001/* java.util.Date
002   Copyright (C) 1998, 1999, 2000, 2001, 2005  Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038package java.util;
039
040import gnu.java.lang.CPStringBuilder;
041
042import java.io.IOException;
043import java.io.ObjectInputStream;
044import java.io.ObjectOutputStream;
045import java.io.Serializable;
046import java.text.DateFormat;
047import java.text.SimpleDateFormat;
048
049/**
050 * <p>
051 * This class represents a specific time in milliseconds since the epoch.
052 * The epoch is 1970, January 1 00:00:00.0000 UTC.  
053 * </p>
054 * <p>
055 * <code>Date</code> is intended to reflect universal time coordinate (UTC),
056 * but this depends on the underlying host environment.  Most operating systems 
057 * don't handle the leap second, which occurs about once every year or
058 * so.  The leap second is added to the last minute of the day on either
059 * the 30th of June or the 31st of December, creating a minute 61 seconds
060 * in length.
061 * </p>
062 * <p>
063 * The representations of the date fields are as follows:
064 * <ul>
065 * <li>
066 * Years are specified as the difference between the year
067 * and 1900.  Thus, the final year used is equal to
068 * 1900 + y, where y is the input value.
069 * </li>
070 * <li>
071 * Months are represented using zero-based indexing,
072 * making 0 January and 11 December.
073 * </li>
074 * <li>
075 * Dates are represented with the usual values of
076 * 1 through to 31.
077 * </li>
078 * <li>
079 * Hours are represented in the twenty-four hour clock,
080 * with integer values from 0 to 23.  12am is 0, and
081 * 12pm is 12.
082 * </li>
083 * <li>
084 * Minutes are again as usual, with values from 0 to 59.
085 * </li>
086 * <li>
087 * Seconds are represented with the values 0 through to 61,
088 * with 60 and 61 being leap seconds (as per the ISO C standard).
089 * </li>
090 * </ul>
091 * </p>
092 * <p>
093 * Prior to JDK 1.1, this class was the sole class handling date and time
094 * related functionality.  However, this particular solution was not
095 * amenable to internationalization.  The new <code>Calendar</code>
096 * class should now be used to handle dates and times, with <code>Date</code>
097 * being used only for values in milliseconds since the epoch.  The
098 * <code>Calendar</code> class, and its concrete implementations, handle
099 * the interpretation of these values into minutes, hours, days, months
100 * and years.  The formatting and parsing of dates is left to the
101 * <code>DateFormat</code> class, which is able to handle the different
102 * types of date format which occur in different locales.
103 * </p>
104 *
105 * @see Calendar
106 * @see GregorianCalendar
107 * @see java.text.DateFormat
108 * @author Jochen Hoenicke
109 * @author Per Bothner (bothner@cygnus.com)
110 * @author Andrew John Hughes (gnu_andrew@member.fsf.org)
111 */
112public class Date
113    implements Cloneable, Comparable<Date>, Serializable
114{
115  /**
116   * This is the serialization UID for this class
117   * for compatability with Sun's JDK.
118   */
119  private static final long serialVersionUID = 7523967970034938905L;
120
121  /**
122   * The time in milliseconds since the epoch.
123   */
124  private transient long time;
125
126  /**
127   * An array of week names used to map names to integer values.
128   */
129  private static final String[] weekNames = { "Sun", "Mon", "Tue", "Wed",
130                                              "Thu", "Fri", "Sat" };
131  /**
132   * An array of month names used to map names to integer values.
133   */
134  private static final String[] monthNames = { "Jan", "Feb", "Mar", "Apr",
135                                               "May", "Jun", "Jul", "Aug",
136                                               "Sep", "Oct", "Nov", "Dec" };
137  /**
138   * Creates a new Date Object representing the current time.
139   */
140  public Date()
141  {
142    time = System.currentTimeMillis();
143  }
144
145  /**
146   * Creates a new Date Object representing the given time.
147   *
148   * @param time the time in milliseconds since the epoch.
149   */
150  public Date(long time)
151  {
152    this.time = time;
153  }
154
155  /**
156   * Creates a new Date Object representing the given time.
157   *
158   * @deprecated use <code>new GregorianCalendar(year+1900, month,
159   * day)</code> instead.
160   * @param year the difference between the required year and 1900.
161   * @param month the month as a value between 0 and 11.
162   * @param day the day as a value between 0 and 31.
163   */
164  public Date(int year, int month, int day)
165  {
166    this(year, month, day, 0, 0, 0);
167  }
168
169  /**
170   * Creates a new Date Object representing the given time.
171   *
172   * @deprecated use <code>new GregorianCalendar(year+1900, month,
173   * day, hour, min)</code> instead.
174   * @param year the difference between the required year and 1900.
175   * @param month the month as a value between 0 and 11.
176   * @param day the day as a value between 0 and 31.
177   * @param hour the hour as a value between 0 and 23, in 24-hour
178   *        clock notation.
179   * @param min the minute as a value between 0 and 59.
180   */
181  public Date(int year, int month, int day, int hour, int min)
182  {
183    this(year, month, day, hour, min, 0);
184  }
185
186  /**
187   * Creates a new Date Object representing the given time.
188   *
189   * @deprecated use <code>new GregorianCalendar(year+1900, month,
190   * day, hour, min, sec)</code> instead. 
191   * @param year the difference between the required year and 1900.
192   * @param month the month as a value between 0 and 11.
