/*
*
* @(#)Calendar.java 1.57 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. 1996-1998 - All Rights Reserved
* (C) Copyright IBM Corp. 1996-1998 - 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.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.text.DateFormat;
import sun.text.resources.LocaleData;
import sun.util.BuddhistCalendar;
import sun.util.calendar.ZoneInfo;
/**
* <code>Calendar</code> is an abstract base class for converting between
* a <code>Date</code> object and a set of integer fields such as
* <code>YEAR</code>, <code>MONTH</code>, <code>DAY</code>, <code>HOUR</code>,
* and so on. (A <code>Date</code> object represents a specific instant in
* time with millisecond precision. See
* {@link Date}
* for information about the <code>Date</code> class.)
*
* <p>
* Subclasses of <code>Calendar</code> interpret a <code>Date</code>
* according to the rules of a specific calendar system. The platform
* provides one concrete subclass of <code>Calendar</code>:
* <code>GregorianCalendar</code>. Future subclasses could represent
* the various types of lunar calendars in use in many parts of the world.
*
* <p>
* Like other locale-sensitive classes, <code>Calendar</code> provides a
* class method, <code>getInstance</code>, for getting a generally useful
* object of this type. <code>Calendar</code>'s <code>getInstance</code> method
* returns a <code>Calendar</code> object whose
* time fields have been initialized with the current date and time:
* <blockquote>
* <pre>
* Calendar rightNow = Calendar.getInstance();
* </pre>
* </blockquote>
*
* <p>A <code>Calendar</code> object can produce all the time field values
* needed to implement the date-time formatting for a particular language and
* calendar style (for example, Japanese-Gregorian, Japanese-Traditional).
* <code>Calendar</code> defines the range of values returned by certain fields,
* as well as their meaning. For example, the first month of the year has value
* <code>MONTH</code> == <code>JANUARY</code> for all calendars. Other values
* are defined by the concrete subclass, such as <code>ERA</code> and
* <code>YEAR</code>. See individual field documentation and subclass
* documentation for details.
*
* <p>When a <code>Calendar</code> is <em>lenient</em>, it accepts a wider range
* of field values than it produces. For example, a lenient
* <code>GregorianCalendar</code> interprets <code>MONTH</code> ==
* <code>JANUARY</code>, <code>DAY_OF_MONTH</code> == 32 as February 1. A
* non-lenient <code>GregorianCalendar</code> throws an exception when given
* out-of-range field settings. When calendars recompute field values for
* return by <code>get()</code>, they normalize them. For example, a
* <code>GregorianCalendar</code> always produces <code>DAY_OF_MONTH</code>
* values between 1 and the length of the month.
*
* <p><code>Calendar</code> defines a locale-specific seven day week using two
* parameters: the first day of the week and the minimal days in first week
* (from 1 to 7). These numbers are taken from the locale resource data when a
* <code>Calendar</code> is constructed. They may also be specified explicitly
* through the API.
*
* <p>When setting or getting the <code>WEEK_OF_MONTH</code> or
* <code>WEEK_OF_YEAR</code> fields, <code>Calendar</code> must determine the
* first week of the month or year as a reference point. The first week of a
* month or year is defined as the earliest seven day period beginning on
* <code>getFirstDayOfWeek()</code> and containing at least
* <code>getMinimalDaysInFirstWeek()</code> days of that month or year. Weeks
* numbered ..., -1, 0 precede the first week; weeks numbered 2, 3,... follow
* it. Note that the normalized numbering returned by <code>get()</code> may be
* different. For example, a specific <code>Calendar</code> subclass may
* designate the week before week 1 of a year as week <em>n</em> of the previous
* year.
*
* <p> When computing a <code>Date</code> from time fields, two special
* circumstances may arise: there may be insufficient information to compute the
* <code>Date</code> (such as only year and month but no day in the month), or
* there may be inconsistent information (such as "Tuesday, July 15, 1996" --
* July 15, 1996 is actually a Monday).
*
* <p>
* <strong>Insufficient information.</strong> The calendar will use default
* information to specify the missing fields. This may vary by calendar; for
* the Gregorian calendar, the default for a field is the same as that of the
* start of the epoch: i.e., YEAR = 1970, MONTH = JANUARY, DATE = 1, etc.
*
* <p>
* <strong>Inconsistent information.</strong> If fields conflict, the calendar
* will give preference to fields set more recently. For example, when
* determining the day, the calendar will look for one of the following
* combinations of fields. The most recent combination, as determined by the
* most recently set single field, will be used.
*
* <blockquote>
* <pre>
* MONTH + DAY_OF_MONTH
* MONTH + WEEK_OF_MONTH + DAY_OF_WEEK
* MONTH + DAY_OF_WEEK_IN_MONTH + DAY_OF_WEEK
* DAY_OF_YEAR
* DAY_OF_WEEK + WEEK_OF_YEAR
* </pre>
* </blockquote>
*
* For the time of day:
*
* <blockquote>
* <pre>
* HOUR_OF_DAY
* AM_PM + HOUR
* </pre>
* </blockquote>
*
* <p>
* <strong>Note:</strong> for some non-Gregorian calendars, different
* fields may be necessary for complete disambiguation. For example, a full
* specification of the historical Arabic astronomical calendar requires year,
* month, day-of-month <em>and</em> day-of-week in some cases.
*
* <p>
* <strong>Note:</strong> There are certain possible ambiguities in
* interpretation of certain singular times, which are resolved in the
* following ways:
* <ol>
* <li> 23:59 is the last minute of the day and 00:00 is the first minute of the
* next day. Thus, 23:59 on Dec 31, 1999 < 00:00 on Jan 1, 2000 < 00:01 on
* Jan 1, 2000.
*
* <li> Although historically not precise, midnight also belongs to "am",
* and noon belongs to "pm", so on the same day,
* 12:00 am (midnight) < 12:01 am, and 12:00 pm (noon) < 12:01 pm
* </ol>
*
* <p>
* The date or time format strings are not part of the definition of a
* calendar, as those must be modifiable or overridable by the user at
* runtime. Use {@link DateFormat}
* to format dates.
