-/* Copyright (C) 1998, 1999 Cygnus Solutions
+/* java.util.GregorianCalendar
+ Copyright (C) 1998, 1999, 2001, 2002, 2003, 2004
+ Free Software Foundation, Inc.
- This file is part of libgcj.
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING. If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library. Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module. An independent module is a module which is not derived from
+or based on this library. If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so. If you do not wish to do so, delete this
+exception statement from your version. */
-This software is copyrighted work licensed under the terms of the
-Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
-details. */
package java.util;
-/**
- * @author Per Bothner <bothner@cygnus.com>
- * @date October 24, 1998.
- */
-/* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3,
- * and "The Java Language Specification", ISBN 0-201-63451-1.
- * Status: "leniency" is not handled, and neither is roll-over in
- * add and roll. This is partly because of unclear specification.
- * hashCode has no spec.
+/**
+ * <p>
+ * This class represents the Gregorian calendar, that is used in most
+ * countries all over the world. It does also handle the Julian calendar
+ * for dates smaller than the date of the change to the Gregorian calendar.
+ * The Gregorian calendar differs from the Julian calendar by a different
+ * leap year rule (no leap year every 100 years, except if year is divisible
+ * by 400).
+ * </p>
+ * <p>
+ * This change date is different from country to country, and can be changed with
+ * <code>setGregorianChange</code>. The first countries to adopt the Gregorian
+ * calendar did so on the 15th of October, 1582. This date followed October
+ * the 4th, 1582 in the Julian calendar system. The non-existant days that were
+ * omitted when the change took place are interpreted as Gregorian dates.
+ * </p>
+ * <p>
+ * Prior to the changeover date, New Year's Day occurred on the 25th of March.
+ * However, this class always takes New Year's Day as being the 1st of January.
+ * Client code should manually adapt the year value, if required, for dates
+ * between January the 1st and March the 24th in years prior to the changeover.
+ * </p>
+ * <p>
+ * Any date infinitely forwards or backwards in time can be represented by
+ * this class. A <em>proleptic</em> calendar system is used, which allows
+ * future dates to be created via the existing rules. This allows meaningful
+ * and consistent dates to be produced for all years. However, dates are only
+ * historically accurate following March the 1st, 4AD when the Julian calendar
+ * system was adopted. Prior to this, leap year rules were applied erraticly.
+ * </p>
+ * <p>
+ * There are two eras available for the Gregorian calendar, namely BC and AD.
+ * </p>
+ * <p>
+ * Weeks are defined as a period of seven days, beginning on the first day
+ * of the week, as returned by <code>getFirstDayOfWeek()</code>, and ending
+ * on the day prior to this.
+ * </p>
+ * <p>
+ * The weeks of the year are numbered from 1 to a possible 53. The first week
+ * of the year is defined as the first week that contains at least the minimum
+ * number of days of the first week in the new year (retrieved via
+ * <code>getMinimalDaysInFirstWeek()</code>). All weeks after this are numbered
+ * from 2 onwards.
+ * </p>
+ * <p>
+ * For example, take the year 2004. It began on a Thursday. The first week
+ * of 2004 depends both on where a week begins and how long it must minimally
+ * last. Let's say that the week begins on a Monday and must have a minimum
+ * of 5 days. In this case, the first week begins on Monday, the 5th of January.
+ * The first 4 days (Thursday to Sunday) are not eligible, as they are too few
+ * to make up the minimum number of days of the first week which must be in
+ * the new year. If the minimum was lowered to 4 days, then the first week
+ * would instead begin on Monday, the 29th of December, 2003. This first week
+ * has 4 of its days in the new year, and is now eligible.
+ * </p>
+ * <p>
+ * The weeks of the month are numbered from 0 to a possible 6. The first week
+ * of the month (numbered 1) is a set of days, prior to the first day of the week,
+ * which number at least the minimum number of days in a week. Unlike the first
+ * week of the year, the first week of the month only uses days from that particular
+ * month. As a consequence, it may have a variable number of days (from the minimum
+ * number required up to a full week of 7) and it need not start on the first day of
+ * the week. It must, however, be following by the first day of the week, as this
+ * marks the beginning of week 2. Any days of the month which occur prior to the
+ * first week (because the first day of the week occurs before the minimum number
+ * of days is met) are seen as week 0.
+ * </p>
+ * <p>
+ * Again, we will take the example of the year 2004 to demonstrate this. September
+ * 2004 begins on a Wednesday. Taking our first day of the week as Monday, and the
+ * minimum length of the first week as 6, we find that week 1 runs from Monday,
+ * the 6th of September to Sunday the 12th. Prior to the 6th, there are only
+ * 5 days (Wednesday through to Sunday). This is too small a number to meet the
+ * minimum, so these are classed as being days in week 0. Week 2 begins on the
+ * 13th, and so on. This changes if we reduce the minimum to 5. In this case,
+ * week 1 is a truncated week from Wednesday the 1st to Sunday the 5th, and week
+ * 0 doesn't exist. The first seven day week is week 2, starting on the 6th.
