/*
* Copyright (C) 1996-2009, International Business Machines
* Corporation and others. All Rights Reserved.
*/
package com.ibm.icu.util;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.text.StringCharacterIterator;
import java.util.Date;
import java.util.Hashtable;
import java.util.LinkedList;
import java.util.Locale;
import java.util.MissingResourceException;
import java.util.Set;
import com.ibm.icu.impl.CalendarData;
import com.ibm.icu.impl.ICUCache;
import com.ibm.icu.impl.ICUResourceBundle;
import com.ibm.icu.impl.SimpleCache;
import com.ibm.icu.text.DateFormat;
import com.ibm.icu.text.DateFormatSymbols;
import com.ibm.icu.text.MessageFormat;
import com.ibm.icu.text.SimpleDateFormat;
/**
* <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><b>Note:</b> This class is similar, but not identical, to the class
* <code>java.util.Calendar</code>. Changes are detailed below.
*
* <p>
* Subclasses of <code>Calendar</code> interpret a <code>Date</code>
* according to the rules of a specific calendar system. ICU4J contains
* several subclasses implementing different international calendar systems.
*
* <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 calendar of a type appropriate to the locale, whose
* time fields have been initialized with the current date and time:
* <blockquote>
* <pre>Calendar rightNow = Calendar.getInstance()</pre>
* </blockquote>
*
* <p>When a <code>ULocale</code> is used by <code>getInstance</code>, its
* '<code>calendar</code>' tag and value are retrieved if present. If a recognized
* value is supplied, a calendar is provided and configured as appropriate.
* Currently recognized tags are "buddhist", "chinese", "coptic", "ethiopic",
* "gregorian", "hebrew", "islamic", "islamic-civil", "japanese", and "roc". For
* example: <blockquote>
* <pre>Calendar cal = Calendar.getInstance(new ULocale("en_US@calendar=japanese"));</pre>
* </blockquote> will return an instance of JapaneseCalendar (using en_US conventions for
* minimum days in first week, start day of week, et cetera).
*
* <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 historial 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> 24:00:00 "belongs" to the following day. That is,
* 23:59 on Dec 31, 1969 < 24:00 on Jan 1, 1970 < 24:01:00 on Jan 1, 1970
*
* <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>: Consider a <code>GregorianCalendar</code>
* originally set to August 31, 1999. Calling <code>roll(Calendar.MONTH,
* 8)</code> sets the calendar to April 30, <strong>1999</strong>. Add
* rule 1 sets the <code>MONTH</code> field to April. Using a
* <code>GregorianCalendar</code>, the <code>DAY_OF_MONTH</code> cannot
* be 31 in the month April. Add rule 2 sets it to the closest possible
* value, 30. Finally, the <strong>roll rule</strong> maintains the
* <code>YEAR</code> field value of 1999.</p>
*
* <p><em>Example</em>: Consider a <code>GregorianCalendar</code>
* originally set to Sunday June 6, 1999. Calling
* <code>roll(Calendar.WEEK_OF_MONTH, -1)</code> sets the calendar to
* Tuesday June 1, 1999, whereas calling
* <code>add(Calendar.WEEK_OF_MONTH, -1)</code> sets the calendar to
* Sunday May 30, 1999. This is because the roll rule imposes an
* additional constraint: The <code>MONTH</code> must not change when the
* <code>WEEK_OF_MONTH</code> is rolled. Taken together with add rule 1,
* the resultant date must be between Tuesday June 1 and Saturday June
* 5. According to add rule 2, the <code>DAY_OF_WEEK</code>, an invariant
* when changing the <code>WEEK_OF_MONTH</code>, is set to Tuesday, the
* closest possible value to Sunday (where Sunday is the first day of the
* week).</p>
*
* <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>
*
* <p><b>Note:</b> You should always use {@link #roll roll} and {@link #add add} rather
* than attempting to perform arithmetic operations directly on the fields
* of a <tt>Calendar</tt>. It is quite possible for <tt>Calendar</tt> subclasses
* to have fields with non-linear behavior, for example missing months
* or days during non-leap years. The subclasses' <tt>add</tt> and <tt>roll</tt>
* methods will take this into account, while simple arithmetic manipulations
* may give invalid results.
*
* <p><big><big><b>Calendar Architecture in ICU4J</b></big></big></p>
*
* <p>Recently the implementation of <code>Calendar</code> has changed
* significantly in order to better support subclassing. The original
* <code>Calendar</code> class was designed to support subclassing, but
* it had only one implemented subclass, <code>GregorianCalendar</code>.
* With the implementation of several new calendar subclasses, including
* the <code>BuddhistCalendar</code>, <code>ChineseCalendar</code>,
* <code>HebrewCalendar</code>, <code>IslamicCalendar</code>, and
* <code>JapaneseCalendar</code>, the subclassing API has been reworked
* thoroughly. This section details the new subclassing API and other
* ways in which <code>com.ibm.icu.util.Calendar</code> differs from
* <code>java.util.Calendar</code>.
* </p>
*
* <p><big><b>Changes</b></big></p>
*
* <p>Overview of changes between the classic <code>Calendar</code>
* architecture and the new architecture.
*
* <ul>
*
* <li>The <code>fields[]</code> array is <code>private</code> now
* instead of <code>protected</code>. Subclasses must access it
* using the methods {@link #internalSet} and
* {@link #internalGet}. <b>Motivation:</b> Subclasses should
* not directly access data members.</li>
*
* <li>The <code>time</code> long word is <code>private</code> now
* instead of <code>protected</code>. Subclasses may access it using
* the method {@link #internalGetTimeInMillis}, which does not
* provoke an update. <b>Motivation:</b> Subclasses should not
* directly access data members.</li>
*
* <li>The scope of responsibility of subclasses has been drastically
* reduced. As much functionality as possible is implemented in the
* <code>Calendar</code> base class. As a result, it is much easier
* to subclass <code>Calendar</code>. <b>Motivation:</b> Subclasses
* should not have to reimplement common code. Certain behaviors are
* common across calendar systems: The definition and behavior of
* week-related fields and time fields, the arithmetic
* ({@link #add(int, int) add} and {@link #roll(int, int) roll}) behavior of many
* fields, and the field validation system.</li>
*
* <li>The subclassing API has been completely redesigned.</li>
*
* <li>The <code>Calendar</code> base class contains some Gregorian
* calendar algorithmic support that subclasses can use (specifically
* in {@link #handleComputeFields}). Subclasses can use the
* methods <code>getGregorianXxx()</code> to obtain precomputed
* values. <b>Motivation:</b> This is required by all
* <code>Calendar</code> subclasses in order to implement consistent
* time zone behavior, and Gregorian-derived systems can use the
* already computed data.</li>
*
* <li>The <code>FIELD_COUNT</code> constant has been removed. Use
* {@link #getFieldCount}. In addition, framework API has been
* added to allow subclasses to define additional fields.
