timezone.java

gcc的组建

	tz = new SimpleTimeZone
	  (10500 * 3600, "Australia/Lord_Howe",
	  Calendar.OCTOBER, -1, Calendar.SUNDAY, 2000 * 3600,
	  Calendar.MARCH, -1, Calendar.SUNDAY, 2000 * 3600, 500 * 3600);
	timezones0.put("Australia/Lord_Howe", tz);
	tz = new SimpleTimeZone
	  (11000 * 3600, "Asia/Magadan",
	   Calendar.MARCH, -1, Calendar.SUNDAY, 3000 * 3600,
	   Calendar.OCTOBER, -1, Calendar.SUNDAY, 3000 * 3600);
	timezones0.put("Asia/Magadan", tz);
	tz = new SimpleTimeZone(11000 * 3600, "SST");
	timezones0.put("SST", tz);
	timezones0.put("Pacific/Efate", tz);
	timezones0.put("Pacific/Guadalcanal", tz);
	timezones0.put("Pacific/Kosrae", tz);
	timezones0.put("Pacific/Noumea", tz);
	timezones0.put("Pacific/Ponape", tz);
	tz = new SimpleTimeZone(11500 * 3600, "Pacific/Norfolk");
	timezones0.put("Pacific/Norfolk", tz);
	tz = new SimpleTimeZone
	  (12000 * 3600, "NST",
	   Calendar.OCTOBER, 1, Calendar.SUNDAY, 3000 * 3600,
	   Calendar.MARCH, 3, Calendar.SUNDAY, 3000 * 3600);
	timezones0.put("NST", tz);
	timezones0.put("Antarctica/McMurdo", tz);
	timezones0.put("Antarctica/South_Pole", tz);
	timezones0.put("Pacific/Auckland", tz);
	tz = new SimpleTimeZone
	  (12000 * 3600, "Asia/Anadyr",
	   Calendar.MARCH, -1, Calendar.SUNDAY, 3000 * 3600,
	   Calendar.OCTOBER, -1, Calendar.SUNDAY, 3000 * 3600);
	timezones0.put("Asia/Anadyr", tz);
	timezones0.put("Asia/Kamchatka", tz);
	tz = new SimpleTimeZone(12000 * 3600, "Pacific/Fiji");
	timezones0.put("Pacific/Fiji", tz);
	timezones0.put("Pacific/Funafuti", tz);
	timezones0.put("Pacific/Kwajalein", tz);
	timezones0.put("Pacific/Majuro", tz);
	timezones0.put("Pacific/Nauru", tz);
	timezones0.put("Pacific/Tarawa", tz);
	timezones0.put("Pacific/Wake", tz);
	timezones0.put("Pacific/Wallis", tz);
	tz = new SimpleTimeZone
	  (12750 * 3600, "Pacific/Chatham",
	   Calendar.OCTOBER, 1, Calendar.SUNDAY, 3750 * 3600,
	   Calendar.MARCH, 3, Calendar.SUNDAY, 3750 * 3600);
	timezones0.put("Pacific/Chatham", tz);
	tz = new SimpleTimeZone(13000 * 3600, "Pacific/Enderbury");
	timezones0.put("Pacific/Enderbury", tz);
	timezones0.put("Pacific/Tongatapu", tz);
	tz = new SimpleTimeZone(14000 * 3600, "Pacific/Kiritimati");
	timezones0.put("Pacific/Kiritimati", tz);
      }
    return timezones0;
  }

  /**
   * Maps a time zone name (with optional GMT offset and daylight time
   * zone name) to one of the known time zones.  This method called
   * with the result of <code>System.getProperty("user.timezone")</code>
   * or <code>getDefaultTimeZoneId()</code>.  Note that giving one of
   * the standard tz data names from ftp://elsie.nci.nih.gov/pub/ is
   * preferred.  
   * The time zone name can be given as follows:
   * <code>(standard zone name)[(GMT offset)[(DST zone name)[DST offset]]]
   * </code>
   * <p>
   * If only a (standard zone name) is given (no numbers in the
   * String) then it gets mapped directly to the TimeZone with that
   * name, if that fails null is returned.
   * <p>
   * Alternately, a POSIX-style TZ string can be given, defining the time zone:
   * <code>std offset dst offset,date/time,date/time</code>
   * See the glibc manual, or the man page for <code>tzset</code> for details
   * of this format.
   * <p>
   * A GMT offset is the offset to add to the local time to get GMT.
   * If a (GMT offset) is included (either in seconds or hours) then
   * an attempt is made to find a TimeZone name matching both the name
   * and the offset (that doesn't observe daylight time, if the
   * timezone observes daylight time then you must include a daylight
   * time zone name after the offset), if that fails then a TimeZone
   * with the given GMT offset is returned (whether or not the
   * TimeZone observes daylight time is ignored), if that also fails
   * the GMT TimeZone is returned.
   * <p>
   * If the String ends with (GMT offset)(daylight time zone name)
   * then an attempt is made to find a TimeZone with the given name and
   * GMT offset that also observes (the daylight time zone name is not
   * currently used in any other way), if that fails a TimeZone with
   * the given GMT offset that observes daylight time is returned, if
   * that also fails the GMT TimeZone is returned.
   * <p>
   * Examples: In Chicago, the time zone id could be "CST6CDT", but
   * the preferred name would be "America/Chicago".  In Indianapolis
   * (which does not have Daylight Savings Time) the string could be
   * "EST5", but the preferred name would be "America/Indianapolis".
   * The standard time zone name for The Netherlands is "Europe/Amsterdam",
   * but can also be given as "CET-1CEST".
   */
  static TimeZone getDefaultTimeZone(String sysTimeZoneId)
  {
    String stdName = null;
    String dstName;
    int stdOffs;
    int dstOffs;
    try
      {
	int idLength = sysTimeZoneId.length();