193   * @param day the day as a value between 0 and 31.
194   * @param hour the hour as a value between 0 and 23, in 24-hour
195   *        clock notation.
196   * @param min the minute as a value between 0 and 59.
197   * @param sec the second as a value between 0 and 61 (with 60
198   *        and 61 being leap seconds).
199   */
200  public Date(int year, int month, int day, int hour, int min, int sec)
201  {
202    GregorianCalendar cal =
203        new GregorianCalendar(year + 1900, month, day, hour, min, sec);
204    time = cal.getTimeInMillis();
205  }
206
207  /**
208   * Creates a new Date from the given string representation.  This
209   * does the same as <code>new Date(Date.parse(s))</code>
210   * @see #parse
211   * @deprecated use <code>java.text.DateFormat.parse(s)</code> instead.  
212   */
213  public Date(String s)
214  {
215    time = parse(s);
216  }
217
218  /**
219   * Returns a copy of this <code>Date</code> object.
220   *
221   * @return a copy, or null if the object couldn't be
222   *         cloned.
223   * @see Object#clone()
224   */
225  public Object clone()
226  {
227    try
228      {
229        return super.clone();
230      }
231    catch (CloneNotSupportedException ex)
232      {
233        return null;
234      }
235  }
236
237  /**
238   * Returns the number of milliseconds since the epoch
239   * specified by the given arguments.  The arguments are
240   * interpreted relative to UTC rather than the local
241   * time zone.
242   *
243   * @deprecated Use <code>Calendar</code> with a UTC
244   *             <code>TimeZone</code> instead.
245   * @param year the difference between the required year and 1900.
246   * @param month the month as a value between 0 and 11.
247   * @param date the day as a value between 0 and 31.
248   * @param hrs the hour as a value between 0 and 23, in 24-hour
249   *        clock notation.
250   * @param min the minute as a value between 0 and 59.
251   * @param sec the second as a value between 0 and 61 (with 60
252   *        and 61 being leap seconds).
253   * @return the time in milliseconds since the epoch.
254   */
255  public static long UTC(int year, int month, int date,
256                         int hrs, int min, int sec)
257  {
258    GregorianCalendar cal =
259      new GregorianCalendar(year + 1900, month, date, hrs, min, sec);
260    cal.set(Calendar.ZONE_OFFSET, 0);
261    cal.set(Calendar.DST_OFFSET, 0);
262    return cal.getTimeInMillis();
263  }
264
265  /**
266   * Gets the time represented by this object.
267   *
268   * @return the time in milliseconds since the epoch.
269   */
270  public long getTime()
271  {
272    return time;
273  }
274
275  /**
276   * Returns the number of minutes offset used with UTC to give the time
277   * represented by this object in the current time zone.  The date information
278   * from this object is also used to determine whether or not daylight savings
279   * time is in effect.  For example, the offset for the UK would be 0 if the
280   * month of the date object was January, and 1 if the month was August.
281   * 
282   * @deprecated use
283   * <code>Calendar.get(Calendar.ZONE_OFFSET)+Calendar.get(Calendar.DST_OFFSET)</code>
284   * instead.
285   * @return The time zone offset in minutes of the local time zone
286   * relative to UTC.  The time represented by this object is used to
287   * determine if we should use daylight savings.
288   */
289  public int getTimezoneOffset()
290  {
291    Calendar cal = Calendar.getInstance();
292    cal.setTimeInMillis(time);
293    return - (cal.get(Calendar.ZONE_OFFSET)
294            + cal.get(Calendar.DST_OFFSET)) / (60 * 1000);
295  }
296
297  /**
298   * Sets the time which this object should represent.
299   *
300   * @param time the time in milliseconds since the epoch.  
301   */
302  public void setTime(long time)
303  {
304    this.time = time;
305  }
306
307  /**
308   * Tests if this date is after the specified date.
309   *
310   * @param when the other date
311   * @return true, if the date represented by this object is
312   * strictly later than the time represented by when.  
313   */
314  public boolean after(Date when)
315  {
316    return time > when.time;
317  }
318
319  /**
320   * Tests if this date is before the specified date.
321   *
322   * @param when the other date
323   * @return true, if the date represented by when is strictly later
324   * than the time represented by this object.
325   */
326  public boolean before(Date when)
327  {
328    return time < when.time;
329  }
330
331  /**
332   * Compares two dates for equality.
333   *
334   * @param obj the object to compare.
335   * @return true, if obj is a Date object and the time represented
336   * by obj is exactly the same as the time represented by this
337   * object.  
338   */
339  public boolean equals(Object obj)
340  {
341    return (obj instanceof Date && time == ((Date) obj).time);
342  }
343
344  /**
345   * Compares two dates.
346   *
347   * @param when the other date.
348   * @return 0, if the date represented
349   * by obj is exactly the same as the time represented by this
350   * object, a negative if this Date is before the other Date, and
351   * a positive value otherwise.  
352   */
353  public int compareTo(Date when)
354  {
355    return (time < when.time) ? -1 : (time == when.time) ? 0 : 1;
356  }
357
358  /**
359   * Computes the hash code of this <code>Date</code> as the
360   * XOR of the most significant and the least significant
361   * 32 bits of the 64 bit milliseconds value.
362   *
363   * @return the hash code.
