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.lang.CPStringBuilder;
  44: 
  45: import gnu.java.text.AttributedFormatBuffer;
  46: import gnu.java.text.FormatBuffer;
  47: import gnu.java.text.FormatCharacterIterator;
  48: import gnu.java.text.StringFormatBuffer;
  49: 
  50: import java.io.IOException;
  51: import java.io.InvalidObjectException;
  52: import java.io.ObjectInputStream;
  53: import java.util.ArrayList;
  54: import java.util.Calendar;
  55: import java.util.Date;
  56: import java.util.GregorianCalendar;
  57: import java.util.Iterator;
  58: import java.util.Locale;
  59: import java.util.TimeZone;
  60: import java.util.regex.Matcher;
  61: import java.util.regex.Pattern;
  62: 
  63: /**
  64:  * SimpleDateFormat provides convenient methods for parsing and formatting
  65:  * dates using Gregorian calendars (see java.util.GregorianCalendar). 
  66:  * This class is not thread-safe; external synchronisation should be applied
  67:  * if an instance is to be accessed from multiple threads.
  68:  */
  69: public class SimpleDateFormat extends DateFormat 
  70: {
  71:   /** 
  72:    * This class is used by <code>SimpleDateFormat</code> as a
  73:    * compiled representation of a format string.  The field
  74:    * ID, size, and character used are stored for each sequence
  75:    * of pattern characters.
  76:    */
  77:   private class CompiledField
  78:   {
  79:     /**
  80:      * The ID of the field within the local pattern characters.
  81:      * Package private for use in out class.
  82:      */
  83:     int field;
  84: 
  85:     /**
  86:      * The size of the character sequence.
  87:      * Package private for use in out class.
  88:      */
  89:     int size;
  90: 
  91:     /**
  92:      * The character used.
  93:      */
  94:     private char character;
  95: 
  96:     /** 
  97:      * Constructs a compiled field using the
  98:      * the given field ID, size and character
  99:      * values.
 100:      *
 101:      * @param f the field ID.
 102:      * @param s the size of the field.
 103:      * @param c the character used.
 104:      */
 105:     public CompiledField(int f, int s, char c)
 106:     {
 107:       field = f;
 108:       size = s;
 109:       character = c;
 110:     }
 111: 
 112:     /**
 113:      * Retrieves the ID of the field relative to
 114:      * the local pattern characters.
 115:      */
 116:     public int getField()
 117:     {
 118:       return field;
 119:     }
 120: 
 121:     /**
 122:      * Retrieves the size of the character sequence.
 123:      */
 124:     public int getSize()
 125:     {
 126:       return size;
 127:     }
 128: 
 129:     /**
 130:      * Retrieves the character used in the sequence.
 131:      */
 132:     public char getCharacter()
 133:     {
 134:       return character;
 135:     }
 136: 
 137:     /**
 138:      * Returns a <code>String</code> representation
 139:      * of the compiled field, primarily for debugging
 140:      * purposes.
 141:      *
 142:      * @return a <code>String</code> representation.
 143:      */
 144:     public String toString()
 145:     {
 146:       CPStringBuilder builder;
 147: 
 148:       builder = new CPStringBuilder(getClass().getName());
 149:       builder.append("[field=");
 150:       builder.append(field);
 151:       builder.append(", size=");
 152:       builder.append(size);
 153:       builder.append(", character=");
 154:       builder.append(character);
 155:       builder.append("]");
 156: 
 157:       return builder.toString();
 158:     }
 159:   }
 160: 
 161:   /**
 162:    * A list of <code>CompiledField</code>s and {@code String}s
 163:    * representing the compiled version of the pattern.
 164:    *
 165:    * @see CompiledField
 166:    * @serial Ignored.
 167:    */
 168:   private transient ArrayList<Object> tokens;
 169: 
 170:   /**
 171:    * The localised data used in formatting,
 172:    * such as the day and month names in the local
 173:    * language, and the localized pattern characters.
 174:    *
 175:    * @see DateFormatSymbols
 176:    * @serial The localisation data.  May not be null.
 177:    */
 178:   private DateFormatSymbols formatData;
 179: 
 180:   /**
 181:    * The date representing the start of the century
 182:    * used for interpreting two digit years.  For
 183:    * example, 24/10/2004 would cause two digit
 184:    * years to be interpreted as representing
 185:    * the years between 2004 and 2104.
 186:    *
 187:    * @see #get2DigitYearStart()
 188:    * @see #set2DigitYearStart(java.util.Date)
 189:    * @see Date
 190:    * @serial The start date of the century for parsing two digit years.
 191:    *         May not be null.
 192:    */
 193:   private Date defaultCenturyStart;
 194: 
 195:   /**
 196:    * The year at which interpretation of two
 197:    * digit years starts.
 198:    *
 199:    * @see #get2DigitYearStart()
 200:    * @see #set2DigitYearStart(java.util.Date)
 201:    * @serial Ignored.
 202:    */
 203:   private transient int defaultCentury;
 204: 
 205:   /**
 206:    * The non-localized pattern string.  This
 207:    * only ever contains the pattern characters
 208:    * stored in standardChars.  Localized patterns
 209:    * are translated to this form.
 210:    *
 211:    * @see #applyPattern(String)
 212:    * @see #applyLocalizedPattern(String)
 213:    * @see #toPattern()
 214:    * @see #toLocalizedPattern()
 215:    * @serial The non-localized pattern string.  May not be null.
 216:    */
 217:   private String pattern;
 218: 
 219:   /**
 220:    * The version of serialized data used by this class.
 221:    * Version 0 only includes the pattern and formatting
 222:    * data.  Version 1 adds the start date for interpreting
 223:    * two digit years.
 224:    *
 225:    * @serial This specifies the version of the data being serialized.
 226:    *         Version 0 (or no version) specifies just <code>pattern</code>
 227:    *         and <code>formatData</code>.  Version 1 adds
 228:    *         the <code>defaultCenturyStart</code>.  This implementation
 229:    *         always writes out version 1 data.
 230:    */
 231:   private int serialVersionOnStream = 1; // 0 indicates JDK1.1.3 or earlier
 232: 
 233:   /**
 234:    * For compatability.
