Source for java.text.SimpleDateFormat

   1: /* SimpleDateFormat.java -- A class for parsing/formating simple 
   2:    date constructs
   3:    Copyright (C) 1998, 1999, 2000, 2001, 2003, 2004, 2005
   4:    Free Software Foundation, Inc.
   5: 
   6: This file is part of GNU Classpath.
   7: 
   8: GNU Classpath is free software; you can redistribute it and/or modify
   9: it under the terms of the GNU General Public License as published by
  10: the Free Software Foundation; either version 2, or (at your option)
  11: any later version.
  12:  
  13: GNU Classpath is distributed in the hope that it will be useful, but
  14: WITHOUT ANY WARRANTY; without even the implied warranty of
  15: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16: General Public License for more details.
  17: 
  18: You should have received a copy of the GNU General Public License
  19: along with GNU Classpath; see the file COPYING.  If not, write to the
  20: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  21: 02110-1301 USA.
  22: 
  23: Linking this library statically or dynamically with other modules is
  24: making a combined work based on this library.  Thus, the terms and
  25: conditions of the GNU General Public License cover the whole
  26: combination.
  27: 
  28: As a special exception, the copyright holders of this library give you
  29: permission to link this library with independent modules to produce an
  30: executable, regardless of the license terms of these independent
  31: modules, and to copy and distribute the resulting executable under
  32: terms of your choice, provided that you also meet, for each linked
  33: independent module, the terms and conditions of the license of that
  34: module.  An independent module is a module which is not derived from
  35: or based on this library.  If you modify this library, you may extend
  36: this exception to your version of the library, but you are not
  37: obligated to do so.  If you do not wish to do so, delete this
  38: exception statement from your version. */
  39: 
  40: 
  41: package java.text;
  42: 
  43: import gnu.java.text.AttributedFormatBuffer;
  44: import gnu.java.text.FormatBuffer;
  45: import gnu.java.text.FormatCharacterIterator;
  46: import gnu.java.text.StringFormatBuffer;
  47: 
  48: import java.io.IOException;
  49: import java.io.InvalidObjectException;
  50: import java.io.ObjectInputStream;
  51: import java.util.ArrayList;
  52: import java.util.Calendar;
  53: import java.util.Date;
  54: import java.util.GregorianCalendar;
  55: import java.util.Iterator;
  56: import java.util.Locale;
  57: import java.util.TimeZone;
  58: import java.util.regex.Matcher;
  59: import java.util.regex.Pattern;
  60: 
  61: /**
  62:  * SimpleDateFormat provides convenient methods for parsing and formatting
  63:  * dates using Gregorian calendars (see java.util.GregorianCalendar). 
  64:  */
  65: public class SimpleDateFormat extends DateFormat 
  66: {
  67:   /** 
  68:    * This class is used by <code>SimpleDateFormat</code> as a
  69:    * compiled representation of a format string.  The field
  70:    * ID, size, and character used are stored for each sequence
  71:    * of pattern characters.
  72:    */
  73:   private class CompiledField
  74:   {
  75:     /**
  76:      * The ID of the field within the local pattern characters.
  77:      * Package private for use in out class.
  78:      */
  79:     int field;
  80: 
  81:     /**
  82:      * The size of the character sequence.
  83:      * Package private for use in out class.
  84:      */
  85:     int size;
  86: 
  87:     /**
  88:      * The character used.
  89:      */
  90:     private char character;
  91: 
  92:     /** 
  93:      * Constructs a compiled field using the
  94:      * the given field ID, size and character
  95:      * values.
  96:      *
  97:      * @param f the field ID.
  98:      * @param s the size of the field.
  99:      * @param c the character used.
 100:      */
 101:     public CompiledField(int f, int s, char c)
 102:     {
 103:       field = f;
 104:       size = s;
 105:       character = c;
 106:     }
 107: 
 108:     /**
 109:      * Retrieves the ID of the field relative to
 110:      * the local pattern characters.
 111:      */
 112:     public int getField()
 113:     {
 114:       return field;
 115:     }
 116: 
 117:     /**
 118:      * Retrieves the size of the character sequence.
 119:      */
 120:     public int getSize()
 121:     {
 122:       return size;
 123:     }
 124: 
 125:     /**
 126:      * Retrieves the character used in the sequence.
 127:      */
 128:     public char getCharacter()
 129:     {
 130:       return character;
 131:     }
 132: 
 133:     /**
 134:      * Returns a <code>String</code> representation
 135:      * of the compiled field, primarily for debugging
 136:      * purposes.
 137:      *
 138:      * @return a <code>String</code> representation.
 139:      */
 140:     public String toString()
 141:     {
 142:       StringBuffer builder;
 143: 
 144:       builder = new StringBuffer(getClass().getName());
 145:       builder.append("[field=");
 146:       builder.append(field);
 147:       builder.append(", size=");
 148:       builder.append(size);
 149:       builder.append(", character=");
 150:       builder.append(character);
 151:       builder.append("]");
 152: 
 153:       return builder.toString();
 154:     }
 155:   }
 156: 
 157:   /**
 158:    * A list of <code>CompiledField</code>s,
 159:    * representing the compiled version of the pattern.
 160:    *
 161:    * @see CompiledField
 162:    * @serial Ignored.
 163:    */
 164:   private transient ArrayList tokens;
 165: 
 166:   /**
 167:    * The localised data used in formatting,
 168:    * such as the day and month names in the local
 169:    * language, and the localized pattern characters.
 170:    *
 171:    * @see DateFormatSymbols
 172:    * @serial The localisation data.  May not be null.
 173:    */
 174:   private DateFormatSymbols formatData;
 175: 
 176:   /**
 177:    * The date representing the start of the century
 178:    * used for interpreting two digit years.  For
 179:    * example, 24/10/2004 would cause two digit
 180:    * years to be interpreted as representing
 181:    * the years between 2004 and 2104.
 182:    *
 183:    * @see #get2DigitYearStart()
 184:    * @see #set2DigitYearStart(java.util.Date)
 185:    * @see Date
 186:    * @serial The start date of the century for parsing two digit years.
 187:    *         May not be null.