+ * </p>
+ * <p>
+ * On using the <code>clear()</code> method, the Gregorian calendar returns
+ * to its default value of the 1st of January, 1970 AD 00:00:00 (the epoch).
+ * The day of the week is set to the correct day for that particular time.
+ * The day is also the first of the month, and the date is in week 0.
+ * </p>
+ *
+ * @see Calendar
+ * @see TimeZone
+ * @see Calendar#getFirstDayOfWeek()
+ * @see Calendar#getMinimalDaysInFirstWeek()
*/
-
-public class GregorianCalendar extends Calendar {
+public class GregorianCalendar extends Calendar
+{
+ /**
+ * Constant representing the era BC (Before Christ).
+ */
public static final int BC = 0;
+
+ /**
+ * Constant representing the era AD (Anno Domini).
+ */
public static final int AD = 1;
- // The fields are as specified in Sun's "Serialized Form"
- // in the JDK 1.2 beta 4 API specification.
- // Value from a simple test program (getGregorianChange.getTime()).
- long gregorianCutover = -12219292800000L;
-
- private final static int[] mins = {
- 0 /* ERA */,
- 1 /* YEAR */,
- 0 /* MONTH */,
- 0 /* WEEK_OF_YEAR */,
- 0 /* WEEK_OF_MONTH */,
- 1 /* DATE */,
- 1 /* DAY_OF_YEAR */,
- 1 /* DAY_OF_WEEK */,
- -1 /* DAY_OF_WEEK_IN_MONTH */,
- 0 /* AM_PM */,
- 0 /* HOUR */,
- 0 /* HOUR_OF_DAY */,
- 0 /* MINUTE */,
- 0 /* SECOND */,
- 0 /* MILLISECOND */,
- -43200000 /* ZONE_OFFSET */,
- 0 /* DST_OFFSET */
- };
-
- private final static int[] maxs = {
- 1 /* ERA */,
- 5000000 /* YEAR */,
- 11 /* MONTH */,
- 54 /* WEEK_OF_YEAR */,
- 6 /* WEEK_OF_MONTH */,
- 31 /* DATE */,
- 366 /* DAY_OF_YEAR */,
- 7 /* DAY_OF_WEEK */,
- 6 /* DAY_OF_WEEK_IN_MONTH */,
- 1 /* AM_PM */,
- 12 /* HOUR */,
- 23 /* HOUR_OF_DAY */,
- 59 /* MINUTE */,
- 59 /* SECOND */,
- 999 /* MILLISECOND */,
- 43200000 /* ZONE_OFFSET */,
- 3600000 /* DST_OFFSET */
- };
-
- private final static int[] leastMaximums = {
- 1 /* ERA */,
- 5000000 /* YEAR */,
- 11 /* MONTH */,
- 53 /* WEEK_OF_YEAR */,
- 6 /* WEEK_OF_MONTH */,
- 28 /* DATE */,
- 365 /* DAY_OF_YEAR */,
- 7 /* DAY_OF_WEEK */,
- 4 /* DAY_OF_WEEK_IN_MONTH */,
- 1 /* AM_PM */,
- 11 /* HOUR */,
- 23 /* HOUR_OF_DAY */,
- 59 /* MINUTE */,
- 59 /* SECOND */,
- 999 /* MILLISECOND */,
- 43200000 /* ZONE_OFFSET */,
- 3600000 /* DST_OFFSET */
- };
-
- public GregorianCalendar ()
+ /**
+ * The point at which the Gregorian calendar rules were used.
+ * This is locale dependent; the default for most catholic
+ * countries is midnight (UTC) on October 5, 1582 (Julian),
+ * or October 15, 1582 (Gregorian).
+ *
+ * @serial the changeover point from the Julian calendar
+ * system to the Gregorian.
+ */
+ private long gregorianCutover;
+
+ /**
+ * For compatability with Sun's JDK.
+ */
+ static final long serialVersionUID = -8125100834729963327L;
+
+ /**
+ * The name of the resource bundle. Used only by getBundle()
+ */
+ private static final String bundleName = "gnu.java.locale.Calendar";
+
+ /**
+ * Days in the epoch. Relative Jan 1, year '0' which is not a leap year.
+ * (although there is no year zero, this does not matter.)
+ * This is consistent with the formula:
+ * = (year-1)*365L + ((year-1) >> 2)
+ *
+ * Plus the gregorian correction:
+ * Math.floor((year-1) / 400.) - Math.floor((year-1) / 100.);
+ * For a correct julian date, the correction is -2 instead.
+ *
+ * The gregorian cutover in 1582 was 10 days, so by calculating the
+ * correction from year zero, we have 15 non-leap days (even centuries)
+ * minus 3 leap days (year 400,800,1200) = 12. Subtracting two corrects
+ * this to the correct number 10.