*
* <p><strong>Field manipulation methods</strong></p>
*
* <p><code>Calendar</code> fields can be changed using three methods:
* <code>set()</code>, <code>add()</code>, and <code>roll()</code>.</p>
*
* <p><strong><code>set(f, value)</code></strong> changes field
* <code>f</code> to <code>value</code>. In addition, it sets an
* internal member variable to indicate that field <code>f</code> has
* been changed. Although field <code>f</code> is changed immediately,
* the calendar's milliseconds is not recomputed until the next call to
* <code>get()</code>, <code>getTime()</code>, or
* <code>getTimeInMillis()</code> is made. Thus, multiple calls to
* <code>set()</code> do not trigger multiple, unnecessary
* computations. As a result of changing a field using
* <code>set()</code>, other fields may also change, depending on the
* field, the field value, and the calendar system. In addition,
* <code>get(f)</code> will not necessarily return <code>value</code>
* after the fields have been recomputed. The specifics are determined by
* the concrete calendar class.</p>
*
* <p><em>Example</em>: Consider a <code>GregorianCalendar</code>
* originally set to August 31, 1999. Calling <code>set(Calendar.MONTH,
* Calendar.SEPTEMBER)</code> sets the calendar to September 31,
* 1999. This is a temporary internal representation that resolves to
* October 1, 1999 if <code>getTime()</code>is then called. However, a
* call to <code>set(Calendar.DAY_OF_MONTH, 30)</code> before the call to
* <code>getTime()</code> sets the calendar to September 30, 1999, since
* no recomputation occurs after <code>set()</code> itself.</p>
*
* <p><strong><code>add(f, delta)</code></strong> adds <code>delta</code>
* to field <code>f</code>. This is equivalent to calling <code>set(f,
* get(f) + delta)</code> with two adjustments:</p>
*
* <blockquote>
* <p><strong>Add rule 1</strong>. The value of field <code>f</code>
* after the call minus the value of field <code>f</code> before the
* call is <code>delta</code>, modulo any overflow that has occurred in
* field <code>f</code>. Overflow occurs when a field value exceeds its
* range and, as a result, the next larger field is incremented or
* decremented and the field value is adjusted back into its range.</p>
*
* <p><strong>Add rule 2</strong>. If a smaller field is expected to be
* invariant, but it is impossible for it to be equal to its
* prior value because of changes in its minimum or maximum after field
* <code>f</code> is changed, then its value is adjusted to be as close
* as possible to its expected value. A smaller field represents a
* smaller unit of time. <code>HOUR</code> is a smaller field than
* <code>DAY_OF_MONTH</code>. No adjustment is made to smaller fields
* that are not expected to be invariant. The calendar system
* determines what fields are expected to be invariant.</p>
* </blockquote>
*
* <p>In addition, unlike <code>set()</code>, <code>add()</code> forces
* an immediate recomputation of the calendar's milliseconds and all
* fields.</p>
*
* <p><em>Example</em>: Consider a <code>GregorianCalendar</code>
* originally set to August 31, 1999. Calling <code>add(Calendar.MONTH,
* 13)</code> sets the calendar to September 30, 2000. <strong>Add rule
* 1</strong> sets the <code>MONTH</code> field to September, since
* adding 13 months to August gives September of the next year. Since
* <code>DAY_OF_MONTH</code> cannot be 31 in September in a
* <code>GregorianCalendar</code>, <strong>add rule 2</strong> sets the
* <code>DAY_OF_MONTH</code> to 30, the closest possible value. Although
* it is a smaller field, <code>DAY_OF_WEEK</code> is not adjusted by
* rule 2, since it is expected to change when the month changes in a
* <code>GregorianCalendar</code>.</p>
*
* <p><strong><code>roll(f, delta)</code></strong> adds
* <code>delta</code> to field <code>f</code> without changing larger
* fields. This is equivalent to calling <code>add(f, delta)</code> with
* the following adjustment:</p>
*
* <blockquote>
* <p><strong>Roll rule</strong>. Larger fields are unchanged after the
* call. A larger field represents a larger unit of
* time. <code>DAY_OF_MONTH</code> is a larger field than
* <code>HOUR</code>.</p>
* </blockquote>
*
* <p><em>Example</em>: See {@link java.util.GregorianCalendar#roll(int, int)}.
*
* <p><strong>Usage model</strong>. To motivate the behavior of
* <code>add()</code> and <code>roll()</code>, consider a user interface
* component with increment and decrement buttons for the month, day, and
* year, and an underlying <code>GregorianCalendar</code>. If the
* interface reads January 31, 1999 and the user presses the month
* increment button, what should it read? If the underlying
* implementation uses <code>set()</code>, it might read March 3, 1999. A
* better result would be February 28, 1999. Furthermore, if the user
* presses the month increment button again, it should read March 31,
* 1999, not March 28, 1999. By saving the original date and using either
* <code>add()</code> or <code>roll()</code>, depending on whether larger
* fields should be affected, the user interface can behave as most users
* will intuitively expect.</p>
*
* @see Date
* @see GregorianCalendar
* @see TimeZone
* @see java.text.DateFormat
* @version 1.51 10/17/00
* @author Mark Davis, David Goldsmith, Chen-Lieh Huang, Alan Liu
* @since JDK1.1
*/
public abstract class Calendar implements Serializable, Cloneable {
// Data flow in Calendar
// ---------------------
// The current time is represented in two ways by Calendar: as UTC
// milliseconds from the epoch start (1 January 1970 0:00 UTC), and as local
// fields such as MONTH, HOUR, AM_PM, etc. It is possible to compute the
// millis from the fields, and vice versa. The data needed to do this
// conversion is encapsulated by a TimeZone object owned by the Calendar.
// The data provided by the TimeZone object may also be overridden if the
// user sets the ZONE_OFFSET and/or DST_OFFSET fields directly. The class
// keeps track of what information was most recently set by the caller, and
// uses that to compute any other information as needed.
// If the user sets the fields using set(), the data flow is as follows.
// This is implemented by the Calendar subclass's computeTime() method.
// During this process, certain fields may be ignored. The disambiguation
// algorithm for resolving which fields to pay attention to is described
// above.
// local fields (YEAR, MONTH, DATE, HOUR, MINUTE, etc.)
// |
// | Using Calendar-specific algorithm
// V
// local standard millis
// |
// | Using TimeZone or user-set ZONE_OFFSET / DST_OFFSET
// V
// UTC millis (in time data member)
// If the user sets the UTC millis using setTime(), the data flow is as
// follows. This is implemented by the Calendar subclass's computeFields()
// method.
// UTC millis (in time data member)
// |
// | Using TimeZone getOffset()
// V
// local standard millis
// |
// | Using Calendar-specific algorithm
// V
// local fields (YEAR, MONTH, DATE, HOUR, MINUTE, etc.)
// In general, a round trip from fields, through local and UTC millis, and
// back out to fields is made when necessary. This is implemented by the
// complete() method. Resolving a partial set of fields into a UTC millis
// value allows all remaining fields to be generated from that value. If
// the Calendar is lenient, the fields are also renormalized to standard
// ranges when they are regenerated.
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* era, e.g., AD or BC in the Julian calendar. This is a calendar-specific
* value; see subclass documentation.
* @see GregorianCalendar#AD
* @see GregorianCalendar#BC
*/
public final static int ERA = 0;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* year. This is a calendar-specific value; see subclass documentation.
*/
public final static int YEAR = 1;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* month. This is a calendar-specific value. The first month of the year is
* <code>JANUARY</code> which is 0; the last depends on the number of months in a year.