* <b>Motivation: </b>The number of fields is not constant across
* calendar systems.</li>
*
* <li>The range of handled dates has been narrowed from +/-
* ~300,000,000 years to +/- ~5,000,000 years. In practical terms
* this should not affect clients. However, it does mean that client
* code cannot be guaranteed well-behaved results with dates such as
* <code>Date(Long.MIN_VALUE)</code> or
* <code>Date(Long.MAX_VALUE)</code>. Instead, the
* <code>Calendar</code> constants {@link #MIN_DATE},
* {@link #MAX_DATE}, {@link #MIN_MILLIS},
* {@link #MAX_MILLIS}, {@link #MIN_JULIAN}, and
* {@link #MAX_JULIAN} should be used. <b>Motivation:</b> With
* the addition of the {@link #JULIAN_DAY} field, Julian day
* numbers must be restricted to a 32-bit <code>int</code>. This
* restricts the overall supported range. Furthermore, restricting
* the supported range simplifies the computations by removing
* special case code that was used to accomodate arithmetic overflow
* at millis near <code>Long.MIN_VALUE</code> and
* <code>Long.MAX_VALUE</code>.</li>
*
* <li>New fields are implemented: {@link #JULIAN_DAY} defines
* single-field specification of the
* date. {@link #MILLISECONDS_IN_DAY} defines a single-field
* specification of the wall time. {@link #DOW_LOCAL} and
* {@link #YEAR_WOY} implement localized day-of-week and
* week-of-year behavior.</li>
*
* <li>Subclasses can access millisecond constants
* {@link #ONE_SECOND}, {@link #ONE_MINUTE},
* {@link #ONE_HOUR}, {@link #ONE_DAY}, and
* {@link #ONE_WEEK} defined in <code>Calendar</code>.</li>
*
* <li>New API has been added to suport calendar-specific subclasses
* of <code>DateFormat</code>.</li>
*
* <li>Several subclasses have been implemented, representing
* various international calendar systems.</li>
*
* </ul>
*
* <p><big><b>Subclass API</b></big></p>
*
* <p>The original <code>Calendar</code> API was based on the experience
* of implementing a only a single subclass,
* <code>GregorianCalendar</code>. As a result, all of the subclassing
* kinks had not been worked out. The new subclassing API has been
* refined based on several implemented subclasses. This includes methods
* that must be overridden and methods for subclasses to call. Subclasses
* no longer have direct access to <code>fields</code> and
* <code>stamp</code>. Instead, they have new API to access
* these. Subclasses are able to allocate the <code>fields</code> array
* through a protected framework method; this allows subclasses to
* specify additional fields. </p>
*
* <p>More functionality has been moved into the base class. The base
* class now contains much of the computational machinery to support the
* Gregorian calendar. This is based on two things: (1) Many calendars
* are based on the Gregorian calendar (such as the Buddhist and Japanese
* imperial calendars). (2) <em>All</em> calendars require basic
* Gregorian support in order to handle timezone computations. </p>
*
* <p>Common computations have been moved into
* <code>Calendar</code>. Subclasses no longer compute the week related
* fields and the time related fields. These are commonly handled for all
* calendars by the base class. </p>
*
* <p><b>Subclass computation of time <tt>=></tt> fields</b>
*
* <p>The {@link #ERA}, {@link #YEAR},
* {@link #EXTENDED_YEAR}, {@link #MONTH},
* {@link #DAY_OF_MONTH}, and {@link #DAY_OF_YEAR} fields are
* computed by the subclass, based on the Julian day. All other fields
* are computed by <code>Calendar</code>.
*
* <ul>
*
* <li>Subclasses should implement {@link #handleComputeFields}
* to compute the {@link #ERA}, {@link #YEAR},
* {@link #EXTENDED_YEAR}, {@link #MONTH},
* {@link #DAY_OF_MONTH}, and {@link #DAY_OF_YEAR} fields,
* based on the value of the {@link #JULIAN_DAY} field. If there
* are calendar-specific fields not defined by <code>Calendar</code>,
* they must also be computed. These are the only fields that the
* subclass should compute. All other fields are computed by the base
* class, so time and week fields behave in a consistent way across
* all calendars. The default version of this method in
* <code>Calendar</code> implements a proleptic Gregorian
* calendar. Within this method, subclasses may call
* <code>getGregorianXxx()</code> to obtain the Gregorian calendar
* month, day of month, and extended year for the given date.</li>
*
* </ul>
*
* <p><b>Subclass computation of fields <tt>=></tt> time</b>
*
* <p>The interpretation of most field values is handled entirely by
* <code>Calendar</code>. <code>Calendar</code> determines which fields
* are set, which are not, which are set more recently, and so on. In
* addition, <code>Calendar</code> handles the computation of the time
* from the time fields and handles the week-related fields. The only
* thing the subclass must do is determine the extended year, based on
* the year fields, and then, given an extended year and a month, it must
* return a Julian day number.
*
* <ul>
*
* <li>Subclasses should implement {@link #handleGetExtendedYear}
* to return the extended year for this calendar system, based on the
* {@link #YEAR}, {@link #EXTENDED_YEAR}, and any fields that
* the calendar system uses that are larger than a year, such as
* {@link #ERA}.</li>
*
* <li>Subclasses should implement {@link #handleComputeMonthStart}
* to return the Julian day number
* associated with a month and extended year. This is the Julian day
* number of the day before the first day of the month. The month
* number is zero-based. This computation should not depend on any
* field values.</li>
*
* </ul>
*
* <p><b>Other methods</b>
*
* <ul>
*
* <li>Subclasses should implement {@link #handleGetMonthLength}
* to return the number of days in a
* given month of a given extended year. The month number, as always,
* is zero-based.</li>
*
* <li>Subclasses should implement {@link #handleGetYearLength}
* to return the number of days in the given
* extended year. This method is used by
* <tt>computeWeekFields</tt> to compute the
* {@link #WEEK_OF_YEAR} and {@link #YEAR_WOY} fields.</li>
*
* <li>Subclasses should implement {@link #handleGetLimit}
* to return the {@link #MINIMUM},
* {@link #GREATEST_MINIMUM}, {@link #LEAST_MAXIMUM}, or
* {@link #MAXIMUM} of a field, depending on the value of
* <code>limitType</code>. This method only needs to handle the
* fields {@link #ERA}, {@link #YEAR}, {@link #MONTH},
* {@link #WEEK_OF_YEAR}, {@link #WEEK_OF_MONTH},
* {@link #DAY_OF_MONTH}, {@link #DAY_OF_YEAR},
* {@link #DAY_OF_WEEK_IN_MONTH}, {@link #YEAR_WOY}, and
* {@link #EXTENDED_YEAR}. Other fields are invariant (with
* respect to calendar system) and are handled by the base
* class.</li>
*
* <li>Optionally, subclasses may override {@link #validateField}
* to check any subclass-specific fields. If the
* field's value is out of range, the method should throw an
* <code>IllegalArgumentException</code>. The method may call
* <code>super.validateField(field)</code> to handle fields in a
* generic way, that is, to compare them to the range
* <code>getMinimum(field)</code>..<code>getMaximum(field)</code>.</li>
*
* <li>Optionally, subclasses may override
* {@link #handleCreateFields} to create an <code>int[]</code>
* array large enough to hold the calendar's fields. This is only
* necessary if the calendar defines additional fields beyond those
* defined by <code>Calendar</code>. The length of the result must be
* at least {@link #BASE_FIELD_COUNT} and no more than
* {@link #MAX_FIELD_COUNT}.</li>
*
* <li>Optionally, subclasses may override
* {@link #handleGetDateFormat} to create a
* <code>DateFormat</code> appropriate to this calendar. This is only
* required if a calendar subclass redefines the use of a field (for
* example, changes the {@link #ERA} field from a symbolic field
* to a numeric one) or defines an additional field.</li>
*
* <li>Optionally, subclasses may override {@link #roll roll} and
* {@link #add add} to handle fields that are discontinuous. For
* example, in the Hebrew calendar the month "Adar I" only
* occurs in leap years; in other years the calendar jumps from
* Shevat (month #4) to Adar (month #6). The {@link
* HebrewCalendar#add HebrewCalendar.add} and {@link
* HebrewCalendar#roll HebrewCalendar.roll} methods take this into
* account, so that adding 1 month to Shevat gives the proper result
* (Adar) in a non-leap year. The protected utility method {@link
* #pinField pinField} is often useful when implementing these two
* methods. </li>
*
* </ul>
*
* <p><big><b>Normalized behavior</b></big>
*
* <p>The behavior of certain fields has been made consistent across all
* calendar systems and implemented in <code>Calendar</code>.