364   */
365  public int hashCode()
366  {
367    return (int) time ^ (int) (time >>> 32);
368  }
369
370  /**
371   * <p>
372   * Returns a string representation of this date using
373   * the following date format:
374   * </p>
375   * <p>
376   * <code>day mon dd hh:mm:ss zz yyyy</code>
377   * </p>
378   * <p>where the fields used here are:
379   * <ul>
380   * <li>
381   * <code>day</code> -- the day of the week
382   * (Sunday through to Saturday).
383   * </li>
384   * <li>
385   * <code>mon</code> -- the month (Jan to Dec).
386   * </li>
387   * <li>
388   * <code>dd</code> -- the day of the month
389   * as two decimal digits (01 to 31).
390   * </li>
391   * <li>
392   * <code>hh</code> -- the hour of the day
393   * as two decimal digits in 24-hour clock notation
394   * (01 to 23).
395   * </li>
396   * <li>
397   * <code>mm</code> -- the minute of the day
398   * as two decimal digits (01 to 59).
399   * </li>
400   * <li>
401   * <code>ss</code> -- the second of the day
402   * as two decimal digits (01 to 61).
403   * </li>
404   * <li>
405   * <code>zz</code> -- the time zone information if available.
406   * The possible time zones used include the abbreviations
407   * recognised by <code>parse()</code> (e.g. GMT, CET, etc.)
408   * and may reflect the fact that daylight savings time is in
409   * effect.  The empty string is used if there is no time zone
410   * information.
411   * </li>
412   * <li>
413   * <code>yyyy</code> -- the year as four decimal digits.
414   * </li>
415   * </ul>
416   * <p>
417   * The <code>DateFormat</code> class should now be 
418   * preferred over using this method.
419   * </p>
420   *
421   * @return A string of the form 'day mon dd hh:mm:ss zz yyyy'
422   * @see #parse(String)
423   * @see DateFormat
424   */
425  public String toString()
426  {
427    Calendar cal = Calendar.getInstance();
428    cal.setTimeInMillis(time);
429    String day = "0" + cal.get(Calendar.DATE);
430    String hour = "0" + cal.get(Calendar.HOUR_OF_DAY);
431    String min = "0" + cal.get(Calendar.MINUTE);
432    String sec = "0" + cal.get(Calendar.SECOND);
433    String year = "000" + cal.get(Calendar.YEAR);
434    return weekNames[cal.get(Calendar.DAY_OF_WEEK) - 1] + " "
435      + monthNames[cal.get(Calendar.MONTH)] + " "
436      + day.substring(day.length() - 2) + " "
437      + hour.substring(hour.length() - 2) + ":"
438      + min.substring(min.length() - 2) + ":"
439      + sec.substring(sec.length() - 2) + " "
440      +
441      cal.getTimeZone().getDisplayName(cal.getTimeZone().inDaylightTime(this),
442                                       TimeZone.SHORT) + " " +
443      year.substring(year.length() - 4);
444  }
445
446  /** 
447   * Returns a locale-dependent string representation of this
448   * <code>Date</code> object.
449   *
450   * @deprecated Use DateFormat.format(Date)
451   * @return A locale-dependent string representation.
452   * @see #parse(String)
453   * @see DateFormat
454   */
455  public String toLocaleString()
456  {
457    return java.text.DateFormat.getInstance().format(this);
458  }
459
460  /** 
461   * <p>
462   * Returns a string representation of this <code>Date</code>
463   * object using GMT rather than the local timezone.
464   * The following date format is used:
465   * </p>
466   * <p>
467   * <code>d mon yyyy hh:mm:ss GMT</code>
468   * </p>
469   * <p>where the fields used here are:
470   * <ul>
471   * <li>
472   * <code>d</code> -- the day of the month
473   * as one or two decimal digits (1 to 31).
474   * </li>
475   * <li>
476   * <code>mon</code> -- the month (Jan to Dec).
477   * </li>
478   * <li>
479   * <code>yyyy</code> -- the year as four decimal digits.
480   * </li>
481   * <li>
482   * <code>hh</code> -- the hour of the day
483   * as two decimal digits in 24-hour clock notation
484   * (01 to 23).
485   * </li>
486   * <li>
487   * <code>mm</code> -- the minute of the day
488   * as two decimal digits (01 to 59).
489   * </li>
490   * <li>
491   * <code>ss</code> -- the second of the day
492   * as two decimal digits (01 to 61).
493   * </li>
494   * <li>
495   * <code>GMT</code> -- the literal string "GMT"
496   * indicating Greenwich Mean Time as opposed to
497   * the local timezone.
498   * </li>
499   * </ul>
500   * 
501   * @deprecated Use DateFormat.format(Date) with a GMT TimeZone.
502   * @return A string of the form 'd mon yyyy hh:mm:ss GMT' using
503   *         GMT as opposed to the local timezone.
504   * @see #parse(String)
505   * @see DateFormat
506   */
507  public String toGMTString()
508  {
509    java.text.DateFormat format = java.text.DateFormat.getInstance();
510    format.setTimeZone(TimeZone.getTimeZone("GMT"));
511    return format.format(this);
512  }
513
514  /**
515   * Parses the time zone string.
516   *
517   * @param tok The token containing the time zone.
518   * @param sign The sign (+ or -) used by the time zone.
519   * @return An integer representing the number of minutes offset
520   *         from GMT for the time zone.