 188:    */
 189:   private Date defaultCenturyStart;
 190: 
 191:   /**
 192:    * The year at which interpretation of two
 193:    * digit years starts.
 194:    *
 195:    * @see #get2DigitYearStart()
 196:    * @see #set2DigitYearStart(java.util.Date)
 197:    * @serial Ignored.
 198:    */
 199:   private transient int defaultCentury;
 200: 
 201:   /**
 202:    * The non-localized pattern string.  This
 203:    * only ever contains the pattern characters
 204:    * stored in standardChars.  Localized patterns
 205:    * are translated to this form.
 206:    *
 207:    * @see #applyPattern(String)
 208:    * @see #applyLocalizedPattern(String)
 209:    * @see #toPattern()
 210:    * @see #toLocalizedPattern()
 211:    * @serial The non-localized pattern string.  May not be null.
 212:    */
 213:   private String pattern;
 214: 
 215:   /**
 216:    * The version of serialized data used by this class.
 217:    * Version 0 only includes the pattern and formatting
 218:    * data.  Version 1 adds the start date for interpreting
 219:    * two digit years.
 220:    *
 221:    * @serial This specifies the version of the data being serialized.
 222:    *         Version 0 (or no version) specifies just <code>pattern</code>
 223:    *         and <code>formatData</code>.  Version 1 adds
 224:    *         the <code>defaultCenturyStart</code>.  This implementation
 225:    *         always writes out version 1 data.
 226:    */
 227:   private int serialVersionOnStream = 1; // 0 indicates JDK1.1.3 or earlier
 228: 
 229:   /**
 230:    * For compatability.
 231:    */
 232:   private static final long serialVersionUID = 4774881970558875024L;
 233: 
 234:   // This string is specified in the root of the CLDR.  We set it here
 235:   // rather than doing a DateFormatSymbols(Locale.US).getLocalPatternChars()
 236:   // since someone could theoretically change those values (though unlikely).
 237:   private static final String standardChars = "GyMdkHmsSEDFwWahKzYeugAZ";
 238: 
 239:   /**
 240:    * Reads the serialized version of this object.
 241:    * If the serialized data is only version 0,
 242:    * then the date for the start of the century
 243:    * for interpreting two digit years is computed.
 244:    * The pattern is parsed and compiled following the process
 245:    * of reading in the serialized data.
 246:    *
 247:    * @param stream the object stream to read the data from.
 248:    * @throws IOException if an I/O error occurs.
 249:    * @throws ClassNotFoundException if the class of the serialized data
 250:    *         could not be found.
 251:    * @throws InvalidObjectException if the pattern is invalid.
 252:    */ 
 253:   private void readObject(ObjectInputStream stream)
 254:     throws IOException, ClassNotFoundException
 255:   {
 256:     stream.defaultReadObject();
 257:     if (serialVersionOnStream < 1)
 258:       {
 259:         computeCenturyStart ();
 260:     serialVersionOnStream = 1;
 261:       }
 262:     else
 263:       // Ensure that defaultCentury gets set.
 264:       set2DigitYearStart(defaultCenturyStart);
 265: 
 266:     // Set up items normally taken care of by the constructor.
 267:     tokens = new ArrayList();
 268:     try
 269:       {
 270:     compileFormat(pattern);
 271:       }
 272:     catch (IllegalArgumentException e)
 273:       {
 274:     throw new InvalidObjectException("The stream pattern was invalid.");
 275:       }
 276:   }
 277: 
 278:   /**
 279:    * Compiles the supplied non-localized pattern into a form
 280:    * from which formatting and parsing can be performed.
 281:    * This also detects errors in the pattern, which will
 282:    * be raised on later use of the compiled data.
 283:    *
 284:    * @param pattern the non-localized pattern to compile.
 285:    * @throws IllegalArgumentException if the pattern is invalid.
 286:    */
 287:   private void compileFormat(String pattern) 
 288:   {
 289:     // Any alphabetical characters are treated as pattern characters
 290:     // unless enclosed in single quotes.
 291: 
 292:     char thisChar;
 293:     int pos;
 294:     int field;
 295:     CompiledField current = null;
 296: 
 297:     for (int i = 0; i < pattern.length(); i++)
 298:       {
 299:     thisChar = pattern.charAt(i);
 300:     field = standardChars.indexOf(thisChar);
 301:     if (field == -1)
 302:       {
 303:         current = null;
 304:         if ((thisChar >= 'A' && thisChar <= 'Z')
 305:         || (thisChar >= 'a' && thisChar <= 'z'))
 306:           {
 307:         // Not a valid letter
 308:         throw new IllegalArgumentException("Invalid letter "
 309:                            + thisChar +
 310:                            "encountered at character "
 311:                            + i + ".");
 312:           }
 313:         else if (thisChar == '\'')
 314:           {
 315:         // Quoted text section; skip to next single quote
 316:         pos = pattern.indexOf('\'', i + 1);
 317:         // First look for '' -- meaning a single quote.
 318:         if (pos == i + 1)
 319:           tokens.add("'");
 320:         else
 321:           {
 322:             // Look for the terminating quote.  However, if we
 323:             // see a '', that represents a literal quote and
 324:             // we must iterate.
 325:             StringBuffer buf = new StringBuffer();
 326:             int oldPos = i + 1;
 327:             do
 328:               {
 329:             if (pos == -1)
 330:               throw new IllegalArgumentException("Quotes starting at character "
 331:                                  + i +
 332:                                  " not closed.");
 333:             buf.append(pattern.substring(oldPos, pos));
 334:             if (pos + 1 >= pattern.length()
 335:                 || pattern.charAt(pos + 1) != '\'')
 336:               break;
 337:             buf.append('\'');
 338:             oldPos = pos + 2;
 339:             pos = pattern.indexOf('\'', pos + 2);
 340:               }
 341:             while (true);
 342:             tokens.add(buf.toString());
 343:           }
 344:         i = pos;
 345:           }
 346:         else
 347:           {
 348:         // A special character
 349:         tokens.add(new Character(thisChar));
 350:           }
 351:       }
 352:     else
 353:       {
 354:         // A valid field
 355:         if ((current != null) && (field == current.field))
 356:           current.size++;
 357:         else
 358:           {
 359:         current = new CompiledField(field, 1, thisChar);
 360:         tokens.add(current);
 361:           }
 362:       }
 363:       }
 364:   }
 365: 
 366:   /**
 367:    * Returns a string representation of this
 368:    * class.
