1 /* 2 * Copyright (c) 1996, 2017, 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 id="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 * @implSpec 145 * <ul><li>The {@link #format(Date, StringBuffer, FieldPosition)} and 146 * {@link #parse(String, ParsePosition)} methods may throw 147 * {@code NullPointerException}, if any of their parameter is {@code null}. 148 * The subclass may provide its own implementation and specification about 149 * {@code NullPointerException}.</li> 150 * <li>The {@link #setCalendar(Calendar)}, {@link 151 * #setNumberFormat(NumberFormat)} and {@link #setTimeZone(TimeZone)} methods 152 * do not throw {@code NullPointerException} when their parameter is 153 * {@code null}, but any subsequent operations on the same instance may throw 154 * {@code NullPointerException}.</li> 155 * <li>The {@link #getCalendar()}, {@link #getNumberFormat()} and 156 * {@link getTimeZone()} methods may return {@code null}, if the respective 157 * values of this instance is set to {@code null} through the corresponding 158 * setter methods. For Example: {@link #getTimeZone()} may return {@code null}, 159 * if the {@code TimeZone} value of this instance is set as 160 * {@link #setTimeZone(java.util.TimeZone) setTimeZone(null)}.</li> 161 * </ul> 162 * 163 * @see Format 164 * @see NumberFormat 165 * @see SimpleDateFormat 166 * @see java.util.Calendar 167 * @see java.util.GregorianCalendar 168 * @see java.util.TimeZone 169 * @author Mark Davis, Chen-Lieh Huang, Alan Liu 170 * @since 1.1 171 */ 172 public abstract class DateFormat extends Format { 173 174 /** 175 * The {@link Calendar} instance used for calculating the date-time fields 176 * and the instant of time. This field is used for both formatting and 177 * parsing. 178 * 179 * <p>Subclasses should initialize this field to a {@link Calendar} 180 * appropriate for the {@link Locale} associated with this 181 * <code>DateFormat</code>. 182 * @serial 183 */ 184 protected Calendar calendar; 185 186 /** 187 * The number formatter that <code>DateFormat</code> uses to format numbers 188 * in dates and times. Subclasses should initialize this to a number format 189 * appropriate for the locale associated with this <code>DateFormat</code>. 190 * @serial 191 */ 192 protected NumberFormat numberFormat; 193 194 /** 195 * Useful constant for ERA field alignment. 196 * Used in FieldPosition of date/time formatting. 197 */ 198 public static final int ERA_FIELD = 0; 199 /** 200 * Useful constant for YEAR field alignment. 201 * Used in FieldPosition of date/time formatting. 202 */ 203 public static final int YEAR_FIELD = 1; 204 /** 205 * Useful constant for MONTH field alignment. 206 * Used in FieldPosition of date/time formatting. 207 */ 208 public static final int MONTH_FIELD = 2; 209 /** 210 * Useful constant for DATE field alignment. 211 * Used in FieldPosition of date/time formatting. 212 */ 213 public static final int DATE_FIELD = 3; 214 /** 215 * Useful constant for one-based HOUR_OF_DAY field alignment. 216 * Used in FieldPosition of date/time formatting. 217 * HOUR_OF_DAY1_FIELD is used for the one-based 24-hour clock. 218 * For example, 23:59 + 01:00 results in 24:59. 219 */ 220 public static final int HOUR_OF_DAY1_FIELD = 4; 221 /** 222 * Useful constant for zero-based HOUR_OF_DAY field alignment. 223 * Used in FieldPosition of date/time formatting. 224 * HOUR_OF_DAY0_FIELD is used for the zero-based 24-hour clock. 225 * For example, 23:59 + 01:00 results in 00:59. 226 */ 227 public static final int HOUR_OF_DAY0_FIELD = 5; 228 /** 229 * Useful constant for MINUTE field alignment. 230 * Used in FieldPosition of date/time formatting. 231 */ 232 public static final int MINUTE_FIELD = 6; 233 /** 234 * Useful constant for SECOND field alignment. 235 * Used in FieldPosition of date/time formatting. 236 */ 237 public static final int SECOND_FIELD = 7; 238 /** 239 * Useful constant for MILLISECOND field alignment. 240 * Used in FieldPosition of date/time formatting. 241 */ 242 public static final int MILLISECOND_FIELD = 8; 243 /** 244 * Useful constant for DAY_OF_WEEK field alignment. 245 * Used in FieldPosition of date/time formatting. 