*
* <ul>
*
* <li>Time is normalized. Even though some calendar systems transition
* between days at sunset or at other times, all ICU4J calendars
* transition between days at <em>local zone midnight</em>. This
* allows ICU4J to centralize the time computations in
* <code>Calendar</code> and to maintain basic correpsondences
* between calendar systems. Affected fields: {@link #AM_PM},
* {@link #HOUR}, {@link #HOUR_OF_DAY}, {@link #MINUTE},
* {@link #SECOND}, {@link #MILLISECOND},
* {@link #ZONE_OFFSET}, and {@link #DST_OFFSET}.</li>
*
* <li>DST behavior is normalized. Daylight savings time behavior is
* computed the same for all calendar systems, and depends on the
* value of several <code>GregorianCalendar</code> fields: the
* {@link #YEAR}, {@link #MONTH}, and
* {@link #DAY_OF_MONTH}. As a result, <code>Calendar</code>
* always computes these fields, even for non-Gregorian calendar
* systems. These fields are available to subclasses.</li>
*
* <li>Weeks are normalized. Although locales define the week
* differently, in terms of the day on which it starts, and the
* designation of week number one of a month or year, they all use a
* common mechanism. Furthermore, the day of the week has a simple
* and consistent definition throughout history. For example,
* although the Gregorian calendar introduced a discontinuity when
* first instituted, the day of week was not disrupted. For this
* reason, the fields {@link #DAY_OF_WEEK}, <code>WEEK_OF_YEAR,
* WEEK_OF_MONTH</code>, {@link #DAY_OF_WEEK_IN_MONTH},
* {@link #DOW_LOCAL}, {@link #YEAR_WOY} are all computed in
* a consistent way in the base class, based on the
* {@link #EXTENDED_YEAR}, {@link #DAY_OF_YEAR},
* {@link #MONTH}, and {@link #DAY_OF_MONTH}, which are
* computed by the subclass.</li>
*
* </ul>
*
* <p><big><b>Supported range</b></big>
*
* <p>The allowable range of <code>Calendar</code> has been
* narrowed. <code>GregorianCalendar</code> used to attempt to support
* the range of dates with millisecond values from
* <code>Long.MIN_VALUE</code> to <code>Long.MAX_VALUE</code>. This
* introduced awkward constructions (hacks) which slowed down
* performance. It also introduced non-uniform behavior at the
* boundaries. The new <code>Calendar</code> protocol specifies the
* maximum range of supportable dates as those having Julian day numbers
* of <code>-0x7F000000</code> to <code>+0x7F000000</code>. This
* corresponds to years from ~5,000,000 BCE to ~5,000,000 CE. Programmers
* should use the constants {@link #MIN_DATE} (or
* {@link #MIN_MILLIS} or {@link #MIN_JULIAN}) and
* {@link #MAX_DATE} (or {@link #MAX_MILLIS} or
* {@link #MAX_JULIAN}) in <code>Calendar</code> to specify an
* extremely early or extremely late date.</p>
*
* <p><big><b>General notes</b></big>
*
* <ul>
*
* <li>Calendars implementations are <em>proleptic</em>. For example,
* even though the Gregorian calendar was not instituted until the
* 16th century, the <code>GregorianCalendar</code> class supports
* dates before the historical onset of the calendar by extending the
* calendar system backward in time. Similarly, the
* <code>HebrewCalendar</code> extends backward before the start of
* its epoch into zero and negative years. Subclasses do not throw
* exceptions because a date precedes the historical start of a
* calendar system. Instead, they implement
* {@link #handleGetLimit} to return appropriate limits on
* {@link #YEAR}, {@link #ERA}, etc. fields. Then, if the
* calendar is set to not be lenient, out-of-range field values will
* trigger an exception.</li>
*
* <li>Calendar system subclasses compute a <em>extended
* year</em>. This differs from the {@link #YEAR} field in that
* it ranges over all integer values, including zero and negative
* values, and it encapsulates the information of the
* {@link #YEAR} field and all larger fields. Thus, for the
* Gregorian calendar, the {@link #EXTENDED_YEAR} is computed as
* <code>ERA==AD ? YEAR : 1-YEAR</code>. Another example is the Mayan
* long count, which has years (<code>KUN</code>) and nested cycles
* of years (<code>KATUN</code> and <code>BAKTUN</code>). The Mayan
* {@link #EXTENDED_YEAR} is computed as <code>TUN + 20 * (KATUN
* + 20 * BAKTUN)</code>. The <code>Calendar</code> base class uses
* the {@link #EXTENDED_YEAR} field to compute the week-related
* fields.</li>
*
* </ul>
*
* @see Date
* @see GregorianCalendar
* @see TimeZone
* @see DateFormat
* @author Mark Davis, David Goldsmith, Chen-Lieh Huang, Alan Liu, Laura Werner
* @stable ICU 2.0
*/
public abstract class Calendar implements Serializable, Cloneable, Comparable {
// 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
* @stable ICU 2.0
*/
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.
* @stable ICU 2.0
*/
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>; 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
* @stable ICU 2.0
*/
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
* @stable ICU 2.0
*/
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
* @stable ICU 2.0
*/
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
* @stable ICU 2.0
*/
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
* @stable ICU 2.0
*/
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.
* @stable ICU 2.0
*/
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
* @stable ICU 2.0
*/
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>15</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
* @stable ICU 2.0
*/
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
* @stable ICU 2.0
*/
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
* @stable ICU 2.0
*/
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
* @stable ICU 2.0
*/
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.
* @stable ICU 2.0
*/
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.
* @stable ICU 2.0
*/
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.
* @stable ICU 2.0
*/
public final static int MILLISECOND = 14;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* raw offset from GMT in milliseconds.
* @stable ICU 2.0
*/
public final static int ZONE_OFFSET = 15;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* daylight savings offset in milliseconds.
* @stable ICU 2.0
*/
public final static int DST_OFFSET = 16;
/**
* Field number for <code>get()</code> and <code>set()</code>
* indicating the extended year corresponding to the
* <code>WEEK_OF_YEAR</code> field. This may be one greater or less
* than the value of <code>EXTENDED_YEAR</code>.
* @stable ICU 2.0
*/
public static final int YEAR_WOY = 17;
/**
* Field number for <code>get()</code> and <code>set()</code>
* indicating the localized day of week. This will be a value from 1
* to 7 inclusive, with 1 being the localized first day of the week.
* @stable ICU 2.0
*/
public static final int DOW_LOCAL = 18;
/**
* Field number for <code>get()</code> and <code>set()</code>
* indicating the extended year. This is a single number designating
* the year of this calendar system, encompassing all supra-year
* fields. For example, for the Julian calendar system, year numbers
* are positive, with an era of BCE or CE. An extended year value for
* the Julian calendar system assigns positive values to CE years and
* negative values to BCE years, with 1 BCE being year 0.
* @stable ICU 2.0
*/
public static final int EXTENDED_YEAR = 19;
/**
* Field number for <code>get()</code> and <code>set()</code>
* indicating the modified Julian day number. This is different from
* the conventional Julian day number in two regards. First, it
* demarcates days at local zone midnight, rather than noon GMT.
* Second, it is a local number; that is, it depends on the local time
* zone. It can be thought of as a single number that encompasses all
* the date-related fields.
* @stable ICU 2.0
*/
public static final int JULIAN_DAY = 20;
/**
* Field number for <code>get()</code> and <code>set()</code>
* indicating the milliseconds in the day. This ranges from 0 to
* 23:59:59.999 (regardless of DST). This field behaves
* <em>exactly</em> like a composite of all time-related fields, not
* including the zone fields. As such, it also reflects
* discontinuities of those fields on DST transition days. On a day of
* DST onset, it will jump forward. On a day of DST cessation, it will
* jump backward. This reflects the fact that is must be combined with
* the DST_OFFSET field to obtain a unique local time value.
* @stable ICU 2.0
*/
public static final int MILLISECONDS_IN_DAY = 21;
/**
* The number of fields defined by this class. Subclasses may define
* addition fields starting with this number.
* @stable ICU 2.0
*/
protected static final int BASE_FIELD_COUNT = 22;
/**
* The maximum number of fields possible. Subclasses must not define
* more total fields than this number.
* @stable ICU 2.0
*/
protected static final int MAX_FIELD_COUNT = 32;
/**
* Value of the <code>DAY_OF_WEEK</code> field indicating
* Sunday.
* @stable ICU 2.0
*/
public final static int SUNDAY = 1;
/**
* Value of the <code>DAY_OF_WEEK</code> field indicating
* Monday.
* @stable ICU 2.0
*/
public final static int MONDAY = 2;
/**
* Value of the <code>DAY_OF_WEEK</code> field indicating
* Tuesday.
* @stable ICU 2.0
*/
public final static int TUESDAY = 3;
/**
* Value of the <code>DAY_OF_WEEK</code> field indicating
* Wednesday.
* @stable ICU 2.0
*/
public final static int WEDNESDAY = 4;
/**
* Value of the <code>DAY_OF_WEEK</code> field indicating
* Thursday.
* @stable ICU 2.0
*/
public final static int THURSDAY = 5;
/**
* Value of the <code>DAY_OF_WEEK</code> field indicating
* Friday.
* @stable ICU 2.0
*/
public final static int FRIDAY = 6;
/**
* Value of the <code>DAY_OF_WEEK</code> field indicating
* Saturday.
* @stable ICU 2.0
*/
public final static int SATURDAY = 7;
/**
* Value of the <code>MONTH</code> field indicating the
* first month of the year.
* @stable ICU 2.0
*/
public final static int JANUARY = 0;
/**
* Value of the <code>MONTH</code> field indicating the
* second month of the year.
* @stable ICU 2.0
*/
public final static int FEBRUARY = 1;
/**
* Value of the <code>MONTH</code> field indicating the
* third month of the year.
* @stable ICU 2.0
*/
public final static int MARCH = 2;
/**
* Value of the <code>MONTH</code> field indicating the
* fourth month of the year.