521   */
522  private static int parseTz(String tok, char sign)
523    throws IllegalArgumentException
524  {
525    int num;
526
527    try
528      {
529        // parseInt doesn't handle '+' so strip off sign.
530        num = Integer.parseInt(tok.substring(1));
531      }
532    catch (NumberFormatException ex)
533      {
534        throw new IllegalArgumentException(tok);
535      }
536
537    // Convert hours to minutes.
538    if (num < 24)
539      num *= 60;
540    else
541      num = (num / 100) * 60 + num % 100;
542
543    return sign == '-' ? -num : num;
544  }
545
546  /**
547   * Parses the month string.
548   *
549   * @param tok the token containing the month.
550   * @return An integer between 0 and 11, representing
551   *         a month from January (0) to December (11),
552   *         or -1 if parsing failed.
553   */
554  private static int parseMonth(String tok)
555  {
556    // Initialize strings for month names.
557    // We could possibly use the fields of DateFormatSymbols but that is
558    // localized and thus might not match the English words specified.
559    String months[] = { "JANUARY", "FEBRUARY", "MARCH", "APRIL", "MAY",
560                        "JUNE", "JULY", "AUGUST", "SEPTEMBER", "OCTOBER",
561                        "NOVEMBER", "DECEMBER" };
562
563    int i;
564    for (i = 0; i < 12; i++)
565      if (months[i].startsWith(tok))
566        return i;
567
568    // Return -1 if not found.
569    return -1;
570  }
571
572  /**
573   * Parses the day of the week string.
574   *
575   * @param tok the token containing the day of the week.
576   * @return true if the token was parsed successfully.
577   */
578  private static boolean parseDayOfWeek(String tok)
579  {
580    // Initialize strings for days of the week names.
581    // We could possibly use the fields of DateFormatSymbols but that is
582    // localized and thus might not match the English words specified.
583    String daysOfWeek[] = { "SUNDAY", "MONDAY", "TUESDAY", "WEDNESDAY",
584                            "THURSDAY", "FRIDAY", "SATURDAY" };
585
586    int i;
587    for (i = 0; i < 7; i++)
588      if (daysOfWeek[i].startsWith(tok))
589        return true;
590
591    return false;
592  }
593
594  /** 
595   * <p>
596   * Parses a String and returns the time, in milliseconds since the
597   * epoch, it represents.  Most syntaxes are handled, including
598   * the IETF date standard "day, dd mon yyyy hh:mm:ss zz" (see
599   * <code>toString()</code> for definitions of these fields).
600   * Standard U.S. time zone abbreviations are recognised, in
601   * addition to time zone offsets in positive or negative minutes.
602   * If a time zone is specified, the specified time is assumed to
603   * be in UTC and the appropriate conversion is applied, following
604   * parsing, to convert this to the local time zone.  If no zone
605   * is specified, the time is assumed to already be in the local
606   * time zone.
607   * </p>
608   * <p>
609   * The method parses the string progressively from left to right.
610   * At the end of the parsing process, either a time is returned
611   * or an <code>IllegalArgumentException</code> is thrown to signify
612   * failure.  The ASCII characters A-Z, a-z, 0-9, and ',', '+', '-',
613   * ':' and '/' are the only characters permitted within the string,
614   * besides whitespace and characters enclosed within parantheses
615   * '(' and ')'.  
616   * </p>
617   * <p>
618   * A sequence of consecutive digits are recognised as a number,
619   * and interpreted as follows:
620   * <ul>
621   * <li>
622   * A number preceded by a sign (+ or -) is taken to be a time zone
623   * offset.  The time zone offset can be specified in either hours
624   * or minutes.  The former is assumed if the number is less than 24.
625   * Otherwise, the offset is assumed to be in minutes.  A - indicates
626   * a time zone west of GMT, while a + represents a time zone to the
627   * east of GMT.  The time zones are always assumed to be relative
628   * to GMT, and a (redundant) specification of this can be included
629   * with the time zone.  For example, '-9', 'utc-9' and 'GMT-9' all
630   * represent a time zone nine hours west of GMT.  Similarly,
631   * '+4', 'ut+4' and 'UTC+4' all give 4 hours east of GMT.
632   * </li>
633   * <li>
634   * A number equal to or greater than 70 is regarded as a year specification.
635   * Values lower than 70 are only assumed to indicate a year if both the
636   * day of the month and the month itself have already been recognised.
637   * Year values less than 100 are interpreted as being relative to the current
638   * century when the <code>Date</code> class is initialised..  Given a century,
639   * x, the year is assumed to be within the range x - 80 to x + 19.  The value
640   * itself is then used as a match against the two last digits of one of these
641   * years.  For example, take x to be 2004.  A two-digit year is assumed to fall
642   * within the range x - 80 (1924) and x + 19 (2023).  Thus, any intepreted value
643   * between 0 and 23 is assumed to be 2000 to 2023 and values between 24 and 99
644   * are taken as being 1924 to 1999.  This only applies for the case of 2004.
645   * With a different year, the values will be interpreted differently. 2005
646   * will used 0 to 24 as 2000 to 2024 and 25 to 99 as 1925 to 1999, for example.
647   * This behaviour differs from that of <code>SimpleDateFormat</code> and is
648   * time-dependent (a two-digit year will be interpreted differently depending
649   * on the time the code is run).
650   * </li>
651   * <li>
652   * Numbers followed by a colon are interpreted by first an hour, and then
653   * as a minute, once an hour has been found.