246 */ 247 public static final int DAY_OF_WEEK_FIELD = 9; 248 /** 249 * Useful constant for DAY_OF_YEAR field alignment. 250 * Used in FieldPosition of date/time formatting. 251 */ 252 public static final int DAY_OF_YEAR_FIELD = 10; 253 /** 254 * Useful constant for DAY_OF_WEEK_IN_MONTH field alignment. 255 * Used in FieldPosition of date/time formatting. 256 */ 257 public static final int DAY_OF_WEEK_IN_MONTH_FIELD = 11; 258 /** 259 * Useful constant for WEEK_OF_YEAR field alignment. 260 * Used in FieldPosition of date/time formatting. 261 */ 262 public static final int WEEK_OF_YEAR_FIELD = 12; 263 /** 264 * Useful constant for WEEK_OF_MONTH field alignment. 265 * Used in FieldPosition of date/time formatting. 266 */ 267 public static final int WEEK_OF_MONTH_FIELD = 13; 268 /** 269 * Useful constant for AM_PM field alignment. 270 * Used in FieldPosition of date/time formatting. 271 */ 272 public static final int AM_PM_FIELD = 14; 273 /** 274 * Useful constant for one-based HOUR field alignment. 275 * Used in FieldPosition of date/time formatting. 276 * HOUR1_FIELD is used for the one-based 12-hour clock. 277 * For example, 11:30 PM + 1 hour results in 12:30 AM. 278 */ 279 public static final int HOUR1_FIELD = 15; 280 /** 281 * Useful constant for zero-based HOUR field alignment. 282 * Used in FieldPosition of date/time formatting. 283 * HOUR0_FIELD is used for the zero-based 12-hour clock. 284 * For example, 11:30 PM + 1 hour results in 00:30 AM. 285 */ 286 public static final int HOUR0_FIELD = 16; 287 /** 288 * Useful constant for TIMEZONE field alignment. 289 * Used in FieldPosition of date/time formatting. 290 */ 291 public static final int TIMEZONE_FIELD = 17; 292 293 // Proclaim serial compatibility with 1.1 FCS 294 private static final long serialVersionUID = 7218322306649953788L; 295 296 /** 297 * Formats the given {@code Object} into a date-time string. The formatted 298 * string is appended to the given {@code StringBuffer}. 299 * 300 * @param obj Must be a {@code Date} or a {@code Number} representing a 301 * millisecond offset from the <a href="../util/Calendar.html#Epoch">Epoch</a>. 302 * @param toAppendTo The string buffer for the returning date-time string. 303 * @param fieldPosition keeps track on the position of the field within 304 * the returned string. For example, given a date-time text 305 * {@code "1996.07.10 AD at 15:08:56 PDT"}, if the given {@code fieldPosition} 306 * is {@link DateFormat#YEAR_FIELD}, the begin index and end index of 307 * {@code fieldPosition} will be set to 0 and 4, respectively. 308 * Notice that if the same date-time field appears more than once in a 309 * pattern, the {@code fieldPosition} will be set for the first occurrence 310 * of that date-time field. For instance, formatting a {@code Date} to the 311 * date-time string {@code "1 PM PDT (Pacific Daylight Time)"} using the 312 * pattern {@code "h a z (zzzz)"} and the alignment field 313 * {@link DateFormat#TIMEZONE_FIELD}, the begin index and end index of 314 * {@code fieldPosition} will be set to 5 and 8, respectively, for the 315 * first occurrence of the timezone pattern character {@code 'z'}. 316 * @return the string buffer passed in as {@code toAppendTo}, 317 * with formatted text appended. 318 * @exception IllegalArgumentException if the {@code Format} cannot format 319 * the given {@code obj}. 320 * @see java.text.Format 321 */ 322 public final StringBuffer format(Object obj, StringBuffer toAppendTo, 323 FieldPosition fieldPosition) 324 { 325 if (obj instanceof Date) 326 return format( (Date)obj, toAppendTo, fieldPosition ); 327 else if (obj instanceof Number) 328 return format( new Date(((Number)obj).longValue()), 329 toAppendTo, fieldPosition ); 330 else 331 throw new IllegalArgumentException("Cannot format given Object as a Date"); 332 } 333 334 /** 335 * Formats a {@link Date} into a date-time string. The formatted 336 * string is appended to the given {@code StringBuffer}. 337 * 338 * @param date a Date to be formatted into a date-time string. 339 * @param toAppendTo the string buffer for the returning date-time string. 