 235:    */
 236:   private static final long serialVersionUID = 4774881970558875024L;
 237: 
 238:   // This string is specified in the root of the CLDR.
 239:   private static final String standardChars = "GyMdkHmsSEDFwWahKzYeugAZvcL";
 240: 
 241:   /**  
 242:    * Represents the position of the RFC822 timezone pattern character
 243:    * in the array of localized pattern characters.  In the
 244:    * U.S. locale, this is 'Z'.  The value is the offset of the current
 245:    * time from GMT e.g. -0500 would be five hours prior to GMT.
 246:    */  
 247:   private static final int RFC822_TIMEZONE_FIELD = 23;
 248: 
 249:   /**
 250:    * Reads the serialized version of this object.
 251:    * If the serialized data is only version 0,
 252:    * then the date for the start of the century
 253:    * for interpreting two digit years is computed.
 254:    * The pattern is parsed and compiled following the process
 255:    * of reading in the serialized data.
 256:    *
 257:    * @param stream the object stream to read the data from.
 258:    * @throws IOException if an I/O error occurs.
 259:    * @throws ClassNotFoundException if the class of the serialized data
 260:    *         could not be found.
 261:    * @throws InvalidObjectException if the pattern is invalid.
 262:    */ 
 263:   private void readObject(ObjectInputStream stream)
 264:     throws IOException, ClassNotFoundException
 265:   {
 266:     stream.defaultReadObject();
 267:     if (serialVersionOnStream < 1)
 268:       {
 269:         computeCenturyStart ();
 270:     serialVersionOnStream = 1;
 271:       }
 272:     else
 273:       // Ensure that defaultCentury gets set.
 274:       set2DigitYearStart(defaultCenturyStart);
 275: 
 276:     // Set up items normally taken care of by the constructor.
 277:     tokens = new ArrayList<Object>();
 278:     try
 279:       {
 280:     compileFormat(pattern);
 281:       }
 282:     catch (IllegalArgumentException e)
 283:       {
 284:     throw new InvalidObjectException("The stream pattern was invalid.");
 285:       }
 286:   }
 287: 
 288:   /**
 289:    * Compiles the supplied non-localized pattern into a form
 290:    * from which formatting and parsing can be performed.
 291:    * This also detects errors in the pattern, which will
 292:    * be raised on later use of the compiled data.
 293:    *
 294:    * @param pattern the non-localized pattern to compile.
 295:    * @throws IllegalArgumentException if the pattern is invalid.
 296:    */
 297:   private void compileFormat(String pattern) 
 298:   {
 299:     // Any alphabetical characters are treated as pattern characters
 300:     // unless enclosed in single quotes.
 301: 
 302:     char thisChar;
 303:     int pos;
 304:     int field;
 305:     CompiledField current = null;
 306: 
 307:     for (int i = 0; i < pattern.length(); i++)
 308:       {
 309:     thisChar = pattern.charAt(i);
 310:     field = standardChars.indexOf(thisChar);
 311:     if (field == -1)
 312:       {
 313:         current = null;
 314:         if ((thisChar >= 'A' && thisChar <= 'Z')
 315:         || (thisChar >= 'a' && thisChar <= 'z'))
 316:           {
 317:         // Not a valid letter
 318:         throw new IllegalArgumentException("Invalid letter "
 319:                            + thisChar +
 320:                            " encountered at character "
 321:                            + i + ".");
 322:           }
 323:         else if (thisChar == '\'')
 324:           {
 325:         // Quoted text section; skip to next single quote
 326:         pos = pattern.indexOf('\'', i + 1);
 327:         // First look for '' -- meaning a single quote.
 328:         if (pos == i + 1)
 329:           tokens.add("'");
 330:         else
 331:           {
 332:             // Look for the terminating quote.  However, if we
 333:             // see a '', that represents a literal quote and
 334:             // we must iterate.
 335:             CPStringBuilder buf = new CPStringBuilder();
 336:             int oldPos = i + 1;
 337:             do
 338:               {
 339:             if (pos == -1)
 340:               throw new IllegalArgumentException("Quotes starting at character "
 341:                                  + i +
 342:                                  " not closed.");
 343:             buf.append(pattern.substring(oldPos, pos));
 344:             if (pos + 1 >= pattern.length()
 345:                 || pattern.charAt(pos + 1) != '\'')
 346:               break;
 347:             buf.append('\'');
 348:             oldPos = pos + 2;
 349:             pos = pattern.indexOf('\'', pos + 2);
 350:               }
 351:             while (true);
 352:             tokens.add(buf.toString());
 353:           }
 354:         i = pos;
 355:           }
 356:         else
 357:           {
 358:         // A special character
 359:         tokens.add(Character.valueOf(thisChar));
 360:           }
 361:       }
 362:     else
 363:       {
 364:         // A valid field
 365:         if ((current != null) && (field == current.field))
 366:           current.size++;
 367:         else
 368:           {
 369:         current = new CompiledField(field, 1, thisChar);
 370:         tokens.add(current);
 371:           }
 372:       }
 373:       }
 374:   }
 375: 
 376:   /**
 377:    * Returns a string representation of this
 378:    * class.
 379:    *
 380:    * @return a string representation of the <code>SimpleDateFormat</code>
 381:    *         instance.
 382:    */
 383:   public String toString() 
 384:   {
 385:     CPStringBuilder output = new CPStringBuilder(getClass().getName());
 386:     output.append("[tokens=");
 387:     output.append(tokens);
 388:     output.append(", formatData=");
 389:     output.append(formatData);
 390:     output.append(", defaultCenturyStart=");
 391:     output.append(defaultCenturyStart);
 392:     output.append(", defaultCentury=");
 393:     output.append(defaultCentury);
 394:     output.append(", pattern=");
 395:     output.append(pattern);
 396:     output.append(", serialVersionOnStream=");
 397:     output.append(serialVersionOnStream);
 398:     output.append(", standardChars=");
 399:     output.append(standardChars);
 400:     output.append("]");
 401:     return output.toString();
 402:   }
 403: 
 404:   /**
 405:    * Constructs a SimpleDateFormat using the default pattern for
 406:    * the default locale.