	int index = 0;
	int prevIndex;
	char c;

	// get std
	do
	  c = sysTimeZoneId.charAt(index++);
	while (c != '+' && c != '-' && c != ',' && c != ':'
	       && ! Character.isDigit(c) && c != '\0' && index < idLength);

	if (index >= idLength)
	  return (TimeZone)timezones().get(sysTimeZoneId);

	stdName = sysTimeZoneId.substring(0, --index);
	prevIndex = index;

	// get the std offset
	do
	  c = sysTimeZoneId.charAt(index++);
	while ((c == '-' || c == '+' || c == ':' || Character.isDigit(c))
	       && index < idLength);
	if (index < idLength)
	  index--;

	{ // convert the dst string to a millis number
	    String offset = sysTimeZoneId.substring(prevIndex, index);
	    prevIndex = index;

	    if (offset.charAt(0) == '+' || offset.charAt(0) == '-')
	      stdOffs = parseTime(offset.substring(1));
	    else
	      stdOffs = parseTime(offset);

	    if (offset.charAt(0) == '-')
	      stdOffs = -stdOffs;

	    // TZ timezone offsets are positive when WEST of the meridian.
	    stdOffs = -stdOffs;
	}

	// Done yet? (Format: std offset)
	if (index >= idLength)
	  {
	    // Do we have an existing timezone with that name and offset?
	    TimeZone tz = (TimeZone) timezones().get(stdName);
	    if (tz != null)
	      if (tz.getRawOffset() == stdOffs)
		return tz;

	    // Custom then.
	    return new SimpleTimeZone(stdOffs, stdName);
	  }

	// get dst
	do
	  c = sysTimeZoneId.charAt(index++);
	while (c != '+' && c != '-' && c != ',' && c != ':'
	       && ! Character.isDigit(c) && c != '\0' && index < idLength);

	// Done yet? (Format: std offset dst)
	if (index >= idLength)
	  {
	    // Do we have an existing timezone with that name and offset 
	    // which has DST?
	    TimeZone tz = (TimeZone) timezones().get(stdName);
	    if (tz != null)
	      if (tz.getRawOffset() == stdOffs && tz.useDaylightTime())
		return tz;

	    // Custom then.
	    return new SimpleTimeZone(stdOffs, stdName);
	  }

	// get the dst offset
	dstName = sysTimeZoneId.substring(prevIndex, --index);
	prevIndex = index;
	do
	  c = sysTimeZoneId.charAt(index++);
	while ((c == '-' || c == '+' || c == ':' || Character.isDigit(c))
	       && index < idLength);
	if (index < idLength)
	  index--;

	{ // convert the dst string to a millis number
	    String offset = sysTimeZoneId.substring(prevIndex, index);
	    prevIndex = index;

	    if (offset.charAt(0) == '+' || offset.charAt(0) == '-')
	      dstOffs = parseTime(offset.substring(1));
	    else
	      dstOffs = parseTime(offset);

	    if (offset.charAt(0) == '-')
	      dstOffs = -dstOffs;

	    // TZ timezone offsets are positive when WEST of the meridian.
	    dstOffs = -dstOffs;
	}

