gregoriancalendar.java

gcc的组建

      }

    if (isSet[DAY_OF_MONTH])
      if (fields[DAY_OF_MONTH] < 1
          || fields[DAY_OF_MONTH] > month_days[month]
          + ((month == 1) ? leap : 0))
	throw new IllegalArgumentException("Illegal DAY_OF_MONTH.");

    if (isSet[DAY_OF_YEAR]
        && (fields[DAY_OF_YEAR] < 1 || fields[DAY_OF_YEAR] > 365 + leap))
      throw new IllegalArgumentException("Illegal DAY_OF_YEAR.");

    if (isSet[DAY_OF_WEEK]
        && (fields[DAY_OF_WEEK] < 1 || fields[DAY_OF_WEEK] > 7))
      throw new IllegalArgumentException("Illegal DAY_OF_WEEK.");

    if (isSet[DAY_OF_WEEK_IN_MONTH])
      {
	int weeks = (month == 1 && leap == 0) ? 4 : 5;
	if (fields[DAY_OF_WEEK_IN_MONTH] < -weeks
	    || fields[DAY_OF_WEEK_IN_MONTH] > weeks)
	  throw new IllegalArgumentException("Illegal DAY_OF_WEEK_IN_MONTH.");
      }

    if (isSet[AM_PM] && fields[AM_PM] != AM && fields[AM_PM] != PM)
      throw new IllegalArgumentException("Illegal AM_PM.");
    if (isSet[HOUR] && (fields[HOUR] < 0 || fields[HOUR] > 11))
      throw new IllegalArgumentException("Illegal HOUR.");
    if (isSet[HOUR_OF_DAY]
        && (fields[HOUR_OF_DAY] < 0 || fields[HOUR_OF_DAY] > 23))
      throw new IllegalArgumentException("Illegal HOUR_OF_DAY.");
    if (isSet[MINUTE] && (fields[MINUTE] < 0 || fields[MINUTE] > 59))
      throw new IllegalArgumentException("Illegal MINUTE.");
    if (isSet[SECOND] && (fields[SECOND] < 0 || fields[SECOND] > 59))
      throw new IllegalArgumentException("Illegal SECOND.");
    if (isSet[MILLISECOND]
        && (fields[MILLISECOND] < 0 || fields[MILLISECOND] > 999))
      throw new IllegalArgumentException("Illegal MILLISECOND.");
    if (isSet[ZONE_OFFSET]
        && (fields[ZONE_OFFSET] < -12 * 60 * 60 * 1000L
        || fields[ZONE_OFFSET] > 12 * 60 * 60 * 1000L))
      throw new IllegalArgumentException("Illegal ZONE_OFFSET.");
    if (isSet[DST_OFFSET]
        && (fields[DST_OFFSET] < -12 * 60 * 60 * 1000L
        || fields[DST_OFFSET] > 12 * 60 * 60 * 1000L))
      throw new IllegalArgumentException("Illegal DST_OFFSET.");
  }

  /**
   * Converts the time field values (<code>fields</code>) to
   * milliseconds since the epoch UTC (<code>time</code>).
   *
   * @throws IllegalArgumentException if any calendar fields
   *         are invalid.
   */
  protected synchronized void computeTime()
  {
    int millisInDay = 0;
    int era = fields[ERA];
    int year = fields[YEAR];
    int month = fields[MONTH];
    int day = fields[DAY_OF_MONTH];

    int minute = fields[MINUTE];
    int second = fields[SECOND];
    int millis = fields[MILLISECOND];
    int[] month_days = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
    int[] dayCount = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
    int hour = 0;

    if (! isLenient())
      nonLeniencyCheck();

    if (! isSet[MONTH] && (! isSet[DAY_OF_WEEK] || isSet[WEEK_OF_YEAR]))
      {
	// 5: YEAR + DAY_OF_WEEK + WEEK_OF_YEAR
	if (isSet[WEEK_OF_YEAR])
	  {
	    int first = getFirstDayOfMonth(year, 0);
	    int offs = 1;
	    int daysInFirstWeek = getFirstDayOfWeek() - first;
	    if (daysInFirstWeek <= 0)
	      daysInFirstWeek += 7;

	    if (daysInFirstWeek < getMinimalDaysInFirstWeek())
	      offs += daysInFirstWeek;
	    else
	      offs -= 7 - daysInFirstWeek;
	    month = 0;
	    day = offs + 7 * (fields[WEEK_OF_YEAR] - 1);
	    offs = fields[DAY_OF_WEEK] - getFirstDayOfWeek();

	    if (offs < 0)
	      offs += 7;
	    day += offs;
	  }
	else
	  {
	    // 4:  YEAR + DAY_OF_YEAR
	    month = 0;
	    day = fields[DAY_OF_YEAR];
	  }
      }
    else
      {
	if (isSet[DAY_OF_WEEK])
	  {
	    int first = getFirstDayOfMonth(year, month);