* @stable ICU 2.0
*/
public final static int APRIL = 3;
/**
* Value of the <code>MONTH</code> field indicating the
* fifth month of the year.
* @stable ICU 2.0
*/
public final static int MAY = 4;
/**
* Value of the <code>MONTH</code> field indicating the
* sixth month of the year.
* @stable ICU 2.0
*/
public final static int JUNE = 5;
/**
* Value of the <code>MONTH</code> field indicating the
* seventh month of the year.
* @stable ICU 2.0
*/
public final static int JULY = 6;
/**
* Value of the <code>MONTH</code> field indicating the
* eighth month of the year.
* @stable ICU 2.0
*/
public final static int AUGUST = 7;
/**
* Value of the <code>MONTH</code> field indicating the
* ninth month of the year.
* @stable ICU 2.0
*/
public final static int SEPTEMBER = 8;
/**
* Value of the <code>MONTH</code> field indicating the
* tenth month of the year.
* @stable ICU 2.0
*/
public final static int OCTOBER = 9;
/**
* Value of the <code>MONTH</code> field indicating the
* eleventh month of the year.
* @stable ICU 2.0
*/
public final static int NOVEMBER = 10;
/**
* Value of the <code>MONTH</code> field indicating the
* twelfth month of the year.
* @stable ICU 2.0
*/
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.
* @stable ICU 2.0
*/
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.
* @stable ICU 2.0
*/
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.
* @stable ICU 2.0
*/
public final static int PM = 1;
/**
* Value returned by getDayOfWeekType(int dayOfWeek) to indicate a
* weekday.
* @see #WEEKEND
* @see #WEEKEND_ONSET
* @see #WEEKEND_CEASE
* @see #getDayOfWeekType
* @stable ICU 2.0
*/
public static final int WEEKDAY = 0;
/**
* Value returned by getDayOfWeekType(int dayOfWeek) to indicate a
* weekend day.
* @see #WEEKDAY
* @see #WEEKEND_ONSET
* @see #WEEKEND_CEASE
* @see #getDayOfWeekType
* @stable ICU 2.0
*/
public static final int WEEKEND = 1;
/**
* Value returned by getDayOfWeekType(int dayOfWeek) to indicate a
* day that starts as a weekday and transitions to the weekend.
* Call getWeekendTransition() to get the point of transition.
* @see #WEEKDAY
* @see #WEEKEND
* @see #WEEKEND_CEASE
* @see #getDayOfWeekType
* @stable ICU 2.0
*/
public static final int WEEKEND_ONSET = 2;
/**
* Value returned by getDayOfWeekType(int dayOfWeek) to indicate a
* day that starts as the weekend and transitions to a weekday.
* Call getWeekendTransition() to get the point of transition.
* @see #WEEKDAY
* @see #WEEKEND
* @see #WEEKEND_ONSET
* @see #getDayOfWeekType
* @stable ICU 2.0
*/
public static final int WEEKEND_CEASE = 3;
/**
* The number of milliseconds in one second.
* @stable ICU 2.0
*/
protected static final int ONE_SECOND = 1000;
/**
* The number of milliseconds in one minute.
* @stable ICU 2.0
*/
protected static final int ONE_MINUTE = 60*ONE_SECOND;
/**
* The number of milliseconds in one hour.
* @stable ICU 2.0
*/
protected static final int ONE_HOUR = 60*ONE_MINUTE;
/**
* The number of milliseconds in one day. Although ONE_DAY and
* ONE_WEEK can fit into ints, they must be longs in order to prevent
* arithmetic overflow when performing (bug 4173516).
* @stable ICU 2.0
*/
protected static final long ONE_DAY = 24*ONE_HOUR;
/**
* The number of milliseconds in one week. Although ONE_DAY and
* ONE_WEEK can fit into ints, they must be longs in order to prevent
* arithmetic overflow when performing (bug 4173516).
* @stable ICU 2.0
*/
protected static final long ONE_WEEK = 7*ONE_DAY;
/**
* The Julian day of the Gregorian epoch, that is, January 1, 1 on the
* Gregorian calendar.
* @stable ICU 2.0
*/
protected static final int JAN_1_1_JULIAN_DAY = 1721426;
/**
* The Julian day of the epoch, that is, January 1, 1970 on the
* Gregorian calendar.
* @stable ICU 2.0
*/
protected static final int EPOCH_JULIAN_DAY = 2440588;
/**
* The minimum supported Julian day. This value is equivalent to
* <code>MIN_MILLIS</code> and <code>MIN_DATE</code>.
* @see #JULIAN_DAY
* @stable ICU 2.0
*/
protected static final int MIN_JULIAN = -0x7F000000;
/**
* The minimum supported epoch milliseconds. This value is equivalent
* to <code>MIN_JULIAN</code> and <code>MIN_DATE</code>.
* @stable ICU 2.0
*/
protected static final long MIN_MILLIS = -184303902528000000L;
// Get around bug in jikes 1.12 for now. Later, use:
//protected static final long MIN_MILLIS = (MIN_JULIAN - EPOCH_JULIAN_DAY) * ONE_DAY;
/**
* The minimum supported <code>Date</code>. This value is equivalent
* to <code>MIN_JULIAN</code> and <code>MIN_MILLIS</code>.
* @stable ICU 2.0
*/
protected static final Date MIN_DATE = new Date(MIN_MILLIS);
/**
* The maximum supported Julian day. This value is equivalent to
* <code>MAX_MILLIS</code> and <code>MAX_DATE</code>.
* @see #JULIAN_DAY
* @stable ICU 2.0
*/
protected static final int MAX_JULIAN = +0x7F000000;
/**
* The maximum supported epoch milliseconds. This value is equivalent
* to <code>MAX_JULIAN</code> and <code>MAX_DATE</code>.
* @stable ICU 2.0
*/
protected static final long MAX_MILLIS = (MAX_JULIAN - EPOCH_JULIAN_DAY) * ONE_DAY;
/**
* The maximum supported <code>Date</code>. This value is equivalent
* to <code>MAX_JULIAN</code> and <code>MAX_MILLIS</code>.
* @stable ICU 2.0
*/
protected static final Date MAX_DATE = new Date(MAX_MILLIS);
// 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 at least <code>BASE_FIELD_COUNT</code> integers.
* @see #handleCreateFields
* @serial
*/
private transient int fields[];
/**
* 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.
*/
private transient int stamp[];
/**
* The currently set time for this calendar, expressed in milliseconds after
* January 1, 1970, 0:00:00 GMT.
* @see <tt>isTimeSet</tt>
* @serial
*/
private 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
*/
private transient boolean isTimeSet;
/**
* 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
*/
private transient boolean areFieldsSet;
/**
* True if all fields have been set. This is only false in a few
* situations: In a newly created, partially constructed object. After
* a call to clear(). In an object just read from a stream using
* readObject(). Once computeFields() has been called this is set to
* true and stays true until one of the above situations recurs.
* @serial
*/
private transient boolean areAllFieldsSet;
/**
* True if all fields have been virtually set, but have not yet been
* computed. This occurs only in setTimeInMillis(), or after readObject().
* A calendar set to this state will compute all fields from the time if it
* becomes necessary, but otherwise will delay such computation.
*/
private transient boolean areFieldsVirtuallySet;
/**
* 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;
/**
* First day of the weekend in this calendar's locale. Must be in
* the range SUNDAY...SATURDAY (1..7). The weekend starts at
* weekendOnsetMillis milliseconds after midnight on that day of
* the week. This value is taken from locale resource data.
*/
private int weekendOnset;
/**
* Milliseconds after midnight at which the weekend starts on the
* day of the week weekendOnset. Times that are greater than or
* equal to weekendOnsetMillis are considered part of the weekend.
* Must be in the range 0..24*60*60*1000-1. This value is taken
* from locale resource data.
*/
private int weekendOnsetMillis;
/**
* Day of the week when the weekend stops in this calendar's
* locale. Must be in the range SUNDAY...SATURDAY (1..7). The
* weekend stops at weekendCeaseMillis milliseconds after midnight
* on that day of the week. This value is taken from locale
* resource data.
*/
private int weekendCease;
/**
* Milliseconds after midnight at which the weekend stops on the
* day of the week weekendCease. Times that are greater than or
* equal to weekendCeaseMillis are considered not to be the
* weekend. Must be in the range 0..24*60*60*1000-1. This value
* is taken from locale resource data.
*/
private int weekendCeaseMillis;
/**
* Cache to hold the firstDayOfWeek and minimalDaysInFirstWeek
* of a Locale.