+ */
+ private static final int EPOCH_DAYS = 719162;
+
+ /**
+ * Constructs a new GregorianCalender representing the current
+ * time, using the default time zone and the default locale.
+ */
+ public GregorianCalendar()
{
- this(null, null);
+ this(TimeZone.getDefault(), Locale.getDefault());
}
- public GregorianCalendar (TimeZone zone)
+ /**
+ * Constructs a new GregorianCalender representing the current
+ * time, using the specified time zone and the default locale.
+ *
+ * @param zone a time zone.
+ */
+ public GregorianCalendar(TimeZone zone)
{
- this (zone, null);
+ this(zone, Locale.getDefault());
}
- public GregorianCalendar (Locale locale)
+ /**
+ * Constructs a new GregorianCalender representing the current
+ * time, using the default time zone and the specified locale.
+ *
+ * @param locale a locale.
+ */
+ public GregorianCalendar(Locale locale)
{
- this (null, locale);
+ this(TimeZone.getDefault(), locale);
}
- public GregorianCalendar (TimeZone zone, Locale locale)
+ /**
+ * Constructs a new GregorianCalender representing the current
+ * time with the given time zone and the given locale.
+ *
+ * @param zone a time zone.
+ * @param locale a locale.
+ */
+ public GregorianCalendar(TimeZone zone, Locale locale)
{
- super (zone, locale);
- setDefaultTime ();
+ this(zone, locale, false);
+ setTimeInMillis(System.currentTimeMillis());
+ complete();
}
- public GregorianCalendar (int year, int month, int date)
+ /**
+ * Common constructor that all constructors should call.
+ * @param zone a time zone.
+ * @param locale a locale.
+ * @param unused unused parameter to make the signature differ from
+ * the public constructor (TimeZone, Locale).
+ */
+ private GregorianCalendar(TimeZone zone, Locale locale, boolean unused)
{
- this((TimeZone) null);
- setDefaultTime ();
- set (year, month, date);
+ super(zone, locale);
+ ResourceBundle rb = ResourceBundle.getBundle(bundleName, locale,
+ ClassLoader
+ .getSystemClassLoader());
+ gregorianCutover = ((Date) rb.getObject("gregorianCutOver")).getTime();
}
- public GregorianCalendar (int year, int month, int date,
- int hour, int minute)
+ /**
+ * Constructs a new GregorianCalendar representing midnight on the
+ * given date with the default time zone and locale.
+ * @param year corresponds to the YEAR time field.
+ * @param month corresponds to the MONTH time field.
+ * @param day corresponds to the DAY time field.
+ */
+ public GregorianCalendar(int year, int month, int day)
{
- this((TimeZone) null);
- setDefaultTime ();
- set (year, month, date, hour, minute);
+ this(TimeZone.getDefault(), Locale.getDefault(), false);
+ set(year, month, day);
}
- public GregorianCalendar (int year, int month, int date,
- int hour, int minute, int second)
+ /**
+ * Constructs a new GregorianCalendar representing midnight on the
+ * given date with the default time zone and locale.
+ *
+ * @param year corresponds to the YEAR time field.
+ * @param month corresponds to the MONTH time field.
+ * @param day corresponds to the DAY time field.
+ * @param hour corresponds to the HOUR_OF_DAY time field.
+ * @param minute corresponds to the MINUTE time field.
+ */
+ public GregorianCalendar(int year, int month, int day, int hour, int minute)
{
- this((TimeZone) null);
- setDefaultTime ();
- set (year, month, date, hour, minute, second);
+ this(TimeZone.getDefault(), Locale.getDefault(), false);
+ set(year, month, day, hour, minute);
}
- private final void setDefaultTime ()
+ /**
+ * Constructs a new GregorianCalendar representing midnight on the
+ * given date with the default time zone and locale.
+ *
+ * @param year corresponds to the YEAR time field.
+ * @param month corresponds to the MONTH time field.
+ * @param day corresponds to the DAY time field.
+ * @param hour corresponds to the HOUR_OF_DAY time field.
+ * @param minute corresponds to the MINUTE time field.
+ * @param second corresponds to the SECOND time field.
+ */
+ public GregorianCalendar(int year, int month, int day, int hour, int minute,
+ int second)
{
- setTimeInMillis (System.currentTimeMillis());
+ this(TimeZone.getDefault(), Locale.getDefault(), false);
+ set(year, month, day, hour, minute, second);
}
- public int getMinimum(int calfield) { return mins[calfield]; }
- public int getGreatestMinimum(int calfield) { return mins[calfield]; }
- public int getMaximum(int calfield) { return maxs[calfield]; }
- public int getLeastMaximum(int calfield) { return leastMaximums[calfield]; }
+ /**
+ * Sets the date of the switch from Julian dates to Gregorian dates.
