1 /*
2 * Copyright (c) 1996, 2013, 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 * <p>You can use a DateFormat to parse also.
101 * <blockquote>
102 * <pre>{@code
103 * myDate = df.parse(myString);
104 * }</pre>
105 * </blockquote>
106 * <p>Use {@code getDateInstance} to get the normal date format for that country.
107 * There are other static factory methods available.
108 * Use {@code getTimeInstance} to get the time format for that country.
109 * Use {@code getDateTimeInstance} to get a date and time format. You can pass in
110 * different options to these factory methods to control the length of the
111 * result; from {@link #SHORT} to {@link #MEDIUM} to {@link #LONG} to {@link #FULL}. The exact result depends
112 * on the locale, but generally:
113 * <ul><li>{@link #SHORT} is completely numeric, such as {@code 12.13.52} or {@code 3:30pm}
114 * <li>{@link #MEDIUM} is longer, such as {@code Jan 12, 1952}
115 * <li>{@link #LONG} is longer, such as {@code January 12, 1952} or {@code 3:30:32pm}
116 * <li>{@link #FULL} is pretty completely specified, such as
117 * {@code Tuesday, April 12, 1952 AD or 3:30:42pm PST}.
118 * </ul>
119 *
120 * <p>You can also set the time zone on the format if you wish.
121 * If you want even more control over the format or parsing,
122 * (or want to give your users more control),
123 * you can try casting the {@code DateFormat} you get from the factory methods
124 * to a {@link SimpleDateFormat}. This will work for the majority
125 * of countries; just remember to put it in a {@code try} block in case you
126 * encounter an unusual one.
127 *
128 * <p>You can also use forms of the parse and format methods with
129 * {@link ParsePosition} and {@link FieldPosition} to
130 * allow you to
131 * <ul><li>progressively parse through pieces of a string.
132 * <li>align any particular field, or find out where it is for selection
133 * on the screen.
134 * </ul>
135 *
136 * <h3><a name="synchronization">Synchronization</a></h3>
137 *
138 * <p>
139 * Date formats are not synchronized.
140 * It is recommended to create separate format instances for each thread.
141 * If multiple threads access a format concurrently, it must be synchronized
142 * externally.
143 *
144 * @see Format
145 * @see NumberFormat
146 * @see SimpleDateFormat
147 * @see java.util.Calendar
148 * @see java.util.GregorianCalendar
149 * @see java.util.TimeZone
150 * @author Mark Davis, Chen-Lieh Huang, Alan Liu
151 */
152 public abstract class DateFormat extends Format {
153
154 /**
155 * The {@link Calendar} instance used for calculating the date-time fields
156 * and the instant of time. This field is used for both formatting and
157 * parsing.
158 *
159 * <p>Subclasses should initialize this field to a {@link Calendar}
160 * appropriate for the {@link Locale} associated with this
161 * <code>DateFormat</code>.
162 * @serial
163 */
164 protected Calendar calendar;
165
166 /**
167 * The number formatter that <code>DateFormat</code> uses to format numbers
168 * in dates and times. Subclasses should initialize this to a number format
169 * appropriate for the locale associated with this <code>DateFormat</code>.
170 * @serial
171 */
172 protected NumberFormat numberFormat;
173
174 /**
175 * Useful constant for ERA field alignment.
176 * Used in FieldPosition of date/time formatting.
177 */
178 public static final int ERA_FIELD = 0;
179 /**
180 * Useful constant for YEAR field alignment.
181 * Used in FieldPosition of date/time formatting.
182 */
183 public static final int YEAR_FIELD = 1;
184 /**
185 * Useful constant for MONTH field alignment.
186 * Used in FieldPosition of date/time formatting.
187 */
188 public static final int MONTH_FIELD = 2;
189 /**
190 * Useful constant for DATE field alignment.
191 * Used in FieldPosition of date/time formatting.
192 */
193 public static final int DATE_FIELD = 3;
194 /**
195 * Useful constant for one-based HOUR_OF_DAY field alignment.
196 * Used in FieldPosition of date/time formatting.
197 * HOUR_OF_DAY1_FIELD is used for the one-based 24-hour clock.
198 * For example, 23:59 + 01:00 results in 24:59.
199 */
200 public static final int HOUR_OF_DAY1_FIELD = 4;
201 /**
202 * Useful constant for zero-based HOUR_OF_DAY field alignment.
203 * Used in FieldPosition of date/time formatting.