340 * @param fieldPosition keeps track on the position of the field within 341 * the returned string. For example, given a date-time text 342 * {@code "1996.07.10 AD at 15:08:56 PDT"}, if the given {@code fieldPosition} 343 * is {@link DateFormat#YEAR_FIELD}, the begin index and end index of 344 * {@code fieldPosition} will be set to 0 and 4, respectively. 345 * Notice that if the same date-time field appears more than once in a 346 * pattern, the {@code fieldPosition} will be set for the first occurrence 347 * of that date-time field. For instance, formatting a {@code Date} to the 348 * date-time string {@code "1 PM PDT (Pacific Daylight Time)"} using the 349 * pattern {@code "h a z (zzzz)"} and the alignment field 350 * {@link DateFormat#TIMEZONE_FIELD}, the begin index and end index of 351 * {@code fieldPosition} will be set to 5 and 8, respectively, for the 352 * first occurrence of the timezone pattern character {@code 'z'}. 353 * @return the string buffer passed in as {@code toAppendTo}, with formatted 354 * text appended. 355 */ 356 public abstract StringBuffer format(Date date, StringBuffer toAppendTo, 357 FieldPosition fieldPosition); 358 359 /** 360 * Formats a {@link Date} into a date-time string. 361 * 362 * @param date the time value to be formatted into a date-time string. 363 * @return the formatted date-time string. 364 */ 365 public final String format(Date date) 366 { 367 return format(date, new StringBuffer(), 368 DontCareFieldPosition.INSTANCE).toString(); 369 } 370 371 /** 372 * Parses text from the beginning of the given string to produce a date. 373 * The method may not use the entire text of the given string. 374 * <p> 375 * See the {@link #parse(String, ParsePosition)} method for more information 376 * on date parsing. 377 * 378 * @param source A <code>String</code> whose beginning should be parsed. 379 * @return A <code>Date</code> parsed from the string. 380 * @exception ParseException if the beginning of the specified string 381 * cannot be parsed. 382 */ 383 public Date parse(String source) throws ParseException 384 { 385 ParsePosition pos = new ParsePosition(0); 386 Date result = parse(source, pos); 387 if (pos.index == 0) 388 throw new ParseException("Unparseable date: \"" + source + "\"" , 389 pos.errorIndex); 390 return result; 391 } 392 393 /** 394 * Parse a date/time string according to the given parse position. For 395 * example, a time text {@code "07/10/96 4:5 PM, PDT"} will be parsed into a {@code Date} 396 * that is equivalent to {@code Date(837039900000L)}. 397 * 398 * <p> By default, parsing is lenient: If the input is not in the form used 399 * by this object's format method but can still be parsed as a date, then 400 * the parse succeeds. Clients may insist on strict adherence to the 401 * format by calling {@link #setLenient(boolean) setLenient(false)}. 402 * 403 * <p>This parsing operation uses the {@link #calendar} to produce 404 * a {@code Date}. As a result, the {@code calendar}'s date-time 405 * fields and the {@code TimeZone} value may have been 406 * overwritten, depending on subclass implementations. Any {@code 407 * TimeZone} value that has previously been set by a call to 408 * {@link #setTimeZone(java.util.TimeZone) setTimeZone} may need 409 * to be restored for further operations. 410 * 411 * @param source The date/time string to be parsed 412 * 413 * @param pos On input, the position at which to start parsing; on 414 * output, the position at which parsing terminated, or the 415 * start position if the parse failed. 416 * 417 * @return A {@code Date}, or {@code null} if the input could not be parsed 418 */ 419 public abstract Date parse(String source, ParsePosition pos); 420 421 /** 422 * Parses text from a string to produce a <code>Date</code>. 423 * <p> 424 * The method attempts to parse text starting at the index given by 425 * <code>pos</code>. 426 * If parsing succeeds, then the index of <code>pos</code> is updated 427 * to the index after the last character used (parsing does not necessarily 428 * use all characters up to the end of the string), and the parsed 429 * date is returned. The updated <code>pos</code> can be used to 430 * indicate the starting point for the next call to this method. 