*/
private static Hashtable cachedLocaleData = new Hashtable(3);
/**
* Value of the time stamp <code>stamp[]</code> indicating that
* a field has not been set since the last call to <code>clear()</code>.
* @see #INTERNALLY_SET
* @see #MINIMUM_USER_STAMP
* @stable ICU 2.0
*/
protected static final int UNSET = 0;
/**
* Value of the time stamp <code>stamp[]</code> indicating that a field
* has been set via computations from the time or from other fields.
* @see #UNSET
* @see #MINIMUM_USER_STAMP
* @stable ICU 2.0
*/
protected static final int INTERNALLY_SET = 1;
/**
* If the time stamp <code>stamp[]</code> has a value greater than or
* equal to <code>MINIMUM_USER_SET</code> then it has been set by the
* user via a call to <code>set()</code>.
* @see #UNSET
* @see #INTERNALLY_SET
* @stable ICU 2.0
*/
protected static final int MINIMUM_USER_STAMP = 2;
/**
* The next available value for <code>stamp[]</code>, an internal array.
* @serial
*/
private transient 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;
// haven't been compatible for awhile, no longer try
// jdk1.4.2 serialver
private static final long serialVersionUID = 6222646104888790989L;
/**
* Bitmask for internalSet() defining which fields may legally be set
* by subclasses. Any attempt to set a field not in this bitmask
* results in an exception, because such fields must be set by the base
* class.
*/
private transient int internalSetMask;
/**
* The Gregorian year, as computed by computeGregorianFields() and
* returned by getGregorianYear().
*/
private transient int gregorianYear;
/**
* The Gregorian month, as computed by computeGregorianFields() and
* returned by getGregorianMonth().
*/
private transient int gregorianMonth;
/**
* The Gregorian day of the year, as computed by
* computeGregorianFields() and returned by getGregorianDayOfYear().
*/
private transient int gregorianDayOfYear;
/**
* The Gregorian day of the month, as computed by
* computeGregorianFields() and returned by getGregorianDayOfMonth().
*/
private transient int gregorianDayOfMonth;
/**
* Constructs a Calendar with the default time zone
* and locale.
* @see TimeZone#getDefault
* @stable ICU 2.0
*/
protected Calendar()
{
this(TimeZone.getDefault(), ULocale.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
* @stable ICU 2.0
*/
protected Calendar(TimeZone zone, Locale aLocale)
{
this(zone, ULocale.forLocale(aLocale));
}
/**
* Constructs a calendar with the specified time zone and locale.
* @param zone the time zone to use
* @param locale the ulocale for the week data
* @stable ICU 3.2
*/
protected Calendar(TimeZone zone, ULocale locale)
{
this.zone = zone;
setWeekData(locale);
initInternal();
}
private void initInternal()
{
// Allocate fields through the framework method. Subclasses
// may override this to define additional fields.
fields = handleCreateFields();
///CLOVER:OFF
// todo: fix, difficult to test without subclassing
if (fields == null || fields.length < BASE_FIELD_COUNT ||
fields.length > MAX_FIELD_COUNT) {
throw new IllegalStateException("Invalid fields[]");
}
///CLOVER:ON
stamp = new int[fields.length];
int mask = (1 << ERA) |
(1 << YEAR) |
(1 << MONTH) |
(1 << DAY_OF_MONTH) |
(1 << DAY_OF_YEAR) |
(1 << EXTENDED_YEAR);
for (int i=BASE_FIELD_COUNT; i<fields.length; ++i) {
mask |= (1 << i);
}
internalSetMask = mask;
}
/**
* Gets a calendar using the default time zone and locale.
* @return a Calendar.
* @stable ICU 2.0
*/
public static synchronized Calendar getInstance()
{
return getInstanceInternal(null, null);
}
/**
* Gets a calendar using the specified time zone and default locale.
* @param zone the time zone to use
* @return a Calendar.
* @stable ICU 2.0
*/
public static synchronized Calendar getInstance(TimeZone zone)
{
return getInstanceInternal(zone, null);
}
/**
* Gets a calendar using the default time zone and specified locale.
* @param aLocale the locale for the week data
* @return a Calendar.
* @stable ICU 2.0
*/
public static synchronized Calendar getInstance(Locale aLocale)
{
return getInstanceInternal(null, ULocale.forLocale(aLocale));
}
/**
* Gets a calendar using the default time zone and specified locale.
* @param locale the ulocale for the week data
* @return a Calendar.
* @stable ICU 3.2
*/
public static synchronized Calendar getInstance(ULocale locale)
{
return getInstanceInternal(null, locale);
}
/**
* Gets a calendar with the specified time zone and locale.
* @param zone the time zone to use
* @param aLocale the locale for the week data
* @return a Calendar.
* @stable ICU 2.0
*/
public static synchronized Calendar getInstance(TimeZone zone,
Locale aLocale) {
return getInstanceInternal(zone, ULocale.forLocale(aLocale));
}
/**
* Gets a calendar with the specified time zone and locale.
* @param zone the time zone to use
* @param locale the ulocale for the week data
* @return a Calendar.
* @stable ICU 3.2
*/
public static synchronized Calendar getInstance(TimeZone zone,
ULocale locale) {
return getInstanceInternal(zone, locale);
}
/*
* All getInstance implementations call this private method to create a new
* Calendar instance.
*/
private static Calendar getInstanceInternal(TimeZone tz, ULocale locale) {
if (locale == null) {
locale = ULocale.getDefault();
}
if (tz == null) {
tz = TimeZone.getDefault();
}
Calendar cal = getShim().createInstance(locale);
cal.setTimeZone(tz);
cal.setTimeInMillis(System.currentTimeMillis());
return cal;
}
private static final String[] calTypes = {
"gregorian",
"japanese",
"buddhist",
"roc",
"persian",
"islamic-civil",
"islamic",
"hebrew",
"chinese",
"indian",
"coptic",
"ethiopic",
"ethiopic-amete-alem",
};
// must be in the order of calTypes above
private static final int CALTYPE_GREGORIAN = 0;
private static final int CALTYPE_JAPANESE = 1;
private static final int CALTYPE_BUDDHIST = 2;
private static final int CALTYPE_ROC = 3;
private static final int CALTYPE_PERSIAN = 4; // not yet implemented
private static final int CALTYPE_ISLAMIC_CIVIL = 5;
private static final int CALTYPE_ISLAMIC = 6;
private static final int CALTYPE_HEBREW = 7;
private static final int CALTYPE_CHINESE = 8;
private static final int CALTYPE_INDIAN = 9;
private static final int CALTYPE_COPTIC = 10;
private static final int CALTYPE_ETHIOPIC = 11;
private static final int CALTYPE_ETHIOPIC_AMETE_ALEM = 12;
private static final int CALTYPE_UNKNOWN = -1;
private static int getCalendarTypeForLocale(ULocale l) {
int calType = CALTYPE_UNKNOWN;
// canonicalize, so grandfathered variant will be transformed to keywords
ULocale canonical = ULocale.createCanonical(l.toString());
String calTypeStr = canonical.getKeywordValue("calendar");
if (calTypeStr != null) {
calType = getCalendarType(calTypeStr);
if (calType != CALTYPE_UNKNOWN) {
return calType;
}
}
// when calendar keyword is not available or not supported, read supplementalData
// to get the default calendar type for the locale's region
String region = canonical.getCountry();
if (region.length() == 0) {
ULocale fullLoc = ULocale.addLikelySubtags(canonical);
region = fullLoc.getCountry();
}
try {
UResourceBundle rb = UResourceBundle.getBundleInstance(
ICUResourceBundle.ICU_BASE_NAME,
"supplementalData",
ICUResourceBundle.ICU_DATA_CLASS_LOADER);
UResourceBundle calPref = rb.get("calendarPreferenceData");
UResourceBundle order = null;
try {
order = calPref.get(region);
} catch (MissingResourceException mre) {
// use "001" as fallback
order = calPref.get("001");
}
// the first calendar type is the default for the region
calTypeStr = order.getString(0);
calType = getCalendarType(calTypeStr);
} catch (MissingResourceException mre) {
// fall through
}
if (calType == CALTYPE_UNKNOWN) {
return CALTYPE_GREGORIAN;
}
return calType;
}
private static int getCalendarType(String s) {
if (s != null) {
s = s.toLowerCase();
for (int i = 0; i < calTypes.length; ++i) {
if (s.equals(calTypes[i])) {
return i;
}
}
}
return CALTYPE_UNKNOWN;
}
/**
* Gets the list of locales for which Calendars are installed.
