/*
*
* @(#)SimpleTimeZone.java 1.47 06/10/10
*
* Portions Copyright 2000-2008 Sun Microsystems, Inc. All Rights
* Reserved. Use is subject to license terms.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 only, as published by the Free Software Foundation.
*
* This program 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 version 2 for more details (a copy is
* included at /legal/license.txt).
*
* You should have received a copy of the GNU General Public License
* version 2 along with this work; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 or visit www.sun.com if you need additional
* information or have any questions.
*/
/*
* (C) Copyright Taligent, Inc. 1996 - All Rights Reserved
* (C) Copyright IBM Corp. 1996 - All Rights Reserved
*
* The original version of this source code and documentation is copyrighted
* and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
* materials are provided under terms of a License Agreement between Taligent
* and Sun. This technology is protected by multiple US and International
* patents. This notice and attribution to Taligent may not be removed.
* Taligent is a registered trademark of Taligent, Inc.
*
*/
package java.util;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.IOException;
import sun.util.calendar.CalendarDate;
import sun.util.calendar.Gregorian;
/**
* <code>SimpleTimeZone</code> is a concrete subclass of <code>TimeZone</code>
* that represents a time zone for use with a Gregorian calendar.
* The class holds an offset from GMT, called <em>raw offset</em>, and start
* and end rules for a daylight saving time schedule. Since it only holds
* single values for each, it cannot handle historical changes in the offset
* from GMT and the daylight saving schedule, except that the {@link
* #setStartYear setStartYear} method can specify the year when the daylight
* saving time schedule starts in effect.
* <p>
* To construct a <code>SimpleTimeZone</code> with a daylight saving time
* schedule, the schedule can be described with a set of rules,
* <em>start-rule</em> and <em>end-rule</em>. A day when daylight saving time
* starts or ends is specified by a combination of <em>month</em>,
* <em>day-of-month</em>, and <em>day-of-week</em> values. The <em>month</em>
* value is represented by a Calendar {@link Calendar#MONTH MONTH} field
* value, such as {@link Calendar#MARCH}. The <em>day-of-week</em> value is
* represented by a Calendar {@link Calendar#DAY_OF_WEEK DAY_OF_WEEK} value,
* such as {@link Calendar#SUNDAY SUNDAY}. The meanings of value combinations
* are as follows.
*
* <ul>
* <li><b>Exact day of month</b><br>
* To specify an exact day of month, set the <em>month</em> and
* <em>day-of-month</em> to an exact value, and <em>day-of-week</em> to zero. For
* example, to specify March 1, set the <em>month</em> to {@link Calendar#MARCH
* MARCH}, <em>day-of-month</em> to 1, and <em>day-of-week</em> to 0.</li>
*
* <li><b>Day of week on or after day of month</b><br>
* To specify a day of week on or after an exact day of month, set the
* <em>month</em> to an exact month value, <em>day-of-month</em> to the day on
* or after which the rule is applied, and <em>day-of-week</em> to a {@link
* Calendar#DAY_OF_WEEK DAY_OF_WEEK} field value. For example, to specify the
* second Sunday of April, set <em>month</em> to {@link Calendar#APRIL APRIL},
* <em>day-of-month</em> to 8, and <em>day-of-week</em> to {@link
* Calendar#SUNDAY SUNDAY}.</li>
*
* <li><b>Day of week on or before day of month</b><br>
* To specify a day of the week on or before an exact day of the month, set
* <em>day-of-month</em> and <em>day-of-week</em> to a negative value. For
* example, to specify the last Wednesday on or before the 21st of March, set
* <em>month</em> to {@link Calendar#MARCH MARCH}, <em>day-of-month</em> is -21
* and <em>day-of-week</em> is {@link Calendar#WEDNESDAY -WEDNESDAY}. </li>
*
* <li><b>Last day-of-week of month</b><br>
* To specify, the last day-of-week of the month, set <em>day-of-week</em> to a
* {@link Calendar#DAY_OF_WEEK DAY_OF_WEEK} value and <em>day-of-month</em> to
* -1. For example, to specify the last Sunday of October, set <em>month</em>
* to {@link Calendar#OCTOBER OCTOBER}, <em>day-of-week</em> to {@link
* Calendar#SUNDAY SUNDAY} and <em>day-of-month</em> to -1. </li>
*
* </ul>
* The time of the day at which daylight saving time starts or ends is
* specified by a millisecond value within the day. There are three kinds of
* <em>mode</em>s to specify the time: {@link #WALL_TIME}, {@link
* #STANDARD_TIME} and {@link #UTC_TIME}. For example, if daylight
* saving time ends
* at 2:00 am in the wall clock time, it can be specified by 7200000
* milliseconds in the {@link #WALL_TIME} mode. In this case, the wall clock time
* for an <em>end-rule</em> means the same thing as the daylight time.
* <p>
* The following are examples of parameters for constructing time zone objects.
* <pre><code>
* // Base GMT offset: -8:00
* // DST starts: at 2:00am in standard time
* // on the first Sunday in April
* // DST ends: at 2:00am in daylight time
* // on the last Sunday in October
* // Save: 1 hour
* SimpleTimeZone(-28800000,
* "America/Los_Angeles",
* Calendar.APRIL, 1, -Calendar.SUNDAY,
* 7200000,
* Calendar.OCTOBER, -1, Calendar.SUNDAY,
* 7200000,
* 3600000)
*
* // Base GMT offset: +1:00
* // DST starts: at 1:00am in UTC time
* // on the last Sunday in March
* // DST ends: at 1:00am in UTC time
* // on the last Sunday in October
* // Save: 1 hour
* SimpleTimeZone(3600000,
* "Europe/Paris",
* Calendar.MARCH, -1, Calendar.SUNDAY,
* 3600000, SimpleTimeZone.UTC_TIME,
* Calendar.OCTOBER, -1, Calendar.SUNDAY,
* 3600000, SimpleTimeZone.UTC_TIME,
* 3600000)
* </code></pre>
* These parameter rules are also applicable to the set rule methods, such as
* <code>setStartRule</code>.
*
* @since 1.1
* @see Calendar
* @see GregorianCalendar
* @see TimeZone
* @version 1.47, 10/10/06
* @author David Goldsmith, Mark Davis, Chen-Lieh Huang, Alan Liu
*/
public class SimpleTimeZone extends TimeZone {
/**
* Constructs a SimpleTimeZone with the given base time zone offset from GMT
* and time zone ID with no daylight saving time schedule.
*
* @param rawOffset The base time zone offset in milliseconds to GMT.
* @param ID The time zone name that is given to this instance.
*/
public SimpleTimeZone(int rawOffset, String ID)
{
this.rawOffset = rawOffset;
setID (ID);
dstSavings = millisPerHour; // In case user sets rules later
}
/**
* Constructs a SimpleTimeZone with the given base time zone offset from
* GMT, time zone ID, and rules for starting and ending the daylight
* time.
* Both <code>startTime</code> and <code>endTime</code> are specified to be
* represented in the wall clock time. The amount of daylight saving is
* assumed to be 3600000 milliseconds (i.e., one hour). This constructor is
* equivalent to:
* <pre><code>
* SimpleTimeZone(rawOffset,
* ID,
* startMonth,
* startDay,
* startDayOfWeek,
* startTime,
* SimpleTimeZone.{@link #WALL_TIME},
* endMonth,
* endDay,
* endDayOfWeek,
* endTime,
* SimpleTimeZone.{@link #WALL_TIME},
* 3600000)
* </code></pre>
*
* @param rawOffset The given base time zone offset from GMT.
* @param ID The time zone ID which is given to this object.
* @param startMonth The daylight saving time starting month. Month is
* a {@link Calendar#MONTH MONTH} field value (0-based. e.g., 0
* for January).