654   * </li>
655   * <li>
656   * <li>
657   * Numbers followed by a slash are regarded first as a month, and then as
658   * a day of the month once the month has been found.  This follows the
659   * U.S. date format of mm/dd, rather than the European dd/mm.  Months
660   * are converted to the recognised value - 1 before storage, in order
661   * to put the number within the range 0 to 11.
662   * </li>
663   * <li>
664   * Numbers followed by commas, whitespace, hyphens or the end of the string
665   * are interpreted in the following order: hour, minute, second, day of month.
666   * The first type not already recognised in the current string being parsed is
667   * assumed.
668   * </li>
669   * </ul>
670   * </p>
671   * <p>
672   * A sequence of consecutive alphabetic characters is recognised as a word,
673   * and interpreted as follows, in a case-insentive fashion:
674   * <ul>
675   * <li>
676   * The characters 'AM' or 'PM' restrict the hour value to a value between 0
677   * and 12.  In the latter case, 12 is added to the hour value before storage.
678   * </li>
679   * <li>
680   * Any words which match any prefix of one of the days of the week ('Monday',
681   * 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday' and 'Sunday'),
682   * are simply ignored.
683   * </li>
684   * <li>
685   * Any words which match any prefix of one of the months of the year ('January',
686   * 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September',
687   * 'October', 'November', 'December') are recognised and interpreted as the
688   * appropriate value between 0 and 11.  The first match made against a
689   * month is the one used, in the order specified here.  For example, 'Ma' is
690   * intepreted as 'March' (2) and not as 'May' (4).  Similarly, 'Ju' is 'June',
691   * and not 'July'.
692   * </li>
693   * <li>
694   * The words 'GMT', 'UT' and 'UTC' are interpreted as specifying UTC as the
695   * time zone in use for this date.
696   * </li>
697   * <li>
698   * The word pairs 'EST'/'EDT', 'CST'/'CDT', 'MST'/'MDT' and 'PST'/'PDT' are
699   * interpreted as the appropriate U.S. time zone abbreviation.  Each pair
700   * is the standard and daylight savings time zone specification, respectively,
701   * for each zone within the U.S, these being Eastern Standard/Daylight Time
702   * (-5), Central Standard/Daylight Time (-6), Mountain Standard/Daylight Time
703   * (-7) and Pacific Standard/Daylight Time (-8).
704   * </li>
705   * </ul>
706   *
707   * @param string The String to parse.
708   * @return The time in milliseconds since the epoch.
709   * @throws IllegalArgumentException if the string fails to parse.
710   * @deprecated Use DateFormat.parse(String)
711   * @see #toString()
712   * @see SimpleDateFormat
713   */
714  public static long parse(String string)
715  {
716    // Initialize date/time fields before parsing begins.
717    int year = -1;
718    int month = -1;
719    int day = -1;
720    int hour = -1;
721    int minute = -1;
722    int second = -1;
723    int timezone = 0;
724    boolean localTimezone = true;
725
726    // Trim out any nested stuff in parentheses now to make parsing easier.
727    CPStringBuilder buf = new CPStringBuilder();
728    int parenNesting = 0;
729    int len = string.length();
730    for (int i = 0;  i < len;  i++)
731      {
732        char ch = string.charAt(i);
733        if (ch >= 'a' && ch <= 'z')
734          ch -= 'a' - 'A';
735        if (ch == '(')
736          parenNesting++;
737        else if (parenNesting == 0)
738          buf.append(ch);
739        else if (ch == ')')
740          parenNesting--;
741      }
742    int tmpMonth;
743
744    // Make all chars upper case to simplify comparisons later.
745    // Also ignore commas; treat them as delimiters.
746    StringTokenizer strtok = new StringTokenizer(buf.toString(), " \t\n\r,");
747
748    while (strtok.hasMoreTokens())
749      {
750        String tok = strtok.nextToken();
751        char firstch = tok.charAt(0);
752        if ((firstch == '+' || firstch == '-') && year >= 0)
753          {
754            timezone = parseTz(tok, firstch);
755            localTimezone = false;
756          }
757        else if (firstch >= '0' && firstch <= '9')
758          {
759            int lastPunct = -1;
760            while (tok != null && tok.length() > 0)
761              {
762                int punctOffset = tok.length();
763                int num = 0;
764                int punct;
765                for (int i = 0;  ;  i++)
766                  {
767                    if (i >= punctOffset)
768                      {
769                        punct = -1;
770                        break;
771                      }
772                    else
773                      {
774                        punct = tok.charAt(i);
775                        if (punct >= '0' && punct <= '9')
776                          {
777                            if (num > 999999999) // in case of overflow
778                              throw new IllegalArgumentException(tok);
779                            num = 10 * num + (punct - '0');
780                          }
781                        else
782                          {
783                            punctOffset = i;
784                            break;
785                          }
786                      }
787                      
788                  }
789
790                if (punct == ':')
791                  {
792                    if (hour < 0)
793                      hour = num;
794                    else
795                      minute = num;
796                  }
797                else if (lastPunct == ':' && hour >= 0 && (minute < 0 || second < 0))
798                  {
799                    if (minute < 0)
800                      minute = num;
801                    else
802                      second = num;
803                  }
804                else if ((num >= 70
805                          && (punct == ' ' || punct == ','
806                              || punct == '/' || punct < 0))
807                         || (num < 70 && day >= 0 && month >= 0 && year < 0))
808                  {
809                    if (num >= 100)
810                      year = num;
811                    else
812                      {
813                        int curYear = 1900 + new Date().getYear();
814                        int firstYear = curYear - 80;
815                        year = firstYear / 100 * 100 + num;
816                        if (year < firstYear)
817                          year += 100;
818                      }
819                  }
820                else if (punct == '/')
821                  {
822                    if (month < 0)
823                      month = num - 1;
824                    else
825                      day = num;
826                  }
827                else if (hour >= 0 && minute < 0)
828                  minute = num;
829                else if (minute >= 0 && second < 0)
830                  second = num;
831                else if (day < 0)
832                  day = num;
833                else
834                  throw new IllegalArgumentException(tok);
835
836                // Advance string if there's more to process in this token.