 407:    */
 408:   public SimpleDateFormat() 
 409:   {
 410:     /*
 411:      * There does not appear to be a standard API for determining 
 412:      * what the default pattern for a locale is, so use package-scope
 413:      * variables in DateFormatSymbols to encapsulate this.
 414:      */
 415:     super();
 416:     Locale locale = Locale.getDefault();
 417:     calendar = new GregorianCalendar(locale);
 418:     computeCenturyStart();
 419:     tokens = new ArrayList<Object>();
 420:     formatData = new DateFormatSymbols(locale);
 421:     pattern = (formatData.dateFormats[DEFAULT] + ' '
 422:            + formatData.timeFormats[DEFAULT]);
 423:     compileFormat(pattern);
 424:     numberFormat = NumberFormat.getInstance(locale);
 425:     numberFormat.setGroupingUsed (false);
 426:     numberFormat.setParseIntegerOnly (true);
 427:     numberFormat.setMaximumFractionDigits (0);
 428:   }
 429:   
 430:   /**
 431:    * Creates a date formatter using the specified non-localized pattern,
 432:    * with the default DateFormatSymbols for the default locale.
 433:    *
 434:    * @param pattern the pattern to use.
 435:    * @throws NullPointerException if the pattern is null.
 436:    * @throws IllegalArgumentException if the pattern is invalid.
 437:    */
 438:   public SimpleDateFormat(String pattern) 
 439:   {
 440:     this(pattern, Locale.getDefault());
 441:   }
 442: 
 443:   /**
 444:    * Creates a date formatter using the specified non-localized pattern,
 445:    * with the default DateFormatSymbols for the given locale.
 446:    *
 447:    * @param pattern the non-localized pattern to use.
 448:    * @param locale the locale to use for the formatting symbols.
 449:    * @throws NullPointerException if the pattern is null.
 450:    * @throws IllegalArgumentException if the pattern is invalid.
 451:    */
 452:   public SimpleDateFormat(String pattern, Locale locale) 
 453:   {
 454:     super();
 455:     calendar = new GregorianCalendar(locale);
 456:     computeCenturyStart();
 457:     tokens = new ArrayList<Object>();
 458:     formatData = new DateFormatSymbols(locale);
 459:     compileFormat(pattern);
 460:     this.pattern = pattern;
 461:     numberFormat = NumberFormat.getInstance(locale);
 462:     numberFormat.setGroupingUsed (false);
 463:     numberFormat.setParseIntegerOnly (true);
 464:     numberFormat.setMaximumFractionDigits (0);
 465:   }
 466: 
 467:   /**
 468:    * Creates a date formatter using the specified non-localized
 469:    * pattern. The specified DateFormatSymbols will be used when
 470:    * formatting.
 471:    *
 472:    * @param pattern the non-localized pattern to use.
 473:    * @param formatData the formatting symbols to use.
 474:    * @throws NullPointerException if the pattern or formatData is null.
 475:    * @throws IllegalArgumentException if the pattern is invalid.
 476:    */
 477:   public SimpleDateFormat(String pattern, DateFormatSymbols formatData)
 478:   {
 479:     super();
 480:     calendar = new GregorianCalendar();
 481:     computeCenturyStart ();
 482:     tokens = new ArrayList<Object>();
 483:     if (formatData == null)
 484:       throw new NullPointerException("formatData");
 485:     this.formatData = formatData;
 486:     compileFormat(pattern);
 487:     this.pattern = pattern;
 488:     numberFormat = NumberFormat.getInstance();
 489:     numberFormat.setGroupingUsed (false);
 490:     numberFormat.setParseIntegerOnly (true);
 491:     numberFormat.setMaximumFractionDigits (0);
 492:   }
 493: 
 494:   /**
 495:    * This method returns a string with the formatting pattern being used
 496:    * by this object.  This string is unlocalized.
 497:    *
 498:    * @return The format string.
 499:    */
 500:   public String toPattern()
 501:   {
 502:     return pattern;
 503:   }
 504: 
 505:   /**
 506:    * This method returns a string with the formatting pattern being used
 507:    * by this object.  This string is localized.
 508:    *
 509:    * @return The format string.
 510:    */
 511:   public String toLocalizedPattern()
 512:   {
 513:     String localChars = formatData.getLocalPatternChars();
 514:     return translateLocalizedPattern(pattern, standardChars, localChars);
 515:   }
 516: 
 517:   /**
 518:    * This method sets the formatting pattern that should be used by this
 519:    * object.  This string is not localized.
 520:    *
 521:    * @param pattern The new format pattern.
 522:    * @throws NullPointerException if the pattern is null.
 523:    * @throws IllegalArgumentException if the pattern is invalid.
 524:    */
 525:   public void applyPattern(String pattern)
 526:   {
 527:     tokens.clear();
 528:     compileFormat(pattern);
 529:     this.pattern = pattern;
 530:   }
 531: 
 532:   /**
 533:    * This method sets the formatting pattern that should be used by this
 534:    * object.  This string is localized.
 535:    *
 536:    * @param pattern The new format pattern.
 537:    * @throws NullPointerException if the pattern is null.
 538:    * @throws IllegalArgumentException if the pattern is invalid.
 539:    */
 540:   public void applyLocalizedPattern(String pattern)
 541:   {
 542:     String localChars = formatData.getLocalPatternChars();
 543:     pattern = translateLocalizedPattern(pattern, localChars, standardChars);
 544:     applyPattern(pattern);
 545:   }
 546: 
 547:   /**
 548:    * Translates either from or to a localized variant of the pattern
 549:    * string.  For example, in the German locale, 't' (for 'tag') is
 550:    * used instead of 'd' (for 'date').  This method translates
 551:    * a localized pattern (such as 'ttt') to a non-localized pattern
 552:    * (such as 'ddd'), or vice versa.  Non-localized patterns use
 553:    * a standard set of characters, which match those of the U.S. English
 554:    * locale.
 555:    *
 556:    * @param pattern the pattern to translate.
 557:    * @param oldChars the old set of characters (used in the pattern).