* @param startDay The day of the month on which the daylight saving time starts.
* See the class description for the special cases of this parameter.
* @param startDayOfWeek The daylight saving time starting day-of-week.
* See the class description for the special cases of this parameter.
* @param startTime The daylight saving time starting time in local wall clock
* time (in milliseconds within the day), which is local
* standard time in this case.
* @param endMonth The daylight saving time ending month. Month is
* a {@link Calendar#MONTH MONTH} field
* value (0-based. e.g., 9 for October).
* @param endDay The day of the month on which the daylight saving time ends.
* See the class description for the special cases of this parameter.
* @param endDayOfWeek The daylight saving time ending day-of-week.
* See the class description for the special cases of this parameter.
* @param endTime The daylight saving ending time in local wall clock time,
* (in milliseconds within the day) which is local daylight
* time in this case.
* @exception IllegalArgumentException if the month, day, dayOfWeek, or time
* parameters are out of range for the start or end rule
*/
public SimpleTimeZone(int rawOffset, String ID,
int startMonth, int startDay, int startDayOfWeek, int startTime,
int endMonth, int endDay, int endDayOfWeek, int endTime)
{
this(rawOffset, ID,
startMonth, startDay, startDayOfWeek, startTime, WALL_TIME,
endMonth, endDay, endDayOfWeek, endTime, WALL_TIME,
millisPerHour);
}
/**
* Constructs a SimpleTimeZone with the given base time zone offset from
* GMT, time zone ID, and rules for starting and ending the daylight
* time.
* Both <code>startTime</code> and <code>endTime</code> are assumed to be
* represented in the wall clock time. This constructor is equivalent to:
* <pre><code>
* SimpleTimeZone(rawOffset,
* ID,
* startMonth,
* startDay,
* startDayOfWeek,
* startTime,
* SimpleTimeZone.{@link #WALL_TIME},
* endMonth,
* endDay,
* endDayOfWeek,
* endTime,
* SimpleTimeZone.{@link #WALL_TIME},
* dstSavings)
* </code></pre>
*
* @param rawOffset The given base time zone offset from GMT.
* @param ID The time zone ID which is given to this object.
* @param startMonth The daylight saving time starting month. Month is
* a {@link Calendar#MONTH MONTH} field
* value (0-based. e.g., 0 for January).
* @param startDay The day of the month on which the daylight saving time starts.
* See the class description for the special cases of this parameter.
* @param startDayOfWeek The daylight saving time starting day-of-week.
* See the class description for the special cases of this parameter.
* @param startTime The daylight saving time starting time in local wall clock
* time, which is local standard time in this case.
* @param endMonth The daylight saving time ending month. Month is
* a {@link Calendar#MONTH MONTH} field
* value (0-based. e.g., 9 for October).
* @param endDay The day of the month on which the daylight saving time ends.
* See the class description for the special cases of this parameter.
* @param endDayOfWeek The daylight saving time ending day-of-week.
* See the class description for the special cases of this parameter.
* @param endTime The daylight saving ending time in local wall clock time,
* which is local daylight time in this case.
* @param dstSavings The amount of time in milliseconds saved during
* daylight saving time.
* @exception IllegalArgumentException if the month, day, dayOfWeek, or time
* parameters are out of range for the start or end rule
* @since 1.2
*/
public SimpleTimeZone(int rawOffset, String ID,
int startMonth, int startDay, int startDayOfWeek, int startTime,
int endMonth, int endDay, int endDayOfWeek, int endTime,
int dstSavings)
{
this(rawOffset, ID,
startMonth, startDay, startDayOfWeek, startTime, WALL_TIME,
endMonth, endDay, endDayOfWeek, endTime, WALL_TIME,
dstSavings);
}
/**
* Constructs a SimpleTimeZone with the given base time zone offset from
* GMT, time zone ID, and rules for starting and ending the daylight
* time.
* This constructor takes the full set of the start and end rules
* parameters, including modes of <code>startTime</code> and
* <code>endTime</code>. The mode specifies either {@link #WALL_TIME wall
* time} or {@link #STANDARD_TIME standard time} or {@link #UTC_TIME UTC
* time}.
*
* @param rawOffset The given base time zone offset from GMT.
* @param ID The time zone ID which is given to this object.
* @param startMonth The daylight saving time starting month. Month is
* a {@link Calendar#MONTH MONTH} field
* value (0-based. e.g., 0 for January).
* @param startDay The day of the month on which the daylight saving time starts.
* See the class description for the special cases of this parameter.
* @param startDayOfWeek The daylight saving time starting day-of-week.
* See the class description for the special cases of this parameter.
* @param startTime The daylight saving time starting time in the time mode
* specified by <code>startTimeMode</code>.
* @param startTimeMode The mode of the start time specified by startTime.
* @param endMonth The daylight saving time ending month. Month is
* a {@link Calendar#MONTH MONTH} field
* value (0-based. e.g., 9 for October).
* @param endDay The day of the month on which the daylight saving time ends.
* See the class description for the special cases of this parameter.
* @param endDayOfWeek The daylight saving time ending day-of-week.
* See the class description for the special cases of this parameter.
* @param endTime The daylight saving ending time in time time mode
* specified by <code>endTimeMode</code>.
* @param endTimeMode The mode of the end time specified by endTime
* @param dstSavings The amount of time in milliseconds saved during
* daylight saving time.
*
* @exception IllegalArgumentException if the month, day, dayOfWeek, time more, or
* time parameters are out of range for the start or end rule, or if a time mode
* value is invalid.
*
* @see #WALL_TIME
* @see #STANDARD_TIME
* @see #UTC_TIME
*
* @since 1.4
*/
public SimpleTimeZone(int rawOffset, String ID,
int startMonth, int startDay, int startDayOfWeek,
int startTime, int startTimeMode,
int endMonth, int endDay, int endDayOfWeek,
int endTime, int endTimeMode,
int dstSavings) {
// Workaround fix for 4278609 (JCK failure)
if (endMonth == Calendar.JANUARY && endDay == 1 &&
endDayOfWeek == 0 && endTime == 0 && endTimeMode == WALL_TIME &&
dstSavings > 0) {
endMonth = Calendar.DECEMBER;
endDay = 31;
endTime = (24 * 60 * 60 * 1000) - dstSavings;
endTimeMode = STANDARD_TIME;
}
setID(ID);
this.rawOffset = rawOffset;
this.startMonth = startMonth;
this.startDay = startDay;
this.startDayOfWeek = startDayOfWeek;
this.startTime = startTime;
this.startTimeMode = startTimeMode;
this.endMonth = endMonth;
this.endDay = endDay;
this.endDayOfWeek = endDayOfWeek;
this.endTime = endTime;
this.endTimeMode = endTimeMode;
this.dstSavings = dstSavings;
// this.useDaylight is set by decodeRules
decodeRules();
if (dstSavings <= 0) {
throw new IllegalArgumentException("Illegal daylight saving value: " + dstSavings);
}
}
/**
* Sets the daylight saving time starting year.
*
* @param year The daylight saving starting year.
*/
public void setStartYear(int year)
{
startYear = year;
}
/**
* Sets the daylight saving time start rule. For example, if daylight saving
* time starts on the first Sunday in April at 2 am in local wall clock
* time, you can set the start rule by calling:
* <pre><code>setStartRule(Calendar.APRIL, 1, Calendar.SUNDAY, 2*60*60*1000);</code></pre>
*
* @param startMonth The daylight saving time starting month. Month is
* a {@link Calendar#MONTH MONTH} field
* value (0-based. e.g., 0 for January).
* @param startDay The day of the month on which the daylight saving time starts.