+ * You can use <code>new Date(Long.MAX_VALUE)</code> to use a pure
+ * Julian calendar, or <code>Long.MIN_VALUE</code> for a pure Gregorian
+ * calendar.
+ *
+ * @param date the date of the change.
+ */
+ public void setGregorianChange(Date date)
+ {
+ gregorianCutover = date.getTime();
+ }
+
+ /**
+ * Gets the date of the switch from Julian dates to Gregorian dates.
+ *
+ * @return the date of the change.
+ */
+ public final Date getGregorianChange()
+ {
+ return new Date(gregorianCutover);
+ }
+
+ /**
+ * <p>
+ * Determines if the given year is a leap year. The result is
+ * undefined if the Gregorian change took place in 1800, so that
+ * the end of February is skipped, and that year is specified.
+ * (well...).
+ * </p>
+ * <p>
+ * To specify a year in the BC era, use a negative value calculated
+ * as 1 - y, where y is the required year in BC. So, 1 BC is 0,
+ * 2 BC is -1, 3 BC is -2, etc.
+ * </p>
+ *
+ * @param year a year (use a negative value for BC).
+ * @return true, if the given year is a leap year, false otherwise.
+ */
+ public boolean isLeapYear(int year)
+ {
+ // Only years divisible by 4 can be leap years
+ if ((year & 3) != 0)
+ return false;
- protected native void computeFields();
+ // Is the leap-day a Julian date? Then it's a leap year
+ if (! isGregorian(year, 31 + 29 - 1))
+ return true;
- protected native void computeTime();
+ // Apply gregorian rules otherwise
+ return ((year % 100) != 0 || (year % 400) == 0);
+ }
- public void add (int fld, int amount)
+ /**
+ * Retrieves the day of the week corresponding to the specified
+ * day of the specified year.
+ *
+ * @param year the year in which the dayOfYear occurs.
+ * @param dayOfYear the day of the year (an integer between 0 and
+ * and 366)
+ */
+ private int getWeekDay(int year, int dayOfYear)
{
- if (fld >= ZONE_OFFSET)
- throw new IllegalArgumentException("bad field to add");
- fields[fld] += amount;
- adjust(fld);
+ boolean greg = isGregorian(year, dayOfYear);
+ int day = (int) getLinearDay(year, dayOfYear, greg);
+
+ // The epoch was a thursday.
+ int weekday = (day + THURSDAY) % 7;
+ if (weekday <= 0)
+ weekday += 7;
+ return weekday;
}
- public void roll (int fld, boolean up)
+ /**
+ * Returns the day of the week for the first day of a given month (0..11)
+ */
+ private int getFirstDayOfMonth(int year, int month)
{
- if (fld >= ZONE_OFFSET)
- throw new IllegalArgumentException("bad field to roll");
+ int[] dayCount = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
- int old = fields[fld];
- if (up)
+ if (month > 11)
{
- fields[fld] = old == getMaximum(fld) ? getMinimum(fld)
- : old + 1;
+ year += (month / 12);
+ month = month % 12;
}
- else
+
+ if (month < 0)
{
- fields[fld] = old == getMinimum(fld) ? getMaximum(fld)
- : old - 1;
+ year += (int) month / 12;
+ month = month % 12;
+ if (month < 0)
+ {
+ month += 12;
+ year--;
+ }
}
+
+ int dayOfYear = dayCount[month] + 1;
+ if (month > 1)
+ if (isLeapYear(year))
+ dayOfYear++;
+
+ boolean greg = isGregorian(year, dayOfYear);
+ int day = (int) getLinearDay(year, dayOfYear, greg);
+
+ // The epoch was a thursday.
+ int weekday = (day + THURSDAY) % 7;
+ if (weekday <= 0)
+ weekday += 7;
+ return weekday;
+ }
+
+ /**
+ * Takes a year, and a (zero based) day of year and determines
+ * if it is gregorian or not.
+ */
+ private boolean isGregorian(int year, int 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.);
+
+ return ((relativeDay + gregFactor) * 60L * 60L * 24L * 1000L >= gregorianCutover);
}
- private void adjust (int fld)
+ /**
+ * Check set fields for validity, without leniency.