 558:    * @param newChars the new set of characters (which will be used in the
 559:    *                 pattern).
 560:    * @return a version of the pattern using the characters in
 561:    *         <code>newChars</code>.
 562:    */
 563:   private String translateLocalizedPattern(String pattern,
 564:                        String oldChars, String newChars)
 565:   {
 566:     int len = pattern.length();
 567:     CPStringBuilder buf = new CPStringBuilder(len);
 568:     boolean quoted = false;
 569:     for (int i = 0;  i < len;  i++)
 570:       {
 571:     char ch = pattern.charAt(i);
 572:     if (ch == '\'')
 573:       quoted = ! quoted;
 574:     if (! quoted)
 575:       {
 576:         int j = oldChars.indexOf(ch);
 577:         if (j >= 0)
 578:           ch = newChars.charAt(j);
 579:       }
 580:     buf.append(ch);
 581:       }
 582:     return buf.toString();
 583:   }
 584: 
 585:   /** 
 586:    * Returns the start of the century used for two digit years.
 587:    *
 588:    * @return A <code>Date</code> representing the start of the century
 589:    * for two digit years.
 590:    */
 591:   public Date get2DigitYearStart()
 592:   {
 593:     return defaultCenturyStart;
 594:   }
 595: 
 596:   /**
 597:    * Sets the start of the century used for two digit years.
 598:    *
 599:    * @param date A <code>Date</code> representing the start of the century for
 600:    * two digit years.
 601:    */
 602:   public void set2DigitYearStart(Date date)
 603:   {
 604:     defaultCenturyStart = date;
 605:     calendar.clear();
 606:     calendar.setTime(date);
 607:     int year = calendar.get(Calendar.YEAR);
 608:     defaultCentury = year - (year % 100);
 609:   }
 610: 
 611:   /**
 612:    * This method returns a copy of the format symbol information used
 613:    * for parsing and formatting dates.
 614:    *
 615:    * @return a copy of the date format symbols.
 616:    */
 617:   public DateFormatSymbols getDateFormatSymbols()
 618:   {
 619:     return (DateFormatSymbols) formatData.clone();
 620:   }
 621: 
 622:   /**
 623:    * This method sets the format symbols information used for parsing
 624:    * and formatting dates.
 625:    *
 626:    * @param formatData The date format symbols.
 627:    * @throws NullPointerException if <code>formatData</code> is null.
 628:    */
 629:    public void setDateFormatSymbols(DateFormatSymbols formatData)
 630:    {
 631:      if (formatData == null)
 632:        {
 633:      throw new
 634:        NullPointerException("The supplied format data was null.");
 635:        }
 636:      this.formatData = formatData;
 637:    }
 638: 
 639:   /**
 640:    * This methods tests whether the specified object is equal to this
 641:    * object.  This will be true if and only if the specified object:
 642:    * <p>
 643:    * <ul>
 644:    * <li>Is not <code>null</code>.</li>
 645:    * <li>Is an instance of <code>SimpleDateFormat</code>.</li>
 646:    * <li>Is equal to this object at the superclass (i.e., <code>DateFormat</code>)
 647:    *     level.</li>
 648:    * <li>Has the same formatting pattern.</li>
 649:    * <li>Is using the same formatting symbols.</li>
 650:    * <li>Is using the same century for two digit years.</li>
 651:    * </ul>
 652:    *
 653:    * @param o The object to compare for equality against.
 654:    *
 655:    * @return <code>true</code> if the specified object is equal to this object,
 656:    * <code>false</code> otherwise.
 657:    */
 658:   public boolean equals(Object o)
 659:   {
 660:     if (!super.equals(o))
 661:       return false;
 662: 
 663:     if (!(o instanceof SimpleDateFormat))
 664:       return false;
 665: 
 666:     SimpleDateFormat sdf = (SimpleDateFormat)o;
 667: 
 668:     if (defaultCentury != sdf.defaultCentury)
 669:       return false;
 670: 
 671:     if (!toPattern().equals(sdf.toPattern()))
 672:       return false;
 673: 
 674:     if (!getDateFormatSymbols().equals(sdf.getDateFormatSymbols()))
 675:       return false;
 676: 
 677:     return true;
 678:   }
 679: 
 680:   /**
 681:    * This method returns a hash value for this object.
 682:    *
 683:    * @return A hash value for this object.
 684:    */
 685:   public int hashCode()
 686:   {
 687:     return super.hashCode() ^ toPattern().hashCode() ^ defaultCentury ^
 688:       getDateFormatSymbols().hashCode();
 689:   }
 690: 
 691: 
 692:   /**
 693:    * Formats the date input according to the format string in use,
 694:    * appending to the specified StringBuffer.  The input StringBuffer
 695:    * is returned as output for convenience.
 696:    */
 697:   private void formatWithAttribute(Date date, FormatBuffer buffer, FieldPosition pos)
 698:   {
 699:     String temp;
 700:     calendar.setTime(date);
 701: 
 702:     // go through vector, filling in fields where applicable, else toString
 703:     Iterator<Object> iter = tokens.iterator();
 704:     while (iter.hasNext())
 705:       {
 706:     Object o = iter.next();
 707:     if (o instanceof CompiledField)
 708:       {
 709:         CompiledField cf = (CompiledField) o;
 710:         int beginIndex = buffer.length();
 711:         
 712:         switch (cf.getField())
 713:           {
 714:           case ERA_FIELD:
 715:         buffer.append (formatData.eras[calendar.get (Calendar.ERA)], DateFormat.Field.ERA);
 716:         break;
 717:           case YEAR_FIELD:
 718:         // If we have two digits, then we truncate.  Otherwise, we
 719:         // use the size of the pattern, and zero pad.