* @see #JANUARY
* @see #FEBRUARY
* @see #MARCH
* @see #APRIL
* @see #MAY
* @see #JUNE
* @see #JULY
* @see #AUGUST
* @see #SEPTEMBER
* @see #OCTOBER
* @see #NOVEMBER
* @see #DECEMBER
* @see #UNDECIMBER
*/
public final static int MONTH = 2;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* week number within the current year. The first week of the year, as
* defined by <code>getFirstDayOfWeek()</code> and
* <code>getMinimalDaysInFirstWeek()</code>, has value 1. Subclasses define
* the value of <code>WEEK_OF_YEAR</code> for days before the first week of
* the year.
* @see #getFirstDayOfWeek
* @see #getMinimalDaysInFirstWeek
*/
public final static int WEEK_OF_YEAR = 3;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* week number within the current month. The first week of the month, as
* defined by <code>getFirstDayOfWeek()</code> and
* <code>getMinimalDaysInFirstWeek()</code>, has value 1. Subclasses define
* the value of <code>WEEK_OF_MONTH</code> for days before the first week of
* the month.
* @see #getFirstDayOfWeek
* @see #getMinimalDaysInFirstWeek
*/
public final static int WEEK_OF_MONTH = 4;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* day of the month. This is a synonym for <code>DAY_OF_MONTH</code>.
* The first day of the month has value 1.
* @see #DAY_OF_MONTH
*/
public final static int DATE = 5;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* day of the month. This is a synonym for <code>DATE</code>.
* The first day of the month has value 1.
* @see #DATE
*/
public final static int DAY_OF_MONTH = 5;
/**
* Field number for <code>get</code> and <code>set</code> indicating the day
* number within the current year. The first day of the year has value 1.
*/
public final static int DAY_OF_YEAR = 6;
/**
* Field number for <code>get</code> and <code>set</code> indicating the day
* of the week. This field takes values <code>SUNDAY</code>,
* <code>MONDAY</code>, <code>TUESDAY</code>, <code>WEDNESDAY</code>,
* <code>THURSDAY</code>, <code>FRIDAY</code>, and <code>SATURDAY</code>.
* @see #SUNDAY
* @see #MONDAY
* @see #TUESDAY
* @see #WEDNESDAY
* @see #THURSDAY
* @see #FRIDAY
* @see #SATURDAY
*/
public final static int DAY_OF_WEEK = 7;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* ordinal number of the day of the week within the current month. Together
* with the <code>DAY_OF_WEEK</code> field, this uniquely specifies a day
* within a month. Unlike <code>WEEK_OF_MONTH</code> and
* <code>WEEK_OF_YEAR</code>, this field's value does <em>not</em> depend on
* <code>getFirstDayOfWeek()</code> or
* <code>getMinimalDaysInFirstWeek()</code>. <code>DAY_OF_MONTH 1</code>
* through <code>7</code> always correspond to <code>DAY_OF_WEEK_IN_MONTH
* 1</code>; <code>8</code> through <code>14</code> correspond to
* <code>DAY_OF_WEEK_IN_MONTH 2</code>, and so on.
* <code>DAY_OF_WEEK_IN_MONTH 0</code> indicates the week before
* <code>DAY_OF_WEEK_IN_MONTH 1</code>. Negative values count back from the
* end of the month, so the last Sunday of a month is specified as
* <code>DAY_OF_WEEK = SUNDAY, DAY_OF_WEEK_IN_MONTH = -1</code>. Because
* negative values count backward they will usually be aligned differently
* within the month than positive values. For example, if a month has 31
* days, <code>DAY_OF_WEEK_IN_MONTH -1</code> will overlap
* <code>DAY_OF_WEEK_IN_MONTH 5</code> and the end of <code>4</code>.
* @see #DAY_OF_WEEK
* @see #WEEK_OF_MONTH
*/
public final static int DAY_OF_WEEK_IN_MONTH = 8;
/**
* Field number for <code>get</code> and <code>set</code> indicating
* whether the <code>HOUR</code> is before or after noon.
* E.g., at 10:04:15.250 PM the <code>AM_PM</code> is <code>PM</code>.
* @see #AM
* @see #PM
* @see #HOUR
*/
public final static int AM_PM = 9;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* hour of the morning or afternoon. <code>HOUR</code> is used for the 12-hour
* clock.
* E.g., at 10:04:15.250 PM the <code>HOUR</code> is 10.
* @see #AM_PM
* @see #HOUR_OF_DAY
*/
public final static int HOUR = 10;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* hour of the day. <code>HOUR_OF_DAY</code> is used for the 24-hour clock.
* E.g., at 10:04:15.250 PM the <code>HOUR_OF_DAY</code> is 22.
* @see #HOUR
*/
public final static int HOUR_OF_DAY = 11;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* minute within the hour.
* E.g., at 10:04:15.250 PM the <code>MINUTE</code> is 4.
*/
public final static int MINUTE = 12;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* second within the minute.
* E.g., at 10:04:15.250 PM the <code>SECOND</code> is 15.
*/
public final static int SECOND = 13;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* millisecond within the second.
* E.g., at 10:04:15.250 PM the <code>MILLISECOND</code> is 250.
*/
public final static int MILLISECOND = 14;
/**
* Field number for <code>get</code> and <code>set</code>
* indicating the raw offset from GMT in milliseconds.
* <p>
* This field reflects the correct GMT offset value of the time
* zone of this <code>Calendar</code> if the
* <code>TimeZone</code> implementation subclass supports
* historical GMT offset changes.
*/
public final static int ZONE_OFFSET = 15;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* daylight savings offset in milliseconds.
* <p>
* This field reflects the correct daylight saving offset value of
* the time zone of this <code>Calendar</code> if the
* <code>TimeZone</code> implementation subclass supports
* historical Daylight Saving Time schedule changes.
*/
public final static int DST_OFFSET = 16;
/**
* The number of distinct fields recognized by <code>get</code> and <code>set</code>.
* Field numbers range from <code>0..FIELD_COUNT-1</code>.
*/
public final static int FIELD_COUNT = 17;
/**
* Value of the <code>DAY_OF_WEEK</code> field indicating
* Sunday.
*/
public final static int SUNDAY = 1;
/**
* Value of the <code>DAY_OF_WEEK</code> field indicating
* Monday.
*/
public final static int MONDAY = 2;
/**
* Value of the <code>DAY_OF_WEEK</code> field indicating
* Tuesday.
*/
public final static int TUESDAY = 3;
/**
* Value of the <code>DAY_OF_WEEK</code> field indicating
* Wednesday.
*/
public final static int WEDNESDAY = 4;
/**
* Value of the <code>DAY_OF_WEEK</code> field indicating
* Thursday.
*/
public final static int THURSDAY = 5;
/**
* Value of the <code>DAY_OF_WEEK</code> field indicating
* Friday.
*/
public final static int FRIDAY = 6;
/**
* Value of the <code>DAY_OF_WEEK</code> field indicating
* Saturday.
*/
public final static int SATURDAY = 7;
/**
* Value of the <code>MONTH</code> field indicating the
* first month of the year.
*/
public final static int JANUARY = 0;
/**
* Value of the <code>MONTH</code> field indicating the
* second month of the year.
*/
public final static int FEBRUARY = 1;
/**
* Value of the <code>MONTH</code> field indicating the
* third month of the year.