+ *
+ * @throws IllegalArgumentException if a field is invalid
+ */
+ private void nonLeniencyCheck() throws IllegalArgumentException
{
- int value = fields[fld];
- int radix = maxs[fld] + 1;
- switch (fld)
+ int[] month_days = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
+ int year = fields[YEAR];
+ int month = fields[MONTH];
+ int leap = isLeapYear(year) ? 1 : 0;
+
+ if (isSet[ERA] && fields[ERA] != AD && fields[ERA] != BC)
+ throw new IllegalArgumentException("Illegal ERA.");
+ if (isSet[YEAR] && fields[YEAR] < 1)
+ throw new IllegalArgumentException("Illegal YEAR.");
+ if (isSet[MONTH] && (month < 0 || month > 11))
+ throw new IllegalArgumentException("Illegal MONTH.");
+ if (isSet[WEEK_OF_YEAR])
{
- case MONTH:
- case SECOND:
- case MILLISECOND:
- if (value >= radix)
+ int daysInYear = 365 + leap;
+ daysInYear += (getFirstDayOfMonth(year, 0) - 1); // pad first week
+ int last = getFirstDayOfMonth(year, 11) + 4;
+ if (last > 7)
+ last -= 7;
+ daysInYear += 7 - last;
+ int weeks = daysInYear / 7;
+ if (fields[WEEK_OF_YEAR] < 1 || fields[WEEK_OF_YEAR] > weeks)
+ throw new IllegalArgumentException("Illegal WEEK_OF_YEAR.");
+ }
+
+ if (isSet[WEEK_OF_MONTH])
+ {
+ int weeks = (month == 1 && leap == 0) ? 4 : 5;
+ if (fields[WEEK_OF_MONTH] < 1 || fields[WEEK_OF_MONTH] > weeks)
+ throw new IllegalArgumentException("Illegal WEEK_OF_MONTH.");
+ }
+
+ 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 next = value / radix;
- fields[fld] = value - radix * next;
- fields[fld - 1] += next;
- adjust(fld - 1);
+ 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 if (value < 0) // min[fld]
+ else
{
- int next = (value - radix - 1) / radix;
- fields[fld] = value - radix * next;
- fields[fld - 1] += next;
- adjust(fld - 1);
+ // 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--;
}
- break;
}
+ 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;
}
- public final Date getGregorianChange() { return new Date(gregorianCutover); }
- public void setGregorianChange (Date date)
- { gregorianCutover = date.getTime(); }
+ /**
+ * 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.
- public boolean isLeapYear(int year)
+ 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()
{
- if ((year % 4) != 0)
+ 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;
- if ((year % 100) != 0 || (year % 400) == 0)
- return true;
- // year divisible by 100 but not 400.
- GregorianCalendar date = new GregorianCalendar(year, FEBRUARY, 28);
- return gregorianCutover < date.getTimeInMillis();
+
+ GregorianCalendar cal = (GregorianCalendar) o;
+ return (cal.gregorianCutover == gregorianCutover
+ && super.equals(o));
}
- public boolean after (Object cal)
+ /**
+ * Adds the specified amount of time to the given time field. The
+ * amount may be negative to subtract the time. If the field overflows
+ * it does what you expect: Jan, 25 + 10 Days is Feb, 4.
+ * @param field one of the time field constants.
+ * @param amount the amount of time to add.
+ * @exception IllegalArgumentException if <code>field</code> is
+ * <code>ZONE_OFFSET</code>, <code>DST_OFFSET</code>, or invalid; or
+ * if <code>amount</code> contains an out-of-range value and the calendar
+ * is not in lenient mode.
+ */
+ public void add(int field, int amount)
{
- return cal instanceof Calendar
- && getTimeInMillis() > ((Calendar) cal).getTimeInMillis();
+ switch (field)
+ {
+ case YEAR:
+ complete();
+ fields[YEAR] += amount;
+ isTimeSet = false;
+ break;
+ case MONTH:
+ complete();
+ int months = fields[MONTH] + amount;
+ fields[YEAR] += months / 12;
+ fields[MONTH] = months % 12;
+ if (fields[MONTH] < 0)
+ {
+ fields[MONTH] += 12;
+ fields[YEAR]--;
+ }
+ int maxDay = getActualMaximum(DAY_OF_MONTH);
+ if (fields[DAY_OF_MONTH] > maxDay)
+ fields[DAY_OF_MONTH] = maxDay;
+ set(YEAR, fields[YEAR]);
+ set(MONTH, fields[MONTH]);
+ break;
+ case DAY_OF_MONTH:
+ case DAY_OF_YEAR:
+ case DAY_OF_WEEK:
+ if (! isTimeSet)
+ computeTime();
+ time += amount * (24 * 60 * 60 * 1000L);
+ areFieldsSet = false;
+ break;
+ case WEEK_OF_YEAR:
+ case WEEK_OF_MONTH:
+ case DAY_OF_WEEK_IN_MONTH:
+ if (! isTimeSet)
+ computeTime();
+ time += amount * (7 * 24 * 60 * 60 * 1000L);
+ areFieldsSet = false;
+ break;
+ case AM_PM:
+ if (! isTimeSet)
+ computeTime();
+ time += amount * (12 * 60 * 60 * 1000L);
+ areFieldsSet = false;
+ break;
+ case HOUR:
+ case HOUR_OF_DAY:
+ if (! isTimeSet)
+ computeTime();
+ time += amount * (60 * 60 * 1000L);
+ areFieldsSet = false;
+ break;
+ case MINUTE:
+ if (! isTimeSet)
+ computeTime();
+ time += amount * (60 * 1000L);
+ areFieldsSet = false;
+ break;
+ case SECOND:
+ if (! isTimeSet)
+ computeTime();
+ time += amount * (1000L);
+ areFieldsSet = false;
+ break;
+ case MILLISECOND:
+ if (! isTimeSet)
+ computeTime();
+ time += amount;
+ areFieldsSet = false;
+ break;
+ case ZONE_OFFSET:
+ case DST_OFFSET:default:
+ throw new IllegalArgumentException("Invalid or unknown field");
+ }
}
- public boolean before (Object cal)
+ /**
+ * Rolls the specified time field up or down. This means add one
+ * to the specified field, but don't change the other fields. If
+ * the maximum for this field is reached, start over with the
+ * minimum value.