 720:         buffer.setDefaultAttribute (DateFormat.Field.YEAR);
 721:         if (cf.getSize() == 2)
 722:           {
 723:             temp = "00"+String.valueOf (calendar.get (Calendar.YEAR));
 724:             buffer.append (temp.substring (temp.length() - 2));
 725:           }
 726:         else
 727:           withLeadingZeros (calendar.get (Calendar.YEAR), cf.getSize(), buffer);
 728:         break;
 729:           case MONTH_FIELD:
 730:         buffer.setDefaultAttribute (DateFormat.Field.MONTH);
 731:         if (cf.getSize() < 3)
 732:           withLeadingZeros (calendar.get (Calendar.MONTH) + 1, cf.getSize(), buffer);
 733:         else if (cf.getSize() < 4)
 734:           buffer.append (formatData.shortMonths[calendar.get (Calendar.MONTH)]);
 735:         else
 736:           buffer.append (formatData.months[calendar.get (Calendar.MONTH)]);
 737:         break;
 738:           case DATE_FIELD:
 739:         buffer.setDefaultAttribute (DateFormat.Field.DAY_OF_MONTH);
 740:         withLeadingZeros (calendar.get (Calendar.DATE), cf.getSize(), buffer);
 741:         break;
 742:           case HOUR_OF_DAY1_FIELD: // 1-24
 743:         buffer.setDefaultAttribute(DateFormat.Field.HOUR_OF_DAY1);
 744:         withLeadingZeros ( ((calendar.get (Calendar.HOUR_OF_DAY) + 23) % 24) + 1, 
 745:                    cf.getSize(), buffer);
 746:         break;
 747:           case HOUR_OF_DAY0_FIELD: // 0-23
 748:         buffer.setDefaultAttribute (DateFormat.Field.HOUR_OF_DAY0);
 749:         withLeadingZeros (calendar.get (Calendar.HOUR_OF_DAY), cf.getSize(), buffer);
 750:         break;
 751:           case MINUTE_FIELD:
 752:         buffer.setDefaultAttribute (DateFormat.Field.MINUTE);
 753:         withLeadingZeros (calendar.get (Calendar.MINUTE),
 754:                   cf.getSize(), buffer);
 755:         break;
 756:           case SECOND_FIELD:
 757:         buffer.setDefaultAttribute (DateFormat.Field.SECOND);
 758:         withLeadingZeros(calendar.get (Calendar.SECOND), 
 759:                  cf.getSize(), buffer);
 760:         break;
 761:           case MILLISECOND_FIELD:
 762:         buffer.setDefaultAttribute (DateFormat.Field.MILLISECOND);
 763:         withLeadingZeros (calendar.get (Calendar.MILLISECOND), cf.getSize(), buffer);
 764:         break;
 765:           case DAY_OF_WEEK_FIELD:
 766:         buffer.setDefaultAttribute (DateFormat.Field.DAY_OF_WEEK);
 767:         if (cf.getSize() < 4)
 768:           buffer.append (formatData.shortWeekdays[calendar.get (Calendar.DAY_OF_WEEK)]);
 769:         else
 770:           buffer.append (formatData.weekdays[calendar.get (Calendar.DAY_OF_WEEK)]);
 771:         break;
 772:           case DAY_OF_YEAR_FIELD:
 773:         buffer.setDefaultAttribute (DateFormat.Field.DAY_OF_YEAR);
 774:         withLeadingZeros (calendar.get (Calendar.DAY_OF_YEAR), cf.getSize(), buffer);
 775:         break;
 776:           case DAY_OF_WEEK_IN_MONTH_FIELD:
 777:         buffer.setDefaultAttribute (DateFormat.Field.DAY_OF_WEEK_IN_MONTH);
 778:         withLeadingZeros (calendar.get (Calendar.DAY_OF_WEEK_IN_MONTH), 
 779:                  cf.getSize(), buffer);
 780:         break;
 781:           case WEEK_OF_YEAR_FIELD:
 782:         buffer.setDefaultAttribute (DateFormat.Field.WEEK_OF_YEAR);
 783:         withLeadingZeros (calendar.get (Calendar.WEEK_OF_YEAR),
 784:                   cf.getSize(), buffer);
 785:         break;
 786:           case WEEK_OF_MONTH_FIELD:
 787:         buffer.setDefaultAttribute (DateFormat.Field.WEEK_OF_MONTH);
 788:         withLeadingZeros (calendar.get (Calendar.WEEK_OF_MONTH),
 789:                   cf.getSize(), buffer);
 790:         break;
 791:           case AM_PM_FIELD:
 792:         buffer.setDefaultAttribute (DateFormat.Field.AM_PM);
 793:         buffer.append (formatData.ampms[calendar.get (Calendar.AM_PM)]);
 794:         break;
 795:           case HOUR1_FIELD: // 1-12
 796:         buffer.setDefaultAttribute (DateFormat.Field.HOUR1);
 797:         withLeadingZeros (((calendar.get (Calendar.HOUR) + 11) % 12) + 1,
 798:                   cf.getSize(), buffer);
 799:         break;
 800:           case HOUR0_FIELD: // 0-11
 801:         buffer.setDefaultAttribute (DateFormat.Field.HOUR0);
 802:         withLeadingZeros (calendar.get (Calendar.HOUR), cf.getSize(), buffer);
 803:         break;
 804:           case TIMEZONE_FIELD:
 805:         buffer.setDefaultAttribute (DateFormat.Field.TIME_ZONE);
 806:         TimeZone zone = calendar.getTimeZone();
 807:         boolean isDST = calendar.get (Calendar.DST_OFFSET) != 0;
 808:         // FIXME: XXX: This should be a localized time zone.