431 * If an error occurs, then the index of <code>pos</code> is not 432 * changed, the error index of <code>pos</code> is set to the index of 433 * the character where the error occurred, and null is returned. 434 * <p> 435 * See the {@link #parse(String, ParsePosition)} method for more information 436 * on date parsing. 437 * 438 * @param source A <code>String</code>, part of which should be parsed. 439 * @param pos A <code>ParsePosition</code> object with index and error 440 * index information as described above. 441 * @return A <code>Date</code> parsed from the string. In case of 442 * error, returns null. 443 * @throws NullPointerException if {@code source} or {@code pos} is null. 444 */ 445 public Object parseObject(String source, ParsePosition pos) { 446 return parse(source, pos); 447 } 448 449 /** 450 * Constant for full style pattern. 451 */ 452 public static final int FULL = 0; 453 /** 454 * Constant for long style pattern. 455 */ 456 public static final int LONG = 1; 457 /** 458 * Constant for medium style pattern. 459 */ 460 public static final int MEDIUM = 2; 461 /** 462 * Constant for short style pattern. 463 */ 464 public static final int SHORT = 3; 465 /** 466 * Constant for default style pattern. Its value is MEDIUM. 467 */ 468 public static final int DEFAULT = MEDIUM; 469 470 /** 471 * Gets the time formatter with the default formatting style 472 * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale. 473 * <p>This is equivalent to calling 474 * {@link #getTimeInstance(int, Locale) getTimeInstance(DEFAULT, 475 * Locale.getDefault(Locale.Category.FORMAT))}. 476 * @see java.util.Locale#getDefault(java.util.Locale.Category) 477 * @see java.util.Locale.Category#FORMAT 478 * @return a time formatter. 479 */ 480 public static final DateFormat getTimeInstance() 481 { 482 return get(DEFAULT, 0, 1, Locale.getDefault(Locale.Category.FORMAT)); 483 } 484 485 /** 486 * Gets the time formatter with the given formatting style 487 * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale. 488 * <p>This is equivalent to calling 489 * {@link #getTimeInstance(int, Locale) getTimeInstance(style, 490 * Locale.getDefault(Locale.Category.FORMAT))}. 491 * @see java.util.Locale#getDefault(java.util.Locale.Category) 492 * @see java.util.Locale.Category#FORMAT 493 * @param style the given formatting style. For example, 494 * SHORT for "h:mm a" in the US locale. 495 * @return a time formatter. 496 */ 497 public static final DateFormat getTimeInstance(int style) 498 { 499 return get(style, 0, 1, Locale.getDefault(Locale.Category.FORMAT)); 500 } 501 502 /** 503 * Gets the time formatter with the given formatting style 504 * for the given locale. 505 * @param style the given formatting style. For example, 506 * SHORT for "h:mm a" in the US locale. 507 * @param aLocale the given locale. 508 * @return a time formatter. 509 */ 510 public static final DateFormat getTimeInstance(int style, 511 Locale aLocale) 512 { 513 return get(style, 0, 1, aLocale); 514 } 515 516 /** 517 * Gets the date formatter with the default formatting style 518 * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale. 519 * <p>This is equivalent to calling 520 * {@link #getDateInstance(int, Locale) getDateInstance(DEFAULT, 521 * Locale.getDefault(Locale.Category.FORMAT))}. 522 * @see java.util.Locale#getDefault(java.util.Locale.Category) 523 * @see java.util.Locale.Category#FORMAT 524 * @return a date formatter. 525 */ 526 public static final DateFormat getDateInstance() 527 { 528 return get(0, DEFAULT, 2, Locale.getDefault(Locale.Category.FORMAT)); 529 } 530 531 /** 532 * Gets the date formatter with the given formatting style 533 * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale. 534 * <p>This is equivalent to calling 535 * {@link #getDateInstance(int, Locale) getDateInstance(style, 536 * Locale.getDefault(Locale.Category.FORMAT))}. 537 * @see java.util.Locale#getDefault(java.util.Locale.Category) 538 * @see java.util.Locale.Category#FORMAT 539 * @param style the given formatting style. For example, 540 * SHORT for "M/d/yy" in the US locale. 541 * @return a date formatter. 542 */ 543 public static final DateFormat getDateInstance(int style) 544 { 545 return get(0, style, 2, Locale.getDefault(Locale.Category.FORMAT)); 546 } 547 548 /** 549 * Gets the date formatter with the given formatting style 550 * for the given locale. 