204 * HOUR_OF_DAY0_FIELD is used for the zero-based 24-hour clock.
205 * For example, 23:59 + 01:00 results in 00:59.
206 */
207 public static final int HOUR_OF_DAY0_FIELD = 5;
208 /**
209 * Useful constant for MINUTE field alignment.
210 * Used in FieldPosition of date/time formatting.
211 */
212 public static final int MINUTE_FIELD = 6;
213 /**
214 * Useful constant for SECOND field alignment.
215 * Used in FieldPosition of date/time formatting.
216 */
217 public static final int SECOND_FIELD = 7;
218 /**
219 * Useful constant for MILLISECOND field alignment.
220 * Used in FieldPosition of date/time formatting.
221 */
222 public static final int MILLISECOND_FIELD = 8;
223 /**
224 * Useful constant for DAY_OF_WEEK field alignment.
225 * Used in FieldPosition of date/time formatting.
226 */
227 public static final int DAY_OF_WEEK_FIELD = 9;
228 /**
229 * Useful constant for DAY_OF_YEAR field alignment.
230 * Used in FieldPosition of date/time formatting.
231 */
232 public static final int DAY_OF_YEAR_FIELD = 10;
233 /**
234 * Useful constant for DAY_OF_WEEK_IN_MONTH field alignment.
235 * Used in FieldPosition of date/time formatting.
236 */
237 public static final int DAY_OF_WEEK_IN_MONTH_FIELD = 11;
238 /**
239 * Useful constant for WEEK_OF_YEAR field alignment.
240 * Used in FieldPosition of date/time formatting.
241 */
242 public static final int WEEK_OF_YEAR_FIELD = 12;
243 /**
244 * Useful constant for WEEK_OF_MONTH field alignment.
245 * Used in FieldPosition of date/time formatting.
246 */
247 public static final int WEEK_OF_MONTH_FIELD = 13;
248 /**
249 * Useful constant for AM_PM field alignment.
250 * Used in FieldPosition of date/time formatting.
251 */
252 public static final int AM_PM_FIELD = 14;
253 /**
254 * Useful constant for one-based HOUR field alignment.
255 * Used in FieldPosition of date/time formatting.
256 * HOUR1_FIELD is used for the one-based 12-hour clock.
257 * For example, 11:30 PM + 1 hour results in 12:30 AM.
258 */
259 public static final int HOUR1_FIELD = 15;
260 /**
261 * Useful constant for zero-based HOUR field alignment.
262 * Used in FieldPosition of date/time formatting.
263 * HOUR0_FIELD is used for the zero-based 12-hour clock.
264 * For example, 11:30 PM + 1 hour results in 00:30 AM.
265 */
266 public static final int HOUR0_FIELD = 16;
267 /**
268 * Useful constant for TIMEZONE field alignment.
269 * Used in FieldPosition of date/time formatting.
270 */
271 public static final int TIMEZONE_FIELD = 17;
272
273 // Proclaim serial compatibility with 1.1 FCS
274 private static final long serialVersionUID = 7218322306649953788L;
275
276 /**
277 * Overrides Format.
278 * Formats a time object into a time string. Examples of time objects
279 * are a time value expressed in milliseconds and a Date object.
280 * @param obj must be a Number or a Date.
281 * @param toAppendTo the string buffer for the returning time string.
282 * @return the string buffer passed in as toAppendTo, with formatted text appended.
283 * @param fieldPosition keeps track of the position of the field
284 * within the returned string.
285 * On input: an alignment field,
286 * if desired. On output: the offsets of the alignment field. For
287 * example, given a time text "1996.07.10 AD at 15:08:56 PDT",
288 * if the given fieldPosition is DateFormat.YEAR_FIELD, the
289 * begin index and end index of fieldPosition will be set to
290 * 0 and 4, respectively.
291 * Notice that if the same time field appears
292 * more than once in a pattern, the fieldPosition will be set for the first
293 * occurrence of that time field. For instance, formatting a Date to
294 * the time string "1 PM PDT (Pacific Daylight Time)" using the pattern
295 * "h a z (zzzz)" and the alignment field DateFormat.TIMEZONE_FIELD,
296 * the begin index and end index of fieldPosition will be set to
297 * 5 and 8, respectively, for the first occurrence of the timezone
298 * pattern character 'z'.