 809:         String zoneID = zone.getDisplayName
 810:           (isDST, cf.getSize() > 3 ? TimeZone.LONG : TimeZone.SHORT);
 811:         buffer.append (zoneID);
 812:         break;
 813:           case RFC822_TIMEZONE_FIELD:
 814:         buffer.setDefaultAttribute(DateFormat.Field.TIME_ZONE);
 815:         int pureMinutes = (calendar.get(Calendar.ZONE_OFFSET) +
 816:                    calendar.get(Calendar.DST_OFFSET)) / (1000 * 60);
 817:         String sign = (pureMinutes < 0) ? "-" : "+";
 818:                 pureMinutes = Math.abs(pureMinutes);
 819:         int hours = pureMinutes / 60;
 820:         int minutes = pureMinutes % 60;
 821:         buffer.append(sign);
 822:         withLeadingZeros(hours, 2, buffer);
 823:         withLeadingZeros(minutes, 2, buffer);
 824:         break;
 825:           default:
 826:         throw new IllegalArgumentException ("Illegal pattern character " +
 827:                             cf.getCharacter());
 828:           }
 829:         if (pos != null && (buffer.getDefaultAttribute() == pos.getFieldAttribute()
 830:                 || cf.getField() == pos.getField()))
 831:           {
 832:         pos.setBeginIndex(beginIndex);
 833:         pos.setEndIndex(buffer.length());
 834:           }
 835:       } 
 836:       else
 837:     {  
 838:       buffer.append(o.toString(), null);
 839:     }
 840:       }
 841:   }
 842:   
 843:   public StringBuffer format(Date date, StringBuffer buffer, FieldPosition pos)
 844:   {
 845:     formatWithAttribute(date, new StringFormatBuffer (buffer), pos);
 846: 
 847:     return buffer;
 848:   }
 849: 
 850:   public AttributedCharacterIterator formatToCharacterIterator(Object date)
 851:     throws IllegalArgumentException
 852:   {
 853:     if (date == null)
 854:       throw new NullPointerException("null argument");
 855:     if (!(date instanceof Date))
 856:       throw new IllegalArgumentException("argument should be an instance of java.util.Date");
 857: 
 858:     AttributedFormatBuffer buf = new AttributedFormatBuffer();
 859:     formatWithAttribute((Date)date, buf,
 860:             null);
 861:     buf.sync();
 862:         
 863:     return new FormatCharacterIterator(buf.getBuffer().toString(),
 864:                        buf.getRanges(),
 865:                        buf.getAttributes());
 866:   }
 867: 
 868:   private void withLeadingZeros(int value, int length, FormatBuffer buffer) 
 869:   {
 870:     String valStr = String.valueOf(value);
 871:     for (length -= valStr.length(); length > 0; length--)
 872:       buffer.append('0');
 873:     buffer.append(valStr);
 874:   }
 875: 
 876:   private boolean expect(String source, ParsePosition pos, char ch)
 877:   {
 878:     int x = pos.getIndex();
 879:     boolean r = x < source.length() && source.charAt(x) == ch;
 880:     if (r)
 881:       pos.setIndex(x + 1);
 882:     else
 883:       pos.setErrorIndex(x);
 884:     return r;
 885:   }
 886: 
 887:   /**
 888:    * This method parses the specified string into a date.
 889:    * 
 890:    * @param dateStr The date string to parse.
 891:    * @param pos The input and output parse position
 892:    *
 893:    * @return The parsed date, or <code>null</code> if the string cannot be
 894:    * parsed.
 895:    */
 896:   public Date parse (String dateStr, ParsePosition pos)
 897:   {
 898:     int fmt_index = 0;
 899:     int fmt_max = pattern.length();
 900: 
 901:     calendar.clear();
 902:     boolean saw_timezone = false;
 903:     int quote_start = -1;
 904:     boolean is2DigitYear = false;
 905:     try
 906:       {
 907:     for (; fmt_index < fmt_max; ++fmt_index)
 908:       {
 909:         char ch = pattern.charAt(fmt_index);
 910:         if (ch == '\'')
 911:           {
 912:         if (fmt_index < fmt_max - 1
 913:             && pattern.charAt(fmt_index + 1) == '\'')
 914:           {
 915:             if (! expect (dateStr, pos, ch))
 916:               return null;
 917:             ++fmt_index;
 918:           }
 919:         else
 920:           quote_start = quote_start < 0 ? fmt_index : -1;
 921:         continue;
 922:           }
 923:         
 924:         if (quote_start != -1
 925:         || ((ch < 'a' || ch > 'z')
 926:             && (ch < 'A' || ch > 'Z')))
 927:           {
 928:                 if (quote_start == -1 && ch == ' ')
 929:                   {
 930:                     // A single unquoted space in the pattern may match
 931:                     // any number of spaces in the input.
 932:                     int index = pos.getIndex();
 933:                     int save = index;
 934:                     while (index < dateStr.length()
 935:                            && Character.isWhitespace(dateStr.charAt(index)))
 936:                       ++index;
 937:                     if (index > save)
 938:                       pos.setIndex(index);
 939:                     else
 940:                       {
 941:                         // Didn't see any whitespace.
 942:                         pos.setErrorIndex(index);
 943:                         return null;
 944:                       }
 945:                   }
 946:                 else if (! expect (dateStr, pos, ch))
 947:           return null;
 948:         continue;
 949:           }
 950:         
 951:         // We've arrived at a potential pattern character in the
 952:         // pattern.
 953:         int fmt_count = 1;
 954:         while (++fmt_index < fmt_max && pattern.charAt(fmt_index) == ch)
 955:           {
 956:         ++fmt_count;
 957:           }
 958:         
 959:         // We might need to limit the number of digits to parse in
 960:         // some cases.  We look to the next pattern character to
 961:         // decide.
 962:         boolean limit_digits = false;
 963:         if (fmt_index < fmt_max
 964:         && standardChars.indexOf(pattern.charAt(fmt_index)) >= 0)
 965:           limit_digits = true;
 966:         --fmt_index;
 967:         
 968:         // We can handle most fields automatically: most either are
 969:         // numeric or are looked up in a string vector.  In some cases
 970:         // we need an offset.  When numeric, `offset' is added to the
 971:         // resulting value.  When doing a string lookup, offset is the
 972:         // initial index into the string array.