551 * @param style the given formatting style. For example, 552 * SHORT for "M/d/yy" in the US locale. 553 * @param aLocale the given locale. 554 * @return a date formatter. 555 */ 556 public static final DateFormat getDateInstance(int style, 557 Locale aLocale) 558 { 559 return get(0, style, 2, aLocale); 560 } 561 562 /** 563 * Gets the date/time formatter with the default formatting style 564 * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale. 565 * <p>This is equivalent to calling 566 * {@link #getDateTimeInstance(int, int, Locale) getDateTimeInstance(DEFAULT, 567 * DEFAULT, Locale.getDefault(Locale.Category.FORMAT))}. 568 * @see java.util.Locale#getDefault(java.util.Locale.Category) 569 * @see java.util.Locale.Category#FORMAT 570 * @return a date/time formatter. 571 */ 572 public static final DateFormat getDateTimeInstance() 573 { 574 return get(DEFAULT, DEFAULT, 3, Locale.getDefault(Locale.Category.FORMAT)); 575 } 576 577 /** 578 * Gets the date/time formatter with the given date and time 579 * formatting styles for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale. 580 * <p>This is equivalent to calling 581 * {@link #getDateTimeInstance(int, int, Locale) getDateTimeInstance(dateStyle, 582 * timeStyle, Locale.getDefault(Locale.Category.FORMAT))}. 583 * @see java.util.Locale#getDefault(java.util.Locale.Category) 584 * @see java.util.Locale.Category#FORMAT 585 * @param dateStyle the given date formatting style. For example, 586 * SHORT for "M/d/yy" in the US locale. 587 * @param timeStyle the given time formatting style. For example, 588 * SHORT for "h:mm a" in the US locale. 589 * @return a date/time formatter. 590 */ 591 public static final DateFormat getDateTimeInstance(int dateStyle, 592 int timeStyle) 593 { 594 return get(timeStyle, dateStyle, 3, Locale.getDefault(Locale.Category.FORMAT)); 595 } 596 597 /** 598 * Gets the date/time formatter with the given formatting styles 599 * for the given locale. 600 * @param dateStyle the given date formatting style. 601 * @param timeStyle the given time formatting style. 602 * @param aLocale the given locale. 603 * @return a date/time formatter. 604 */ 605 public static final DateFormat 606 getDateTimeInstance(int dateStyle, int timeStyle, Locale aLocale) 607 { 608 return get(timeStyle, dateStyle, 3, aLocale); 609 } 610 611 /** 612 * Get a default date/time formatter that uses the SHORT style for both the 613 * date and the time. 614 * 615 * @return a date/time formatter 616 */ 617 public static final DateFormat getInstance() { 618 return getDateTimeInstance(SHORT, SHORT); 619 } 620 621 /** 622 * Returns an array of all locales for which the 623 * <code>get*Instance</code> methods of this class can return 624 * localized instances. 625 * The returned array represents the union of locales supported by the Java 626 * runtime and by installed 627 * {@link java.text.spi.DateFormatProvider DateFormatProvider} implementations. 628 * It must contain at least a <code>Locale</code> instance equal to 629 * {@link java.util.Locale#US Locale.US}. 630 * 631 * @return An array of locales for which localized 632 * <code>DateFormat</code> instances are available. 633 */ 634 public static Locale[] getAvailableLocales() 635 { 636 LocaleServiceProviderPool pool = 637 LocaleServiceProviderPool.getPool(DateFormatProvider.class); 638 return pool.getAvailableLocales(); 639 } 640 641 /** 642 * Set the calendar to be used by this date format. Initially, the default 643 * calendar for the specified or default locale is used. 644 * 645 * <p>Any {@link java.util.TimeZone TimeZone} and {@linkplain 646 * #isLenient() leniency} values that have previously been set are 647 * overwritten by {@code newCalendar}'s values. 648 * 649 * @param newCalendar the new {@code Calendar} to be used by the date format 650 */ 651 public void setCalendar(Calendar newCalendar) 652 { 653 this.calendar = newCalendar; 654 } 655 656 /** 657 * Gets the calendar associated with this date/time formatter. 658 * 659 * @return the calendar associated with this date/time formatter. 