 369:    *
 370:    * @return a string representation of the <code>SimpleDateFormat</code>
 371:    *         instance.
 372:    */
 373:   public String toString() 
 374:   {
 375:     StringBuffer output = new StringBuffer(getClass().getName());
 376:     output.append("[tokens=");
 377:     output.append(tokens);
 378:     output.append(", formatData=");
 379:     output.append(formatData);
 380:     output.append(", defaultCenturyStart=");
 381:     output.append(defaultCenturyStart);
 382:     output.append(", defaultCentury=");
 383:     output.append(defaultCentury);
 384:     output.append(", pattern=");
 385:     output.append(pattern);
 386:     output.append(", serialVersionOnStream=");
 387:     output.append(serialVersionOnStream);
 388:     output.append(", standardChars=");
 389:     output.append(standardChars);
 390:     output.append("]");
 391:     return output.toString();
 392:   }
 393: 
 394:   /**
 395:    * Constructs a SimpleDateFormat using the default pattern for
 396:    * the default locale.
 397:    */
 398:   public SimpleDateFormat() 
 399:   {
 400:     /*
 401:      * There does not appear to be a standard API for determining 
 402:      * what the default pattern for a locale is, so use package-scope
 403:      * variables in DateFormatSymbols to encapsulate this.
 404:      */
 405:     super();
 406:     Locale locale = Locale.getDefault();
 407:     calendar = new GregorianCalendar(locale);
 408:     computeCenturyStart();
 409:     tokens = new ArrayList();
 410:     formatData = new DateFormatSymbols(locale);
 411:     pattern = (formatData.dateFormats[DEFAULT] + ' '
 412:            + formatData.timeFormats[DEFAULT]);
 413:     compileFormat(pattern);
 414:     numberFormat = NumberFormat.getInstance(locale);
 415:     numberFormat.setGroupingUsed (false);
 416:     numberFormat.setParseIntegerOnly (true);
 417:     numberFormat.setMaximumFractionDigits (0);
 418:   }
 419:   
 420:   /**
 421:    * Creates a date formatter using the specified non-localized pattern,
 422:    * with the default DateFormatSymbols for the default locale.
 423:    *
 424:    * @param pattern the pattern to use.
 425:    * @throws NullPointerException if the pattern is null.
 426:    * @throws IllegalArgumentException if the pattern is invalid.
 427:    */
 428:   public SimpleDateFormat(String pattern) 
 429:   {
 430:     this(pattern, Locale.getDefault());
 431:   }
 432: 
 433:   /**
 434:    * Creates a date formatter using the specified non-localized pattern,
 435:    * with the default DateFormatSymbols for the given locale.
 436:    *
 437:    * @param pattern the non-localized pattern to use.
 438:    * @param locale the locale to use for the formatting symbols.
 439:    * @throws NullPointerException if the pattern is null.
 440:    * @throws IllegalArgumentException if the pattern is invalid.
 441:    */
 442:   public SimpleDateFormat(String pattern, Locale locale) 
 443:   {
 444:     super();
 445:     calendar = new GregorianCalendar(locale);
 446:     computeCenturyStart();
 447:     tokens = new ArrayList();
 448:     formatData = new DateFormatSymbols(locale);
 449:     compileFormat(pattern);
 450:     this.pattern = pattern;
 451:     numberFormat = NumberFormat.getInstance(locale);
 452:     numberFormat.setGroupingUsed (false);
 453:     numberFormat.setParseIntegerOnly (true);
 454:     numberFormat.setMaximumFractionDigits (0);
 455:   }
 456: 
 457:   /**
 458:    * Creates a date formatter using the specified non-localized
 459:    * pattern. The specified DateFormatSymbols will be used when
 460:    * formatting.
 461:    *
 462:    * @param pattern the non-localized pattern to use.
 463:    * @param formatData the formatting symbols to use.
 464:    * @throws NullPointerException if the pattern or formatData is null.
 465:    * @throws IllegalArgumentException if the pattern is invalid.
 466:    */
 467:   public SimpleDateFormat(String pattern, DateFormatSymbols formatData)
 468:   {
 469:     super();
 470:     calendar = new GregorianCalendar();
 471:     computeCenturyStart ();
 472:     tokens = new ArrayList();
 473:     if (formatData == null)
 474:       throw new NullPointerException("formatData");
 475:     this.formatData = formatData;
 476:     compileFormat(pattern);
 477:     this.pattern = pattern;
 478:     numberFormat = NumberFormat.getInstance();
 479:     numberFormat.setGroupingUsed (false);
 480:     numberFormat.setParseIntegerOnly (true);
 481:     numberFormat.setMaximumFractionDigits (0);
 482:   }
 483: 
 484:   /**
 485:    * This method returns a string with the formatting pattern being used
 486:    * by this object.  This string is unlocalized.
 487:    *
 488:    * @return The format string.
 489:    */
 490:   public String toPattern()
 491:   {
 492:     return pattern;
 493:   }
 494: 
 495:   /**
 496:    * This method returns a string with the formatting pattern being used
 497:    * by this object.  This string is localized.
 498:    *
 499:    * @return The format string.
 500:    */
 501:   public String toLocalizedPattern()
 502:   {
 503:     String localChars = formatData.getLocalPatternChars();
 504:     return translateLocalizedPattern(pattern, standardChars, localChars);
 505:   }
 506: 
 507:   /**
 508:    * This method sets the formatting pattern that should be used by this
 509:    * object.  This string is not localized.
 510:    *
 511:    * @param pattern The new format pattern.
 512:    * @throws NullPointerException if the pattern is null.
 513:    * @throws IllegalArgumentException if the pattern is invalid.
 514:    */
 515:   public void applyPattern(String pattern)
 516:   {
 517:     tokens = new ArrayList();
 518:     compileFormat(pattern);
 519:     this.pattern = pattern;
 520:   }
 521: 
 522:   /**
 523:    * This method sets the formatting pattern that should be used by this
 524:    * object.  This string is localized.
