720L;
799
800 // table of all instances in this class, used by readResolve
801 private static final Map instanceMap = new HashMap(18);
802 // Maps from Calendar constant (such as Calendar.ERA) to Field
803 // constant (such as Field.ERA).
804 private static final Field[] calendarToFieldMapping =
805 new Field[Calendar.FIELD_COUNT];
806
807 /** Calendar field. */
808 private int calendarField;
809
810 /**
811 * Returns the <code>Field</code> constant that corresponds to
812 * the <code>Calendar</code> constant <code>calendarField</code>.
813 * If there is no direct mapping between the <code>Calendar</code>
814 * constant and a <code>Field</code>, null is returned.
815 *
816 * @throws IllegalArgumentException if <code>calendarField</code> is
817 * not the value of a <code>Calendar</code> field constant.
818 * @param calendarField Calendar field constant
819 * @return Field instance representing calendarField.
820 * @see java.util.Calendar
821 */
822 public static Field ofCalendarField(int calendarField) {
823 if (calendarField < 0 || calendarField >=
824 calendarToFieldMapping.length) {
825 throw new IllegalArgumentException("Unknown Calendar constant "
826 + calendarField);
827 }
828 return calendarToFieldMapping[calendarField];
829 }
830
831 /**
832 * Creates a <code>Field</code>.
833 *
834 * @param name the name of the <code>Field</code>
835 * @param calendarField the <code>Calendar</code> constant this
836 * <code>Field</code> corresponds to; any value, even one
837 * outside the range of legal <code>Calendar</code> values may
838 * be used, but <code>-1</code> should be used for values
839 * that don't correspond to legal <code>Calendar</code> values
840 */
841 protected Field(String name, int calendarField) {
842 super(name);
843 this.calendarField = calendarField;
844 if (this.getClass() == DateFormat.Field.class) {
845 instanceMap.put(name, this);
846 if (calendarField >= 0) {
847 // assert(calendarField < Calendar.FIELD_COUNT);
848 calendarToFieldMapping[calendarField] = this;
849 }
850 }
851 }
852
853 /**
854 * Returns the <code>Calendar</code> field associated with this
855 * attribute. For example, if this represents the hours field of
856 * a <code>Calendar</code>, this would return
857 * <code>Calendar.HOUR</code>. If there is no corresponding
858 * <code>Calendar</code> constant, this will return -1.
859 *
860 * @return Calendar constant for this field
861 * @see java.util.Calendar
862 */
863 public int getCalendarField() {
864 return calendarField;
865 }
866
867 /**
868 * Resolves instances being deserialized to the predefined constants.
869 *
870 * @throws InvalidObjectException if the constant could not be
871 * resolved.
872 * @return resolved DateFormat.Field constant
873 */
874 protected Object readResolve() throws InvalidObjectException {
875 if (this.getClass() != DateFormat.Field.class) {
876 throw new InvalidObjectException("subclass didn't correctly implement readResolve");
877 }
878
879 Object instance = instanceMap.get(getName());
880 if (instance != null) {
881 return instance;
882 } else {
883 throw new InvalidObjectException("unknown attribute name");
884 }
885 }
886
887 //
888 // The constants
889 //
890
891 /**
892 * Constant identifying the era field.
893 */
894 public final static Field ERA = new Field("era", Calendar.ERA);
895
896 /**
897 * Constant identifying the year field.
898 */
899 public final static Field YEAR = new Field("year", Calendar.YEAR);
900
901 /**
902 * Constant identifying the month field.
903 */
904 public final static Field MONTH = new Field("month", Calendar.MONTH);
905
906 /**
907 * Constant identifying the day of month field.
908 */
909 public final static Field DAY_OF_MONTH = new
910 Field("day of month", Calendar.DAY_OF_MONTH);
911
912 /**
913 * Constant identifying the hour of day field, where the legal values
914 * are 1 to 24.
915 */
916 public final static Field HOUR_OF_DAY1 = new Field("hour of day 1",-1);
917
918 /**
919 * Constant identifying the hour of day field, where the legal values
920 * are 0 to 23.
921 */
922 public final static Field HOUR_OF_DAY0 = new
923 Field("hour of day", Calendar.HOUR_OF_DAY);
924
925 /**
926 * Constant identifying the minute field.
927 */
928 public final static Field MINUTE =new Field("minute", Calendar.MINUTE);
929
930 /**
931 * Constant identifying the second field.
932 */
933 public final static Field SECOND =new Field("second", Calendar.SECOND);
934
935 /**
936 * Constant identifying the millisecond field.
937 */
938 public final static Field MILLISECOND = new
939 Field("millisecond", Calendar.MILLISECOND);
940
941 /**
942 * Constant identifying the day of week field.
943 */
944 public final static Field DAY_OF_WEEK = new
945 Field("day of week", Calendar.DAY_OF_WEEK);
946
947 /**
948 * Constant identifying the day of year field.
949 */
950 public final static Field DAY_OF_YEAR = new
951 Field("day of year", Calendar.DAY_OF_YEAR);
952
953 /**
954 * Constant identifying the day of week field.
955 */
956 public final static Field DAY_OF_WEEK_IN_MONTH =
957 new Field("day of week in month",
958 Calendar.DAY_OF_WEEK_IN_MONTH);
959
960 /**
961 * Constant identifying the week of year field.
962 */
963 public final static Field WEEK_OF_YEAR = new
964 Field("week of year", Calendar.WEEK_OF_YEAR);
965
966 /**
967 * Constant identifying the week of month field.
968 */
969 public final static Field WEEK_OF_MONTH = new
970 Field("week of month", Calendar.WEEK_OF_MONTH);
971
972 /**
973 * Constant identifying the time of day indicator
974 * (e.g. "a.m." or "p.m.") field.
975 */
976 public final static Field AM_PM = new
977 Field("am pm", Calendar.AM_PM);
978
979 /**
980 * Constant identifying the hour field, where the legal values are
981 * 1 to 12.
982 */
983 public final static Field HOUR1 = new Field("hour 1", -1);
984
985 /**
986 * Constant identifying the hour field, where the legal values are
987 * 0 to 11.
988 */
989 public final static Field HOUR0 = new
990 Field("hour", Calendar.HOUR);
991
992 /**
993 * Constant identifying the time zone field.
994 */
995 public final static Field TIME_ZONE = new Field("time zone", -1);
996 }
997
998 /**
999 * Obtains a DateFormat instance from a DateFormatProvider
1000 * implementation.
1001 */
1002 private static class DateFormatGetter
1003 implements LocaleServiceProviderPool.LocalizedObjectGetter<DateFormatProvider, DateFormat> {
1004 private static final DateFormatGetter INSTANCE = new DateFormatGetter();
1005
1006 public DateFormat getObject(DateFormatProvider dateFormatProvider,
1007 Locale locale,
1008 String key,
1009 Object... params) {
1010 assert params.length == 3;
1011
1012 int timeStyle = (Integer)params[0];
1013 int dateStyle = (Integer)params[1];
1014 int flags = (Integer)params[2];
1015
1016 switch (flags) {
1017 case 1:
1018 return dateFormatProvider.getTimeInstance(timeStyle, locale);
1019 case 2:
1020 return dateFormatProvider.getDateInstance(dateStyle, locale);
1021 case 3:
1022 return dateFormatProvider.getDateTimeInstance(dateStyle, timeStyle, locale);
1023 default:
1024 assert false : "should not happen";
1025 }
1026
1027 return null;
1028 }
1029 }
1030 }