*/
public final static int MARCH = 2;
/**
* Value of the <code>MONTH</code> field indicating the
* fourth month of the year.
*/
public final static int APRIL = 3;
/**
* Value of the <code>MONTH</code> field indicating the
* fifth month of the year.
*/
public final static int MAY = 4;
/**
* Value of the <code>MONTH</code> field indicating the
* sixth month of the year.
*/
public final static int JUNE = 5;
/**
* Value of the <code>MONTH</code> field indicating the
* seventh month of the year.
*/
public final static int JULY = 6;
/**
* Value of the <code>MONTH</code> field indicating the
* eighth month of the year.
*/
public final static int AUGUST = 7;
/**
* Value of the <code>MONTH</code> field indicating the
* ninth month of the year.
*/
public final static int SEPTEMBER = 8;
/**
* Value of the <code>MONTH</code> field indicating the
* tenth month of the year.
*/
public final static int OCTOBER = 9;
/**
* Value of the <code>MONTH</code> field indicating the
* eleventh month of the year.
*/
public final static int NOVEMBER = 10;
/**
* Value of the <code>MONTH</code> field indicating the
* twelfth month of the year.
*/
public final static int DECEMBER = 11;
/**
* Value of the <code>MONTH</code> field indicating the
* thirteenth month of the year. Although <code>GregorianCalendar</code>
* does not use this value, lunar calendars do.
*/
public final static int UNDECIMBER = 12;
/**
* Value of the <code>AM_PM</code> field indicating the
* period of the day from midnight to just before noon.
*/
public final static int AM = 0;
/**
* Value of the <code>AM_PM</code> field indicating the
* period of the day from noon to just before midnight.
*/
public final static int PM = 1;
// Internal notes:
// Calendar contains two kinds of time representations: current "time" in
// milliseconds, and a set of time "fields" representing the current time.
// The two representations are usually in sync, but can get out of sync
// as follows.
// 1. Initially, no fields are set, and the time is invalid.
// 2. If the time is set, all fields are computed and in sync.
// 3. If a single field is set, the time is invalid.
// Recomputation of the time and fields happens when the object needs
// to return a result to the user, or use a result for a computation.
/**
* The field values for the currently set time for this calendar.
* This is an array of <code>FIELD_COUNT</code> integers, with index values
* <code>ERA</code> through <code>DST_OFFSET</code>.
* @serial
*/
protected int fields[]; // NOTE: Make transient when possible
/**
* The flags which tell if a specified time field for the calendar is set.
* A new object has no fields set. After the first call to a method
* which generates the fields, they all remain set after that.
* This is an array of <code>FIELD_COUNT</code> booleans, with index values
* <code>ERA</code> through <code>DST_OFFSET</code>.
* @serial
*/
protected boolean isSet[]; // NOTE: Remove when possible
/**
* Pseudo-time-stamps which specify when each field was set. There
* are two special values, UNSET and INTERNALLY_SET. Values from
* MINIMUM_USER_SET to Integer.MAX_VALUE are legal user set values.
*/
transient int stamp[];
/**
* The currently set time for this calendar, expressed in milliseconds after
* January 1, 1970, 0:00:00 GMT.
* @see #isTimeSet
* @serial
*/
protected long time;
/**
* True if then the value of <code>time</code> is valid.
* The time is made invalid by a change to an item of <code>field[]</code>.
* @see #time
* @serial
*/
protected boolean isTimeSet; // NOTE: Make transient when possible
/**
* True if <code>fields[]</code> are in sync with the currently set time.
* If false, then the next attempt to get the value of a field will
* force a recomputation of all fields from the current value of
* <code>time</code>.
* @serial
*/
protected boolean areFieldsSet; // NOTE: Make transient when possible
/**
* True if all fields have been set.
* @serial
*/
transient boolean areAllFieldsSet;
/**
* True if this calendar allows out-of-range field values during computation
* of <code>time</code> from <code>fields[]</code>.
* @see #setLenient
* @serial
*/
private boolean lenient = true;
/**
* The <code>TimeZone</code> used by this calendar. </code>Calendar</code>
* uses the time zone data to translate between locale and GMT time.
* @serial
*/
private TimeZone zone;
/**
* The first day of the week, with possible values <code>SUNDAY</code>,
* <code>MONDAY</code>, etc. This is a locale-dependent value.
* @serial
*/
private int firstDayOfWeek;
/**
* The number of days required for the first week in a month or year,
* with possible values from 1 to 7. This is a locale-dependent value.
* @serial
*/
private int minimalDaysInFirstWeek;
/**
* Cache to hold the firstDayOfWeek and minimalDaysInFirstWeek
* of a Locale.
*/
private static Hashtable cachedLocaleData = new Hashtable(3);
// Special values of stamp[]
static final int UNSET = 0;
static final int INTERNALLY_SET = 1;
static final int MINIMUM_USER_STAMP = 2;
/**
* The next available value for <code>stamp[]</code>, an internal array.
* This actually should not be written out to the stream, and will probably
* be removed from the stream in the near future. In the meantime,
* a value of <code>MINIMUM_USER_STAMP</code> should be used.
* @serial
*/
private int nextStamp = MINIMUM_USER_STAMP;
// the internal serial version which says which version was written
// - 0 (default) for version up to JDK 1.1.5
// - 1 for version from JDK 1.1.6, which writes a correct 'time' value
// as well as compatible values for other fields. This is a
// transitional format.
// - 2 (not implemented yet) a future version, in which fields[],
// areFieldsSet, and isTimeSet become transient, and isSet[] is
// removed. In JDK 1.1.6 we write a format compatible with version 2.
static final int currentSerialVersion = 1;
/**
* The version of the serialized data on the stream. Possible values:
* <dl>
* <dt><b>0</b> or not present on stream</dt>
* <dd>
* JDK 1.1.5 or earlier.
* </dd>
* <dt><b>1</b></dt>
* <dd>
* JDK 1.1.6 or later. Writes a correct 'time' value
* as well as compatible values for other fields. This is a
* transitional format.
* </dd>
* </dl>
* When streaming out this class, the most recent format
* and the highest allowable <code>serialVersionOnStream</code>
* is written.
* @serial
* @since JDK1.1.6
*/
private int serialVersionOnStream = currentSerialVersion;
// Proclaim serialization compatibility with JDK 1.1
static final long serialVersionUID = -1807547505821590642L;
/**
* Constructs a Calendar with the default time zone
* and locale.
* @see TimeZone#getDefault
*/
protected Calendar()
{
this(TimeZone.getDefault(), Locale.getDefault());
}
/**
* Constructs a calendar with the specified time zone and locale.
* @param zone the time zone to use
* @param aLocale the locale for the week data
*/
protected Calendar(TimeZone zone, Locale aLocale)
{
fields = new int[FIELD_COUNT];
isSet = new boolean[FIELD_COUNT];
stamp = new int[FIELD_COUNT];
this.zone = zone;
setWeekCountData(aLocale);
}
/**
* Gets a calendar using the default time zone and locale. The
* <code>Calendar</code> returned is based on the current time
* in the default time zone with the default locale.