 973:         int calendar_field;
 974:         boolean is_numeric = true;
 975:         int offset = 0;
 976:         boolean maybe2DigitYear = false;
 977:         boolean oneBasedHour = false;
 978:         boolean oneBasedHourOfDay = false;
 979:         Integer simpleOffset;
 980:         String[] set1 = null;
 981:         String[] set2 = null;
 982:         switch (ch)
 983:           {
 984:           case 'd':
 985:         calendar_field = Calendar.DATE;
 986:         break;
 987:           case 'D':
 988:         calendar_field = Calendar.DAY_OF_YEAR;
 989:         break;
 990:           case 'F':
 991:         calendar_field = Calendar.DAY_OF_WEEK_IN_MONTH;
 992:         break;
 993:           case 'E':
 994:         is_numeric = false;
 995:         offset = 1;
 996:         calendar_field = Calendar.DAY_OF_WEEK;
 997:         set1 = formatData.getWeekdays();
 998:         set2 = formatData.getShortWeekdays();
 999:         break;
1000:           case 'w':
1001:         calendar_field = Calendar.WEEK_OF_YEAR;
1002:         break;
1003:           case 'W':
1004:         calendar_field = Calendar.WEEK_OF_MONTH;
1005:         break;
1006:           case 'M':
1007:         calendar_field = Calendar.MONTH;
1008:         if (fmt_count <= 2)
1009:           offset = -1;
1010:         else
1011:           {
1012:             is_numeric = false;
1013:             set1 = formatData.getMonths();
1014:             set2 = formatData.getShortMonths();
1015:           }
1016:         break;
1017:           case 'y':
1018:         calendar_field = Calendar.YEAR;
1019:         if (fmt_count <= 2)
1020:           maybe2DigitYear = true;
1021:         break;
1022:           case 'K':
1023:         calendar_field = Calendar.HOUR;
1024:         break;
1025:           case 'h':
1026:         calendar_field = Calendar.HOUR;
1027:         oneBasedHour = true;
1028:         break;
1029:           case 'H':
1030:         calendar_field = Calendar.HOUR_OF_DAY;
1031:         break;
1032:           case 'k':
1033:         calendar_field = Calendar.HOUR_OF_DAY;
1034:         oneBasedHourOfDay = true;
1035:         break;
1036:           case 'm':
1037:         calendar_field = Calendar.MINUTE;
1038:         break;
1039:           case 's':
1040:         calendar_field = Calendar.SECOND;
1041:         break;
1042:           case 'S':
1043:         calendar_field = Calendar.MILLISECOND;
1044:         break;
1045:           case 'a':
1046:         is_numeric = false;
1047:         calendar_field = Calendar.AM_PM;
1048:         set1 = formatData.getAmPmStrings();
1049:         break;
1050:           case 'z':
1051:           case 'Z':
1052:         // We need a special case for the timezone, because it
1053:         // uses a different data structure than the other cases.
1054:         is_numeric = false;
1055:         calendar_field = Calendar.ZONE_OFFSET;
1056:         String[][] zoneStrings = formatData.getZoneStrings();
1057:         int zoneCount = zoneStrings.length;
1058:         int index = pos.getIndex();
1059:         boolean found_zone = false;
1060:         simpleOffset = computeOffset(dateStr.substring(index), pos);
1061:         if (simpleOffset != null)
1062:           {
1063:             found_zone = true;
1064:             saw_timezone = true;
1065:             calendar.set(Calendar.DST_OFFSET, 0);
1066:             offset = simpleOffset.intValue();
1067:           }
1068:         else
1069:           {
1070:             for (int j = 0;  j < zoneCount;  j++)
1071:               {
1072:             String[] strings = zoneStrings[j];
1073:             int k;
1074:             for (k = 0; k < strings.length; ++k)
1075:               {
1076:                 if (dateStr.startsWith(strings[k], index))
1077:                   break;
1078:               }
1079:             if (k != strings.length)
1080:               {
1081:                 found_zone = true;
1082:                 saw_timezone = true;
1083:                 TimeZone tz = TimeZone.getTimeZone (strings[0]);
1084:                 // Check if it's a DST zone or ordinary 
1085:                 if(k == 3 || k == 4)
1086:                   calendar.set (Calendar.DST_OFFSET, tz.getDSTSavings());
1087:                 else
1088:                   calendar.set (Calendar.DST_OFFSET, 0);
1089:                             offset = tz.getRawOffset ();
1090:                 pos.setIndex(index + strings[k].length());
1091:                 break;
1092:               }
1093:               }
1094:           }
1095:         if (! found_zone)
1096:           {
1097:             pos.setErrorIndex(pos.getIndex());
1098:             return null;
1099:           }
1100:         break;
1101:           default:
1102:         pos.setErrorIndex(pos.getIndex());
1103:         return null;
1104:           }
1105:       
1106:         // Compute the value we should assign to the field.
1107:         int value;
1108:         int index = -1;
1109:         if (is_numeric)
1110:           {
1111:         numberFormat.setMinimumIntegerDigits(fmt_count);
1112:         if (maybe2DigitYear)
1113:           index = pos.getIndex();
1114:         Number n = null;
1115:         if (limit_digits)
1116:           {
1117:             // numberFormat.setMaximumIntegerDigits(fmt_count) may
1118:             // not work as expected. So we explicitly use substring
1119:             // of dateStr.
1120:             int origPos = pos.getIndex();
1121:             pos.setIndex(0);
1122:             n = numberFormat.parse(dateStr.substring(origPos, origPos + fmt_count), pos);
1123:             pos.setIndex(origPos + pos.getIndex());
1124:           }
1125:         else
1126:           n = numberFormat.parse(dateStr, pos);
1127:         if (pos == null || ! (n instanceof Long))
1128:           return null;
1129:         value = n.intValue() + offset;
1130:           }
1131:         else if (set1 != null)
1132:           {
1133:         index = pos.getIndex();
1134:         int i;
1135:         boolean found = false;
1136:         for (i = offset; i < set1.length; ++i)
1137:           {
1138:             if (set1[i] != null)
1139:               if (dateStr.toUpperCase().startsWith(set1[i].toUpperCase(),
1140:                                index))
1141:             {
1142:               found = true;
1143:               pos.setIndex(index + set1[i].length());
1144:               break;
1145:             }
1146:           }
1147:         if (!found && set2 != null)
1148:           {
1149:             for (i = offset; i < set2.length; ++i)
1150:               {
1151:             if (set2[i] != null)
1152:               if (dateStr.toUpperCase().startsWith(set2[i].toUpperCase(),
1153:                                    index))
1154:                 {
1155:                   found = true;
1156:                   pos.setIndex(index + set2[i].length());
1157:                   break;
1158:                 }
1159:               }
1160:           }
1161:         if (!found)
1162:           {
1163:             pos.setErrorIndex(index);
1164:             return null;
1165:           }
1166:         value = i;
1167:           }
1168:         else
1169:           value = offset;
1170:       
1171:         if (maybe2DigitYear)
1172:           {
1173:         // Parse into default century if the numeric year string has 
1174:         // exactly 2 digits.