* See the class description for the special cases of this parameter.
* @param startDayOfWeek The daylight saving time starting day-of-week.
* See the class description for the special cases of this parameter.
* @param startTime The daylight saving time starting time in local wall clock
* time, which is local standard time in this case.
* @exception IllegalArgumentException if the <code>startMonth</code>, <code>startDay</code>,
* <code>startDayOfWeek</code>, or <code>startTime</code> parameters are out of range
*/
public void setStartRule(int startMonth, int startDay, int startDayOfWeek, int startTime)
{
this.startMonth = startMonth;
this.startDay = startDay;
this.startDayOfWeek = startDayOfWeek;
this.startTime = startTime;
startTimeMode = WALL_TIME;
// useDaylight = true; // Set by decodeRules
decodeStartRule();
}
/**
* Sets the daylight saving time start rule to a fixed date within a month.
* This method is equivalent to:
* <pre><code>setStartRule(startMonth, startDay, 0, startTime)</code></pre>
*
* @param startMonth The daylight saving time starting month. Month is
* a {@link Calendar#MONTH MONTH} field
* value (0-based. e.g., 0 for January).
* @param startDay The day of the month on which the daylight saving time starts.
* @param startTime The daylight saving time starting time in local wall clock
* time, which is local standard time in this case.
* See the class description for the special cases of this parameter.
* @exception IllegalArgumentException if the <code>startMonth</code>,
* <code>startDayOfMonth</code>, or <code>startTime</code> parameters are out of range
* @since 1.2
*/
public void setStartRule(int startMonth, int startDay, int startTime) {
setStartRule(startMonth, startDay, 0, startTime);
}
/**
* Sets the daylight saving time start rule to a weekday before or after the given date within
* a month, e.g., the first Monday on or after the 8th.
*
* @param startMonth The daylight saving time starting month. Month is
* a {@link Calendar#MONTH MONTH} field
* value (0-based. e.g., 0 for January).
* @param startDay The day of the month on which the daylight saving time starts.
* @param startDayOfWeek The daylight saving time starting day-of-week.
* @param startTime The daylight saving time starting time in local wall clock
* time, which is local standard time in this case.
* @param after If true, this rule selects the first <code>dayOfWeek</code> on or
* <em>after</em> <code>dayOfMonth</code>. If false, this rule
* selects the last <code>dayOfWeek</code> on or <em>before</em>
* <code>dayOfMonth</code>.
* @exception IllegalArgumentException if the <code>startMonth</code>, <code>startDay</code>,
* <code>startDayOfWeek</code>, or <code>startTime</code> parameters are out of range
* @since 1.2
*/
public void setStartRule(int startMonth, int startDay, int startDayOfWeek,
int startTime, boolean after)
{
// TODO: this method doesn't check the initial values of dayOfMonth or dsyOfWeek.
if (after) {
setStartRule(startMonth, startDay, -startDayOfWeek, startTime);
} else {
setStartRule(startMonth, -startDay, -startDayOfWeek, startTime);
}
}
/**
* Sets the daylight saving time end rule. For example, if daylight saving time
* ends on the last Sunday in October at 2 am in wall clock time,
* you can set the end rule by calling:
* <code>setEndRule(Calendar.OCTOBER, -1, Calendar.SUNDAY, 2*60*60*1000);</code>
*
* @param endMonth The daylight saving time ending month. Month is
* a {@link Calendar#MONTH MONTH} field
* value (0-based. e.g., 9 for October).
* @param endDay The day of the month on which the daylight saving time ends.
* See the class description for the special cases of this parameter.
* @param endDayOfWeek The daylight saving time ending day-of-week.
* See the class description for the special cases of this parameter.
* @param endTime The daylight saving ending time in local wall clock time,
* (in milliseconds within the day) which is local daylight
* time in this case.
* @exception IllegalArgumentException if the <code>endMonth</code>, <code>endDay</code>,
* <code>endDayOfWeek</code>, or <code>endTime</code> parameters are out of range
*/
public void setEndRule(int endMonth, int endDay, int endDayOfWeek,
int endTime)
{
this.endMonth = endMonth;
this.endDay = endDay;
this.endDayOfWeek = endDayOfWeek;
this.endTime = endTime;
this.endTimeMode = WALL_TIME;
// useDaylight = true; // Set by decodeRules
decodeEndRule();
}
/**
* Sets the daylight saving time end rule to a fixed date within a month.
* This method is equivalent to:
* <pre><code>setEndRule(endMonth, endDay, 0, endTime)</code></pre>
*
* @param endMonth The daylight saving time ending month. Month is
* a {@link Calendar#MONTH MONTH} field
* value (0-based. e.g., 9 for October).
* @param endDay The day of the month on which the daylight saving time ends.
* @param endTime The daylight saving ending time in local wall clock time,
* (in milliseconds within the day) which is local daylight
* time in this case.
* @exception IllegalArgumentException the <code>endMonth</code>, <code>endDay</code>,
* or <code>endTime</code> parameters are out of range
* @since 1.2
*/
public void setEndRule(int endMonth, int endDay, int endTime)
{
setEndRule(endMonth, endDay, 0, endTime);
}
/**
* Sets the daylight saving time end rule to a weekday before or after the given date within
* a month, e.g., the first Monday on or after the 8th.
*
* @param endMonth The daylight saving time ending month. Month is
* a {@link Calendar#MONTH MONTH} field
* value (0-based. e.g., 9 for October).
* @param endDay The day of the month on which the daylight saving time ends.
* @param endDayOfWeek The daylight saving time ending day-of-week.
* @param endTime The daylight saving ending time in local wall clock time,
* (in milliseconds within the day) which is local daylight
* time in this case.
* @param after If true, this rule selects the first <code>endDayOfWeek</code> on
* or <em>after</em> <code>endDay</code>. If false, this rule
* selects the last <code>endDayOfWeek</code> on or before
* <code>endDay</code> of the month.
* @exception IllegalArgumentException the <code>endMonth</code>, <code>endDay</code>,
* <code>endDayOfWeek</code>, or <code>endTime</code> parameters are out of range
* @since 1.2
*/
public void setEndRule(int endMonth, int endDay, int endDayOfWeek, int endTime, boolean after)
{
if (after) {
setEndRule(endMonth, endDay, -endDayOfWeek, endTime);
} else {
setEndRule(endMonth, -endDay, -endDayOfWeek, endTime);
}
}
/**
* Returns the offset of this time zone from UTC at the given
* time. If daylight saving time is in effect at the given time,
* the offset value is adjusted with the amount of daylight
* saving.
*
* @param date the time at which the time zone offset is found
* @return the amount of time in milliseconds to add to UTC to get
* local time.
* @since 1.4
*/
public int getOffset(long date) {
return getOffsets(date, null);
}
/**
* @see TimeZone#getOffsets
*/
int getOffsets(long date, int[] offsets) {
int offset;
calc:
{
if (!useDaylight) {
offset = rawOffset;
break calc;
}
// get standard local time
CalendarDate cdate = Gregorian.getCalendarDate(date + rawOffset);
int year = cdate.getYear();
// if it's BC, assume no DST.
if (year <= 0) {
offset = rawOffset;
break calc;
}
int month = cdate.getMonth();
int monthLength = staticMonthLength[month];
int prevMonthLength = staticMonthLength[(month + Calendar.DECEMBER) % 12];
if (Gregorian.isLeapYear(year)) {
if (month == Calendar.FEBRUARY) {
++monthLength;
} else if (month == Calendar.MARCH) {
++prevMonthLength;
}
}
offset = getOffset(GregorianCalendar.AD, year, month, cdate.getDate(),
cdate.getDayOfWeek(), cdate.getTimeOfDay(),
monthLength, prevMonthLength);
}
if (offsets != null) {
offsets[0] = rawOffset;
offsets[1] = offset - rawOffset;
}
return offset;
}
/**
* Returns the difference in milliseconds between local time and
* UTC, taking into account both the raw offset and the effect of
* daylight saving, for the specified date and time. This method
* assumes that the start and end month are distinct. It also
* uses a default {@link GregorianCalendar} object as its
* underlying calendar, such as for determining leap years. Do
* not use the result of this method with a calendar other than a
* default <code>GregorianCalendar</code>.