837                if (punct < 0 || punctOffset + 1 >= tok.length())
838                  tok = null;
839                else
840                  tok = tok.substring(punctOffset + 1);
841                lastPunct = punct;
842              }
843          }
844        else if (firstch >= 'A' && firstch <= 'Z')
845          {
846            if (tok.equals("AM"))
847              {
848                if (hour < 1 || hour > 12)
849                  throw new IllegalArgumentException(tok);
850                if (hour == 12)
851                  hour = 0;
852              }
853            else if (tok.equals("PM"))
854              {
855                if (hour < 1 || hour > 12)
856                  throw new IllegalArgumentException(tok);
857                if (hour < 12)
858                  hour += 12;
859              }
860            else if (parseDayOfWeek(tok))
861              { /* Ignore it; throw the token away. */ }
862            else if (tok.equals("UT") || tok.equals("UTC") || tok.equals("GMT"))
863              localTimezone = false;
864            else if (tok.startsWith("UT") || tok.startsWith("GMT"))
865              {
866                int signOffset = 3;
867                if (tok.charAt(1) == 'T' && tok.charAt(2) != 'C')
868                  signOffset = 2;
869
870                char sign = tok.charAt(signOffset);
871                if (sign != '+' && sign != '-')
872                  throw new IllegalArgumentException(tok);
873
874                timezone = parseTz(tok.substring(signOffset), sign);
875                localTimezone = false;
876              }
877            else if ((tmpMonth = parseMonth(tok)) >= 0)
878              month = tmpMonth;
879            else if (tok.length() == 3 && tok.charAt(2) == 'T')
880              {
881                // Convert timezone offset from hours to minutes.
882                char ch = tok.charAt(0);
883                if (ch == 'E')
884                  timezone = -5 * 60;
885                else if (ch == 'C')
886                  timezone = -6 * 60;
887                else if (ch == 'M')
888                  timezone = -7 * 60;
889                else if (ch == 'P')
890                  timezone = -8 * 60;
891                else
892                  throw new IllegalArgumentException(tok);
893
894                // Shift 60 minutes for Daylight Savings Time.
895                if (tok.charAt(1) == 'D')
896                  timezone += 60;
897                else if (tok.charAt(1) != 'S')
898                  throw new IllegalArgumentException(tok);
899
900                localTimezone = false;
901              }
902            else
903              throw new IllegalArgumentException(tok);
904          }
905        else
906          throw new IllegalArgumentException(tok);
907      }
908
909    // Unspecified hours, minutes, or seconds should default to 0.
910    if (hour < 0)
911      hour = 0;
912    if (minute < 0)
913      minute = 0;
914    if (second < 0)
915      second = 0;
916
917    // Throw exception if any other fields have not been recognized and set.
918    if (year < 0 || month < 0 || day < 0)
919      throw new IllegalArgumentException("Missing field");
920
921    // Return the time in either local time or relative to GMT as parsed.
922    // If no time-zone was specified, get the local one (in minutes) and
923    // convert to milliseconds before adding to the UTC.
924    GregorianCalendar cal
925      = new GregorianCalendar(year, month, day, hour, minute, second);
926    if (!localTimezone)
927      {
928        cal.set(Calendar.ZONE_OFFSET, timezone * 60 * 1000);
929        cal.set(Calendar.DST_OFFSET, 0);
930      }
931    return cal.getTimeInMillis();
932  }
933
934  /**
935   * Returns the difference between the year represented by this
936   * <code>Date</code> object and 1900.
937   *
938   * @return the year minus 1900 represented by this date object.
939   * @deprecated Use Calendar instead of Date, and use get(Calendar.YEAR)
940   * instead.  Note the 1900 difference in the year.
941   * @see Calendar
942   * @see #setYear(int)
943   */
944  public int getYear()
945  {
946    Calendar cal = Calendar.getInstance();
947    cal.setTimeInMillis(time);
948    return cal.get(Calendar.YEAR) - 1900;
949  }
950
951  /**
952   * Sets the year to the specified year, plus 1900.  The other
953   * fields are only altered as required to match the same date
954   * and time in the new year.  Usually, this will mean that
955   * the fields are not changed at all, but in the case of
956   * a leap day or leap second, the fields will change in
957   * relation to the existence of such an event in the new year.
958   * For example, if the date specifies February the 29th, 2000,
959   * then this will become March the 1st if the year is changed
960   * to 2001, as 2001 is not a leap year.  Similarly, a seconds
961   * value of 60 or 61 may result in the seconds becoming 0 and
962   * the minute increasing by 1, if the new time does not include
963   * a leap second.