299 * @see java.text.Format
300 */
301 public final StringBuffer format(Object obj, StringBuffer toAppendTo,
302 FieldPosition fieldPosition)
303 {
304 if (obj instanceof Date)
305 return format( (Date)obj, toAppendTo, fieldPosition );
306 else if (obj instanceof Number)
307 return format( new Date(((Number)obj).longValue()),
308 toAppendTo, fieldPosition );
309 else
310 throw new IllegalArgumentException("Cannot format given Object as a Date");
311 }
312
313 /**
314 * Formats a Date into a date/time string.
315 * @param date a Date to be formatted into a date/time string.
316 * @param toAppendTo the string buffer for the returning date/time string.
317 * @param fieldPosition keeps track of the position of the field
318 * within the returned string.
319 * On input: an alignment field,
320 * if desired. On output: the offsets of the alignment field. For
321 * example, given a time text "1996.07.10 AD at 15:08:56 PDT",
322 * if the given fieldPosition is DateFormat.YEAR_FIELD, the
323 * begin index and end index of fieldPosition will be set to
324 * 0 and 4, respectively.
325 * Notice that if the same time field appears
326 * more than once in a pattern, the fieldPosition will be set for the first
327 * occurrence of that time field. For instance, formatting a Date to
328 * the time string "1 PM PDT (Pacific Daylight Time)" using the pattern
329 * "h a z (zzzz)" and the alignment field DateFormat.TIMEZONE_FIELD,
330 * the begin index and end index of fieldPosition will be set to
331 * 5 and 8, respectively, for the first occurrence of the timezone
332 * pattern character 'z'.
333 * @return the string buffer passed in as toAppendTo, with formatted text appended.
334 */
335 public abstract StringBuffer format(Date date, StringBuffer toAppendTo,
336 FieldPosition fieldPosition);
337
338 /**
339 * Formats a Date into a date/time string.
340 * @param date the time value to be formatted into a time string.
341 * @return the formatted time string.
342 */
343 public final String format(Date date)
344 {
345 return format(date, new StringBuffer(),
346 DontCareFieldPosition.INSTANCE).toString();
347 }
348
349 /**
350 * Parses text from the beginning of the given string to produce a date.
351 * The method may not use the entire text of the given string.
352 * <p>
353 * See the {@link #parse(String, ParsePosition)} method for more information
354 * on date parsing.
355 *
356 * @param source A <code>String</code> whose beginning should be parsed.
357 * @return A <code>Date</code> parsed from the string.
358 * @exception ParseException if the beginning of the specified string
359 * cannot be parsed.
360 */
361 public Date parse(String source) throws ParseException
362 {
363 ParsePosition pos = new ParsePosition(0);
364 Date result = parse(source, pos);
365 if (pos.index == 0)
366 throw new ParseException("Unparseable date: \"" + source + "\"" ,
367 pos.errorIndex);
368 return result;
369 }
370
371 /**
372 * Parse a date/time string according to the given parse position. For
373 * example, a time text {@code "07/10/96 4:5 PM, PDT"} will be parsed into a {@code Date}
374 * that is equivalent to {@code Date(837039900000L)}.
375 *
376 * <p> By default, parsing is lenient: If the input is not in the form used
377 * by this object's format method but can still be parsed as a date, then
378 * the parse succeeds. Clients may insist on strict adherence to the
379 * format by calling {@link #setLenient(boolean) setLenient(false)}.
380 *
381 * <p>This parsing operation uses the {@link #calendar} to produce
382 * a {@code Date}. As a result, the {@code calendar}'s date-time
383 * fields and the {@code TimeZone} value may have been
384 * overwritten, depending on subclass implementations. Any {@code
385 * TimeZone} value that has previously been set by a call to
386 * {@link #setTimeZone(java.util.TimeZone) setTimeZone} may need
387 * to be restored for further operations.
388 *
389 * @param source The date/time string to be parsed
390 *
391 * @param pos On input, the position at which to start parsing; on
392 * output, the position at which parsing terminated, or the
393 * start position if the parse failed.
394 *
395 * @return A {@code Date}, or {@code null} if the input could not be parsed
396 */
397 public abstract Date parse(String source, ParsePosition pos);
398
399 /**
400 * Parses text from a string to produce a <code>Date</code>.
401 * <p>
402 * The method attempts to parse text starting at the index given by
403 * <code>pos</code>.
404 * If parsing succeeds, then the index of <code>pos</code> is updated
405 * to the index after the last character used (parsing does not necessarily
406 * use all characters up to the end of the string), and the parsed
407 * date is returned. The updated <code>pos</code> can be used to
408 * indicate the starting point for the next call to this method.