*
* <p><em>Note: In general, clients should use
* <code>Calendar.get(ZONE_OFFSET) + Calendar.get(DST_OFFSET)</code>
* instead of calling this method.</em>
*
* @param era The era of the given date.
* @param year The year in the given date.
* @param month The month in the given date. Month is 0-based. e.g.,
* 0 for January.
* @param day The day-in-month of the given date.
* @param dayOfWeek The day-of-week of the given date.
* @param millis The milliseconds in day in <em>standard</em> local time.
* @return The milliseconds to add to UTC to get local time.
* @exception IllegalArgumentException the <code>era</code>,
* <code>month</code>, <code>day</code>, <code>dayOfWeek</code>,
* or <code>millis</code> parameters are out of range
*/
public int getOffset(int era, int year, int month, int day, int dayOfWeek,
int millis)
{
// Check the month before indexing into staticMonthLength. This
// duplicates the test that occurs in the 7-argument getOffset(),
// however, this is unavoidable. We don't mind because this method, in
// fact, should not be called; internal code should always call the
// 7-argument getOffset(), and outside code should use Calendar.get(int
// field) with fields ZONE_OFFSET and DST_OFFSET. We can't get rid of
// this method because it's public API. - liu 8/10/98
if (month < Calendar.JANUARY
|| month > Calendar.DECEMBER) {
throw new IllegalArgumentException("Illegal month " + month);
}
int monthLength, prevMonthLength;
if ((era == GregorianCalendar.AD) && Gregorian.isLeapYear(year)) {
monthLength = staticLeapMonthLength[month];
prevMonthLength = (month > 1) ? staticLeapMonthLength[month - 1] : 31;
} else {
monthLength = staticMonthLength[month];
prevMonthLength = (month > 1) ? staticMonthLength[month - 1] : 31;
}
if (true) {
/* Use this parameter checking code for normal operation. Only one
* of these two blocks should actually get compiled into the class
* file. */
if ((era != GregorianCalendar.AD && era != GregorianCalendar.BC)
|| month < Calendar.JANUARY
|| month > Calendar.DECEMBER
|| day < 1
|| day > monthLength
|| dayOfWeek < Calendar.SUNDAY
|| dayOfWeek > Calendar.SATURDAY
|| millis < 0
|| millis >= millisPerDay) {
throw new IllegalArgumentException();
}
} else {
/* This parameter checking code is better for debugging, but
* overkill for normal operation. Only one of these two blocks
* should actually get compiled into the class file. */
if (era != GregorianCalendar.AD && era != GregorianCalendar.BC) {
throw new IllegalArgumentException("Illegal era " + era);
}
if (month < Calendar.JANUARY
|| month > Calendar.DECEMBER) {
throw new IllegalArgumentException("Illegal month " + month);
}
if (day < 1 || day > monthLength) {
throw new IllegalArgumentException("Illegal day " + day);
}
if (dayOfWeek < Calendar.SUNDAY
|| dayOfWeek > Calendar.SATURDAY) {
throw new IllegalArgumentException("Illegal day of week " + dayOfWeek);
}
if (millis < 0 || millis >= millisPerDay) {
throw new IllegalArgumentException("Illegal millis " + millis);
}
}
return getOffset(era, year, month, day, dayOfWeek, millis,
monthLength, prevMonthLength);
}
/**
* Gets offset, for current date, modified in case of
* daylight saving time. This is the offset to add <em>to</em> UTC to get local time.
* Gets the time zone offset, for current date, modified in case of daylight
* saving time. This is the offset to add to UTC to get local time. Assume
* that the start and end month are distinct.
* @param era The era of the given date.
* @param year The year in the given date.
* @param month The month in the given date. Month is 0-based. e.g.,
* 0 for January.
* @param day The day-in-month of the given date.
* @param dayOfWeek The day-of-week of the given date.
* @param millis The milliseconds in day in <em>standard</em> local time.
* @param monthLength The length of the given month in days.
* @param prevMonthLength The length of the previous month in days.
* @return The offset to add to GMT to get local time.
* @exception IllegalArgumentException the era, month, day,
* dayOfWeek, millis, or monthLength parameters are out of range
*/
private int getOffset(int era, int year, int month, int day, int dayOfWeek,
int millis, int monthLength, int prevMonthLength) {
int result = rawOffset;
// Bail out if we are before the onset of daylight saving time
if (!useDaylight || year < startYear || era != GregorianCalendar.AD) {
return result;
}
// Check for southern hemisphere. We assume that the start and end
// month are different.
boolean southern = (startMonth > endMonth);
// Compare the date to the starting and ending rules.+1 = date>rule, -1
// = date<rule, 0 = date==rule.
int startCompare = compareToRule(month, monthLength, prevMonthLength,
day, dayOfWeek, millis,
startTimeMode == UTC_TIME ? -rawOffset : 0,
startMode, startMonth, startDayOfWeek,
startDay, startTime);
int endCompare = 0;
/* We don't always have to compute endCompare. For many instances,
* startCompare is enough to determine if we are in DST or not. In the
* northern hemisphere, if we are before the start rule, we can't have
* DST. In the southern hemisphere, if we are after the start rule, we
* must have DST. This is reflected in the way the next if statement
* (not the one immediately following) short circuits. */
if (southern != (startCompare >= 0)) {
/* For the ending rule comparison, we add the dstSavings to the millis
* passed in to convert them from standard to wall time. We then must
* normalize the millis to the range 0..millisPerDay-1. */
endCompare = compareToRule(month, monthLength, prevMonthLength,
day, dayOfWeek, millis,
endTimeMode == WALL_TIME ? dstSavings :
(endTimeMode == UTC_TIME ? -rawOffset : 0),
endMode, endMonth, endDayOfWeek,
endDay, endTime);
}
// Check for both the northern and southern hemisphere cases. We
// assume that in the northern hemisphere, the start rule is before the
// end rule within the calendar year, and vice versa for the southern
// hemisphere.
if ((!southern && (startCompare >= 0 && endCompare < 0)) ||
(southern && (startCompare >= 0 || endCompare < 0))) {
result += dstSavings;
}
return result;
}
/**
* Compares the given date in the year to the given rule and returns 1, 0,
* or -1, depending on whether the date is after, equal to, or before the
* rule date. The millis are compared directly against the ruleMillis, so
* any standard-daylight adjustments must be handled by the caller.
*
* @return 1 if the date is after the rule date, -1 if the date is before
* the rule date, or 0 if the date is equal to the rule date.