* @return the list of locales for which Calendars are installed.
* @stable ICU 2.0
*/
public static Locale[] getAvailableLocales()
{
if (shim == null) {
return ICUResourceBundle.getAvailableLocales(ICUResourceBundle.ICU_BASE_NAME);
}
return getShim().getAvailableLocales();
}
/**
* Gets the list of locales for which Calendars are installed.
* @return the list of locales for which Calendars are installed.
* @draft ICU 3.2 (retain)
* @provisional This API might change or be removed in a future release.
*/
public static ULocale[] getAvailableULocales()
{
if (shim == null) {
return ICUResourceBundle.getAvailableULocales(ICUResourceBundle.ICU_BASE_NAME);
}
return getShim().getAvailableULocales();
}
// ==== Factory Stuff ====
/**
* A CalendarFactory is used to register new calendar implementation.
* The factory should be able to create a calendar instance for the
* specified locale.
*
* @prototype
*/
/* public */ static abstract class CalendarFactory {
public boolean visible() {
return true;
}
public abstract Set getSupportedLocaleNames();
public Calendar createCalendar(ULocale loc) {
return null;
}
protected CalendarFactory() {
}
}
// shim so we can build without service code
static abstract class CalendarShim {
abstract Locale[] getAvailableLocales();
abstract ULocale[] getAvailableULocales();
abstract Object registerFactory(CalendarFactory factory);
abstract boolean unregister(Object k);
abstract Calendar createInstance(ULocale l);
}
private static CalendarShim shim;
private static CalendarShim getShim() {
if (shim == null) {
try {
Class cls = Class.forName("com.ibm.icu.util.CalendarServiceShim");
shim = (CalendarShim)cls.newInstance();
}
catch (MissingResourceException e) {
throw e;
}
catch (Exception e) {
throw new RuntimeException(e.getMessage());
}
}
return shim;
}
static Calendar createInstance(ULocale locale) {
Calendar cal = null;
TimeZone zone = TimeZone.getDefault();
int calType = getCalendarTypeForLocale(locale);
if (calType == CALTYPE_UNKNOWN) {
// fallback to Gregorian
calType = CALTYPE_GREGORIAN;
}
switch (calType) {
case CALTYPE_GREGORIAN:
cal = new GregorianCalendar(zone, locale);
break;
case CALTYPE_JAPANESE:
cal = new JapaneseCalendar(zone, locale);
break;
case CALTYPE_BUDDHIST:
cal = new BuddhistCalendar(zone, locale);
break;
case CALTYPE_ROC:
cal = new TaiwanCalendar(zone, locale);
break;
case CALTYPE_PERSIAN:
// Not yet implemented in ICU4J
cal = new GregorianCalendar(zone, locale);
break;
case CALTYPE_ISLAMIC_CIVIL:
cal = new IslamicCalendar(zone, locale);
break;
case CALTYPE_ISLAMIC:
cal = new IslamicCalendar(zone, locale);
((IslamicCalendar)cal).setCivil(false);
break;
case CALTYPE_HEBREW:
cal = new HebrewCalendar(zone, locale);
break;
case CALTYPE_CHINESE:
cal = new ChineseCalendar(zone, locale);
break;
case CALTYPE_INDIAN:
cal = new IndianCalendar(zone, locale);
break;
case CALTYPE_COPTIC:
cal = new CopticCalendar(zone, locale);
break;
case CALTYPE_ETHIOPIC:
cal = new EthiopicCalendar(zone, locale);
break;
case CALTYPE_ETHIOPIC_AMETE_ALEM:
cal = new EthiopicCalendar(zone, locale);
((EthiopicCalendar)cal).setAmeteAlemEra(true);
break;
default:
// we must not get here, because unknown type is mapped to
// Gregorian at the beginning of this method.
throw new IllegalArgumentException("Unknown calendar type");
}
return cal;
}
///CLOVER:OFF
/**
* Register a new CalendarFactory. getInstance(TimeZone, ULocale, String) will
* try to locate a registered factories matching the factoryName. Only registered
* factories will be found.
* @prototype
*/
/* public */ static Object registerFactory(CalendarFactory factory) {
if (factory == null) {
throw new IllegalArgumentException("factory must not be null");
}
return getShim().registerFactory(factory);
}
/**
* Unregister the CalendarFactory associated with this key
* (obtained from register).
* @prototype
*/
/* public */ static boolean unregister(Object registryKey) {
if (registryKey == null) {
throw new IllegalArgumentException("registryKey must not be null");
}
if (shim == null) {
return false;
}
return shim.unregister(registryKey);
}
///CLOVER:ON
// ==== End of factory Stuff ====
// //TODO: The table below should be retrieved from ICU resource when CLDR supplementalData
// // is fully updated.
// private static final String[][] CALPREF = {
// {"001", "gregorian"},
// {"AE", "gregorian", "islamic", "islamic-civil"},
// {"AF", "gregorian", "islamic", "islamic-civil", "persian"},
// {"BH", "gregorian", "islamic", "islamic-civil"},
// {"CN", "gregorian", "chinese"},
// {"CX", "gregorian", "chinese"},
// {"DJ", "gregorian", "islamic", "islamic-civil"},
// {"DZ", "gregorian", "islamic", "islamic-civil"},
// {"EG", "gregorian", "islamic", "islamic-civil", "coptic"},
// {"EH", "gregorian", "islamic", "islamic-civil"},
// {"ER", "gregorian", "islamic", "islamic-civil"},
// {"ET", "gregorian", "ethiopic", "ethiopic-amete-alem"},
// {"HK", "gregorian", "chinese"},
// {"IL", "gregorian", "hebrew"},
// {"IL", "gregorian", "islamic", "islamic-civil"},
// {"IN", "gregorian", "indian"},
// {"IQ", "gregorian", "islamic", "islamic-civil"},
// {"IR", "gregorian", "islamic", "islamic-civil", "persian"},
// {"JO", "gregorian", "islamic", "islamic-civil"},
// {"JP", "gregorian", "japanese"},
// {"KM", "gregorian", "islamic", "islamic-civil"},
// {"KW", "gregorian", "islamic", "islamic-civil"},
// {"LB", "gregorian", "islamic", "islamic-civil"},
// {"LY", "gregorian", "islamic", "islamic-civil"},
// {"MA", "gregorian", "islamic", "islamic-civil"},
// {"MO", "gregorian", "chinese"},
// {"MR", "gregorian", "islamic", "islamic-civil"},
// {"OM", "gregorian", "islamic", "islamic-civil"},
// {"PS", "gregorian", "islamic", "islamic-civil"},
// {"QA", "gregorian", "islamic", "islamic-civil"},
// {"SA", "gregorian", "islamic", "islamic-civil"},
// {"SD", "gregorian", "islamic", "islamic-civil"},
// {"SG", "gregorian", "chinese"},
// {"SY", "gregorian", "islamic", "islamic-civil"},
// {"TD", "gregorian", "islamic", "islamic-civil"},
// {"TH", "buddhist", "gregorian"},
// {"TN", "gregorian", "islamic", "islamic-civil"},
// {"TW", "gregorian", "roc", "chinese"},
// {"YE", "gregorian", "islamic", "islamic-civil"},
// };
/**
* Given a key and a locale, returns an array of string values in a preferred
* order that would make a difference. These are all and only those values where
* the open (creation) of the service with the locale formed from the input locale
* plus input keyword and that value has different behavior than creation with the
* input locale alone.
* @param key one of the keys supported by this service. For now, only
* "calendar" is supported.
* @param locale the locale
* @param commonlyUsed if set to true it will return only commonly used values
* with the given locale in preferred order. Otherwise,
* it will return all the available values for the locale.
* @return an array of string values for the given key and the locale.
* @draft ICU 4.2
* @provisional This API might change or be removed in a future release.