 525:    *
 526:    * @param pattern The new format pattern.
 527:    * @throws NullPointerException if the pattern is null.
 528:    * @throws IllegalArgumentException if the pattern is invalid.
 529:    */
 530:   public void applyLocalizedPattern(String pattern)
 531:   {
 532:     String localChars = formatData.getLocalPatternChars();
 533:     pattern = translateLocalizedPattern(pattern, localChars, standardChars);
 534:     applyPattern(pattern);
 535:   }
 536: 
 537:   /**
 538:    * Translates either from or to a localized variant of the pattern
 539:    * string.  For example, in the German locale, 't' (for 'tag') is
 540:    * used instead of 'd' (for 'date').  This method translates
 541:    * a localized pattern (such as 'ttt') to a non-localized pattern
 542:    * (such as 'ddd'), or vice versa.  Non-localized patterns use
 543:    * a standard set of characters, which match those of the U.S. English
 544:    * locale.
 545:    *
 546:    * @param pattern the pattern to translate.
 547:    * @param oldChars the old set of characters (used in the pattern).
 548:    * @param newChars the new set of characters (which will be used in the
 549:    *                 pattern).
 550:    * @return a version of the pattern using the characters in
 551:    *         <code>newChars</code>.
 552:    */
 553:   private String translateLocalizedPattern(String pattern,
 554:                        String oldChars, String newChars)
 555:   {
 556:     int len = pattern.length();
 557:     StringBuffer buf = new StringBuffer(len);
 558:     boolean quoted = false;
 559:     for (int i = 0;  i < len;  i++)
 560:       {
 561:     char ch = pattern.charAt(i);
 562:     if (ch == '\'')
 563:       quoted = ! quoted;
 564:     if (! quoted)
 565:       {
 566:         int j = oldChars.indexOf(ch);
 567:         if (j >= 0)
 568:           ch = newChars.charAt(j);
 569:       }
 570:     buf.append(ch);
 571:       }
 572:     return buf.toString();
 573:   }
 574: 
 575:   /** 
 576:    * Returns the start of the century used for two digit years.
 577:    *
 578:    * @return A <code>Date</code> representing the start of the century
 579:    * for two digit years.
 580:    */
 581:   public Date get2DigitYearStart()
 582:   {
 583:     return defaultCenturyStart;
 584:   }
 585: 
 586:   /**
 587:    * Sets the start of the century used for two digit years.
 588:    *
 589:    * @param date A <code>Date</code> representing the start of the century for
 590:    * two digit years.
 591:    */
 592:   public void set2DigitYearStart(Date date)
 593:   {
 594:     defaultCenturyStart = date;
 595:     calendar.clear();
 596:     calendar.setTime(date);
 597:     int year = calendar.get(Calendar.YEAR);
 598:     defaultCentury = year - (year % 100);
 599:   }
 600: 
 601:   /**
 602:    * This method returns a copy of the format symbol information used
 603:    * for parsing and formatting dates.
 604:    *
 605:    * @return a copy of the date format symbols.
 606:    */
 607:   public DateFormatSymbols getDateFormatSymbols()
 608:   {
 609:     return (DateFormatSymbols) formatData.clone();
 610:   }
 611: 
 612:   /**
 613:    * This method sets the format symbols information used for parsing
 614:    * and formatting dates.
 615:    *
 616:    * @param formatData The date format symbols.
 617:    * @throws NullPointerException if <code>formatData</code> is null.
 618:    */
 619:    public void setDateFormatSymbols(DateFormatSymbols formatData)
 620:    {
 621:      if (formatData == null)
 622:        {
 623:      throw new
 624:        NullPointerException("The supplied format data was null.");
 625:        }
 626:      this.formatData = formatData;
 627:    }
 628: 
 629:   /**
 630:    * This methods tests whether the specified object is equal to this
 631:    * object.  This will be true if and only if the specified object:
 632:    * <p>
 633:    * <ul>
 634:    * <li>Is not <code>null</code>.</li>
 635:    * <li>Is an instance of <code>SimpleDateFormat</code>.</li>
 636:    * <li>Is equal to this object at the superclass (i.e., <code>DateFormat</code>)
 637:    *     level.</li>
 638:    * <li>Has the same formatting pattern.</li>
 639:    * <li>Is using the same formatting symbols.</li>
 640:    * <li>Is using the same century for two digit years.</li>
 641:    * </ul>
 642:    *
 643:    * @param o The object to compare for equality against.
 644:    *
 645:    * @return <code>true</code> if the specified object is equal to this object,
 646:    * <code>false</code> otherwise.
 647:    */
 648:   public boolean equals(Object o)
 649:   {
 650:     if (!super.equals(o))
 651:       return false;
 652: 
 653:     if (!(o instanceof SimpleDateFormat))
 654:       return false;
 655: 
 656:     SimpleDateFormat sdf = (SimpleDateFormat)o;
 657: 
 658:     if (defaultCentury != sdf.defaultCentury)
 659:       return false;
 660: 
 661:     if (!toPattern().equals(sdf.toPattern()))
 662:       return false;
 663: 
 664:     if (!getDateFormatSymbols().equals(sdf.getDateFormatSymbols()))
 665:       return false;
 666: 
 667:     return true;
 668:   }
 669: 
 670:   /**
 671:    * This method returns a hash value for this object.
 672:    *
 673:    * @return A hash value for this object.
 674:    */
 675:   public int hashCode()
 676:   {
 677:     return super.hashCode() ^ toPattern().hashCode() ^ defaultCentury ^
 678:       getDateFormatSymbols().hashCode();
 679:   }
 680: 
 681: 
 682:   /**
 683:    * Formats the date input according to the format string in use,
 684:    * appending to the specified StringBuffer.  The input StringBuffer
 685:    * is returned as output for convenience.