+ *
+ * <strong>Note:</strong> There may be situation, where the other
+ * fields must be changed, e.g rolling the month on May, 31.
+ * The date June, 31 is automatically converted to July, 1.
+ * This requires lenient settings.
+ *
+ * @param field the time field. One of the time field constants.
+ * @param up the direction, true for up, false for down.
+ * @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 void roll(int field, boolean up)
{
- return cal instanceof Calendar
- && getTimeInMillis() < ((Calendar) cal).getTimeInMillis();
+ roll(field, up ? 1 : -1);
}
- public boolean equals (Object obj)
+ /**
+ * Checks that the fields are still within their legal bounds,
+ * following use of the <code>roll()</code> method.
+ *
+ * @param field the field to check.
+ * @param delta multipler for alterations to the <code>time</code>.
+ * @see #roll(int, boolean)
+ * @see #roll(int, int)
+ */
+ private void cleanUpAfterRoll(int field, int delta)
{
- if (obj == null || ! (obj instanceof GregorianCalendar))
- return false;
- GregorianCalendar other = (GregorianCalendar) obj;
+ switch (field)
+ {
+ case ERA:
+ case YEAR:
+ case MONTH:
+ // check that day of month is still in correct range
+ if (fields[DAY_OF_MONTH] > getActualMaximum(DAY_OF_MONTH))
+ fields[DAY_OF_MONTH] = getActualMaximum(DAY_OF_MONTH);
+ isTimeSet = false;
+ isSet[WEEK_OF_MONTH] = false;
+ isSet[DAY_OF_WEEK] = false;
+ isSet[DAY_OF_WEEK_IN_MONTH] = false;
+ isSet[DAY_OF_YEAR] = false;
+ isSet[WEEK_OF_YEAR] = false;
+ break;
+ case DAY_OF_MONTH:
+ isSet[WEEK_OF_MONTH] = false;
+ isSet[DAY_OF_WEEK] = false;
+ isSet[DAY_OF_WEEK_IN_MONTH] = false;
+ isSet[DAY_OF_YEAR] = false;
+ isSet[WEEK_OF_YEAR] = false;
+ time += delta * (24 * 60 * 60 * 1000L);
+ break;
+ case WEEK_OF_MONTH:
+ isSet[DAY_OF_MONTH] = false;
+ isSet[DAY_OF_WEEK_IN_MONTH] = false;
+ isSet[DAY_OF_YEAR] = false;
+ isSet[WEEK_OF_YEAR] = false;
+ time += delta * (7 * 24 * 60 * 60 * 1000L);
+ break;
+ case DAY_OF_WEEK_IN_MONTH:
+ isSet[DAY_OF_MONTH] = false;
+ isSet[WEEK_OF_MONTH] = false;
+ isSet[DAY_OF_YEAR] = false;
+ isSet[WEEK_OF_YEAR] = false;
+ time += delta * (7 * 24 * 60 * 60 * 1000L);
+ break;
+ case DAY_OF_YEAR:
+ isSet[MONTH] = false;
+ isSet[DAY_OF_MONTH] = false;
+ isSet[WEEK_OF_MONTH] = false;
+ isSet[DAY_OF_WEEK_IN_MONTH] = false;
+ isSet[DAY_OF_WEEK] = false;
+ isSet[WEEK_OF_YEAR] = false;
+ time += delta * (24 * 60 * 60 * 1000L);
+ break;
+ case WEEK_OF_YEAR:
+ isSet[MONTH] = false;
+ isSet[DAY_OF_MONTH] = false;
+ isSet[WEEK_OF_MONTH] = false;
+ isSet[DAY_OF_WEEK_IN_MONTH] = false;
+ isSet[DAY_OF_YEAR] = false;
+ time += delta * (7 * 24 * 60 * 60 * 1000L);
+ break;
+ case AM_PM:
+ isSet[HOUR_OF_DAY] = false;
+ time += delta * (12 * 60 * 60 * 1000L);
+ break;
+ case HOUR:
+ isSet[HOUR_OF_DAY] = false;
+ time += delta * (60 * 60 * 1000L);
+ break;
+ case HOUR_OF_DAY:
+ isSet[HOUR] = false;
+ isSet[AM_PM] = false;
+ time += delta * (60 * 60 * 1000L);
+ break;
+ case MINUTE:
+ time += delta * (60 * 1000L);
+ break;
+ case SECOND:
+ time += delta * (1000L);
+ break;
+ case MILLISECOND:
+ time += delta;
+ break;
+ }
+ }
+
+ /**
+ * Rolls the specified time field by the given amount. This means
+ * add amount to the specified field, but don't change the other
+ * fields. If the maximum for this field is reached, start over
+ * with the minimum value and vice versa for negative amounts.