	// Done yet? (Format: std offset dst offset)
	// FIXME: We don't support DST without a rule given. Should we?
	if (index >= idLength)
	  {
	    // Time Zone existing with same name, dst and offsets?
	    TimeZone tz = (TimeZone) timezones().get(stdName);
	    if (tz != null)
	      if (tz.getRawOffset() == stdOffs && tz.useDaylightTime()
	          && tz.getDSTSavings() == (dstOffs - stdOffs))
		return tz;

	    return new SimpleTimeZone(stdOffs, stdName);
	  }

	// get the DST rule
	if (sysTimeZoneId.charAt(index) == ','
	    || sysTimeZoneId.charAt(index) == ';')
	  {
	    index++;
	    int offs = index;
	    while (sysTimeZoneId.charAt(index) != ','
	           && sysTimeZoneId.charAt(index) != ';')
	      index++;
	    String startTime = sysTimeZoneId.substring(offs, index);
	    index++;
	    String endTime = sysTimeZoneId.substring(index);

	    index = startTime.indexOf('/');
	    int startMillis;
	    int endMillis;
	    String startDate;
	    String endDate;
	    if (index != -1)
	      {
		startDate = startTime.substring(0, index);
		startMillis = parseTime(startTime.substring(index + 1));
	      }
	    else
	      {
		startDate = startTime;
		// if time isn't given, default to 2:00:00 AM.
		startMillis = 2 * 60 * 60 * 1000;
	      }
	    index = endTime.indexOf('/');
	    if (index != -1)
	      {
		endDate = endTime.substring(0, index);
		endMillis = parseTime(endTime.substring(index + 1));
	      }
	    else
	      {
		endDate = endTime;
		// if time isn't given, default to 2:00:00 AM.
		endMillis = 2 * 60 * 60 * 1000;
	      }

	    int[] start = getDateParams(startDate);
	    int[] end = getDateParams(endDate);
	    return new SimpleTimeZone(stdOffs, stdName, start[0], start[1],
	                              start[2], startMillis, end[0], end[1],
	                              end[2], endMillis, (dstOffs - stdOffs));
	  }
      }

    // FIXME: Produce a warning here?
    catch (IndexOutOfBoundsException _)
      {
      }
    catch (NumberFormatException _)
      {
      }

    return null;
  }

  /**
   * Parses and returns the params for a POSIX TZ date field,
   * in the format int[]{ month, day, dayOfWeek }, following the
   * SimpleTimeZone constructor rules.
   */
  private static int[] getDateParams(String date)
  {
    int[] dayCount = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
    int month;

    if (date.charAt(0) == 'M' || date.charAt(0) == 'm')
      {
	int day;

	// Month, week of month, day of week
	month = Integer.parseInt(date.substring(1, date.indexOf('.')));
	int week = Integer.parseInt(date.substring(date.indexOf('.') + 1,
	                                           date.lastIndexOf('.')));
	int dayOfWeek = Integer.parseInt(date.substring(date.lastIndexOf('.')
	                                                + 1));
	if (week == 5)
	  day = -1; // last day of month is -1 in java, 5 in TZ
	else
	  // first day of week starting on or after.
	  day = (week - 1) * 7 + 1;

	dayOfWeek++; // Java day of week is one-based, Sunday is first day.
	month--; // Java month is zero-based.
	return new int[] { month, day, dayOfWeek };
      }

    // julian day, either zero-based 0<=n<=365 (incl feb 29)
    // or one-based 1<=n<=365 (no feb 29)
    int julianDay; // Julian day, 

    if (date.charAt(0) != 'J' || date.charAt(0) != 'j')
      {
	julianDay = Integer.parseInt(date.substring(1));
	julianDay++; // make 1-based
	// Adjust day count to include feb 29.
	dayCount = new int[]
	           {
	             0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335
	           };
      }
    else
      // 1-based julian day
      julianDay = Integer.parseInt(date);

    int i = 11;
    while (i > 0)
      if (dayCount[i] < julianDay)
	break;
      else
	i--;
    julianDay -= dayCount[i];
    month = i;
    return new int[] { month, julianDay, 0 };
  }

  /**
   * Parses a time field hh[:mm[:ss]], returning the result
   * in milliseconds. No leading sign.
   */
  private static int parseTime(String time)
  {
    int millis = 0;
    int i = 0;

    while (i < time.length())
      if (time.charAt(i) == ':')
	break;
      else
	i++;
    millis = 60 * 60 * 1000 * Integer.parseInt(time.substring(0, i));
    if (i >= time.length())
      return millis;

    int iprev = ++i;
    while (i < time.length())
      if (time.charAt(i) == ':')
	break;
      else
	i++;
    if (i >= time.length())
      return millis;

    millis += 60 * 1000 * Integer.parseInt(time.substring(iprev, i));
    millis += 1000 * Integer.parseInt(time.substring(++i));
    return millis;
  }

  /**
   * Gets the time zone offset, for current date, modified in case of 
   * daylight savings.  This is the offset to add to UTC to get the local
   * time.
   * @param era the era of the given date
   * @param year the year of the given date
   * @param month the month of the given date, 0 for January.
   * @param day the day of month
   * @param dayOfWeek the day of week
   * @param milliseconds the millis in the day (in local standard time)
   * @return the time zone offset in milliseconds.