 686:    */
 687:   private void formatWithAttribute(Date date, FormatBuffer buffer, FieldPosition pos)
 688:   {
 689:     String temp;
 690:     AttributedCharacterIterator.Attribute attribute;
 691:     calendar.setTime(date);
 692: 
 693:     // go through vector, filling in fields where applicable, else toString
 694:     Iterator iter = tokens.iterator();
 695:     while (iter.hasNext())
 696:       {
 697:     Object o = iter.next();
 698:     if (o instanceof CompiledField)
 699:       {
 700:         CompiledField cf = (CompiledField) o;
 701:         int beginIndex = buffer.length();
 702:         
 703:         switch (cf.getField())
 704:           {
 705:           case ERA_FIELD:
 706:         buffer.append (formatData.eras[calendar.get (Calendar.ERA)], DateFormat.Field.ERA);
 707:         break;
 708:           case YEAR_FIELD:
 709:         // If we have two digits, then we truncate.  Otherwise, we
 710:         // use the size of the pattern, and zero pad.
 711:         buffer.setDefaultAttribute (DateFormat.Field.YEAR);
 712:         if (cf.getSize() == 2)
 713:           {
 714:             temp = "00"+String.valueOf (calendar.get (Calendar.YEAR));
 715:             buffer.append (temp.substring (temp.length() - 2));
 716:           }
 717:         else
 718:           withLeadingZeros (calendar.get (Calendar.YEAR), cf.getSize(), buffer);
 719:         break;
 720:           case MONTH_FIELD:
 721:         buffer.setDefaultAttribute (DateFormat.Field.MONTH);
 722:         if (cf.getSize() < 3)
 723:           withLeadingZeros (calendar.get (Calendar.MONTH) + 1, cf.getSize(), buffer);
 724:         else if (cf.getSize() < 4)
 725:           buffer.append (formatData.shortMonths[calendar.get (Calendar.MONTH)]);
 726:         else
 727:           buffer.append (formatData.months[calendar.get (Calendar.MONTH)]);
 728:         break;
 729:           case DATE_FIELD:
 730:         buffer.setDefaultAttribute (DateFormat.Field.DAY_OF_MONTH);
 731:         withLeadingZeros (calendar.get (Calendar.DATE), cf.getSize(), buffer);
 732:         break;
 733:           case HOUR_OF_DAY1_FIELD: // 1-24
 734:         buffer.setDefaultAttribute(DateFormat.Field.HOUR_OF_DAY1);
 735:         withLeadingZeros ( ((calendar.get (Calendar.HOUR_OF_DAY) + 23) % 24) + 1, 
 736:                    cf.getSize(), buffer);
 737:         break;
 738:           case HOUR_OF_DAY0_FIELD: // 0-23
 739:         buffer.setDefaultAttribute (DateFormat.Field.HOUR_OF_DAY0);
 740:         withLeadingZeros (calendar.get (Calendar.HOUR_OF_DAY), cf.getSize(), buffer);
 741:         break;
 742:           case MINUTE_FIELD:
 743:         buffer.setDefaultAttribute (DateFormat.Field.MINUTE);
 744:         withLeadingZeros (calendar.get (Calendar.MINUTE),
 745:                   cf.getSize(), buffer);
 746:         break;
 747:           case SECOND_FIELD:
 748:         buffer.setDefaultAttribute (DateFormat.Field.SECOND);
 749:         withLeadingZeros(calendar.get (Calendar.SECOND), 
 750:                  cf.getSize(), buffer);
 751:         break;
 752:           case MILLISECOND_FIELD:
 753:         buffer.setDefaultAttribute (DateFormat.Field.MILLISECOND);
 754:         withLeadingZeros (calendar.get (Calendar.MILLISECOND), cf.getSize(), buffer);
 755:         break;
 756:           case DAY_OF_WEEK_FIELD:
 757:         buffer.setDefaultAttribute (DateFormat.Field.DAY_OF_WEEK);
 758:         if (cf.getSize() < 4)
 759:           buffer.append (formatData.shortWeekdays[calendar.get (Calendar.DAY_OF_WEEK)]);
 760:         else
 761:           buffer.append (formatData.weekdays[calendar.get (Calendar.DAY_OF_WEEK)]);
 762:         break;
 763:           case DAY_OF_YEAR_FIELD:
 764:         buffer.setDefaultAttribute (DateFormat.Field.DAY_OF_YEAR);
 765:         withLeadingZeros (calendar.get (Calendar.DAY_OF_YEAR), cf.getSize(), buffer);
 766:         break;
 767:           case DAY_OF_WEEK_IN_MONTH_FIELD:
 768:         buffer.setDefaultAttribute (DateFormat.Field.DAY_OF_WEEK_IN_MONTH);
 769:         withLeadingZeros (calendar.get (Calendar.DAY_OF_WEEK_IN_MONTH), 
 770:                  cf.getSize(), buffer);
 771:         break;
 772:           case WEEK_OF_YEAR_FIELD:
 773:         buffer.setDefaultAttribute (DateFormat.Field.WEEK_OF_YEAR);
 774:         withLeadingZeros (calendar.get (Calendar.WEEK_OF_YEAR),
 775:                   cf.getSize(), buffer);
 776:         break;
 777:           case WEEK_OF_MONTH_FIELD:
 778:         buffer.setDefaultAttribute (DateFormat.Field.WEEK_OF_MONTH);
 779:         withLeadingZeros (calendar.get (Calendar.WEEK_OF_MONTH),
 780:                   cf.getSize(), buffer);
 781:         break;
 782:           case AM_PM_FIELD:
 783:         buffer.setDefaultAttribute (DateFormat.Field.AM_PM);
 784:         buffer.append (formatData.ampms[calendar.get (Calendar.AM_PM)]);
 785:         break;
 786:           case HOUR1_FIELD: // 1-12
 787:         buffer.setDefaultAttribute (DateFormat.Field.HOUR1);
 788:         withLeadingZeros (((calendar.get (Calendar.HOUR) + 11) % 12) + 1,
 789:                   cf.getSize(), buffer);
 790:         break;
 791:           case HOUR0_FIELD: // 0-11
 792:         buffer.setDefaultAttribute (DateFormat.Field.HOUR0);
 793:         withLeadingZeros (calendar.get (Calendar.HOUR), cf.getSize(), buffer);
 794:         break;
 795:           case TIMEZONE_FIELD:
 796:         buffer.setDefaultAttribute (DateFormat.Field.TIME_ZONE);
 797:         TimeZone zone = calendar.getTimeZone();
 798:         boolean isDST = calendar.get (Calendar.DST_OFFSET) != 0;
 799:         // FIXME: XXX: This should be a localized time zone.