	    // 3: YEAR + MONTH + DAY_OF_WEEK_IN_MONTH + DAY_OF_WEEK
	    if (isSet[DAY_OF_WEEK_IN_MONTH])
	      {
		if (fields[DAY_OF_WEEK_IN_MONTH] < 0)
		  {
		    month++;
		    first = getFirstDayOfMonth(year, month);
		    day = 1 + 7 * (fields[DAY_OF_WEEK_IN_MONTH]);
		  }
		else
		  day = 1 + 7 * (fields[DAY_OF_WEEK_IN_MONTH] - 1);

		int offs = fields[DAY_OF_WEEK] - first;
		if (offs < 0)
		  offs += 7;
		day += offs;
	      }
	    else
	      { // 2: YEAR + MONTH + WEEK_OF_MONTH + DAY_OF_WEEK
		int offs = 1;
		int daysInFirstWeek = getFirstDayOfWeek() - first;
		if (daysInFirstWeek <= 0)
		  daysInFirstWeek += 7;

		if (daysInFirstWeek < getMinimalDaysInFirstWeek())
		  offs += daysInFirstWeek;
		else
		  offs -= 7 - daysInFirstWeek;

		day = offs + 7 * (fields[WEEK_OF_MONTH] - 1);
		offs = fields[DAY_OF_WEEK] - getFirstDayOfWeek();
		if (offs <= 0)
		  offs += 7;
		day += offs;
	      }
	  }

	// 1:  YEAR + MONTH + DAY_OF_MONTH
      }
    if (era == BC && year > 0)
      year = 1 - year;

    // rest of code assumes day/month/year set
    // should negative BC years be AD?
    // get the hour (but no check for validity)
    if (isSet[HOUR])
      {
	hour = fields[HOUR];
	if (fields[AM_PM] == PM)
	  hour += 12;
      }
    else
      hour = fields[HOUR_OF_DAY];

    // Read the era,year,month,day fields and convert as appropriate.
    // Calculate number of milliseconds into the day
    // This takes care of both h, m, s, ms over/underflows.
    long allMillis = (((hour * 60L) + minute) * 60L + second) * 1000L + millis;
    day += allMillis / (24 * 60 * 60 * 1000L);
    millisInDay = (int) (allMillis % (24 * 60 * 60 * 1000L));

    if (month < 0)
      {
	year += (int) month / 12;
	month = month % 12;
	if (month < 0)
	  {
	    month += 12;
	    year--;
	  }
      }
    if (month > 11)
      {
	year += (month / 12);
	month = month % 12;
      }

    month_days[1] = isLeapYear(year) ? 29 : 28;

    while (day <= 0)
      {
	if (month == 0)
	  {
	    year--;
	    month_days[1] = isLeapYear(year) ? 29 : 28;
	  }
	month = (month + 11) % 12;
	day += month_days[month];
      }
    while (day > month_days[month])
      {
	day -= (month_days[month]);
	month = (month + 1) % 12;
	if (month == 0)
	  {
	    year++;
	    month_days[1] = isLeapYear(year) ? 29 : 28;
	  }
      }

    // ok, by here we have valid day,month,year,era and millisinday
    int dayOfYear = dayCount[month] + day - 1; // (day starts on 1)
    if (isLeapYear(year) && month > 1)
      dayOfYear++;

    int relativeDay = (year - 1) * 365 + ((year - 1) >> 2) + dayOfYear
                      - EPOCH_DAYS; // gregorian days from 1 to epoch.
    int gregFactor = (int) Math.floor((double) (year - 1) / 400.)
                     - (int) Math.floor((double) (year - 1) / 100.);

    if ((relativeDay + gregFactor) * 60L * 60L * 24L * 1000L >= gregorianCutover)
      relativeDay += gregFactor;
    else
      relativeDay -= 2;

    time = relativeDay * (24 * 60 * 60 * 1000L) + millisInDay;