*/
public static final String[] getKeywordValuesForLocale(String key, ULocale locale, boolean commonlyUsed) {
// Resolve region
String prefRegion = locale.getCountry();
if (prefRegion.length() == 0){
ULocale loc = ULocale.addLikelySubtags(locale);
prefRegion = loc.getCountry();
}
// Read preferred calendar values from supplementalData calendarPreferences
LinkedList values = new LinkedList();
UResourceBundle rb = UResourceBundle.getBundleInstance(
ICUResourceBundle.ICU_BASE_NAME,
"supplementalData",
ICUResourceBundle.ICU_DATA_CLASS_LOADER);
UResourceBundle calPref = rb.get("calendarPreferenceData");
UResourceBundle order = null;
try {
order = calPref.get(prefRegion);
} catch (MissingResourceException mre) {
// use "001" as fallback
order = calPref.get("001");
}
String[] caltypes = order.getStringArray();
if (commonlyUsed) {
// we have all commonly used calendar for the target region
return caltypes;
}
// if not commonlyUsed, add all preferred calendars in the order
for (int i = 0; i < caltypes.length; i++) {
values.add(caltypes[i]);
}
// then, add other available clanedars
for (int i = 0; i < calTypes.length; i++) {
if (!values.contains(calTypes[i])) {
values.add(calTypes[i]);
}
}
return (String[])values.toArray(new String[values.size()]);
}
/**
* Gets this Calendar's current time.
* @return the current time.
* @stable ICU 2.0
*/
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.
* @stable ICU 2.0
*/
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.
* @stable ICU 2.0
*/
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.
* @stable ICU 2.0
*/
public void setTimeInMillis( long millis ) {
if (millis > MAX_MILLIS) {
millis = MAX_MILLIS;
} else if (millis < MIN_MILLIS) {
millis = MIN_MILLIS;
}
time = millis;
areFieldsSet = areAllFieldsSet = false;
isTimeSet = areFieldsVirtuallySet = true;
}
/**
* Gets the value for a given time field.
* @param field the given time field.
* @return the value for the given time field.
* @stable ICU 2.0
*/
public final int get(int field)
{
complete();
return fields[field];
}
/**
* Gets the value for a given time field. This is an internal method
* for subclasses that does <em>not</em> trigger any calculations.
* @param field the given time field.
* @return the value for the given time field.
* @stable ICU 2.0
*/
protected final int internalGet(int field)
{
return fields[field];
}
/**
* Get the value for a given time field, or return the given default
* value if the field is not set. This is an internal method for
* subclasses that does <em>not</em> trigger any calculations.
* @param field the given time field.
* @param defaultValue value to return if field is not set
* @return the value for the given time field of defaultValue if the
* field is unset
* @stable ICU 2.0
*/
protected final int internalGet(int field, int defaultValue) {
return (stamp[field] > UNSET) ? fields[field] : defaultValue;
}
/**
* 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.
* @stable ICU 2.0
*/
public final void set(int field, int value)
{
if (areFieldsVirtuallySet) {
computeFields();
}
fields[field] = value;
stamp[field] = nextStamp++;
isTimeSet = areFieldsSet = areFieldsVirtuallySet = false;
}
/**
* 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.
* @stable ICU 2.0
*/
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.
* @stable ICU 2.0
*/
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.
* @stable ICU 2.0
*/
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.
* @stable ICU 2.0
*/
public final void clear()
{
for (int i=0; i<fields.length; ++i) {
fields[i] = stamp[i] = 0; // UNSET == 0
}
isTimeSet = areFieldsSet = areAllFieldsSet = areFieldsVirtuallySet = false;
}
/**
* Clears the value in the given time field.
* @param field the time field to be cleared.
* @stable ICU 2.0
*/
public final void clear(int field)
{
if (areFieldsVirtuallySet) {
computeFields();
}
fields[field] = 0;
stamp[field] = UNSET;
isTimeSet = areFieldsSet = areAllFieldsSet = areFieldsVirtuallySet = false;
}
/**
* Determines if the given time field has a value set.
* @return true if the given time field has a value set; false otherwise.
* @stable ICU 2.0
*/
public final boolean isSet(int field)
{
return areFieldsVirtuallySet || (stamp[field] != UNSET);
}
/**
* Fills in any unset fields in the time field list.
* @stable ICU 2.0
*/
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.
* @stable ICU 2.0
*/
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (this.getClass() != obj.getClass()) {
return false;
}
Calendar that = (Calendar) obj;
return isEquivalentTo(that) &&
getTimeInMillis() == that.getTime().getTime();
}
/**
* Returns true if the given Calendar object is equivalent to this
* one. An equivalent Calendar will behave exactly as this one
* does, but it may be set to a different time. By contrast, for
* the equals() method to return true, the other Calendar must
* be set to the same time.
*
* @param other the Calendar to be compared with this Calendar
* @stable ICU 2.4
*/
public boolean isEquivalentTo(Calendar other) {
return this.getClass() == other.getClass() &&
isLenient() == other.isLenient() &&
getFirstDayOfWeek() == other.getFirstDayOfWeek() &&
getMinimalDaysInFirstWeek() == other.getMinimalDaysInFirstWeek() &&
getTimeZone().equals(other.getTimeZone());
}
/**
* Returns a hash code for this calendar.
* @return a hash code value for this object.
* @stable ICU 2.0
*/
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);
}
/**
* Return the difference in milliseconds between the moment this
* calendar is set to and the moment the given calendar or Date object
* is set to.
*/
private long compare(Object that) {
long thatMs;
if (that instanceof Calendar) {
thatMs = ((Calendar)that).getTimeInMillis();
} else if (that instanceof Date) {
thatMs = ((Date)that).getTime();
} else {
throw new IllegalArgumentException(that + "is not a Calendar or Date");
}
return getTimeInMillis() - thatMs;
}
/**
* 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.
* @stable ICU 2.0
*/
public boolean before(Object when) {
return compare(when) < 0;
}
/**
* 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.
* @stable ICU 2.0
*/
public boolean after(Object when) {
return compare(when) > 0;
}
/**
* Return the maximum value that this field could have, given the
* current date. For example, with the Gregorian date February 3, 1997
* and the {@link #DAY_OF_MONTH DAY_OF_MONTH} field, the actual maximum
* is 28; for February 3, 1996 it is 29.
*
* <p>The actual maximum computation ignores smaller fields and the
* current value of like-sized fields. For example, the actual maximum
* of the DAY_OF_YEAR or MONTH depends only on the year and supra-year
* fields. The actual maximum of the DAY_OF_MONTH depends, in
* addition, on the MONTH field and any other fields at that
* granularity (such as ChineseCalendar.IS_LEAP_MONTH). The
* DAY_OF_WEEK_IN_MONTH field does not depend on the current
* DAY_OF_WEEK; it returns the maximum for any day of week in the
* current month. Likewise for the WEEK_OF_MONTH and WEEK_OF_YEAR
* fields.
*
* @param field the field whose maximum is desired
* @return the maximum of the given field for the current date of this calendar
* @see #getMaximum
* @see #getLeastMaximum
* @stable ICU 2.0
*/
public int getActualMaximum(int field) {
int result;
switch (field) {
case DAY_OF_MONTH:
{
Calendar cal = (Calendar) clone();
cal.prepareGetActual(field, false);
result = handleGetMonthLength(cal.get(EXTENDED_YEAR), cal.get(MONTH));
}
break;
case DAY_OF_YEAR:
{
Calendar cal = (Calendar) clone();
cal.prepareGetActual(field, false);
result = handleGetYearLength(cal.get(EXTENDED_YEAR));
}
break;
case ERA:
case DAY_OF_WEEK:
case AM_PM:
case HOUR:
case HOUR_OF_DAY:
case MINUTE:
case SECOND:
case MILLISECOND:
case ZONE_OFFSET:
case DST_OFFSET:
case DOW_LOCAL:
case JULIAN_DAY:
case MILLISECONDS_IN_DAY:
// These fields all have fixed minima/maxima
result = getMaximum(field);
break;
default:
// For all other fields, do it the hard way....
result = getActualHelper(field, getLeastMaximum(field), getMaximum(field));
break;
}
return result;
}
/**
* Return the minimum value that this field could have, given the current date.
* For most fields, this is the same as {@link #getMinimum getMinimum}
* and {@link #getGreatestMinimum getGreatestMinimum}. However, some fields,
* especially those related to week number, are more complicated.
* <p>
* For example, assume {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek}
* returns 4 and {@link #getFirstDayOfWeek getFirstDayOfWeek} returns SUNDAY.
* If the first day of the month is Sunday, Monday, Tuesday, or Wednesday
* there will be four or more days in the first week, so it will be week number 1,
* and <code>getActualMinimum(WEEK_OF_MONTH)</code> will return 1. However,
* if the first of the month is a Thursday, Friday, or Saturday, there are
* <em>not</em> four days in that week, so it is week number 0, and
* <code>getActualMinimum(WEEK_OF_MONTH)</code> will return 0.
* <p>
* @param field the field whose actual minimum value is desired.