409 * If an error occurs, then the index of <code>pos</code> is not
410 * changed, the error index of <code>pos</code> is set to the index of
411 * the character where the error occurred, and null is returned.
412 * <p>
413 * See the {@link #parse(String, ParsePosition)} method for more information
414 * on date parsing.
415 *
416 * @param source A <code>String</code>, part of which should be parsed.
417 * @param pos A <code>ParsePosition</code> object with index and error
418 * index information as described above.
419 * @return A <code>Date</code> parsed from the string. In case of
420 * error, returns null.
421 * @exception NullPointerException if <code>pos</code> is null.
422 * @throws NullPointerException if {@code source} is null.
423 */
424 public Object parseObject(String source, ParsePosition pos) {
425 return parse(source, pos);
426 }
427
428 /**
429 * Constant for full style pattern.
430 */
431 public static final int FULL = 0;
432 /**
433 * Constant for long style pattern.
434 */
435 public static final int LONG = 1;
436 /**
437 * Constant for medium style pattern.
438 */
439 public static final int MEDIUM = 2;
440 /**
441 * Constant for short style pattern.
442 */
443 public static final int SHORT = 3;
444 /**
445 * Constant for default style pattern. Its value is MEDIUM.
446 */
447 public static final int DEFAULT = MEDIUM;
448
449 /**
450 * Gets the time formatter with the default formatting style
451 * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.
452 * <p>This is equivalent to calling
453 * {@link #getTimeInstance(int, Locale) getTimeInstance(DEFAULT,
454 * Locale.getDefault(Locale.Category.FORMAT))}.
455 * @see java.util.Locale#getDefault(java.util.Locale.Category)
456 * @see java.util.Locale.Category#FORMAT
457 * @return a time formatter.
458 */
459 public static final DateFormat getTimeInstance()
460 {
461 return get(DEFAULT, 0, 1, Locale.getDefault(Locale.Category.FORMAT));
462 }
463
464 /**
465 * Gets the time formatter with the given formatting style
466 * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.
467 * <p>This is equivalent to calling
468 * {@link #getTimeInstance(int, Locale) getTimeInstance(style,
469 * Locale.getDefault(Locale.Category.FORMAT))}.
470 * @see java.util.Locale#getDefault(java.util.Locale.Category)
471 * @see java.util.Locale.Category#FORMAT
472 * @param style the given formatting style. For example,
473 * SHORT for "h:mm a" in the US locale.
474 * @return a time formatter.
475 */
476 public static final DateFormat getTimeInstance(int style)
477 {
478 return get(style, 0, 1, Locale.getDefault(Locale.Category.FORMAT));
479 }
480
481 /**
482 * Gets the time formatter with the given formatting style
483 * for the given locale.
484 * @param style the given formatting style. For example,
485 * SHORT for "h:mm a" in the US locale.
486 * @param aLocale the given locale.
487 * @return a time formatter.
488 */
489 public static final DateFormat getTimeInstance(int style,
490 Locale aLocale)
491 {
492 return get(style, 0, 1, aLocale);
493 }
494
495 /**
496 * Gets the date formatter with the default formatting style
497 * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.
498 * <p>This is equivalent to calling
499 * {@link #getDateInstance(int, Locale) getDateInstance(DEFAULT,
500 * Locale.getDefault(Locale.Category.FORMAT))}.
501 * @see java.util.Locale#getDefault(java.util.Locale.Category)
502 * @see java.util.Locale.Category#FORMAT
503 * @return a date formatter.
504 */
505 public static final DateFormat getDateInstance()
506 {
507 return get(0, DEFAULT, 2, Locale.getDefault(Locale.Category.FORMAT));
508 }
509
510 /**
511 * Gets the date formatter with the given formatting style
512 * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.
513 * <p>This is equivalent to calling
514 * {@link #getDateInstance(int, Locale) getDateInstance(style,
515 * Locale.getDefault(Locale.Category.FORMAT))}.
516 * @see java.util.Locale#getDefault(java.util.Locale.Category)
517 * @see java.util.Locale.Category#FORMAT
518 * @param style the given formatting style. For example,
519 * SHORT for "M/d/yy" in the US locale.
520 * @return a date formatter.
521 */
522 public static final DateFormat getDateInstance(int style)
523 {
524 return get(0, style, 2, Locale.getDefault(Locale.Category.FORMAT));
525 }
526
527 /**
528 * Gets the date formatter with the given formatting style
529 * for the given locale.