    // the epoch was a Thursday.
    int weekday = (int) (relativeDay + THURSDAY) % 7;
    if (weekday <= 0)
      weekday += 7;
    fields[DAY_OF_WEEK] = weekday;

    // Time zone corrections.
    TimeZone zone = getTimeZone();
    int rawOffset = isSet[ZONE_OFFSET] ? fields[ZONE_OFFSET]
                                       : zone.getRawOffset();

    int dstOffset = isSet[DST_OFFSET] ? fields[DST_OFFSET]
                                      : (zone.getOffset((year < 0) ? BC : AD,
                                                        (year < 0) ? 1 - year
                                                                   : year,
                                                        month, day, weekday,
                                                        millisInDay)
                                      - zone.getRawOffset());

    time -= rawOffset + dstOffset;

    isTimeSet = true;
  }

  /**
   * Get the linear day in days since the epoch, using the
   * Julian or Gregorian calendar as specified.  If you specify a
   * nonpositive year it is interpreted as BC as following: 0 is 1
   * BC, -1 is 2 BC and so on.
   *
   * @param year the year of the date.
   * @param dayOfYear the day of year of the date; 1 based.
   * @param gregorian <code>true</code>, if we should use the Gregorian rules.
   * @return the days since the epoch, may be negative.
   */
  private long getLinearDay(int year, int dayOfYear, boolean gregorian)
  {
    // The 13 is the number of days, that were omitted in the Gregorian
    // Calender until the epoch.
    // We shift right by 2 instead of dividing by 4, to get correct
    // results for negative years (and this is even more efficient).
    long julianDay = (year - 1) * 365L + ((year - 1) >> 2) + (dayOfYear - 1)
                     - EPOCH_DAYS; // gregorian days from 1 to epoch.

    if (gregorian)
      {
	// subtract the days that are missing in gregorian calendar
	// with respect to julian calendar.
	//
	// Okay, here we rely on the fact that the gregorian
	// calendar was introduced in the AD era.  This doesn't work
	// with negative years.
	//
	// The additional leap year factor accounts for the fact that
	// a leap day is not seen on Jan 1 of the leap year.
	int gregOffset = (int) Math.floor((double) (year - 1) / 400.)
	                 - (int) Math.floor((double) (year - 1) / 100.);

	return julianDay + gregOffset;
      }
    else
      julianDay -= 2;
    return julianDay;
  }

  /**
   * Converts the given linear day into era, year, month,
   * day_of_year, day_of_month, day_of_week, and writes the result
   * into the fields array.
   *
   * @param day the linear day.
   * @param gregorian true, if we should use Gregorian rules.
   */
  private void calculateDay(int[] fields, long day, boolean gregorian)
  {
    // the epoch was a Thursday.
    int weekday = (int) (day + THURSDAY) % 7;
    if (weekday <= 0)
      weekday += 7;
    fields[DAY_OF_WEEK] = weekday;

    // get a first approximation of the year.  This may be one 
    // year too big.
    int year = 1970
               + (int) (gregorian
                        ? ((day - 100L) * 400L) / (365L * 400L + 100L - 4L
                        + 1L) : ((day - 100L) * 4L) / (365L * 4L + 1L));
    if (day >= 0)
      year++;

    long firstDayOfYear = getLinearDay(year, 1, gregorian);

    // Now look in which year day really lies.
    if (day < firstDayOfYear)
      {
	year--;
	firstDayOfYear = getLinearDay(year, 1, gregorian);
      }

    day -= firstDayOfYear - 1; // day of year,  one based.

    fields[DAY_OF_YEAR] = (int) day;
    if (year <= 0)
      {
	fields[ERA] = BC;
	fields[YEAR] = 1 - year;
      }
    else
      {
	fields[ERA] = AD;
	fields[YEAR] = year;
      }

    int leapday = isLeapYear(year) ? 1 : 0;
    if (day <= 31 + 28 + leapday)
      {
	fields[MONTH] = (int) day / 32; // 31->JANUARY, 32->FEBRUARY
	fields[DAY_OF_MONTH] = (int) day - 31 * fields[MONTH];
      }
    else
      {
	// A few more magic formulas
	int scaledDay = ((int) day - leapday) * 5 + 8;
	fields[MONTH] = scaledDay / (31 + 30 + 31 + 30 + 31);
	fields[DAY_OF_MONTH] = (scaledDay % (31 + 30 + 31 + 30 + 31)) / 5 + 1;
      }
  }