*
* @return a Calendar.
*/
public static Calendar getInstance()
{
return createCalendar(TimeZone.getDefault(), Locale.getDefault());
}
/**
* Gets a calendar using the specified time zone and default locale.
* The <code>Calendar</code> returned is based on the current time
* in the given time zone with the default locale.
*
* @param zone the time zone to use
* @return a Calendar.
*/
public static Calendar getInstance(TimeZone zone)
{
return createCalendar(zone, Locale.getDefault());
}
/**
* Gets a calendar using the default time zone and specified locale.
* The <code>Calendar</code> returned is based on the current time
* in the default time zone with the given locale.
*
* @param aLocale the locale for the week data
* @return a Calendar.
*/
public static Calendar getInstance(Locale aLocale)
{
return createCalendar(TimeZone.getDefault(), aLocale);
}
/**
* Gets a calendar with the specified time zone and locale.
* The <code>Calendar</code> returned is based on the current time
* in the given time zone with the given locale.
*
* @param zone the time zone to use
* @param aLocale the locale for the week data
* @return a Calendar.
*/
public static Calendar getInstance(TimeZone zone,
Locale aLocale)
{
return createCalendar(zone, aLocale);
}
private static Calendar createCalendar(TimeZone zone,
Locale aLocale)
{
if (aLocale.getLanguage().compareTo("th") == 0) {
if (aLocale.getCountry().compareTo("TH") == 0) {
return new sun.util.BuddhistCalendar(zone, aLocale);
}
}
// else create the default calendar
return new GregorianCalendar(zone, aLocale);
}
/**
* Gets the list of locales for which Calendars are installed.
* @return the list of locales for which Calendars are installed.
*/
public static synchronized Locale[] getAvailableLocales()
{
return DateFormat.getAvailableLocales();
}
/**
* Converts the current field values in <code>fields[]</code>
* to the millisecond time value
* <code>time</code>.
*/
protected abstract void computeTime();
/**
* Converts
* the current millisecond time value
* <code>time</code>
* to field values in <code>fields[]</code>.
* This allows you to sync up the time field values with
* a new time that is set for the calendar. The time is <em>not</em>
* recomputed first; to recompute the time, then the fields, call the
* <code>complete</code> method.
* @see #complete
*/
protected abstract void computeFields();
/**
* Gets this Calendar's current time.
* @return the current time.
* @see #setTime
* @see #getTimeInMillis
*/
public final Date getTime() {
return new Date( getTimeInMillis() );
}
/**
* Sets this Calendar's current time with the given Date.
* <p>
* Note: Calling <code>setTime()</code> with
* <code>Date(Long.MAX_VALUE)</code> or <code>Date(Long.MIN_VALUE)</code>
* may yield incorrect field values from <code>get()</code>.
* @param date the given Date.
* @see #getTime
* @see #setTimeInMillis
*/
public final void setTime(Date date) {
setTimeInMillis( date.getTime() );
}
/**
* Gets this Calendar's current time as a long.
* @return the current time as UTC milliseconds from the epoch.
* @see #getTime
* @see #setTimeInMillis
*/
public long getTimeInMillis() {
if (!isTimeSet) updateTime();
return time;
}
/**
* Sets this Calendar's current time from the given long value.
* @param millis the new time in UTC milliseconds from the epoch.
* @see #setTime
* @see #getTimeInMillis
*/
public void setTimeInMillis(long millis) {
isTimeSet = true;
time = millis;
areFieldsSet = false;
if (!areFieldsSet) {
computeFields();
areFieldsSet = true;
areAllFieldsSet = true;
}
}
/**
* Gets the value for a given time field.
* @param field the given time field.
* @return the value for the given time field.
* @throws ArrayIndexOutOfBoundsException if specified field is out of range
* (<tt>field < 0 || field >= FIELD_COUNT</tt>).
*/
public int get(int field)
{
complete();
return internalGet(field);
//return fields[field];
}
/**
* Gets the value for a given time field. This is an internal
* fast time field value getter for the subclasses.
* @param field the given time field.
* @return the value for the given time field.
*/
protected final int internalGet(int field)
{
return fields[field];
}
/**
* Sets the value for the given time field. This is an internal
* fast setter for subclasses. It does not affect the areFieldsSet, isTimeSet,
* or areAllFieldsSet flags.
*/
final void internalSet(int field, int value)
{
fields[field] = value;
}
/**
* Clears the value of the given calendar field and resets the
* field status flags only. The difference from clear(int) is that
* this method doesn't reset isTimeSet.
*
* @param field the given calendar field.
* @throws ArrayIndexOutOfBoundsException if specified field is out of range
* (<tt>field < 0 || field >= FIELD_COUNT</tt>).
*/
final void internalClear(int field) {
fields[field] = 0;
stamp[field] = UNSET;
areFieldsSet = false;
areAllFieldsSet = false;
isSet[field] = false;
}
/**
* Sets the time field with the given value.
* @param field the given time field.
* @param value the value to be set for the given time field.
* @throws ArrayIndexOutOfBoundsException if specified field is out of range
* (<tt>field < 0 || field >= FIELD_COUNT</tt>).
*/
public void set(int field, int value)
{
isTimeSet = false;
internalSet(field, value);
//fields[field] = value;
stamp[field] = nextStamp++;
if (nextStamp == Integer.MAX_VALUE) {
adjustStamp();
}
areFieldsSet = false;
isSet[field] = true; // Remove later
}
/**
* Sets the values for the fields year, month, and date.
* Previous values of other fields are retained. If this is not desired,
* call <code>clear</code> first.
* @param year the value used to set the YEAR time field.
* @param month the value used to set the MONTH time field.
* Month value is 0-based. e.g., 0 for January.
* @param date the value used to set the DATE time field.
*/
public final void set(int year, int month, int date)
{
set(YEAR, year);
set(MONTH, month);
set(DATE, date);
}
/**
* Sets the values for the fields year, month, date, hour, and minute.
* Previous values of other fields are retained. If this is not desired,
* call <code>clear</code> first.
* @param year the value used to set the YEAR time field.
* @param month the value used to set the MONTH time field.
* Month value is 0-based. e.g., 0 for January.
* @param date the value used to set the DATE time field.
* @param hour the value used to set the HOUR_OF_DAY time field.
* @param minute the value used to set the MINUTE time field.
*/
public final void set(int year, int month, int date, int hour, int minute)
{
set(YEAR, year);
set(MONTH, month);
set(DATE, date);
set(HOUR_OF_DAY, hour);
set(MINUTE, minute);
}
/**
* Sets the values for the fields year, month, date, hour, minute, and second.
* Previous values of other fields are retained. If this is not desired,
* call <code>clear</code> first.
* @param year the value used to set the YEAR time field.
* @param month the value used to set the MONTH time field.
* Month value is 0-based. e.g., 0 for January.
* @param date the value used to set the DATE time field.