964   *
965   * @param year the year minus 1900.
966   * @deprecated Use Calendar instead of Date, and use
967   * set(Calendar.YEAR, year) instead.  Note about the 1900
968   * difference in year.  
969   * @see #getYear()
970   * @see Calendar
971   */
972  public void setYear(int year)
973  {
974    Calendar cal = Calendar.getInstance();
975    cal.setTimeInMillis(time);
976    cal.set(Calendar.YEAR, 1900 + year);
977    time = cal.getTimeInMillis();
978  }
979
980  /**
981   * Returns the month represented by this <code>Date</code> object,
982   * as a value between 0 (January) and 11 (December).
983   *
984   * @return the month represented by this date object (zero based).
985   * @deprecated Use Calendar instead of Date, and use get(Calendar.MONTH)
986   * instead.
987   * @see #setMonth(int)
988   * @see Calendar
989   */
990  public int getMonth()
991  {
992    Calendar cal = Calendar.getInstance();
993    cal.setTimeInMillis(time);
994    return cal.get(Calendar.MONTH);
995  }
996
997  /**
998   * Sets the month to the given value.  The other
999   * fields are only altered as necessary to match
1000   * the same date and time in the new month.  In most
1001   * cases, the other fields won't change at all.  However,
1002   * in the case of a shorter month or a leap second, values
1003   * may be adjusted.  For example, if the day of the month
1004   * is currently 31, and the month value is changed from
1005   * January (0) to September (8), the date will become
1006   * October the 1st, as September only has 30 days.  Similarly,
1007   * a seconds value of 60 or 61 (a leap second) may result
1008   * in the seconds value being reset to 0 and the minutes
1009   * value being incremented by 1, if the new time does
1010   * not include a leap second.
1011   * 
1012   * @param month the month, with a zero-based index
1013   *        from January.
1014   * @deprecated Use Calendar instead of Date, and use
1015   * set(Calendar.MONTH, month) instead.
1016   * @see #getMonth()
1017   * @see Calendar 
1018   */
1019  public void setMonth(int month)
1020  {
1021    Calendar cal = Calendar.getInstance();
1022    cal.setTimeInMillis(time);
1023    cal.set(Calendar.MONTH, month);
1024    time = cal.getTimeInMillis();
1025  }
1026
1027  /**
1028   * Returns the day of the month of this <code>Date</code>
1029   * object, as a value between 0 and 31.
1030   *
1031   * @return the day of month represented by this date object.
1032   * @deprecated Use Calendar instead of Date, and use get(Calendar.DATE)
1033   * instead.
1034   * @see Calendar
1035   * @see #setDate(int)
1036   */
1037  public int getDate()
1038  {
1039    Calendar cal = Calendar.getInstance();
1040    cal.setTimeInMillis(time);
1041    return cal.get(Calendar.DATE);
1042  }
1043
1044  /**
1045   * Sets the date to the given value. The other
1046   * fields are only altered as necessary to match
1047   * the same date and time on the new day of the month.  In most
1048   * cases, the other fields won't change at all.  However,
1049   * in the case of a leap second or the day being out of
1050   * the range of the current month, values
1051   * may be adjusted.  For example, if the day of the month
1052   * is currently 30 and the month is June, a new day of the
1053   * month value of 31 will cause the month to change to July,
1054   * as June only has 30 days .  Similarly,
1055   * a seconds value of 60 or 61 (a leap second) may result
1056   * in the seconds value being reset to 0 and the minutes
1057   * value being incremented by 1, if the new time does
1058   * not include a leap second.
1059   *
1060   * @param date the date.
1061   * @deprecated Use Calendar instead of Date, and use
1062   * set(Calendar.DATE, date) instead. 
1063   * @see Calendar
1064   * @see #getDate()
1065   */
1066  public void setDate(int date)
1067  {
1068    Calendar cal = Calendar.getInstance();
1069    cal.setTimeInMillis(time);
1070    cal.set(Calendar.DATE, date);
1071    time = cal.getTimeInMillis();
1072  }
1073
1074  /**
1075   * Returns the day represented by this <code>Date</code>
1076   * object as an integer between 0 (Sunday) and 6 (Saturday).
1077   *
1078   * @return the day represented by this date object.
1079   * @deprecated Use Calendar instead of Date, and use get(Calendar.DAY_OF_WEEK)
1080   * instead.
1081   * @see Calendar
1082   */
1083  public int getDay()
1084  {
1085    Calendar cal = Calendar.getInstance();
1086    cal.setTimeInMillis(time);
1087    // For Calendar, Sunday is 1.  For Date, Sunday is 0.
1088    return cal.get(Calendar.DAY_OF_WEEK) - 1;
1089  }
1090
1091  /**
1092   * Returns the hours represented by this <code>Date</code>
1093   * object as an integer between 0 and 23.
1094   *
1095   * @return the hours represented by this date object.
1096   * @deprecated Use Calendar instead of Date, and use get(Calendar.HOUR_OF_DAY)
1097   * instead.
1098   * @see Calendar
1099   * @see #setHours(int)
1100   */
1101  public int getHours()
1102  {
1103    Calendar cal = Calendar.getInstance();
1104    cal.setTimeInMillis(time);
1105    return cal.get(Calendar.HOUR_OF_DAY);
1106  }
1107
1108  /**
1109   * Sets the hours to the given value.  The other
1110   * fields are only altered as necessary to match
1111   * the same date and time in the new hour.  In most
1112   * cases, the other fields won't change at all.  However,
1113   * in the case of a leap second, values
1114   * may be adjusted.  For example,
1115   * a seconds value of 60 or 61 (a leap second) may result
1116   * in the seconds value being reset to 0 and the minutes
1117   * value being incremented by 1 if the new hour does
1118   * not contain a leap second.