660 */ 661 public Calendar getCalendar() 662 { 663 return calendar; 664 } 665 666 /** 667 * Allows you to set the number formatter. 668 * @param newNumberFormat the given new NumberFormat. 669 */ 670 public void setNumberFormat(NumberFormat newNumberFormat) 671 { 672 this.numberFormat = newNumberFormat; 673 } 674 675 /** 676 * Gets the number formatter which this date/time formatter uses to 677 * format and parse a time. 678 * @return the number formatter which this date/time formatter uses. 679 */ 680 public NumberFormat getNumberFormat() 681 { 682 return numberFormat; 683 } 684 685 /** 686 * Sets the time zone for the calendar of this {@code DateFormat} object. 687 * This method is equivalent to the following call. 688 * <blockquote><pre>{@code 689 * getCalendar().setTimeZone(zone) 690 * }</pre></blockquote> 691 * 692 * <p>The {@code TimeZone} set by this method is overwritten by a 693 * {@link #setCalendar(java.util.Calendar) setCalendar} call. 694 * 695 * <p>The {@code TimeZone} set by this method may be overwritten as 696 * a result of a call to the parse method. 697 * 698 * @param zone the given new time zone. 699 */ 700 public void setTimeZone(TimeZone zone) 701 { 702 calendar.setTimeZone(zone); 703 } 704 705 /** 706 * Gets the time zone. 707 * This method is equivalent to the following call. 708 * <blockquote><pre>{@code 709 * getCalendar().getTimeZone() 710 * }</pre></blockquote> 711 * 712 * @return the time zone associated with the calendar of DateFormat. 713 */ 714 public TimeZone getTimeZone() 715 { 716 return calendar.getTimeZone(); 717 } 718 719 /** 720 * Specify whether or not date/time parsing is to be lenient. With 721 * lenient parsing, the parser may use heuristics to interpret inputs that 722 * do not precisely match this object's format. With strict parsing, 723 * inputs must match this object's format. 724 * 725 * <p>This method is equivalent to the following call. 726 * <blockquote><pre>{@code 727 * getCalendar().setLenient(lenient) 728 * }</pre></blockquote> 729 * 730 * <p>This leniency value is overwritten by a call to {@link 731 * #setCalendar(java.util.Calendar) setCalendar()}. 732 * 733 * @param lenient when {@code true}, parsing is lenient 734 * @see java.util.Calendar#setLenient(boolean) 735 */ 736 public void setLenient(boolean lenient) 737 { 738 calendar.setLenient(lenient); 739 } 740 741 /** 742 * Tell whether date/time parsing is to be lenient. 743 * This method is equivalent to the following call. 744 * <blockquote><pre>{@code 745 * getCalendar().isLenient() 746 * }</pre></blockquote> 747 * 748 * @return {@code true} if the {@link #calendar} is lenient; 749 * {@code false} otherwise. 750 * @see java.util.Calendar#isLenient() 751 */ 752 public boolean isLenient() 753 { 754 return calendar.isLenient(); 755 } 756 757 /** 758 * Overrides hashCode 759 */ 760 public int hashCode() { 761 return numberFormat.hashCode(); 762 // just enough fields for a reasonable distribution 763 } 764 765 /** 766 * Overrides equals 767 */ 768 public boolean equals(Object obj) { 769 if (this == obj) return true; 770 if (obj == null || getClass() != obj.getClass()) return false; 771 DateFormat other = (DateFormat) obj; 772 return (// calendar.equivalentTo(other.calendar) // THIS API DOESN'T EXIST YET! 773 calendar.getFirstDayOfWeek() == other.calendar.getFirstDayOfWeek() && 774 calendar.getMinimalDaysInFirstWeek() == other.calendar.getMinimalDaysInFirstWeek() && 775 calendar.isLenient() == other.calendar.isLenient() && 776 calendar.getTimeZone().equals(other.calendar.getTimeZone()) && 777 numberFormat.equals(other.numberFormat)); 778 } 779 780 /** 781 * Overrides Cloneable 782 */ 783 public Object clone() 784 { 785 DateFormat other = (DateFormat) super.clone(); 786 other.calendar = (Calendar) calendar.clone(); 787 other.numberFormat = (NumberFormat) numberFormat.clone(); 788 return other; 789 } 790 791 /** 792 * Creates a DateFormat with the given time and/or date style in the given 793 * locale. 