+ *
+ * <strong>Note:</strong> There may be situation, where the other
+ * fields must be changed, e.g rolling the month on May, 31.
+ * The date June, 31 is automatically corrected to June, 30.
+ *
+ * @param field the time field. One of the time field constants.
+ * @param amount the amount by which we should roll.
+ * @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 void roll(int field, int amount)
+ {
+ switch (field)
+ {
+ case DAY_OF_WEEK:
+ // day of week is special: it rolls automatically
+ add(field, amount);
+ return;
+ case ZONE_OFFSET:
+ case DST_OFFSET:
+ throw new IllegalArgumentException("Can't roll time zone");
+ }
+ complete();
+ int min = getActualMinimum(field);
+ int range = getActualMaximum(field) - min + 1;
+ int oldval = fields[field];
+ int newval = (oldval - min + range + amount) % range + min;
+ if (newval < min)
+ newval += range;
+ fields[field] = newval;
+ cleanUpAfterRoll(field, newval - oldval);
+ }
+
+ /**
+ * The minimum values for the calendar fields.
+ */
+ private static final int[] minimums =
+ {
+ BC, 1, 0, 0, 1, 1, 1, SUNDAY, 1, AM,
+ 1, 0, 0, 0, 0, -(12 * 60 * 60 * 1000),
+ 0
+ };
+
+ /**
+ * The maximum values for the calendar fields.
+ */
+ private static final int[] maximums =
+ {
+ AD, 5000000, 11, 53, 5, 31, 366,
+ SATURDAY, 5, PM, 12, 23, 59, 59, 999,
+ +(12 * 60 * 60 * 1000),
+ (12 * 60 * 60 * 1000)
+ };
+
+ /**
+ * Gets the smallest value that is allowed for the specified field.
+ *
+ * @param field one of the time field constants.
+ * @return the smallest value for the specified field.
+ */
+ public int getMinimum(int field)
+ {
+ return minimums[field];
+ }
- for (int i = FIELD_COUNT; --i >= 0; )
+ /**
+ * Gets the biggest value that is allowed for the specified field.
+ *
+ * @param field one of the time field constants.
+ * @return the biggest value.
+ */
+ public int getMaximum(int field)
+ {
+ return maximums[field];
+ }
+
+ /**
+ * Gets the greatest minimum value that is allowed for the specified field.
+ * This is the largest value returned by the <code>getActualMinimum(int)</code>
+ * method.
+ *
+ * @param field the time field. One of the time field constants.
+ * @return the greatest minimum value.
+ * @see #getActualMinimum(int)
+ */
+ public int getGreatestMinimum(int field)
+ {
+ if (field == WEEK_OF_YEAR)
+ return 1;
+ return minimums[field];
+ }
+
+ /**
+ * Gets the smallest maximum value that is allowed for the
+ * specified field. This is the smallest value returned
+ * by the <code>getActualMaximum(int)</code>. For example,
+ * this is 28 for DAY_OF_MONTH (as all months have at least
+ * 28 days).
+ *
+ * @param field the time field. One of the time field constants.
+ * @return the least maximum value.
+ * @see #getActualMaximum(int)
+ * @since 1.2
+ */
+ public int getLeastMaximum(int field)
+ {
+ switch (field)
{
- boolean set = isSet[i];
- if (set != other.isSet[i]
- || (set && fields[i] != other.fields[i]))
- return false;
+ case WEEK_OF_YEAR:
+ return 52;
+ case DAY_OF_MONTH:
+ return 28;
+ case DAY_OF_YEAR:
+ return 365;
+ case DAY_OF_WEEK_IN_MONTH:
+ case WEEK_OF_MONTH:
+ return 4;
+ default:
+ return maximums[field];
}
- if (areFieldsSet != other.areFieldsSet
- || isTimeSet != other.isTimeSet
- || (isTimeSet && time != other.time)
- || getFirstDayOfWeek() != other.getFirstDayOfWeek()
- || getMinimalDaysInFirstWeek() != other.getMinimalDaysInFirstWeek()
- || isLenient() != other.isLenient()
- || ! getTimeZone().equals(other.getTimeZone()))
- return false;
- return true;
}
- public int hashCode ()
+ /**
+ * Gets the actual minimum value that is allowed for the specified field.