* @param hour the value used to set the HOUR_OF_DAY time field.
* @param minute the value used to set the MINUTE time field.
* @param second the value used to set the SECOND time field.
*/
public final void set(int year, int month, int date, int hour, int minute,
int second)
{
set(YEAR, year);
set(MONTH, month);
set(DATE, date);
set(HOUR_OF_DAY, hour);
set(MINUTE, minute);
set(SECOND, second);
}
/**
* Clears the values of all the time fields.
*/
public final void clear()
{
fields = new int[FIELD_COUNT];
stamp = new int[FIELD_COUNT];
areFieldsSet = false;
areAllFieldsSet = false;
isSet = new boolean[FIELD_COUNT]; // Remove later
isTimeSet = false;
}
/**
* Clears the value in the given time field.
* @param field the time field to be cleared.
*/
public final void clear(int field)
{
fields[field] = 0;
stamp[field] = UNSET;
areFieldsSet = false;
areAllFieldsSet = false;
isSet[field] = false; // Remove later
isTimeSet = false;
}
/**
* Determines if the given time field has a value set.
* @return true if the given time field has a value set; false otherwise.
*/
public final boolean isSet(int field)
{
return stamp[field] != UNSET;
// return isSet[field];
}
/**
* Fills in any unset fields in the time field list.
*/
protected void complete()
{
if (!isTimeSet) updateTime();
if (!areFieldsSet) {
computeFields(); // fills in unset fields
areFieldsSet = true;
areAllFieldsSet = true;
}
}
/**
* Compares this calendar to the specified object.
* The result is <code>true</code> if and only if the argument is
* not <code>null</code> and is a <code>Calendar</code> object that
* represents the same calendar as this object.
* @param obj the object to compare with.
* @return <code>true</code> if the objects are the same;
* <code>false</code> otherwise.
*/
public boolean equals(Object obj) {
if (this == obj)
return true;
if (!(obj instanceof Calendar))
return false;
Calendar that = (Calendar)obj;
return getTimeInMillis() == that.getTimeInMillis() &&
lenient == that.lenient &&
firstDayOfWeek == that.firstDayOfWeek &&
minimalDaysInFirstWeek == that.minimalDaysInFirstWeek &&
zone.equals(that.zone);
}
/**
* Returns a hash code for this calendar.
* @return a hash code value for this object.
* @since 1.2
*/
public int hashCode() {
/* Don't include the time because (a) we don't want the hash value to
* move around just because a calendar is set to different times, and
* (b) we don't want to trigger a time computation just to get a hash.
* Note that it is not necessary for unequal objects to always have
* unequal hashes, but equal objects must have equal hashes. */
return (lenient ? 1 : 0)
| (firstDayOfWeek << 1)
| (minimalDaysInFirstWeek << 4)
| (zone.hashCode() << 7);
}
/**
* Compares the time field records.
* Equivalent to comparing result of conversion to UTC.
* @param when the Calendar to be compared with this Calendar.
* @return true if the current time of this Calendar is before
* the time of Calendar when; false otherwise.
*/
public boolean before(Object when) {
return when instanceof Calendar &&
getTimeInMillis() < ((Calendar) when).getTimeInMillis();
}
/**
* Compares the time field records.
* Equivalent to comparing result of conversion to UTC.
* @param when the Calendar to be compared with this Calendar.
* @return true if the current time of this Calendar is after
* the time of Calendar when; false otherwise.
*/
public boolean after(Object when) {
return when instanceof Calendar &&
getTimeInMillis() > ((Calendar) when).getTimeInMillis();
}
/**
* Date Arithmetic function.
* Adds the specified (signed) amount of time to the given time field,
* based on the calendar's rules. For example, to subtract 5 days from
* the current time of the calendar, you can achieve it by calling:
* <p>add(Calendar.DATE, -5).
* @param field the time field.
* @param amount the amount of date or time to be added to the field.
*/
abstract public void add(int field, int amount);
/**
* Time Field Rolling function.
* Adds or subtracts (up/down) a single unit of time on the given time
* field without changing larger fields. For example, to roll the current
* date up by one day, you can achieve it by calling:
* <p>roll(Calendar.DATE, true).
* When rolling on the year or Calendar.YEAR field, it will roll the year
* value in the range between 1 and the value returned by calling
* getMaximum(Calendar.YEAR).
* When rolling on the month or Calendar.MONTH field, other fields like
* date might conflict and, need to be changed. For instance,
* rolling the month on the date 01/31/96 will result in 02/29/96.
* When rolling on the hour-in-day or Calendar.HOUR_OF_DAY field, it will
* roll the hour value in the range between 0 and 23, which is zero-based.
* @param field the time field.
* @param up indicates if the value of the specified time field is to be
* rolled up or rolled down. Use true if rolling up, false otherwise.
* @see Calendar#add
* @see Calendar#set
*/
abstract public void roll(int field, boolean up);
/**
* Time Field Rolling function.
* Add to field a signed amount without changing larger fields.
* A negative roll amount means to roll down.
* [NOTE: This default implementation on Calendar just repeatedly calls the
* version of roll() that takes a boolean and rolls by one unit. This may not
* always do the right thing. For example, if the DAY_OF_MONTH field is 31,
* rolling through February will leave it set to 28. The GregorianCalendar
* version of this function takes care of this problem. Other subclasses
* should also provide overrides of this function that do the right thing.
* @param field the time field.
* @param amount the signed amount to add to <code>field</code>.
* @since 1.2
* @see Calendar#add
* @see Calendar#set
*/
public void roll(int field, int amount)
{
while (amount > 0) {
roll(field, true);
amount--;
}
while (amount < 0) {
roll(field, false);
amount++;
}
}
/**
* Sets the time zone with the given time zone value.
* @param value the given time zone.
*/
public void setTimeZone(TimeZone value)
{
zone = value;
/* Recompute the fields from the time using the new zone. This also
* works if isTimeSet is false (after a call to set()). In that case
* the time will be computed from the fields using the new zone, then
* the fields will get recomputed from that. Consider the sequence of
* calls: cal.setTimeZone(EST); cal.set(HOUR, 1); cal.setTimeZone(PST).
* Is cal set to 1 o'clock EST or 1 o'clock PST? Answer: PST. More
* generally, a call to setTimeZone() affects calls to set() BEFORE AND
* AFTER it up to the next call to complete().
*/
areFieldsSet = false;
}
/**
* Gets the time zone.
* @return the time zone object associated with this calendar.
*/
public TimeZone getTimeZone()
{
return zone;
}
/**
* Specify whether or not date/time interpretation is to be lenient. With
* lenient interpretation, a date such as "February 942, 1996" will be
* treated as being equivalent to the 941st day after February 1, 1996.
* With strict interpretation, such dates will cause an exception to be
* thrown.
*
* @see java.text.DateFormat#setLenient
*/
public void setLenient(boolean lenient)
{
this.lenient = lenient;
}
/**
* Tell whether date/time interpretation is to be lenient.