 800:         String zoneID = zone.getDisplayName
 801:           (isDST, cf.getSize() > 3 ? TimeZone.LONG : TimeZone.SHORT);
 802:         buffer.append (zoneID);
 803:         break;
 804:           case RFC822_TIMEZONE_FIELD:
 805:         buffer.setDefaultAttribute(DateFormat.Field.RFC822_TIME_ZONE);
 806:         int pureMinutes = (calendar.get(Calendar.ZONE_OFFSET) +
 807:                    calendar.get(Calendar.DST_OFFSET)) / (1000 * 60);
 808:         String sign = (pureMinutes < 0) ? "-" : "+";      
 809:         int hours = pureMinutes / 60;
 810:         int minutes = pureMinutes % 60;
 811:         buffer.append(sign);
 812:         withLeadingZeros(hours, 2, buffer);
 813:         withLeadingZeros(minutes, 2, buffer);
 814:         break;
 815:           default:
 816:         throw new IllegalArgumentException ("Illegal pattern character " +
 817:                             cf.getCharacter());
 818:           }
 819:         if (pos != null && (buffer.getDefaultAttribute() == pos.getFieldAttribute()
 820:                 || cf.getField() == pos.getField()))
 821:           {
 822:         pos.setBeginIndex(beginIndex);
 823:         pos.setEndIndex(buffer.length());
 824:           }
 825:       } 
 826:       else
 827:     {  
 828:       buffer.append(o.toString(), null);
 829:     }
 830:       }
 831:   }
 832:   
 833:   public StringBuffer format(Date date, StringBuffer buffer, FieldPosition pos)
 834:   {
 835:     formatWithAttribute(date, new StringFormatBuffer (buffer), pos);
 836: 
 837:     return buffer;
 838:   }
 839: 
 840:   public AttributedCharacterIterator formatToCharacterIterator(Object date)
 841:     throws IllegalArgumentException
 842:   {
 843:     if (date == null)
 844:       throw new NullPointerException("null argument");
 845:     if (!(date instanceof Date))
 846:       throw new IllegalArgumentException("argument should be an instance of java.util.Date");
 847: 
 848:     AttributedFormatBuffer buf = new AttributedFormatBuffer();
 849:     formatWithAttribute((Date)date, buf,
 850:             null);
 851:     buf.sync();
 852:         
 853:     return new FormatCharacterIterator(buf.getBuffer().toString(),
 854:                        buf.getRanges(),
 855:                        buf.getAttributes());
 856:   }
 857: 
 858:   private void withLeadingZeros(int value, int length, FormatBuffer buffer) 
 859:   {
 860:     String valStr = String.valueOf(value);
 861:     for (length -= valStr.length(); length > 0; length--)
 862:       buffer.append('0');
 863:     buffer.append(valStr);
 864:   }
 865: 
 866:   private boolean expect(String source, ParsePosition pos, char ch)
 867:   {
 868:     int x = pos.getIndex();
 869:     boolean r = x < source.length() && source.charAt(x) == ch;
 870:     if (r)
 871:       pos.setIndex(x + 1);
 872:     else
 873:       pos.setErrorIndex(x);
 874:     return r;
 875:   }
 876: 
 877:   /**
 878:    * This method parses the specified string into a date.
 879:    * 
 880:    * @param dateStr The date string to parse.
 881:    * @param pos The input and output parse position
 882:    *
 883:    * @return The parsed date, or <code>null</code> if the string cannot be
 884:    * parsed.
 885:    */
 886:   public Date parse (String dateStr, ParsePosition pos)
 887:   {
 888:     int fmt_index = 0;
 889:     int fmt_max = pattern.length();
 890: 
 891:     calendar.clear();
 892:     boolean saw_timezone = false;
 893:     int quote_start = -1;
 894:     boolean is2DigitYear = false;
 895:     try
 896:       {
 897:     for (; fmt_index < fmt_max; ++fmt_index)
 898:       {
 899:         char ch = pattern.charAt(fmt_index);
 900:         if (ch == '\'')
 901:           {
 902:         int index = pos.getIndex();
 903:         if (fmt_index < fmt_max - 1
 904:             && pattern.charAt(fmt_index + 1) == '\'')
 905:           {
 906:             if (! expect (dateStr, pos, ch))
 907:               return null;
 908:             ++fmt_index;
 909:           }
 910:         else
 911:           quote_start = quote_start < 0 ? fmt_index : -1;
 912:         continue;
 913:           }
 914:         
 915:         if (quote_start != -1
 916:         || ((ch < 'a' || ch > 'z')
 917:             && (ch < 'A' || ch > 'Z')))
 918:           {
 919:         if (! expect (dateStr, pos, ch))
 920:           return null;
 921:         continue;
 922:           }
 923:         
 924:         // We've arrived at a potential pattern character in the
 925:         // pattern.
 926:         int fmt_count = 1;
 927:         while (++fmt_index < fmt_max && pattern.charAt(fmt_index) == ch)
 928:           {
 929:         ++fmt_count;
 930:           }
 931:         
 932:         // We might need to limit the number of digits to parse in
 933:         // some cases.  We look to the next pattern character to
 934:         // decide.
 935:         boolean limit_digits = false;
 936:         if (fmt_index < fmt_max
 937:         && standardChars.indexOf(pattern.charAt(fmt_index)) >= 0)
 938:           limit_digits = true;
 939:         --fmt_index;
 940:         
 941:         // We can handle most fields automatically: most either are
 942:         // numeric or are looked up in a string vector.  In some cases
 943:         // we need an offset.  When numeric, `offset' is added to the
 944:         // resulting value.  When doing a string lookup, offset is the
 945:         // initial index into the string array.