*/
private static int compareToRule(int month, int monthLen, int prevMonthLen,
int dayOfMonth,
int dayOfWeek, int millis, int millisDelta,
int ruleMode, int ruleMonth, int ruleDayOfWeek,
int ruleDay, int ruleMillis)
{
// Make adjustments for startTimeMode and endTimeMode
millis += millisDelta;
while (millis >= millisPerDay) {
millis -= millisPerDay;
++dayOfMonth;
dayOfWeek = 1 + (dayOfWeek % 7); // dayOfWeek is one-based
if (dayOfMonth > monthLen) {
dayOfMonth = 1;
/* When incrementing the month, it is desirable to overflow
* from DECEMBER to DECEMBER+1, since we use the result to
* compare against a real month. Wraparound of the value
* leads to bug 4173604. */
++month;
}
}
while (millis < 0) {
millis += millisPerDay;
--dayOfMonth;
dayOfWeek = 1 + ((dayOfWeek+5) % 7); // dayOfWeek is one-based
if (dayOfMonth < 1) {
dayOfMonth = prevMonthLen;
--month;
}
}
if (month < ruleMonth) {
return -1;
}
if (month > ruleMonth) {
return 1;
}
int ruleDayOfMonth = 0;
switch (ruleMode) {
case DOM_MODE:
ruleDayOfMonth = ruleDay;
break;
case DOW_IN_MONTH_MODE:
// In this case ruleDay is the day-of-week-in-month
if (ruleDay > 0) {
ruleDayOfMonth = 1 + (ruleDay - 1) * 7 +
(7 + ruleDayOfWeek - (dayOfWeek - dayOfMonth + 1)) % 7;
} else {
// Assume ruleDay < 0 here
ruleDayOfMonth = monthLen + (ruleDay + 1) * 7 -
(7 + (dayOfWeek + monthLen - dayOfMonth) - ruleDayOfWeek) % 7;
}
break;
case DOW_GE_DOM_MODE:
ruleDayOfMonth = ruleDay +
(49 + ruleDayOfWeek - ruleDay - dayOfWeek + dayOfMonth) % 7;
break;
case DOW_LE_DOM_MODE:
ruleDayOfMonth = ruleDay -
(49 - ruleDayOfWeek + ruleDay + dayOfWeek - dayOfMonth) % 7;
// Note at this point ruleDayOfMonth may be <1, although it will
// be >=1 for well-formed rules.
break;
}
if (dayOfMonth < ruleDayOfMonth) {
return -1;
}
if (dayOfMonth > ruleDayOfMonth) {
return 1;
}
if (millis < ruleMillis) {
return -1;
}
if (millis > ruleMillis) {
return 1;
}
return 0;
}
/**
* Gets the GMT offset for this time zone.
* @return the GMT offset value in milliseconds
* @see #setRawOffset
*/
public int getRawOffset()
{
// The given date will be taken into account while
// we have the historical time zone data in place.
return rawOffset;
}
/**
* Sets the base time zone offset to GMT.
* This is the offset to add to UTC to get local time.
* @see #getRawOffset
*/
public void setRawOffset(int offsetMillis)
{
this.rawOffset = offsetMillis;
}
/**
* Sets the amount of time in milliseconds that the clock is advanced
* during daylight saving time.
* @param millisSavedDuringDST the number of milliseconds the time is
* advanced with respect to standard time when the daylight saving time rules
* are in effect. A positive number, typically one hour (3600000).
* @see #getDSTSavings
* @since 1.2
*/
public void setDSTSavings(int millisSavedDuringDST) {
if (millisSavedDuringDST <= 0) {
throw new IllegalArgumentException("Illegal daylight saving value: "
+ millisSavedDuringDST);
}
dstSavings = millisSavedDuringDST;
}
/**
* Returns the amount of time in milliseconds that the clock is
* advanced during daylight saving time.
*
* @return the number of milliseconds the time is advanced with
* respect to standard time when the daylight saving rules are in
* effect, or 0 (zero) if this time zone doesn't observe daylight
* saving time.
*
* @see #setDSTSavings
* @since 1.2
*/
public int getDSTSavings() {
if (useDaylight) {
return dstSavings;
}
return 0;
}
/**
* Queries if this time zone uses daylight saving time.
* @return true if this time zone uses daylight saving time;
* false otherwise.
*/
public boolean useDaylightTime()
{
return useDaylight;
}
/**
* Queries if the given date is in daylight saving time.
* @return true if daylight saving time is in effective at the
* given date; false otherwise.
*/
public boolean inDaylightTime(Date date)
{
return (getOffset(date.getTime()) != rawOffset);
}
/**
* Returns a clone of this <code>SimpleTimeZone</code> instance.
* @return a clone of this instance.
*/
public Object clone()
{
return super.clone();
}
/**
* Generates the hash code for the SimpleDateFormat object.
* @return the hash code for this object
*/
public synchronized int hashCode()
{
return startMonth ^ startDay ^ startDayOfWeek ^ startTime ^
endMonth ^ endDay ^ endDayOfWeek ^ endTime ^ rawOffset;
}
/**
* Compares the equality of two <code>SimpleTimeZone</code> objects.
*
* @param obj The <code>SimpleTimeZone</code> object to be compared with.
* @return True if the given <code>obj</code> is the same as this
* <code>SimpleTimeZone</code> object; false otherwise.
*/
public boolean equals(Object obj)
{
if (this == obj) {
return true;
}
if (!(obj instanceof SimpleTimeZone)) {
return false;
}
SimpleTimeZone that = (SimpleTimeZone) obj;
return getID().equals(that.getID()) &&
hasSameRules(that);
}
/**
* Returns true if this zone has the same rules and offset as another zone.
* @param other the TimeZone object to be compared with
* @return true if the given zone is a SimpleTimeZone and has the
* same rules and offset as this one
* @since 1.2
*/
public boolean hasSameRules(TimeZone other) {
if (this == other) {
return true;
}
if (!(other instanceof SimpleTimeZone)) {
return false;
}
SimpleTimeZone that = (SimpleTimeZone) other;
return rawOffset == that.rawOffset &&
useDaylight == that.useDaylight &&
(!useDaylight
// Only check rules if using DST
|| (dstSavings == that.dstSavings &&
startMode == that.startMode &&
startMonth == that.startMonth &&
startDay == that.startDay &&
startDayOfWeek == that.startDayOfWeek &&
startTime == that.startTime &&
startTimeMode == that.startTimeMode &&
endMode == that.endMode &&
endMonth == that.endMonth &&
endDay == that.endDay &&
endDayOfWeek == that.endDayOfWeek &&
endTime == that.endTime &&
endTimeMode == that.endTimeMode &&
startYear == that.startYear));
}
/**
* Returns a string representation of this time zone.
* @return a string representation of this time zone.
*/
public String toString() {
return getClass().getName() +
"[id=" + getID() +
",offset=" + rawOffset +
",dstSavings=" + dstSavings +
",useDaylight=" + useDaylight +
",startYear=" + startYear +
",startMode=" + startMode +
",startMonth=" + startMonth +
",startDay=" + startDay +
",startDayOfWeek=" + startDayOfWeek +
",startTime=" + startTime +
",startTimeMode=" + startTimeMode +
",endMode=" + endMode +
",endMonth=" + endMonth +
",endDay=" + endDay +
",endDayOfWeek=" + endDayOfWeek +
",endTime=" + endTime +
",endTimeMode=" + endTimeMode + ']';
}
// =======================privates===============================
/**
* The month in which daylight saving time starts. This value must be
* between <code>Calendar.JANUARY</code> and
* <code>Calendar.DECEMBER</code> inclusive. This value must not equal
* <code>endMonth</code>.
* <p>If <code>useDaylight</code> is false, this value is ignored.
* @serial
*/
private int startMonth;
/**
* This field has two possible interpretations:
* <dl>
* <dt><code>startMode == DOW_IN_MONTH</code></dt>
* <dd>
* <code>startDay</code> indicates the day of the month of
* <code>startMonth</code> on which daylight
* saving time starts, from 1 to 28, 30, or 31, depending on the
* <code>startMonth</code>.