530 * @param style the given formatting style. For example,
531 * SHORT for "M/d/yy" in the US locale.
532 * @param aLocale the given locale.
533 * @return a date formatter.
534 */
535 public static final DateFormat getDateInstance(int style,
536 Locale aLocale)
537 {
538 return get(0, style, 2, aLocale);
539 }
540
541 /**
542 * Gets the date/time formatter with the default formatting style
543 * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.
544 * <p>This is equivalent to calling
545 * {@link #getDateTimeInstance(int, int, Locale) getDateTimeInstance(DEFAULT,
546 * DEFAULT, Locale.getDefault(Locale.Category.FORMAT))}.
547 * @see java.util.Locale#getDefault(java.util.Locale.Category)
548 * @see java.util.Locale.Category#FORMAT
549 * @return a date/time formatter.
550 */
551 public static final DateFormat getDateTimeInstance()
552 {
553 return get(DEFAULT, DEFAULT, 3, Locale.getDefault(Locale.Category.FORMAT));
554 }
555
556 /**
557 * Gets the date/time formatter with the given date and time
558 * formatting styles for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.
559 * <p>This is equivalent to calling
560 * {@link #getDateTimeInstance(int, int, Locale) getDateTimeInstance(dateStyle,
561 * timeStyle, Locale.getDefault(Locale.Category.FORMAT))}.
562 * @see java.util.Locale#getDefault(java.util.Locale.Category)
563 * @see java.util.Locale.Category#FORMAT
564 * @param dateStyle the given date formatting style. For example,
565 * SHORT for "M/d/yy" in the US locale.
566 * @param timeStyle the given time formatting style. For example,
567 * SHORT for "h:mm a" in the US locale.
568 * @return a date/time formatter.
569 */
570 public static final DateFormat getDateTimeInstance(int dateStyle,
571 int timeStyle)
572 {
573 return get(timeStyle, dateStyle, 3, Locale.getDefault(Locale.Category.FORMAT));
574 }
575
576 /**
577 * Gets the date/time formatter with the given formatting styles
578 * for the given locale.
579 * @param dateStyle the given date formatting style.
580 * @param timeStyle the given time formatting style.
581 * @param aLocale the given locale.
582 * @return a date/time formatter.
583 */
584 public static final DateFormat
585 getDateTimeInstance(int dateStyle, int timeStyle, Locale aLocale)
586 {
587 return get(timeStyle, dateStyle, 3, aLocale);
588 }
589
590 /**
591 * Get a default date/time formatter that uses the SHORT style for both the
592 * date and the time.
593 *
594 * @return a date/time formatter
595 */
596 public static final DateFormat getInstance() {
597 return getDateTimeInstance(SHORT, SHORT);
598 }
599
600 /**
601 * Returns an array of all locales for which the
602 * <code>get*Instance</code> methods of this class can return
603 * localized instances.
604 * The returned array represents the union of locales supported by the Java
605 * runtime and by installed
606 * {@link java.text.spi.DateFormatProvider DateFormatProvider} implementations.
607 * It must contain at least a <code>Locale</code> instance equal to
608 * {@link java.util.Locale#US Locale.US}.
609 *
610 * @return An array of locales for which localized
611 * <code>DateFormat</code> instances are available.
612 */
613 public static Locale[] getAvailableLocales()
614 {
615 LocaleServiceProviderPool pool =
616 LocaleServiceProviderPool.getPool(DateFormatProvider.class);
617 return pool.getAvailableLocales();
618 }
619
620 /**
621 * Set the calendar to be used by this date format. Initially, the default
622 * calendar for the specified or default locale is used.
623 *
624 * <p>Any {@link java.util.TimeZone TimeZone} and {@linkplain
625 * #isLenient() leniency} values that have previously been set are
626 * overwritten by {@code newCalendar}'s values.
627 *
628 * @param newCalendar the new {@code Calendar} to be used by the date format
629 */
630 public void setCalendar(Calendar newCalendar)
631 {
632 this.calendar = newCalendar;
633 }
634
635 /**
636 * Gets the calendar associated with this date/time formatter.
637 *
638 * @return the calendar associated with this date/time formatter.
639 */
640 public Calendar getCalendar()
641 {
642 return calendar;
643 }
644
645 /**
646 * Allows you to set the number formatter.
647 * @param newNumberFormat the given new NumberFormat.