 946:         int calendar_field;
 947:         boolean is_numeric = true;
 948:         int offset = 0;
 949:         boolean maybe2DigitYear = false;
 950:         boolean oneBasedHour = false;
 951:         boolean oneBasedHourOfDay = false;
 952:         Integer simpleOffset;
 953:         String[] set1 = null;
 954:         String[] set2 = null;
 955:         switch (ch)
 956:           {
 957:           case 'd':
 958:         calendar_field = Calendar.DATE;
 959:         break;
 960:           case 'D':
 961:         calendar_field = Calendar.DAY_OF_YEAR;
 962:         break;
 963:           case 'F':
 964:         calendar_field = Calendar.DAY_OF_WEEK_IN_MONTH;
 965:         break;
 966:           case 'E':
 967:         is_numeric = false;
 968:         offset = 1;
 969:         calendar_field = Calendar.DAY_OF_WEEK;
 970:         set1 = formatData.getWeekdays();
 971:         set2 = formatData.getShortWeekdays();
 972:         break;
 973:           case 'w':
 974:         calendar_field = Calendar.WEEK_OF_YEAR;
 975:         break;
 976:           case 'W':
 977:         calendar_field = Calendar.WEEK_OF_MONTH;
 978:         break;
 979:           case 'M':
 980:         calendar_field = Calendar.MONTH;
 981:         if (fmt_count <= 2)
 982:           offset = -1;
 983:         else
 984:           {
 985:             is_numeric = false;
 986:             set1 = formatData.getMonths();
 987:             set2 = formatData.getShortMonths();
 988:           }
 989:         break;
 990:           case 'y':
 991:         calendar_field = Calendar.YEAR;
 992:         if (fmt_count <= 2)
 993:           maybe2DigitYear = true;
 994:         break;
 995:           case 'K':
 996:         calendar_field = Calendar.HOUR;
 997:         break;
 998:           case 'h':
 999:         calendar_field = Calendar.HOUR;
1000:         oneBasedHour = true;
1001:         break;
1002:           case 'H':
1003:         calendar_field = Calendar.HOUR_OF_DAY;
1004:         break;
1005:           case 'k':
1006:         calendar_field = Calendar.HOUR_OF_DAY;
1007:         oneBasedHourOfDay = true;
1008:         break;
1009:           case 'm':
1010:         calendar_field = Calendar.MINUTE;
1011:         break;
1012:           case 's':
1013:         calendar_field = Calendar.SECOND;
1014:         break;
1015:           case 'S':
1016:         calendar_field = Calendar.MILLISECOND;
1017:         break;
1018:           case 'a':
1019:         is_numeric = false;
1020:         calendar_field = Calendar.AM_PM;
1021:         set1 = formatData.getAmPmStrings();
1022:         break;
1023:           case 'z':
1024:           case 'Z':
1025:         // We need a special case for the timezone, because it
1026:         // uses a different data structure than the other cases.
1027:         is_numeric = false;
1028:         calendar_field = Calendar.ZONE_OFFSET;
1029:         String[][] zoneStrings = formatData.getZoneStrings();
1030:         int zoneCount = zoneStrings.length;
1031:         int index = pos.getIndex();
1032:         boolean found_zone = false;
1033:         simpleOffset = computeOffset(dateStr.substring(index), pos);
1034:         if (simpleOffset != null)
1035:           {
1036:             found_zone = true;
1037:             saw_timezone = true;
1038:             calendar.set(Calendar.DST_OFFSET, 0);
1039:             offset = simpleOffset.intValue();
1040:           }
1041:         else
1042:           {
1043:             for (int j = 0;  j < zoneCount;  j++)
1044:               {
1045:             String[] strings = zoneStrings[j];
1046:             int k;
1047:             for (k = 0; k < strings.length; ++k)
1048:               {
1049:                 if (dateStr.startsWith(strings[k], index))
1050:                   break;
1051:               }
1052:             if (k != strings.length)
1053:               {
1054:                 found_zone = true;
1055:                 saw_timezone = true;
1056:                 TimeZone tz = TimeZone.getTimeZone (strings[0]);
1057:                 // Check if it's a DST zone or ordinary 
1058:                 if(k == 3 || k == 4)
1059:                   calendar.set (Calendar.DST_OFFSET, tz.getDSTSavings());
1060:                 else
1061:                   calendar.set (Calendar.DST_OFFSET, 0);
1062:                             offset = tz.getRawOffset ();
1063:                 pos.setIndex(index + strings[k].length());
1064:                 break;
1065:               }
1066:               }
1067:           }
1068:         if (! found_zone)
1069:           {
1070:             pos.setErrorIndex(pos.getIndex());
1071:             return null;
1072:           }
1073:         break;
1074:           default:
1075:         pos.setErrorIndex(pos.getIndex());
1076:         return null;
1077:           }
1078:       
1079:         // Compute the value we should assign to the field.
1080:         int value;
1081:         int index = -1;
1082:         if (is_numeric)
1083:           {
1084:         numberFormat.setMinimumIntegerDigits(fmt_count);
1085:         if (limit_digits)
1086:           numberFormat.setMaximumIntegerDigits(fmt_count);
1087:         if (maybe2DigitYear)
1088:           index = pos.getIndex();
1089:         Number n = numberFormat.parse(dateStr, pos);
1090:         if (pos == null || ! (n instanceof Long))
1091:           return null;
1092:         value = n.intValue() + offset;
1093:           }
1094:         else if (set1 != null)
1095:           {
1096:         index = pos.getIndex();
1097:         int i;
1098:         boolean found = false;
1099:         for (i = offset; i < set1.length; ++i)
1100:           {
1101:             if (set1[i] != null)
1102:               if (dateStr.toUpperCase().startsWith(set1[i].toUpperCase(),
1103:                                index))
1104:             {
1105:               found = true;
1106:               pos.setIndex(index + set1[i].length());
1107:               break;
1108:             }
1109:           }
1110:         if (!found && set2 != null)
1111:           {
1112:             for (i = offset; i < set2.length; ++i)
1113:               {
1114:             if (set2[i] != null)
1115:               if (dateStr.toUpperCase().startsWith(set2[i].toUpperCase(),
1116:                                    index))
1117:                 {
1118:                   found = true;
1119:                   pos.setIndex(index + set2[i].length());
1120:                   break;
1121:                 }
1122:               }
1123:           }
1124:         if (!found)
1125:           {
1126:             pos.setErrorIndex(index);
1127:             return null;
1128:           }
1129:         value = i;
1130:           }
1131:         else
1132:           value = offset;
1133:       
1134:         if (maybe2DigitYear)
1135:           {
1136:         // Parse into default century if the numeric year string has 
1137:         // exactly 2 digits.