794 * @param timeStyle a value from 0 to 3 indicating the time format, 795 * ignored if flags is 2 796 * @param dateStyle a value from 0 to 3 indicating the time format, 797 * ignored if flags is 1 798 * @param flags either 1 for a time format, 2 for a date format, 799 * or 3 for a date/time format 800 * @param loc the locale for the format 801 */ 802 private static DateFormat get(int timeStyle, int dateStyle, 803 int flags, Locale loc) { 804 if ((flags & 1) != 0) { 805 if (timeStyle < 0 || timeStyle > 3) { 806 throw new IllegalArgumentException("Illegal time style " + timeStyle); 807 } 808 } else { 809 timeStyle = -1; 810 } 811 if ((flags & 2) != 0) { 812 if (dateStyle < 0 || dateStyle > 3) { 813 throw new IllegalArgumentException("Illegal date style " + dateStyle); 814 } 815 } else { 816 dateStyle = -1; 817 } 818 819 LocaleProviderAdapter adapter = LocaleProviderAdapter.getAdapter(DateFormatProvider.class, loc); 820 DateFormat dateFormat = get(adapter, timeStyle, dateStyle, loc); 821 if (dateFormat == null) { 822 dateFormat = get(LocaleProviderAdapter.forJRE(), timeStyle, dateStyle, loc); 823 } 824 return dateFormat; 825 } 826 827 private static DateFormat get(LocaleProviderAdapter adapter, int timeStyle, int dateStyle, Locale loc) { 828 DateFormatProvider provider = adapter.getDateFormatProvider(); 829 DateFormat dateFormat; 830 if (timeStyle == -1) { 831 dateFormat = provider.getDateInstance(dateStyle, loc); 832 } else { 833 if (dateStyle == -1) { 834 dateFormat = provider.getTimeInstance(timeStyle, loc); 835 } else { 836 dateFormat = provider.getDateTimeInstance(dateStyle, timeStyle, loc); 837 } 838 } 839 return dateFormat; 840 } 841 842 /** 843 * Create a new date format. 844 */ 845 protected DateFormat() {} 846 847 /** 848 * Defines constants that are used as attribute keys in the 849 * <code>AttributedCharacterIterator</code> returned 850 * from <code>DateFormat.formatToCharacterIterator</code> and as 851 * field identifiers in <code>FieldPosition</code>. 852 * <p> 853 * The class also provides two methods to map 854 * between its constants and the corresponding Calendar constants. 855 * 856 * @since 1.4 857 * @see java.util.Calendar 858 */ 859 public static class Field extends Format.Field { 860 861 // Proclaim serial compatibility with 1.4 FCS 862 private static final long serialVersionUID = 7441350119349544720L; 863 864 // table of all instances in this class, used by readResolve 865 private static final Map<String, Field> instanceMap = new HashMap<>(18); 866 // Maps from Calendar constant (such as Calendar.ERA) to Field 867 // constant (such as Field.ERA). 868 private static final Field[] calendarToFieldMapping = 869 new Field[Calendar.FIELD_COUNT]; 870 871 /** Calendar field. */ 872 private int calendarField; 873 874 /** 875 * Returns the <code>Field</code> constant that corresponds to 876 * the <code>Calendar</code> constant <code>calendarField</code>. 877 * If there is no direct mapping between the <code>Calendar</code> 878 * constant and a <code>Field</code>, null is returned. 879 * 880 * @throws IllegalArgumentException if <code>calendarField</code> is 881 * not the value of a <code>Calendar</code> field constant. 882 * @param calendarField Calendar field constant 883 * @return Field instance representing calendarField. 884 * @see java.util.Calendar 885 */ 886 public static Field ofCalendarField(int calendarField) { 887 if (calendarField < 0 || calendarField >= 888 calendarToFieldMapping.length) { 889 throw new IllegalArgumentException("Unknown Calendar constant " 890 + calendarField); 891 } 892 return calendarToFieldMapping[calendarField]; 893 } 894 895 /** 896 * Creates a <code>Field</code>. 897 * 898 * @param name the name of the <code>Field</code> 899 * @param calendarField the <code>Calendar</code> constant this 900 * <code>Field</code> corresponds to; any value, even one 901 * outside the range of legal <code>Calendar</code> values may 902 * be used, but <code>-1</code> should be used for values 903 * that don't correspond to legal <code>Calendar</code> values 904 */ 905 protected Field(String name, int calendarField) { 906 super(name); 907 this.calendarField = calendarField; 908 if (this.getClass() == DateFormat.Field.class) { 909 instanceMap.put(name, this); 910 if (calendarField >= 0) { 911 // assert(calendarField < Calendar.FIELD_COUNT); 912 calendarToFieldMapping[calendarField] = this; 913 } 914 } 915 } 916 917 /** 918 * Returns the <code>Calendar</code> field associated with this 919 * attribute. For example, if this represents the hours field of 920 * a <code>Calendar</code>, this would return 921 * <code>Calendar.HOUR</code>. If there is no corresponding 922 * <code>Calendar</code> constant, this will return -1. 