* </dd>
* <dt><code>startMode != DOW_IN_MONTH</code></dt>
* <dd>
* <code>startDay</code> indicates which <code>startDayOfWeek</code> in th
* month <code>startMonth</code> daylight
* saving time starts on. For example, a value of +1 and a
* <code>startDayOfWeek</code> of <code>Calendar.SUNDAY</code> indicates the
* first Sunday of <code>startMonth</code>. Likewise, +2 would indicate the
* second Sunday, and -1 the last Sunday. A value of 0 is illegal.
* </dd>
* </ul>
* <p>If <code>useDaylight</code> is false, this value is ignored.
* @serial
*/
private int startDay;
/**
* The day of the week on which daylight saving time starts. This value
* must be between <code>Calendar.SUNDAY</code> and
* <code>Calendar.SATURDAY</code> inclusive.
* <p>If <code>useDaylight</code> is false or
* <code>startMode == DAY_OF_MONTH</code>, this value is ignored.
* @serial
*/
private int startDayOfWeek;
/**
* The time in milliseconds after midnight at which daylight saving
* time starts. This value is expressed as wall time, standard time,
* or UTC time, depending on the setting of <code>startTimeMode</code>.
* <p>If <code>useDaylight</code> is false, this value is ignored.
* @serial
*/
private int startTime;
/**
* The format of startTime, either WALL_TIME, STANDARD_TIME, or UTC_TIME.
* @serial
* @since 1.3
*/
private int startTimeMode;
/**
* The month in which daylight saving time ends. This value must be
* between <code>Calendar.JANUARY</code> and
* <code>Calendar.UNDECIMBER</code>. This value must not equal
* <code>startMonth</code>.
* <p>If <code>useDaylight</code> is false, this value is ignored.
* @serial
*/
private int endMonth;
/**
* This field has two possible interpretations:
* <dl>
* <dt><code>endMode == DOW_IN_MONTH</code></dt>
* <dd>
* <code>endDay</code> indicates the day of the month of
* <code>endMonth</code> on which daylight
* saving time ends, from 1 to 28, 30, or 31, depending on the
* <code>endMonth</code>.
* </dd>
* <dt><code>endMode != DOW_IN_MONTH</code></dt>
* <dd>
* <code>endDay</code> indicates which <code>endDayOfWeek</code> in th
* month <code>endMonth</code> daylight
* saving time ends on. For example, a value of +1 and a
* <code>endDayOfWeek</code> of <code>Calendar.SUNDAY</code> indicates the
* first Sunday of <code>endMonth</code>. Likewise, +2 would indicate the
* second Sunday, and -1 the last Sunday. A value of 0 is illegal.
* </dd>
* </ul>
* <p>If <code>useDaylight</code> is false, this value is ignored.
* @serial
*/
private int endDay;
/**
* The day of the week on which daylight saving time ends. This value
* must be between <code>Calendar.SUNDAY</code> and
* <code>Calendar.SATURDAY</code> inclusive.
* <p>If <code>useDaylight</code> is false or
* <code>endMode == DAY_OF_MONTH</code>, this value is ignored.
* @serial
*/
private int endDayOfWeek;
/**
* The time in milliseconds after midnight at which daylight saving
* time ends. This value is expressed as wall time, standard time,
* or UTC time, depending on the setting of <code>endTimeMode</code>.
* <p>If <code>useDaylight</code> is false, this value is ignored.
* @serial
*/
private int endTime;
/**
* The format of endTime, either WALL_TIME, STANDARD_TIME, or UTC_TIME.
* @serial
* @since 1.3
*/
private int endTimeMode;
/**
* The year in which daylight saving time is first observed. This is an AD
* value. If this value is less than 1 then daylight saving time is observed
* for all AD years.
* <p>If <code>useDaylight</code> is false, this value is ignored.
* @serial
*/
private int startYear;
/**
* The offset in milliseconds between this zone and GMT. Negative offsets
* are to the west of Greenwich. To obtain local <em>standard</em> time,
* add the offset to GMT time. To obtain local wall time it may also be
* necessary to add <code>dstSavings</code>.
* @serial
*/
private int rawOffset;
/**
* A boolean value which is true if and only if this zone uses daylight
* saving time. If this value is false, several other fields are ignored.
* @serial
*/
private boolean useDaylight=false; // indicate if this time zone uses DST
private static final int millisPerHour = 60*60*1000;
private static final int millisPerDay = 24*millisPerHour;
/**
* This field was serialized in JDK 1.1, so we have to keep it that way
* to maintain serialization compatibility. However, there's no need to
* recreate the array each time we create a new time zone.
* @serial An array of bytes containing the values {31, 28, 31, 30, 31, 30,
* 31, 31, 30, 31, 30, 31}. This is ignored as of the Java 2 platform v1.2, however, it must
* be streamed out for compatibility with JDK 1.1.
*/
private final byte monthLength[] = staticMonthLength;
private final static byte staticMonthLength[] = {31,28,31,30,31,30,31,31,30,31,30,31};
private final static byte staticLeapMonthLength[] = {31,29,31,30,31,30,31,31,30,31,30,31};
/**
* Variables specifying the mode of the start rule. Takes the following
* values:
* <dl>
* <dt><code>DOM_MODE</code></dt>
* <dd>
* Exact day of week; e.g., March 1.
* </dd>
* <dt><code>DOW_IN_MONTH_MODE</code></dt>
* <dd>
* Day of week in month; e.g., last Sunday in March.
* </dd>
* <dt><code>DOW_GE_DOM_MODE</code></dt>
* <dd>
* Day of week after day of month; e.g., Sunday on or after March 15.
* </dd>
* <dt><code>DOW_LE_DOM_MODE</code></dt>
* <dd>
* Day of week before day of month; e.g., Sunday on or before March 15.
* </dd>
* </dl>
* The setting of this field affects the interpretation of the
* <code>startDay</code> field.
* <p>If <code>useDaylight</code> is false, this value is ignored.
* @serial
* @since 1.1.4
*/
private int startMode;
/**
* Variables specifying the mode of the end rule. Takes the following
* values:
* <dl>
* <dt><code>DOM_MODE</code></dt>
* <dd>
* Exact day of week; e.g., March 1.
* </dd>
* <dt><code>DOW_IN_MONTH_MODE</code></dt>
* <dd>
* Day of week in month; e.g., last Sunday in March.
* </dd>
* <dt><code>DOW_GE_DOM_MODE</code></dt>
* <dd>
* Day of week after day of month; e.g., Sunday on or after March 15.
* </dd>
* <dt><code>DOW_LE_DOM_MODE</code></dt>
* <dd>
* Day of week before day of month; e.g., Sunday on or before March 15.
* </dd>
* </dl>
* The setting of this field affects the interpretation of the
* <code>endDay</code> field.
* <p>If <code>useDaylight</code> is false, this value is ignored.
* @serial
* @since 1.1.4
*/
private int endMode;
/**
* A positive value indicating the amount of time saved during DST in
* milliseconds.
* Typically one hour (3600000); sometimes 30 minutes (1800000).
* <p>If <code>useDaylight</code> is false, this value is ignored.
* @serial
* @since 1.1.4
*/
private int dstSavings;
/**
* Constants specifying values of startMode and endMode.
*/
private static final int DOM_MODE = 1; // Exact day of month, "Mar 1"
private static final int DOW_IN_MONTH_MODE = 2; // Day of week in month, "lastSun"
private static final int DOW_GE_DOM_MODE = 3; // Day of week after day of month, "Sun>=15"
private static final int DOW_LE_DOM_MODE = 4; // Day of week before day of month, "Sun<=21"
/**
* Constant for a mode of start or end time specified as wall clock
* time. Wall clock time is standard time for the onset rule, and
* daylight time for the end rule.
* @since 1.4
*/
public static final int WALL_TIME = 0; // Zero for backward compatibility
/**
* Constant for a mode of start or end time specified as standard time.