*/
public boolean isLenient()
{
return lenient;
}
/**
* Sets what the first day of the week is; e.g., Sunday in US,
* Monday in France.
* @param value the given first day of the week.
*/
public void setFirstDayOfWeek(int value)
{
if (firstDayOfWeek == value) {
return;
}
firstDayOfWeek = value;
invalidateWeekFields();
}
/**
* Gets what the first day of the week is; e.g., Sunday in US,
* Monday in France.
* @return the first day of the week.
*/
public int getFirstDayOfWeek()
{
return firstDayOfWeek;
}
/**
* Sets what the minimal days required in the first week of the year are;
* For example, if the first week is defined as one that contains the first
* day of the first month of a year, call the method with value 1. If it
* must be a full week, use value 7.
* @param value the given minimal days required in the first week
* of the year.
*/
public void setMinimalDaysInFirstWeek(int value)
{
if (minimalDaysInFirstWeek == value) {
return;
}
minimalDaysInFirstWeek = value;
invalidateWeekFields();
}
/**
* Gets what the minimal days required in the first week of the year are;
* e.g., if the first week is defined as one that contains the first day
* of the first month of a year, getMinimalDaysInFirstWeek returns 1. If
* the minimal days required must be a full week, getMinimalDaysInFirstWeek
* returns 7.
* @return the minimal days required in the first week of the year.
*/
public int getMinimalDaysInFirstWeek()
{
return minimalDaysInFirstWeek;
}
/**
* Gets the minimum value for the given time field.
* e.g., for Gregorian DAY_OF_MONTH, 1.
* @param field the given time field.
* @return the minimum value for the given time field.
*/
abstract public int getMinimum(int field);
/**
* Gets the maximum value for the given time field.
* e.g. for Gregorian DAY_OF_MONTH, 31.
* @param field the given time field.
* @return the maximum value for the given time field.
*/
abstract public int getMaximum(int field);
/**
* Gets the highest minimum value for the given field if varies.
* Otherwise same as getMinimum(). For Gregorian, no difference.
* @param field the given time field.
* @return the highest minimum value for the given time field.
*/
abstract public int getGreatestMinimum(int field);
/**
* Gets the lowest maximum value for the given field if varies.
* Otherwise same as getMaximum(). e.g., for Gregorian DAY_OF_MONTH, 28.
* @param field the given time field.
* @return the lowest maximum value for the given time field.
*/
abstract public int getLeastMaximum(int field);
/**
* Return the minimum value that this field could have, given the current date.
* For the Gregorian calendar, this is the same as getMinimum() and getGreatestMinimum().
*
* The version of this function on Calendar uses an iterative algorithm to determine the
* actual minimum value for the field. There is almost always a more efficient way to
* accomplish this (in most cases, you can simply return getMinimum()). GregorianCalendar
* overrides this function with a more efficient implementation.
*
* @param field the field to determine the minimum of
* @return the minimum of the given field for the current date of this Calendar
* @since 1.2
*/
public int getActualMinimum(int field) {
int fieldValue = getGreatestMinimum(field);
int endValue = getMinimum(field);
// if we know that the minimum value is always the same, just return it
if (fieldValue == endValue) {
return fieldValue;
}
// clone the calendar so we don't mess with the real one, and set it to
// accept anything for the field values
Calendar work = (Calendar)this.clone();
work.setLenient(true);
// now try each value from getLeastMaximum() to getMaximum() one by one until
// we get a value that normalizes to another value. The last value that
// normalizes to itself is the actual minimum for the current date
int result = fieldValue;
do {
work.set(field, fieldValue);
if (work.get(field) != fieldValue) {
break;
} else {
result = fieldValue;
fieldValue--;
}
} while (fieldValue >= endValue);
return result;
}
/**
* Return the maximum value that this field could have, given the current date.
* For example, with the date "Feb 3, 1997" and the DAY_OF_MONTH field, the actual
* maximum would be 28; for "Feb 3, 1996" it s 29. Similarly for a Hebrew calendar,
* for some years the actual maximum for MONTH is 12, and for others 13.
*
* The version of this function on Calendar uses an iterative algorithm to determine the
* actual maximum value for the field. There is almost always a more efficient way to
* accomplish this (in most cases, you can simply return getMaximum()). GregorianCalendar
* overrides this function with a more efficient implementation.
*
* @param field the field to determine the maximum of
* @return the maximum of the given field for the current date of this Calendar
* @since 1.2
*/
public int getActualMaximum(int field) {
int fieldValue = getLeastMaximum(field);
int endValue = getMaximum(field);
// if we know that the maximum value is always the same, just return it
if (fieldValue == endValue) {
return fieldValue;
}
// clone the calendar so we don't mess with the real one, and set it to
// accept anything for the field values
Calendar work = (Calendar)this.clone();
work.setLenient(true);
// if we're counting weeks, set the day of the week to Sunday. We know the
// last week of a month or year will contain the first day of the week.
if (field == WEEK_OF_YEAR || field == WEEK_OF_MONTH)
work.set(DAY_OF_WEEK, firstDayOfWeek);
// now try each value from getLeastMaximum() to getMaximum() one by one until
// we get a value that normalizes to another value. The last value that
// normalizes to itself is the actual maximum for the current date
int result = fieldValue;
do {
work.set(field, fieldValue);
if (work.get(field) != fieldValue) {
break;
} else {
result = fieldValue;
fieldValue++;
}
} while (fieldValue <= endValue);
return result;
}
/**
* Overrides Cloneable
*/
public Object clone()
{
try {
Calendar other = (Calendar) super.clone();
other.fields = new int[FIELD_COUNT];
other.isSet = new boolean[FIELD_COUNT];
other.stamp = new int[FIELD_COUNT];
System.arraycopy(this.fields, 0, other.fields, 0, FIELD_COUNT);
System.arraycopy(this.isSet, 0, other.isSet, 0, FIELD_COUNT);
System.arraycopy(this.stamp, 0, other.stamp, 0, FIELD_COUNT);
other.zone = (TimeZone) zone.clone();
return other;
}
catch (CloneNotSupportedException e) {
// this shouldn't happen, since we are Cloneable
throw new InternalError();
}
}
private static final String[] FIELD_NAME = {
",ERA=", ",YEAR=", ",MONTH=", ",WEEK_OF_YEAR=", ",WEEK_OF_MONTH=", ",DAY_OF_MONTH=",
",DAY_OF_YEAR=", ",DAY_OF_WEEK=", ",DAY_OF_WEEK_IN_MONTH=", ",AM_PM=", ",HOUR=",
",HOUR_OF_DAY=", ",MINUTE=", ",SECOND=", ",MILLISECOND=", ",ZONE_OFFSET=",
",DST_OFFSET="
};
/**
* Return a string representation of this calendar. This method
* is intended to be used only for debugging purposes, and the
* format of the returned string may vary between implementations.
* The returned string may be empty but may not be <code>null</code>.
*
* @return a string representation of this calendar.