1175:         int digit_count = pos.getIndex() - index;
1176:         if (digit_count == 2)
1177:           {
1178:             is2DigitYear = true;
1179:             value += defaultCentury;
1180:           }
1181:           }
1182:         
1183:         // Calendar uses 0-based hours. 
1184:         // I.e. 00:00 AM is midnight, not 12 AM or 24:00
1185:         if (oneBasedHour && value == 12)
1186:           value = 0;
1187: 
1188:         if (oneBasedHourOfDay && value == 24)
1189:           value = 0;
1190:         
1191:         // Assign the value and move on.
1192:         calendar.set(calendar_field, value);
1193:       }
1194:     
1195:     if (is2DigitYear)
1196:       {
1197:         // Apply the 80-20 heuristic to dermine the full year based on 
1198:         // defaultCenturyStart. 
1199:         int year = calendar.get(Calendar.YEAR);
1200:         if (calendar.getTime().compareTo(defaultCenturyStart) < 0)
1201:           calendar.set(Calendar.YEAR, year + 100);      
1202:       }
1203:     if (! saw_timezone)
1204:       {
1205:         // Use the real rules to determine whether or not this
1206:         // particular time is in daylight savings.
1207:         calendar.clear (Calendar.DST_OFFSET);
1208:         calendar.clear (Calendar.ZONE_OFFSET);
1209:       }
1210:         return calendar.getTime();
1211:       }
1212:     catch (IllegalArgumentException x)
1213:       {
1214:         pos.setErrorIndex(pos.getIndex());
1215:     return null;
1216:       }
1217:       }
1218: 
1219:   /**
1220:    * <p>
1221:    * Computes the time zone offset in milliseconds
1222:    * relative to GMT, based on the supplied
1223:    * <code>String</code> representation.
1224:    * </p>
1225:    * <p>
1226:    * The supplied <code>String</code> must be a three
1227:    * or four digit signed number, with an optional 'GMT'
1228:    * prefix.  The first one or two digits represents the hours,
1229:    * while the last two represent the minutes.  The
1230:    * two sets of digits can optionally be separated by
1231:    * ':'.  The mandatory sign prefix (either '+' or '-')
1232:    * indicates the direction of the offset from GMT.
1233:    * </p>
1234:    * <p>
1235:    * For example, 'GMT+0200' specifies 2 hours after
1236:    * GMT, while '-05:00' specifies 5 hours prior to
1237:    * GMT.  The special case of 'GMT' alone can be used
1238:    * to represent the offset, 0.
1239:    * </p>
1240:    * <p>
1241:    * If the <code>String</code> can not be parsed,
1242:    * the result will be null.  The resulting offset
1243:    * is wrapped in an <code>Integer</code> object, in
1244:    * order to allow such failure to be represented.
1245:    * </p>
1246:    *
1247:    * @param zoneString a string in the form 
1248:    *        (GMT)? sign hours : minutes
1249:    *        where sign = '+' or '-', hours
1250:    *        is a one or two digits representing
1251:    *        a number between 0 and 23, and
1252:    *        minutes is two digits representing
1253:    *        a number between 0 and 59.
1254:    * @return the parsed offset, or null if parsing
1255:    *         failed.
1256:    */
1257:   private Integer computeOffset(String zoneString, ParsePosition pos)
1258:   {
1259:     Pattern pattern = 
1260:       Pattern.compile("(GMT)?([+-])([012])?([0-9]):?([0-9]{2})");
1261:     Matcher matcher = pattern.matcher(zoneString);
1262: 
1263:     // Match from start, but ignore trailing parts
1264:     boolean hasAll = matcher.lookingAt();
1265:     try
1266:       {
1267:     // Do we have at least the sign, hour and minute?
1268:     matcher.group(2);
1269:     matcher.group(4);
1270:     matcher.group(5);
1271:       }
1272:     catch (IllegalStateException ise)
1273:       {
1274:     hasAll = false;
1275:       }
1276:     if (hasAll)
1277:       {
1278:     int sign = matcher.group(2).equals("+") ? 1 : -1;
1279:     int hour = Integer.parseInt(matcher.group(4));
1280:     if (!matcher.group(3).equals(""))
1281:       hour += (Integer.parseInt(matcher.group(3)) * 10);
1282:     int minutes = Integer.parseInt(matcher.group(5));
1283: 
1284:     if (hour > 23)
1285:       return null;
1286:     int offset = sign * ((hour * 60) + minutes) * 60000;
1287: 
1288:     // advance the index
1289:     pos.setIndex(pos.getIndex() + matcher.end());
1290:     return Integer.valueOf(offset);
1291:       }
1292:     else if (zoneString.startsWith("GMT"))
1293:       {
1294:     pos.setIndex(pos.getIndex() + 3);
1295:     return Integer.valueOf(0);
1296:       }
1297:     return null;
1298:   }
1299: 
1300:   // Compute the start of the current century as defined by
1301:   // get2DigitYearStart.
1302:   private void computeCenturyStart()
1303:   {
1304:     int year = calendar.get(Calendar.YEAR);
1305:     calendar.set(Calendar.YEAR, year - 80);
1306:     set2DigitYearStart(calendar.getTime());
1307:   }
1308: 
1309:   /**
1310:    * Returns a copy of this instance of
1311:    * <code>SimpleDateFormat</code>.  The copy contains
1312:    * clones of the formatting symbols and the 2-digit
1313:    * year century start date.
1314:    */
1315:   public Object clone()
1316:   {
1317:     SimpleDateFormat clone = (SimpleDateFormat) super.clone();
1318:     clone.setDateFormatSymbols((DateFormatSymbols) formatData.clone());
1319:     clone.set2DigitYearStart((Date) defaultCenturyStart.clone());
1320:     return clone;
1321:   }
1322: 
1323: }