* @since 1.4
*/
public static final int STANDARD_TIME = 1;
/**
* Constant for a mode of start or end time specified as UTC. European
* Union rules are specified as UTC time, for example.
* @since 1.4
*/
public static final int UTC_TIME = 2;
// Proclaim compatibility with 1.1
static final long serialVersionUID = -403250971215465050L;
// the internal serial version which says which version was written
// - 0 (default) for version up to JDK 1.1.3
// - 1 for version from JDK 1.1.4, which includes 3 new fields
// - 2 for JDK 1.3, which includes 2 new fields
static final int currentSerialVersion = 2;
/**
* The version of the serialized data on the stream. Possible values:
* <dl>
* <dt><b>0</b> or not present on stream</dt>
* <dd>
* JDK 1.1.3 or earlier.
* </dd>
* <dt><b>1</b></dt>
* <dd>
* JDK 1.1.4 or later. Includes three new fields: <code>startMode</code>,
* <code>endMode</code>, and <code>dstSavings</code>.
* </dd>
* <dt><b>2</b></dt>
* <dd>
* JDK 1.3 or later. Includes two new fields: <code>startTimeMode</code>
* and <code>endTimeMode</code>.
* </dd>
* </dl>
* When streaming out this class, the most recent format
* and the highest allowable <code>serialVersionOnStream</code>
* is written.
* @serial
* @since 1.1.4
*/
private int serialVersionOnStream = currentSerialVersion;
//----------------------------------------------------------------------
// Rule representation
//
// We represent the following flavors of rules:
// 5 the fifth of the month
// lastSun the last Sunday in the month
// lastMon the last Monday in the month
// Sun>=8 first Sunday on or after the eighth
// Sun<=25 last Sunday on or before the 25th
// This is further complicated by the fact that we need to remain
// backward compatible with the 1.1. Finally, we need to minimize
// API changes. In order to satisfy these requirements, we support
// three representation systems, and we translate between them.
//
// INTERNAL REPRESENTATION
// This is the format SimpleTimeZone objects take after construction or
// streaming in is complete. Rules are represented directly, using an
// unencoded format. We will discuss the start rule only below; the end
// rule is analogous.
// startMode Takes on enumerated values DAY_OF_MONTH,
// DOW_IN_MONTH, DOW_AFTER_DOM, or DOW_BEFORE_DOM.
// startDay The day of the month, or for DOW_IN_MONTH mode, a
// value indicating which DOW, such as +1 for first,
// +2 for second, -1 for last, etc.
// startDayOfWeek The day of the week. Ignored for DAY_OF_MONTH.
//
// ENCODED REPRESENTATION
// This is the format accepted by the constructor and by setStartRule()
// and setEndRule(). It uses various combinations of positive, negative,
// and zero values to encode the different rules. This representation
// allows us to specify all the different rule flavors without altering
// the API.
// MODE startMonth startDay startDayOfWeek
// DOW_IN_MONTH_MODE >=0 !=0 >0
// DOM_MODE >=0 >0 ==0
// DOW_GE_DOM_MODE >=0 >0 <0
// DOW_LE_DOM_MODE >=0 <0 <0
// (no DST) don't care ==0 don't care
//
// STREAMED REPRESENTATION
// We must retain binary compatibility with the 1.1. The 1.1 code only
// handles DOW_IN_MONTH_MODE and non-DST mode, the latter indicated by the
// flag useDaylight. When we stream an object out, we translate into an
// approximate DOW_IN_MONTH_MODE representation so the object can be parsed
// and used by 1.1 code. Following that, we write out the full
// representation separately so that contemporary code can recognize and
// parse it. The full representation is written in a "packed" format,
// consisting of a version number, a length, and an array of bytes. Future
// versions of this class may specify different versions. If they wish to
// include additional data, they should do so by storing them after the
// packed representation below.
//----------------------------------------------------------------------
/**
* Given a set of encoded rules in startDay and startDayOfMonth, decode
* them and set the startMode appropriately. Do the same for endDay and
* endDayOfMonth. Upon entry, the day of week variables may be zero or
* negative, in order to indicate special modes. The day of month
* variables may also be negative. Upon exit, the mode variables will be
* set, and the day of week and day of month variables will be positive.
* This method also recognizes a startDay or endDay of zero as indicating
* no DST.
*/
private void decodeRules()
{
decodeStartRule();
decodeEndRule();
}
/**
* Decode the start rule and validate the parameters. The parameters are
* expected to be in encoded form, which represents the various rule modes
* by negating or zeroing certain values. Representation formats are:
* <p>
* <pre>
* DOW_IN_MONTH DOM DOW>=DOM DOW<=DOM no DST
* ------------ ----- -------- -------- ----------
* month 0..11 same same same don't care
* day -5..5 1..31 1..31 -1..-31 0
* dayOfWeek 1..7 0 -1..-7 -1..-7 don't care
* time 0..ONEDAY same same same don't care
* </pre>
* The range for month does not include UNDECIMBER since this class is
* really specific to GregorianCalendar, which does not use that month.
* The range for time includes ONEDAY (vs. ending at ONEDAY-1) because the
* end rule is an exclusive limit point. That is, the range of times that
* are in DST include those >= the start and < the end. For this reason,
* it should be possible to specify an end of ONEDAY in order to include the
* entire day. Although this is equivalent to time 0 of the following day,
* it's not always possible to specify that, for example, on December 31.
* While arguably the start range should still be 0..ONEDAY-1, we keep
* the start and end ranges the same for consistency.
*/
private void decodeStartRule() {
useDaylight = (startDay != 0) && (endDay != 0);
if (startDay != 0) {
if (startMonth < Calendar.JANUARY || startMonth > Calendar.DECEMBER) {
throw new IllegalArgumentException(
"Illegal start month " + startMonth);
}
if (startTime < 0 || startTime >= millisPerDay) {
throw new IllegalArgumentException(
"Illegal start time " + startTime);
}
if (startDayOfWeek == 0) {
startMode = DOM_MODE;
} else {
if (startDayOfWeek > 0) {
startMode = DOW_IN_MONTH_MODE;
} else {
startDayOfWeek = -startDayOfWeek;
if (startDay > 0) {
startMode = DOW_GE_DOM_MODE;
} else {
startDay = -startDay;
startMode = DOW_LE_DOM_MODE;
}
}
if (startDayOfWeek > Calendar.SATURDAY) {
throw new IllegalArgumentException(
"Illegal start day of week " + startDayOfWeek);
}
}
if (startMode == DOW_IN_MONTH_MODE) {
if (startDay < -5 || startDay > 5) {
throw new IllegalArgumentException(
"Illegal start day of week in month " + startDay);
}
} else if (startDay < 1 || startDay > staticMonthLength[startMonth]) {
throw new IllegalArgumentException(
"Illegal start day " + startDay);
}
}
}
/**
* Decode the end rule and validate the parameters. This method is exactly
* analogous to decodeStartRule().