1138:         int digit_count = pos.getIndex() - index;
1139:         if (digit_count == 2)
1140:           {
1141:             is2DigitYear = true;
1142:             value += defaultCentury;
1143:           }
1144:           }
1145:         
1146:         // Calendar uses 0-based hours. 
1147:         // I.e. 00:00 AM is midnight, not 12 AM or 24:00
1148:         if (oneBasedHour && value == 12)
1149:           value = 0;
1150: 
1151:         if (oneBasedHourOfDay && value == 24)
1152:           value = 0;
1153:         
1154:         // Assign the value and move on.
1155:         calendar.set(calendar_field, value);
1156:       }
1157:     
1158:     if (is2DigitYear)
1159:       {
1160:         // Apply the 80-20 heuristic to dermine the full year based on 
1161:         // defaultCenturyStart. 
1162:         int year = calendar.get(Calendar.YEAR);
1163:         if (calendar.getTime().compareTo(defaultCenturyStart) < 0)
1164:           calendar.set(Calendar.YEAR, year + 100);      
1165:       }
1166:     if (! saw_timezone)
1167:       {
1168:         // Use the real rules to determine whether or not this
1169:         // particular time is in daylight savings.
1170:         calendar.clear (Calendar.DST_OFFSET);
1171:         calendar.clear (Calendar.ZONE_OFFSET);
1172:       }
1173:         return calendar.getTime();
1174:       }
1175:     catch (IllegalArgumentException x)
1176:       {
1177:         pos.setErrorIndex(pos.getIndex());
1178:     return null;
1179:       }
1180:       }
1181: 
1182:   /**
1183:    * <p>
1184:    * Computes the time zone offset in milliseconds
1185:    * relative to GMT, based on the supplied
1186:    * <code>String</code> representation.
1187:    * </p>
1188:    * <p>
1189:    * The supplied <code>String</code> must be a three
1190:    * or four digit signed number, with an optional 'GMT'
1191:    * prefix.  The first one or two digits represents the hours,
1192:    * while the last two represent the minutes.  The
1193:    * two sets of digits can optionally be separated by
1194:    * ':'.  The mandatory sign prefix (either '+' or '-')
1195:    * indicates the direction of the offset from GMT.
1196:    * </p>
1197:    * <p>
1198:    * For example, 'GMT+0200' specifies 2 hours after
1199:    * GMT, while '-05:00' specifies 5 hours prior to
1200:    * GMT.  The special case of 'GMT' alone can be used
1201:    * to represent the offset, 0.
1202:    * </p>
1203:    * <p>
1204:    * If the <code>String</code> can not be parsed,
1205:    * the result will be null.  The resulting offset
1206:    * is wrapped in an <code>Integer</code> object, in
1207:    * order to allow such failure to be represented.
1208:    * </p>
1209:    *
1210:    * @param zoneString a string in the form 
1211:    *        (GMT)? sign hours : minutes
1212:    *        where sign = '+' or '-', hours
1213:    *        is a one or two digits representing
1214:    *        a number between 0 and 23, and
1215:    *        minutes is two digits representing
1216:    *        a number between 0 and 59.
1217:    * @return the parsed offset, or null if parsing
1218:    *         failed.
1219:    */
1220:   private Integer computeOffset(String zoneString, ParsePosition pos)
1221:   {
1222:     Pattern pattern = 
1223:       Pattern.compile("(GMT)?([+-])([012])?([0-9]):?([0-9]{2})");
1224:     Matcher matcher = pattern.matcher(zoneString);
1225: 
1226:     // Match from start, but ignore trailing parts
1227:     boolean hasAll = matcher.lookingAt();
1228:     try
1229:       {
1230:     // Do we have at least the sign, hour and minute?
1231:     matcher.group(2);
1232:     matcher.group(4);
1233:     matcher.group(5);
1234:       }
1235:     catch (IllegalStateException ise)
1236:       {
1237:     hasAll = false;
1238:       }
1239:     if (hasAll)
1240:       {
1241:     int sign = matcher.group(2).equals("+") ? 1 : -1;
1242:     int hour = Integer.parseInt(matcher.group(4));
1243:     if (!matcher.group(3).equals(""))
1244:       hour += (Integer.parseInt(matcher.group(3)) * 10);
1245:     int minutes = Integer.parseInt(matcher.group(5));
1246: 
1247:     if (hour > 23)
1248:       return null;
1249:     int offset = sign * ((hour * 60) + minutes) * 60000;
1250: 
1251:     // advance the index
1252:     pos.setIndex(pos.getIndex() + matcher.end());
1253:     return new Integer(offset);
1254:       }
1255:     else if (zoneString.startsWith("GMT"))
1256:       {
1257:     pos.setIndex(pos.getIndex() + 3);
1258:     return new Integer(0);
1259:       }
1260:     return null;
1261:   }
1262: 
1263:   // Compute the start of the current century as defined by
1264:   // get2DigitYearStart.
1265:   private void computeCenturyStart()
1266:   {
1267:     int year = calendar.get(Calendar.YEAR);
1268:     calendar.set(Calendar.YEAR, year - 80);
1269:     set2DigitYearStart(calendar.getTime());
1270:   }
1271: 
1272:   /**
1273:    * Returns a copy of this instance of
1274:    * <code>SimpleDateFormat</code>.  The copy contains
1275:    * clones of the formatting symbols and the 2-digit
1276:    * year century start date.
1277:    */
1278:   public Object clone()
1279:   {
1280:     SimpleDateFormat clone = (SimpleDateFormat) super.clone();
1281:     clone.setDateFormatSymbols((DateFormatSymbols) formatData.clone());
1282:     clone.set2DigitYearStart((Date) defaultCenturyStart.clone());
1283:     return clone;
1284:   }
1285: 
1286: }