  /**
   * Converts the milliseconds since the epoch UTC
   * (<code>time</code>) to time fields
   * (<code>fields</code>).
   */
  protected synchronized void computeFields()
  {
    boolean gregorian = (time >= gregorianCutover);

    TimeZone zone = getTimeZone();
    fields[ZONE_OFFSET] = zone.getRawOffset();
    long localTime = time + fields[ZONE_OFFSET];

    long day = localTime / (24 * 60 * 60 * 1000L);
    int millisInDay = (int) (localTime % (24 * 60 * 60 * 1000L));

    if (millisInDay < 0)
      {
	millisInDay += (24 * 60 * 60 * 1000);
	day--;
      }

    calculateDay(fields, day, gregorian);
    fields[DST_OFFSET] = zone.getOffset(fields[ERA], fields[YEAR],
                                        fields[MONTH], fields[DAY_OF_MONTH],
                                        fields[DAY_OF_WEEK], millisInDay)
                         - fields[ZONE_OFFSET];

    millisInDay += fields[DST_OFFSET];
    if (millisInDay >= 24 * 60 * 60 * 1000)
      {
	millisInDay -= 24 * 60 * 60 * 1000;
	calculateDay(fields, ++day, gregorian);
      }

    fields[DAY_OF_WEEK_IN_MONTH] = (fields[DAY_OF_MONTH] + 6) / 7;

    // which day of the week are we (0..6), relative to getFirstDayOfWeek
    int relativeWeekday = (7 + fields[DAY_OF_WEEK] - getFirstDayOfWeek()) % 7;

    fields[WEEK_OF_MONTH] = (fields[DAY_OF_MONTH] - relativeWeekday + 12) / 7;

    int weekOfYear = (fields[DAY_OF_YEAR] - relativeWeekday + 6) / 7;

    // Do the Correction: getMinimalDaysInFirstWeek() is always in the 
    // first week.
    int minDays = getMinimalDaysInFirstWeek();
    int firstWeekday = (7 + getWeekDay(fields[YEAR], minDays)
                       - getFirstDayOfWeek()) % 7;
    if (minDays - firstWeekday < 1)
      weekOfYear++;
    fields[WEEK_OF_YEAR] = weekOfYear;

    int hourOfDay = millisInDay / (60 * 60 * 1000);
    fields[AM_PM] = (hourOfDay < 12) ? AM : PM;
    int hour = hourOfDay % 12;
    fields[HOUR] = hour;
    fields[HOUR_OF_DAY] = hourOfDay;
    millisInDay %= (60 * 60 * 1000);
    fields[MINUTE] = millisInDay / (60 * 1000);
    millisInDay %= (60 * 1000);
    fields[SECOND] = millisInDay / (1000);
    fields[MILLISECOND] = millisInDay % 1000;

    areFieldsSet = isSet[ERA] = isSet[YEAR] = isSet[MONTH] = isSet[WEEK_OF_YEAR] = isSet[WEEK_OF_MONTH] = isSet[DAY_OF_MONTH] = isSet[DAY_OF_YEAR] = isSet[DAY_OF_WEEK] = isSet[DAY_OF_WEEK_IN_MONTH] = isSet[AM_PM] = isSet[HOUR] = isSet[HOUR_OF_DAY] = isSet[MINUTE] = isSet[SECOND] = isSet[MILLISECOND] = isSet[ZONE_OFFSET] = isSet[DST_OFFSET] = true;
  }
  
  /**
   * Return a hash code for this object, following the general contract
   * specified by {@link Object#hashCode()}.
   * @return the hash code
   */
  public int hashCode()
  {
    int val = (int) ((gregorianCutover >>> 32) ^ (gregorianCutover & 0xffffffff));
    return super.hashCode() ^ val;
  }

  /**
   * Compares the given calendar with this.  An object, o, is
   * equivalent to this if it is also a <code>GregorianCalendar</code>
   * with the same time since the epoch under the same conditions
   * (same change date and same time zone).
   *
   * @param o the object to that we should compare.
   * @return true, if the given object is a calendar, that represents
   * the same time (but doesn't necessarily have the same fields).
   * @throws IllegalArgumentException if one of the fields
   *         <code>ZONE_OFFSET</code> or <code>DST_OFFSET</code> is
   *         specified, if an unknown field is specified or if one
   *         of the calendar fields receives an illegal value when
   *         leniancy is not enabled.
   */
  public boolean equals(Object o)
  {
    if (! (o instanceof GregorianCalendar))
      return false;

    GregorianCalendar cal = (GregorianCalendar) o;