923 * 924 * @return Calendar constant for this field 925 * @see java.util.Calendar 926 */ 927 public int getCalendarField() { 928 return calendarField; 929 } 930 931 /** 932 * Resolves instances being deserialized to the predefined constants. 933 * 934 * @throws InvalidObjectException if the constant could not be 935 * resolved. 936 * @return resolved DateFormat.Field constant 937 */ 938 @Override 939 protected Object readResolve() throws InvalidObjectException { 940 if (this.getClass() != DateFormat.Field.class) { 941 throw new InvalidObjectException("subclass didn't correctly implement readResolve"); 942 } 943 944 Object instance = instanceMap.get(getName()); 945 if (instance != null) { 946 return instance; 947 } else { 948 throw new InvalidObjectException("unknown attribute name"); 949 } 950 } 951 952 // 953 // The constants 954 // 955 956 /** 957 * Constant identifying the era field. 958 */ 959 public static final Field ERA = new Field("era", Calendar.ERA); 960 961 /** 962 * Constant identifying the year field. 963 */ 964 public static final Field YEAR = new Field("year", Calendar.YEAR); 965 966 /** 967 * Constant identifying the month field. 968 */ 969 public static final Field MONTH = new Field("month", Calendar.MONTH); 970 971 /** 972 * Constant identifying the day of month field. 973 */ 974 public static final Field DAY_OF_MONTH = new 975 Field("day of month", Calendar.DAY_OF_MONTH); 976 977 /** 978 * Constant identifying the hour of day field, where the legal values 979 * are 1 to 24. 980 */ 981 public static final Field HOUR_OF_DAY1 = new Field("hour of day 1",-1); 982 983 /** 984 * Constant identifying the hour of day field, where the legal values 985 * are 0 to 23. 986 */ 987 public static final Field HOUR_OF_DAY0 = new 988 Field("hour of day", Calendar.HOUR_OF_DAY); 989 990 /** 991 * Constant identifying the minute field. 992 */ 993 public static final Field MINUTE =new Field("minute", Calendar.MINUTE); 994 995 /** 996 * Constant identifying the second field. 997 */ 998 public static final Field SECOND =new Field("second", Calendar.SECOND); 999 1000 /** 1001 * Constant identifying the millisecond field. 1002 */ 1003 public static final Field MILLISECOND = new 1004 Field("millisecond", Calendar.MILLISECOND); 1005 1006 /** 1007 * Constant identifying the day of week field. 1008 */ 1009 public static final Field DAY_OF_WEEK = new 1010 Field("day of week", Calendar.DAY_OF_WEEK); 1011 1012 /** 1013 * Constant identifying the day of year field. 1014 */ 1015 public static final Field DAY_OF_YEAR = new 1016 Field("day of year", Calendar.DAY_OF_YEAR); 1017 1018 /** 1019 * Constant identifying the day of week field. 1020 */ 1021 public static final Field DAY_OF_WEEK_IN_MONTH = 1022 new Field("day of week in month", 1023 Calendar.DAY_OF_WEEK_IN_MONTH); 1024 1025 /** 1026 * Constant identifying the week of year field. 1027 */ 1028 public static final Field WEEK_OF_YEAR = new 1029 Field("week of year", Calendar.WEEK_OF_YEAR); 1030 1031 /** 1032 * Constant identifying the week of month field. 1033 */ 1034 public static final Field WEEK_OF_MONTH = new 1035 Field("week of month", Calendar.WEEK_OF_MONTH); 1036 1037 /** 1038 * Constant identifying the time of day indicator 1039 * (e.g. "a.m." or "p.m.") field. 1040 */ 1041 public static final Field AM_PM = new 1042 Field("am pm", Calendar.AM_PM); 1043 1044 /** 1045 * Constant identifying the hour field, where the legal values are 1046 * 1 to 12. 1047 */ 1048 public static final Field HOUR1 = new Field("hour 1", -1); 1049 1050 /** 1051 * Constant identifying the hour field, where the legal values are 1052 * 0 to 11. 1053 */ 1054 public static final Field HOUR0 = new 1055 Field("hour", Calendar.HOUR); 1056 1057 /** 1058 * Constant identifying the time zone field. 1059 */ 1060 public static final Field TIME_ZONE = new Field("time zone", -1); 1061 } 1062 }