* @see decodeStartRule
*/
private void decodeEndRule() {
useDaylight = (startDay != 0) && (endDay != 0);
if (endDay != 0) {
if (endMonth < Calendar.JANUARY || endMonth > Calendar.DECEMBER) {
throw new IllegalArgumentException(
"Illegal end month " + endMonth);
}
if (endTime < 0 || endTime >= millisPerDay) {
throw new IllegalArgumentException(
"Illegal end time " + endTime);
}
if (endDayOfWeek == 0) {
endMode = DOM_MODE;
} else {
if (endDayOfWeek > 0) {
endMode = DOW_IN_MONTH_MODE;
} else {
endDayOfWeek = -endDayOfWeek;
if (endDay > 0) {
endMode = DOW_GE_DOM_MODE;
} else {
endDay = -endDay;
endMode = DOW_LE_DOM_MODE;
}
}
if (endDayOfWeek > Calendar.SATURDAY) {
throw new IllegalArgumentException(
"Illegal end day of week " + endDayOfWeek);
}
}
if (endMode == DOW_IN_MONTH_MODE) {
if (endDay < -5 || endDay > 5) {
throw new IllegalArgumentException(
"Illegal end day of week in month " + endDay);
}
} else if (endDay < 1 || endDay > staticMonthLength[endMonth]) {
throw new IllegalArgumentException(
"Illegal end day " + endDay);
}
}
}
/**
* Make rules compatible to 1.1 code. Since 1.1 code only understands
* day-of-week-in-month rules, we must modify other modes of rules to their
* approximate equivalent in 1.1 terms. This method is used when streaming
* out objects of this class. After it is called, the rules will be modified,
* with a possible loss of information. startMode and endMode will NOT be
* altered, even though semantically they should be set to DOW_IN_MONTH_MODE,
* since the rule modification is only intended to be temporary.
*/
private void makeRulesCompatible()
{
switch (startMode) {
case DOM_MODE:
startDay = 1 + (startDay / 7);
startDayOfWeek = Calendar.SUNDAY;
break;
case DOW_GE_DOM_MODE:
// A day-of-month of 1 is equivalent to DOW_IN_MONTH_MODE
// that is, Sun>=1 == firstSun.
if (startDay != 1) {
startDay = 1 + (startDay / 7);
}
break;
case DOW_LE_DOM_MODE:
if (startDay >= 30) {
startDay = -1;
} else {
startDay = 1 + (startDay / 7);
}
break;
}
switch (endMode) {
case DOM_MODE:
endDay = 1 + (endDay / 7);
endDayOfWeek = Calendar.SUNDAY;
break;
case DOW_GE_DOM_MODE:
// A day-of-month of 1 is equivalent to DOW_IN_MONTH_MODE
// that is, Sun>=1 == firstSun.
if (endDay != 1) {
endDay = 1 + (endDay / 7);
}
break;
case DOW_LE_DOM_MODE:
if (endDay >= 30) {
endDay = -1;
} else {
endDay = 1 + (endDay / 7);
}
break;
}
/*
* Adjust the start and end times to wall time. This works perfectly
* well unless it pushes into the next or previous day. If that
* happens, we attempt to adjust the day rule somewhat crudely. The day
* rules have been forced into DOW_IN_MONTH mode already, so we change
* the day of week to move forward or back by a day. It's possible to
* make a more refined adjustment of the original rules first, but in
* most cases this extra effort will go to waste once we adjust the day
* rules anyway.
*/
switch (startTimeMode) {
case UTC_TIME:
startTime += rawOffset;
break;
}
while (startTime < 0) {
startTime += millisPerDay;
startDayOfWeek = 1 + ((startDayOfWeek+5) % 7); // Back 1 day
}
while (startTime >= millisPerDay) {
startTime -= millisPerDay;
startDayOfWeek = 1 + (startDayOfWeek % 7); // Forward 1 day
}
switch (endTimeMode) {
case UTC_TIME:
endTime += rawOffset + dstSavings;
break;
case STANDARD_TIME:
endTime += dstSavings;
}
while (endTime < 0) {
endTime += millisPerDay;
endDayOfWeek = 1 + ((endDayOfWeek+5) % 7); // Back 1 day
}
while (endTime >= millisPerDay) {
endTime -= millisPerDay;
endDayOfWeek = 1 + (endDayOfWeek % 7); // Forward 1 day
}
}
/**
* Pack the start and end rules into an array of bytes. Only pack
* data which is not preserved by makeRulesCompatible.
*/
private byte[] packRules()
{
byte[] rules = new byte[6];
rules[0] = (byte)startDay;
rules[1] = (byte)startDayOfWeek;
rules[2] = (byte)endDay;
rules[3] = (byte)endDayOfWeek;
// As of serial version 2, include time modes
rules[4] = (byte)startTimeMode;
rules[5] = (byte)endTimeMode;
return rules;
}
/**
* Given an array of bytes produced by packRules, interpret them
* as the start and end rules.
*/
private void unpackRules(byte[] rules)
{
startDay = rules[0];
startDayOfWeek = rules[1];
endDay = rules[2];
endDayOfWeek = rules[3];
// As of serial version 2, include time modes
if (rules.length >= 6) {
startTimeMode = rules[4];
endTimeMode = rules[5];
}
}
/**
* Pack the start and end times into an array of bytes. This is required
* as of serial version 2.
*/
private int[] packTimes() {
int[] times = new int[2];
times[0] = startTime;
times[1] = endTime;
return times;
}
/**
* Unpack the start and end times from an array of bytes. This is required
* as of serial version 2.
*/
private void unpackTimes(int[] times) {
startTime = times[0];
endTime = times[1];
}
/**
* Save the state of this object to a stream (i.e., serialize it).
*
* @serialData We write out two formats, a JDK 1.1 compatible format, using
* <code>DOW_IN_MONTH_MODE</code> rules, in the required section, followed
* by the full rules, in packed format, in the optional section. The
* optional section will be ignored by JDK 1.1 code upon stream in.
* <p> Contents of the optional section: The length of a byte array is
* emitted (int); this is 4 as of this release. The byte array of the given
* length is emitted. The contents of the byte array are the true values of
* the fields <code>startDay</code>, <code>startDayOfWeek</code>,
* <code>endDay</code>, and <code>endDayOfWeek</code>. The values of these
* fields in the required section are approximate values suited to the rule
* mode <code>DOW_IN_MONTH_MODE</code>, which is the only mode recognized by
* JDK 1.1.
*/
private void writeObject(ObjectOutputStream stream)
throws IOException
{
// Construct a binary rule
byte[] rules = packRules();
int[] times = packTimes();
// Convert to 1.1 rules. This step may cause us to lose information.
makeRulesCompatible();
// Write out the 1.1 rules
stream.defaultWriteObject();
// Write out the binary rules in the optional data area of the stream.
stream.writeInt(rules.length);
stream.write(rules);
stream.writeObject(times);
// Recover the original rules. This recovers the information lost
// by makeRulesCompatible.
unpackRules(rules);
unpackTimes(times);
}
/**
* Reconstitute this object from a stream (i.e., deserialize it).
*
* We handle both JDK 1.1
* binary formats and full formats with a packed byte array.
*/
private void readObject(ObjectInputStream stream)
throws IOException, ClassNotFoundException
{
stream.defaultReadObject();
if (serialVersionOnStream < 1) {
// Fix a bug in the 1.1 SimpleTimeZone code -- namely,
// startDayOfWeek and endDayOfWeek were usually uninitialized. We can't do
// too much, so we assume SUNDAY, which actually works most of the time.
if (startDayOfWeek == 0) {
startDayOfWeek = Calendar.SUNDAY;
}
if (endDayOfWeek == 0) {
endDayOfWeek = Calendar.SUNDAY;
}
// The variables dstSavings, startMode, and endMode are post-1.1, so they
// won't be present if we're reading from a 1.1 stream. Fix them up.
startMode = endMode = DOW_IN_MONTH_MODE;
dstSavings = millisPerHour;
} else {
// For 1.1.4, in addition to the 3 new instance variables, we also
// store the actual rules (which have not be made compatible with 1.1)
// in the optional area. Read them in here and parse them.
int length = stream.readInt();
byte[] rules = new byte[length];
stream.readFully(rules);
unpackRules(rules);
}
if (serialVersionOnStream >= 2) {
int[] times = (int[]) stream.readObject();
unpackTimes(times);
}
serialVersionOnStream = currentSerialVersion;
}
}