648 */
649 public void setNumberFormat(NumberFormat newNumberFormat)
650 {
651 this.numberFormat = newNumberFormat;
652 }
653
654 /**
655 * Gets the number formatter which this date/time formatter uses to
656 * format and parse a time.
657 * @return the number formatter which this date/time formatter uses.
658 */
659 public NumberFormat getNumberFormat()
660 {
661 return numberFormat;
662 }
663
664 /**
665 * Sets the time zone for the calendar of this {@code DateFormat} object.
666 * This method is equivalent to the following call.
667 * <blockquote><pre>{@code
668 * getCalendar().setTimeZone(zone)
669 * }</pre></blockquote>
670 *
671 * <p>The {@code TimeZone} set by this method is overwritten by a
672 * {@link #setCalendar(java.util.Calendar) setCalendar} call.
673 *
674 * <p>The {@code TimeZone} set by this method may be overwritten as
675 * a result of a call to the parse method.
676 *
677 * @param zone the given new time zone.
678 */
679 public void setTimeZone(TimeZone zone)
680 {
681 calendar.setTimeZone(zone);
682 }
683
684 /**
685 * Gets the time zone.
686 * This method is equivalent to the following call.
687 * <blockquote><pre>{@code
688 * getCalendar().getTimeZone()
689 * }</pre></blockquote>
690 *
691 * @return the time zone associated with the calendar of DateFormat.
692 */
693 public TimeZone getTimeZone()
694 {
695 return calendar.getTimeZone();
696 }
697
698 /**
699 * Specify whether or not date/time parsing is to be lenient. With
700 * lenient parsing, the parser may use heuristics to interpret inputs that
701 * do not precisely match this object's format. With strict parsing,
702 * inputs must match this object's format.
703 *
704 * <p>This method is equivalent to the following call.
705 * <blockquote><pre>{@code
706 * getCalendar().setLenient(lenient)
707 * }</pre></blockquote>
708 *
709 * <p>This leniency value is overwritten by a call to {@link
710 * #setCalendar(java.util.Calendar) setCalendar()}.
711 *
712 * @param lenient when {@code true}, parsing is lenient
713 * @see java.util.Calendar#setLenient(boolean)
714 */
715 public void setLenient(boolean lenient)
716 {
717 calendar.setLenient(lenient);
718 }
719
720 /**
721 * Tell whether date/time parsing is to be lenient.
722 * This method is equivalent to the following call.
723 * <blockquote><pre>{@code
724 * getCalendar().isLenient()
725 * }</pre></blockquote>
726 *
727 * @return {@code true} if the {@link #calendar} is lenient;
728 * {@code false} otherwise.
729 * @see java.util.Calendar#isLenient()
730 */
731 public boolean isLenient()
732 {
733 return calendar.isLenient();
734 }
735
736 /**
737 * Overrides hashCode
738 */
739 public int hashCode() {
740 return numberFormat.hashCode();
741 // just enough fields for a reasonable distribution
742 }
743
744 /**
745 * Overrides equals
746 */
747 public boolean equals(Object obj) {
748 if (this == obj) return true;
749 if (obj == null || getClass() != obj.getClass()) return false;
750 DateFormat other = (DateFormat) obj;
751 return (// calendar.equivalentTo(other.calendar) // THIS API DOESN'T EXIST YET!
752 calendar.getFirstDayOfWeek() == other.calendar.getFirstDayOfWeek() &&
753 calendar.getMinimalDaysInFirstWeek() == other.calendar.getMinimalDaysInFirstWeek() &&
754 calendar.isLenient() == other.calendar.isLenient() &&
755 calendar.getTimeZone().equals(other.calendar.getTimeZone()) &&
756 numberFormat.equals(other.numberFormat));
757 }
758
759 /**
760 * Overrides Cloneable
761 */
762 public Object clone()
763 {
764 DateFormat other = (DateFormat) super.clone();
765 other.calendar = (Calendar) calendar.clone();
766 other.numberFormat = (NumberFormat) numberFormat.clone();
767 return other;
768 }
769
770 /**
771 * Creates a DateFormat with the given time and/or date style in the given
772 * locale.