*/
public String toString() {
StringBuffer buffer = new StringBuffer();
buffer.append(getClass().getName());
buffer.append("[time=");
buffer.append(isTimeSet ? String.valueOf(time) : "?");
buffer.append(",areFieldsSet=");
buffer.append(areFieldsSet);
buffer.append(",areAllFieldsSet=");
buffer.append(areAllFieldsSet);
buffer.append(",lenient=");
buffer.append(lenient);
buffer.append(",zone=");
buffer.append(zone);
buffer.append(",firstDayOfWeek=");
buffer.append(firstDayOfWeek);
buffer.append(",minimalDaysInFirstWeek=");
buffer.append(minimalDaysInFirstWeek);
for (int i=0; i<FIELD_COUNT; ++i) {
buffer.append(FIELD_NAME[i]);
buffer.append(isSet(i) ? String.valueOf(fields[i]) : "?");
}
buffer.append(']');
return buffer.toString();
}
// =======================privates===============================
/**
* Both firstDayOfWeek and minimalDaysInFirstWeek are locale-dependent.
* They are used to figure out the week count for a specific date for
* a given locale. These must be set when a Calendar is constructed.
* @param desiredLocale the given locale.
*/
private void setWeekCountData(Locale desiredLocale)
{
/* try to get the Locale data from the cache */
int[] data = (int[]) cachedLocaleData.get(desiredLocale);
if (data == null) { /* cache miss */
ResourceBundle resource = LocaleData.getLocaleElements(desiredLocale);
String[] dateTimePatterns =
resource.getStringArray("DateTimeElements");
data = new int[2];
data[0] = Integer.parseInt(dateTimePatterns[0]);
data[1] = Integer.parseInt(dateTimePatterns[1]);
/* cache update */
cachedLocaleData.put(desiredLocale, data);
}
firstDayOfWeek = data[0];
minimalDaysInFirstWeek = data[1];
}
/**
* Recompute the time and update the status fields isTimeSet
* and areFieldsSet. Callers should check isTimeSet and only
* call this method if isTimeSet is false.
*/
private void updateTime() {
computeTime();
// If we are lenient, we need to recompute the fields to normalize
// the values. Also, if we haven't set all the fields yet (i.e.,
// in a newly-created object), we need to fill in the fields. [LIU]
if (isLenient() || !areAllFieldsSet) areFieldsSet = false;
isTimeSet = true;
}
/**
* Adjusts the stamp[] values before nextStamp overflow. nextStamp
* is set to the next stamp value upon the return.
*/
private final void adjustStamp() {
int max = MINIMUM_USER_STAMP;
int newStamp = MINIMUM_USER_STAMP;
for (;;) {
int min = Integer.MAX_VALUE;
for (int i = 0; i < stamp.length; i++) {
int v = stamp[i];
if (v >= newStamp && min > v) {
min = v;
}
if (max < v) {
max = v;
}
}
if (max != min && min == Integer.MAX_VALUE) {
break;
}
for (int i = 0; i < stamp.length; i++) {
if (stamp[i] == min) {
stamp[i] = newStamp;
}
}
newStamp++;
if (min == max) {
break;
}
}
nextStamp = newStamp;
}
/**
* Invalidates the WEEK_OF_MONTH and WEEK_OF_YEAR fields if they
* have been calculated internally.
*/
private void invalidateWeekFields()
{
if (stamp[WEEK_OF_MONTH] == INTERNALLY_SET) {
stamp[WEEK_OF_MONTH] = UNSET;
isSet[WEEK_OF_MONTH] = false;
areFieldsSet = false;
}
if (stamp[WEEK_OF_YEAR] == INTERNALLY_SET) {
stamp[WEEK_OF_YEAR] = UNSET;
isSet[WEEK_OF_YEAR] = false;
areFieldsSet = false;
}
}
/**
* Save the state of this object to a stream (i.e., serialize it).
*
* Ideally, <code>Calendar</code> would only write out its state data and
* the current time, and not write any field data out, such as
* <code>fields[]</code>, <code>isTimeSet</code>, <code>areFieldsSet</code>,
* and <code>isSet[]</code>. <code>nextStamp</code> also should not be part
* of the persistent state. Unfortunately, this didn't happen before JDK 1.1
* shipped. To be compatible with JDK 1.1, we will always have to write out
* the field values and state flags. However, <code>nextStamp</code> can be
* removed from the serialization stream; this will probably happen in the
* near future.
*/
private void writeObject(ObjectOutputStream stream)
throws IOException
{
// Try to compute the time correctly, for the future (stream
// version 2) in which we don't write out fields[] or isSet[].
if (!isTimeSet) {
try {
updateTime();
}
catch (IllegalArgumentException e) {}
}
// If this Calendar has a ZoneInfo, save it and set a
// SimpleTimeZone equvalent (as a single DST schedule) for
// backward compatibility.
TimeZone savedZone = null;
if (zone instanceof ZoneInfo) {
SimpleTimeZone stz = ((ZoneInfo)zone).getLastRuleInstance();
if (stz == null) {
stz = new SimpleTimeZone(zone.getRawOffset(), zone.getID());
}
savedZone = zone;
zone = stz;
}
// Write out the 1.1 FCS object.
stream.defaultWriteObject();
// Write out the ZoneInfo object
// 4802409: we write out even if it is null, a temporary workaround
// the real fix for bug 4844924 in corba-iiop
stream.writeObject(savedZone);
if (savedZone != null) {
zone = savedZone;
}
}
/**
* Reconstitute this object from a stream (i.e., deserialize it).
*/
private void readObject(ObjectInputStream stream)
throws IOException, ClassNotFoundException
{
stream.defaultReadObject();
stamp = new int[FIELD_COUNT];
// Starting with version 2 (not implemented yet), we expect that
// fields[], isSet[], isTimeSet, and areFieldsSet may not be
// streamed out anymore. We expect 'time' to be correct.
if (serialVersionOnStream >= 2)
{
isTimeSet = true;
if (fields == null) fields = new int[FIELD_COUNT];
if (isSet == null) isSet = new boolean[FIELD_COUNT];
}
else if (serialVersionOnStream >= 0)
{
for (int i=0; i<FIELD_COUNT; ++i)
stamp[i] = isSet[i] ? INTERNALLY_SET : UNSET;
}
serialVersionOnStream = currentSerialVersion;
// If there's a ZoneInfo object, use it for zone.
try {
ZoneInfo zi = (ZoneInfo) stream.readObject();
if (zi != null) {
zone = zi;
}
} catch (Exception e) {
}
// If the deserialized object has a SimpleTimeZone, try to
// replace it with a ZoneInfo equivalent (as of 1.4) in order
// to be compatible with the SimpleTimeZone-based
// implementation as much as possible.
TimeZone tz = getTimeZone();
if (tz instanceof SimpleTimeZone) {
String id = tz.getID();
TimeZone zi = TimeZone.getTimeZone(id);
if (zi != null && zi.hasSameRules(tz) && zi.getID().equals(id)) {
setTimeZone(zi);
}
}
}
}