+ * This value is dependent on the values of the other fields. Note that
+ * this calls <code>complete()</code> if not enough fields are set. This
+ * can have ugly side effects. The value given depends on the current
+ * time used by this instance.
+ *
+ * @param field the time field. One of the time field constants.
+ * @return the actual minimum value.
+ * @since 1.2
+ */
+ public int getActualMinimum(int field)
{
- int hashcode = 0;
- for (int i = FIELD_COUNT; --i >= 0; )
+ if (field == WEEK_OF_YEAR)
{
- if (isSet[i])
- hashcode += 37 * fields[i];
+ int min = getMinimalDaysInFirstWeek();
+ if (min == 0)
+ return 1;
+ if (! areFieldsSet || ! isSet[ERA] || ! isSet[YEAR])
+ complete();
+
+ int year = fields[ERA] == AD ? fields[YEAR] : 1 - fields[YEAR];
+ int weekday = getWeekDay(year, min);
+ if ((7 + weekday - getFirstDayOfWeek()) % 7 >= min - 1)
+ return 1;
+ return 0;
+ }
+ return minimums[field];
+ }
+
+ /**
+ * Gets the actual maximum value that is allowed for the specified field.
+ * This value is dependent on the values of the other fields. Note that
+ * this calls <code>complete()</code> if not enough fields are set. This
+ * can have ugly side effects. The value given depends on the current time
+ * used by this instance; thus, leap years have a maximum day of month value of
+ * 29, rather than 28.
+ *
+ * @param field the time field. One of the time field constants.
+ * @return the actual maximum value.
+ */
+ public int getActualMaximum(int field)
+ {
+ switch (field)
+ {
+ case WEEK_OF_YEAR:
+ {
+ if (! areFieldsSet || ! isSet[ERA] || ! isSet[YEAR])
+ complete();
+
+ // This is wrong for the year that contains the gregorian change.
+ // I.e it gives the weeks in the julian year or in the gregorian
+ // year in that case.
+ int year = fields[ERA] == AD ? fields[YEAR] : 1 - fields[YEAR];
+ int lastDay = isLeapYear(year) ? 366 : 365;
+ int weekday = getWeekDay(year, lastDay);
+ int week = (lastDay + 6 - (7 + weekday - getFirstDayOfWeek()) % 7) / 7;
+
+ int minimalDays = getMinimalDaysInFirstWeek();
+ int firstWeekday = getWeekDay(year, minimalDays);
+ /*
+ * Is there a set of days at the beginning of the year, before the
+ * first day of the week, equal to or greater than the minimum number
+ * of days required in the first week?
+ */
+ if (minimalDays - (7 + firstWeekday - getFirstDayOfWeek()) % 7 < 1)
+ return week + 1; /* Add week 1: firstWeekday through to firstDayOfWeek */
+ }
+ case DAY_OF_MONTH:
+ {
+ if (! areFieldsSet || ! isSet[MONTH])
+ complete();
+ int month = fields[MONTH];
+
+ // If you change this, you should also change
+ // SimpleTimeZone.getDaysInMonth();
+ if (month == FEBRUARY)
+ {
+ if (! isSet[YEAR] || ! isSet[ERA])
+ complete();
+ int year = fields[ERA] == AD ? fields[YEAR] : 1 - fields[YEAR];
+ return isLeapYear(year) ? 29 : 28;
+ }
+ else if (month < AUGUST)
+ return 31 - (month & 1);
+ else
+ return 30 + (month & 1);
+ }
+ case DAY_OF_YEAR:
+ {
+ if (! areFieldsSet || ! isSet[ERA] || ! isSet[YEAR])
+ complete();
+ int year = fields[ERA] == AD ? fields[YEAR] : 1 - fields[YEAR];
+ return isLeapYear(year) ? 366 : 365;
+ }
+ case DAY_OF_WEEK_IN_MONTH:
+ {
+ // This is wrong for the month that contains the gregorian change.
+ int daysInMonth = getActualMaximum(DAY_OF_MONTH);
+
+ // That's black magic, I know
+ return (daysInMonth - (fields[DAY_OF_MONTH] - 1) % 7 + 6) / 7;
+ }
+ case WEEK_OF_MONTH:
+ {
+ int daysInMonth = getActualMaximum(DAY_OF_MONTH);
+ int weekday = (daysInMonth - fields[DAY_OF_MONTH]
+ + fields[DAY_OF_WEEK] - SUNDAY) % 7 + SUNDAY;
+ return (daysInMonth + 6 - (7 + weekday - getFirstDayOfWeek()) % 7) / 7;
+ }
+ default:
+ return maximums[field];
}
- if (isTimeSet)
- hashcode += 89 * time;
- return hashcode;
}
}
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