773 * @param timeStyle a value from 0 to 3 indicating the time format,
774 * ignored if flags is 2
775 * @param dateStyle a value from 0 to 3 indicating the time format,
776 * ignored if flags is 1
777 * @param flags either 1 for a time format, 2 for a date format,
778 * or 3 for a date/time format
779 * @param loc the locale for the format
780 */
781 private static DateFormat get(int timeStyle, int dateStyle,
782 int flags, Locale loc) {
783 if ((flags & 1) != 0) {
784 if (timeStyle < 0 || timeStyle > 3) {
785 throw new IllegalArgumentException("Illegal time style " + timeStyle);
786 }
787 } else {
788 timeStyle = -1;
789 }
790 if ((flags & 2) != 0) {
791 if (dateStyle < 0 || dateStyle > 3) {
792 throw new IllegalArgumentException("Illegal date style " + dateStyle);
793 }
794 } else {
795 dateStyle = -1;
796 }
797
798 LocaleProviderAdapter adapter = LocaleProviderAdapter.getAdapter(DateFormatProvider.class, loc);
799 DateFormat dateFormat = get(adapter, timeStyle, dateStyle, loc);
800 if (dateFormat == null) {
801 dateFormat = get(LocaleProviderAdapter.forJRE(), timeStyle, dateStyle, loc);
802 }
803 return dateFormat;
804 }
805
806 private static DateFormat get(LocaleProviderAdapter adapter, int timeStyle, int dateStyle, Locale loc) {
807 DateFormatProvider provider = adapter.getDateFormatProvider();
808 DateFormat dateFormat;
809 if (timeStyle == -1) {
810 dateFormat = provider.getDateInstance(dateStyle, loc);
811 } else {
812 if (dateStyle == -1) {
813 dateFormat = provider.getTimeInstance(timeStyle, loc);
814 } else {
815 dateFormat = provider.getDateTimeInstance(dateStyle, timeStyle, loc);
816 }
817 }
818 return dateFormat;
819 }
820
821 /**
822 * Create a new date format.
823 */
824 protected DateFormat() {}
825
826 /**
827 * Defines constants that are used as attribute keys in the
828 * <code>AttributedCharacterIterator</code> returned
829 * from <code>DateFormat.formatToCharacterIterator</code> and as
830 * field identifiers in <code>FieldPosition</code>.
831 * <p>
832 * The class also provides two methods to map
833 * between its constants and the corresponding Calendar constants.
834 *
835 * @since 1.4
836 * @see java.util.Calendar
837 */
838 public static class Field extends Format.Field {
839
840 // Proclaim serial compatibility with 1.4 FCS
841 private static final long serialVersionUID = 7441350119349544720L;
842
843 // table of all instances in this class, used by readResolve
844 private static final Map<String, Field> instanceMap = new HashMap<>(18);
845 // Maps from Calendar constant (such as Calendar.ERA) to Field
846 // constant (such as Field.ERA).
847 private static final Field[] calendarToFieldMapping =
848 new Field[Calendar.FIELD_COUNT];
849
850 /** Calendar field. */
851 private int calendarField;
852
853 /**
854 * Returns the <code>Field</code> constant that corresponds to
855 * the <code>Calendar</code> constant <code>calendarField</code>.
856 * If there is no direct mapping between the <code>Calendar</code>
857 * constant and a <code>Field</code>, null is returned.
858 *
859 * @throws IllegalArgumentException if <code>calendarField</code> is
860 * not the value of a <code>Calendar</code> field constant.
861 * @param calendarField Calendar field constant
862 * @return Field instance representing calendarField.
863 * @see java.util.Calendar
864 */
865 public static Field ofCalendarField(int calendarField) {
866 if (calendarField < 0 || calendarField >=
867 calendarToFieldMapping.length) {
868 throw new IllegalArgumentException("Unknown Calendar constant "
869 + calendarField);
870 }
871 return calendarToFieldMapping[calendarField];
872 }
873
874 /**
875 * Creates a <code>Field</code>.
876 *
877 * @param name the name of the <code>Field</code>
878 * @param calendarField the <code>Calendar</code> constant this
879 * <code>Field</code> corresponds to; any value, even one
880 * outside the range of legal <code>Calendar</code> values may
881 * be used, but <code>-1</code> should be used for values
882 * that don't correspond to legal <code>Calendar</code> values
883 */
884 protected Field(String name, int calendarField) {
885 super(name);
886 this.calendarField = calendarField;
887 if (this.getClass() == DateFormat.Field.class) {
888 instanceMap.put(name, this);
889 if (calendarField >= 0) {
890 // assert(calendarField < Calendar.FIELD_COUNT);
891 calendarToFieldMapping[calendarField] = this;
892 }
893 }
894 }
895
896 /**
897 * Returns the <code>Calendar</code> field associated with this
898 * attribute. For example, if this represents the hours field of
899 * a <code>Calendar</code>, this would return
900 * <code>Calendar.HOUR</code>. If there is no corresponding
901 * <code>Calendar</code> constant, this will return -1.