1119   *
1120   * @param hours the hours.
1121   * @deprecated Use Calendar instead of Date, and use
1122   * set(Calendar.HOUR_OF_DAY, hours) instead.
1123   * @see Calendar
1124   * @see #getHours() 
1125   */
1126  public void setHours(int hours)
1127  {
1128    Calendar cal = Calendar.getInstance();
1129    cal.setTimeInMillis(time);
1130    cal.set(Calendar.HOUR_OF_DAY, hours);
1131    time = cal.getTimeInMillis();
1132  }
1133
1134  /**
1135   * Returns the number of minutes represented by the <code>Date</code>
1136   * object, as an integer between 0 and 59.
1137   *
1138   * @return the minutes represented by this date object.
1139   * @deprecated Use Calendar instead of Date, and use get(Calendar.MINUTE)
1140   * instead.
1141   * @see Calendar
1142   * @see #setMinutes(int)
1143   */
1144  public int getMinutes()
1145  {
1146    Calendar cal = Calendar.getInstance();
1147    cal.setTimeInMillis(time);
1148    return cal.get(Calendar.MINUTE);
1149  }
1150
1151  /**
1152   * Sets the minutes to the given value.  The other
1153   * fields are only altered as necessary to match
1154   * the same date and time in the new minute.  In most
1155   * cases, the other fields won't change at all.  However,
1156   * in the case of a leap second, values
1157   * may be adjusted.  For example,
1158   * a seconds value of 60 or 61 (a leap second) may result
1159   * in the seconds value being reset to 0 and the minutes
1160   * value being incremented by 1 if the new minute does
1161   * not contain a leap second.
1162   *
1163   * @param minutes the minutes.
1164   * @deprecated Use Calendar instead of Date, and use
1165   * set(Calendar.MINUTE, minutes) instead. 
1166   * @see Calendar
1167   * @see #getMinutes()
1168   */
1169  public void setMinutes(int minutes)
1170  {
1171    Calendar cal = Calendar.getInstance();
1172    cal.setTimeInMillis(time);
1173    cal.set(Calendar.MINUTE, minutes);
1174    time = cal.getTimeInMillis();
1175  }
1176
1177  /**
1178   * Returns the number of seconds represented by the <code>Date</code>
1179   * object, as an integer between 0 and 61 (60 and 61 being leap seconds).
1180   *
1181   * @return the seconds represented by this date object.
1182   * @deprecated Use Calendar instead of Date, and use get(Calendar.SECOND)
1183   * instead.
1184   * @see Calendar
1185   * @see #setSeconds(int)
1186   */
1187  public int getSeconds()
1188  {
1189    Calendar cal = Calendar.getInstance();
1190    cal.setTimeInMillis(time);
1191    return cal.get(Calendar.SECOND);
1192  }
1193
1194  /**
1195   * Sets the seconds to the given value.  The other
1196   * fields are only altered as necessary to match
1197   * the same date and time in the new minute.  In most
1198   * cases, the other fields won't change at all.  However,
1199   * in the case of a leap second, values
1200   * may be adjusted.  For example, setting the
1201   * seconds value to 60 or 61 (a leap second) may result
1202   * in the seconds value being reset to 0 and the minutes
1203   * value being incremented by 1, if the current time does
1204   * not contain a leap second.
1205   *
1206   * @param seconds the seconds.
1207   * @deprecated Use Calendar instead of Date, and use
1208   * set(Calendar.SECOND, seconds) instead.
1209   * @see Calendar
1210   * @see #getSeconds() 
1211   */
1212  public void setSeconds(int seconds)
1213  {
1214    Calendar cal = Calendar.getInstance();
1215    cal.setTimeInMillis(time);
1216    cal.set(Calendar.SECOND, seconds);
1217    time = cal.getTimeInMillis();
1218  }
1219
1220  /**
1221   * Deserializes a <code>Date</code> object from an
1222   * input stream, setting the time (in milliseconds
1223   * since the epoch) to the long value read from the
1224   * stream.
1225   *
1226   * @param input the input stream.
1227   * @throws IOException if an I/O error occurs in the stream.
1228   * @throws ClassNotFoundException if the class of the
1229   *         serialized object could not be found.
1230   */
1231  private void readObject(ObjectInputStream input)
1232    throws IOException, ClassNotFoundException
1233  {
1234    input.defaultReadObject();
1235    time = input.readLong();
1236  }
1237
1238  /**
1239   * Serializes a <code>Date</code> object to an output stream,
1240   * storing the time (in milliseconds since the epoch) as a long
1241   * value in the stream.
1242   *
1243   * @serialdata A long value representing the offset from the epoch
1244   * in milliseconds.  This is the same value that is returned by the
1245   * method getTime().
1246   * @param output the output stream.
1247   * @throws IOException if an I/O error occurs in the stream.
1248   */
1249  private void writeObject(ObjectOutputStream output)
1250    throws IOException
1251  {
1252    output.defaultWriteObject();
1253    output.writeLong(time);
1254  }
1255
1256}