902 *
903 * @return Calendar constant for this field
904 * @see java.util.Calendar
905 */
906 public int getCalendarField() {
907 return calendarField;
908 }
909
910 /**
911 * Resolves instances being deserialized to the predefined constants.
912 *
913 * @throws InvalidObjectException if the constant could not be
914 * resolved.
915 * @return resolved DateFormat.Field constant
916 */
917 @Override
918 protected Object readResolve() throws InvalidObjectException {
919 if (this.getClass() != DateFormat.Field.class) {
920 throw new InvalidObjectException("subclass didn't correctly implement readResolve");
921 }
922
923 Object instance = instanceMap.get(getName());
924 if (instance != null) {
925 return instance;
926 } else {
927 throw new InvalidObjectException("unknown attribute name");
928 }
929 }
930
931 //
932 // The constants
933 //
934
935 /**
936 * Constant identifying the era field.
937 */
938 public static final Field ERA = new Field("era", Calendar.ERA);
939
940 /**
941 * Constant identifying the year field.
942 */
943 public static final Field YEAR = new Field("year", Calendar.YEAR);
944
945 /**
946 * Constant identifying the month field.
947 */
948 public static final Field MONTH = new Field("month", Calendar.MONTH);
949
950 /**
951 * Constant identifying the day of month field.
952 */
953 public static final Field DAY_OF_MONTH = new
954 Field("day of month", Calendar.DAY_OF_MONTH);
955
956 /**
957 * Constant identifying the hour of day field, where the legal values
958 * are 1 to 24.
959 */
960 public static final Field HOUR_OF_DAY1 = new Field("hour of day 1",-1);
961
962 /**
963 * Constant identifying the hour of day field, where the legal values
964 * are 0 to 23.
965 */
966 public static final Field HOUR_OF_DAY0 = new
967 Field("hour of day", Calendar.HOUR_OF_DAY);
968
969 /**
970 * Constant identifying the minute field.
971 */
972 public static final Field MINUTE =new Field("minute", Calendar.MINUTE);
973
974 /**
975 * Constant identifying the second field.
976 */
977 public static final Field SECOND =new Field("second", Calendar.SECOND);
978
979 /**
980 * Constant identifying the millisecond field.
981 */
982 public static final Field MILLISECOND = new
983 Field("millisecond", Calendar.MILLISECOND);
984
985 /**
986 * Constant identifying the day of week field.
987 */
988 public static final Field DAY_OF_WEEK = new
989 Field("day of week", Calendar.DAY_OF_WEEK);
990
991 /**
992 * Constant identifying the day of year field.
993 */
994 public static final Field DAY_OF_YEAR = new
995 Field("day of year", Calendar.DAY_OF_YEAR);
996
997 /**
998 * Constant identifying the day of week field.
999 */
1000 public static final Field DAY_OF_WEEK_IN_MONTH =
1001 new Field("day of week in month",
1002 Calendar.DAY_OF_WEEK_IN_MONTH);
1003
1004 /**
1005 * Constant identifying the week of year field.
1006 */
1007 public static final Field WEEK_OF_YEAR = new
1008 Field("week of year", Calendar.WEEK_OF_YEAR);
1009
1010 /**
1011 * Constant identifying the week of month field.
1012 */
1013 public static final Field WEEK_OF_MONTH = new
1014 Field("week of month", Calendar.WEEK_OF_MONTH);
1015
1016 /**
1017 * Constant identifying the time of day indicator
1018 * (e.g. "a.m." or "p.m.") field.
1019 */
1020 public static final Field AM_PM = new
1021 Field("am pm", Calendar.AM_PM);
1022
1023 /**
1024 * Constant identifying the hour field, where the legal values are
1025 * 1 to 12.
1026 */
1027 public static final Field HOUR1 = new Field("hour 1", -1);
1028
1029 /**
1030 * Constant identifying the hour field, where the legal values are
1031 * 0 to 11.
1032 */
1033 public static final Field HOUR0 = new
1034 Field("hour", Calendar.HOUR);
1035
1036 /**
1037 * Constant identifying the time zone field.
1038 */
1039 public static final Field TIME_ZONE = new Field("time zone", -1);
1040 }
1041 }