* @return the minimum of the given field for the current date of this calendar
*
* @see #getMinimum
* @see #getGreatestMinimum
* @stable ICU 2.0
*/
public int getActualMinimum(int field) {
int result;
switch (field) {
case DAY_OF_WEEK:
case AM_PM:
case HOUR:
case HOUR_OF_DAY:
case MINUTE:
case SECOND:
case MILLISECOND:
case ZONE_OFFSET:
case DST_OFFSET:
case DOW_LOCAL:
case JULIAN_DAY:
case MILLISECONDS_IN_DAY:
// These fields all have fixed minima/maxima
result = getMinimum(field);
break;
default:
// For all other fields, do it the hard way....
result = getActualHelper(field, getGreatestMinimum(field), getMinimum(field));
break;
}
return result;
}
/**
* Prepare this calendar for computing the actual minimum or maximum.
* This method modifies this calendar's fields; it is called on a
* temporary calendar.
*
* <p>Rationale: The semantics of getActualXxx() is to return the
* maximum or minimum value that the given field can take, taking into
* account other relevant fields. In general these other fields are
* larger fields. For example, when computing the actual maximum
* DAY_OF_MONTH, the current value of DAY_OF_MONTH itself is ignored,
* as is the value of any field smaller.
*
* <p>The time fields all have fixed minima and maxima, so we don't
* need to worry about them. This also lets us set the
* MILLISECONDS_IN_DAY to zero to erase any effects the time fields
* might have when computing date fields.
*
* <p>DAY_OF_WEEK is adjusted specially for the WEEK_OF_MONTH and
* WEEK_OF_YEAR fields to ensure that they are computed correctly.
* @stable ICU 2.0
*/
protected void prepareGetActual(int field, boolean isMinimum) {
set(MILLISECONDS_IN_DAY, 0);
switch (field) {
case YEAR:
case EXTENDED_YEAR:
set(DAY_OF_YEAR, getGreatestMinimum(DAY_OF_YEAR));
break;
case YEAR_WOY:
set(WEEK_OF_YEAR, getGreatestMinimum(WEEK_OF_YEAR));
break;
case MONTH:
set(DAY_OF_MONTH, getGreatestMinimum(DAY_OF_MONTH));
break;
case DAY_OF_WEEK_IN_MONTH:
// For dowim, the maximum occurs for the DOW of the first of the
// month.
set(DAY_OF_MONTH, 1);
set(DAY_OF_WEEK, get(DAY_OF_WEEK)); // Make this user set
break;
case WEEK_OF_MONTH:
case WEEK_OF_YEAR:
// If we're counting weeks, set the day of the week to either the
// first or last localized DOW. We know the last week of a month
// or year will contain the first day of the week, and that the
// first week will contain the last DOW.
{
int dow = firstDayOfWeek;
if (isMinimum) {
dow = (dow + 6) % 7; // set to last DOW
if (dow < SUNDAY) {
dow += 7;
}
}
set(DAY_OF_WEEK, dow);
}
break;
}
// Do this last to give it the newest time stamp
set(field, getGreatestMinimum(field));
}
private int getActualHelper(int field, int startValue, int endValue) {
if (startValue == endValue) {
// if we know that the maximum value is always the same, just return it
return startValue;
}
final int delta = (endValue > startValue) ? 1 : -1;
// 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) clone();
work.setLenient(true);
work.prepareGetActual(field, delta < 0);
// now try each value from the start to the end 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
work.set(field, startValue);
// prepareGetActual sets the first day of week in the same week with
// the first day of a month. Unlike WEEK_OF_YEAR, week number for the
// which week contains days from both previous and current month is
// not unique. For example, last several days in the previous month
// is week 5, and the rest of week is week 1.
if (work.get(field) != startValue
&& field != WEEK_OF_MONTH && delta > 0) {
return startValue;
}
int result = startValue;
do {
startValue += delta;
work.add(field, delta);
if (work.get(field) != startValue) {
break;
}
result = startValue;
} while (startValue != endValue);
return result;
}
/**
* Rolls (up/down) a single unit of time on the given field. If the
* field is rolled past its maximum allowable value, it will "wrap" back
* to its minimum and continue rolling. For
* example, to roll the current date up by one day, you can call:
* <p>
* <code>roll({@link #DATE}, true)</code>
* <p>
* When rolling on the {@link #YEAR} field, it will roll the year
* value in the range between 1 and the value returned by calling
* {@link #getMaximum getMaximum}({@link #YEAR}).
* <p>
* When rolling on certain fields, the values of other fields may conflict and
* need to be changed. For example, when rolling the <code>MONTH</code> field
* for the Gregorian date 1/31/96 upward, the <code>DAY_OF_MONTH</code> field
* must be adjusted so that the result is 2/29/96 rather than the invalid
* 2/31/96.
* <p>
* <b>Note:</b> Calling <tt>roll(field, true)</tt> N times is <em>not</em>
* necessarily equivalent to calling <tt>roll(field, N)</tt>. For example,
* imagine that you start with the date Gregorian date January 31, 1995. If you call
* <tt>roll(Calendar.MONTH, 2)</tt>, the result will be March 31, 1995.
* But if you call <tt>roll(Calendar.MONTH, true)</tt>, the result will be
* February 28, 1995. Calling it one more time will give March 28, 1995, which
* is usually not the desired result.
* <p>
* <b>Note:</b> You should always use <tt>roll</tt> and <tt>add</tt> rather
* than attempting to perform arithmetic operations directly on the fields
* of a <tt>Calendar</tt>. It is quite possible for <tt>Calendar</tt> subclasses
* to have fields with non-linear behavior, for example missing months
* or days during non-leap years. The subclasses' <tt>add</tt> and <tt>roll</tt>
* methods will take this into account, while simple arithmetic manipulations
* may give invalid results.
* <p>
* @param field the calendar field to roll.
*
* @param up indicates if the value of the specified time field is to be
* rolled up or rolled down. Use <code>true</code> if rolling up,
* <code>false</code> otherwise.
*
* @exception IllegalArgumentException if the field is invalid or refers
* to a field that cannot be handled by this method.
* @see #roll(int, int)
* @see #add
* @stable ICU 2.0
*/
public final void roll(int field, boolean up)
{
roll(field, up ? +1 : -1);
}
/**
* Rolls (up/down) a specified amount time on the given field. For
* example, to roll the current date up by three days, you can call
* <code>roll(Calendar.DATE, 3)</code>. If the
* field is rolled past its maximum allowable value, it will "wrap" back
* to its minimum and continue rolling.
* For example, calling <code>roll(Calendar.DATE, 10)</code>
* on a Gregorian calendar set to 4/25/96 will result in the date 4/5/96.
* <p>
* When rolling on certain fields, the values of other fields may conflict and
* need to be changed. For example, when rolling the {@link #MONTH MONTH} field
* for the Gregorian date 1/31/96 by +1, the {@link #DAY_OF_MONTH DAY_OF_MONTH} field
* must be adjusted so that the result is 2/29/96 rather than the invalid
* 2/31/96.
* <p>
* The <code>com.ibm.icu.util.Calendar</code> implementation of this method is able to roll
* all fields except for {@link #ERA ERA}, {@link #DST_OFFSET DST_OFFSET},
* and {@link #ZONE_OFFSET ZONE_OFFSET}. Subclasses may, of course, add support for
* additional fields in their overrides of <code>roll</code>.
* <p>
* <b>Note:</b> You should always use <tt>roll</tt> and <tt>add</tt> rather
* than attempting to perform arithmetic operations directly on the fields
* of a <tt>Calendar</tt>. It is quite possible for <tt>Calendar</tt> subclasses
* to have fields with non-linear behavior, for example missing months
* or days during non-leap years. The subclasses' <tt>add</tt> and <tt>roll</tt>
* methods will take this into account, while simple arithmetic manipulations
* may give invalid results.
* <p>
* <b>Subclassing:</b><br>
* This implementation of <code>roll</code> assumes that the behavior of the
* field is continuous between its minimum and maximum, which are found by
* calling {@link #getActualMinimum getActualMinimum} and {@link #getActualMaximum getActualMaximum}.
* For most such fields, simple addition, subtraction, and modulus operations
* are sufficient to perform the roll. For week-related fields,
* the results of {@link #getFirstDayOfWeek getFirstDayOfWeek} and
* {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek} are also necessary.
* Subclasses can override these two methods if their values differ from the defaults.
* <p>
* Subclasses that have fields for which the assumption of continuity breaks
* down must overide <code>roll</code> to handle those fields specially.
* For example, in the Hebrew calendar the month "Adar I"
* only occurs in leap years; in other years the calendar jumps from
* Shevat (month #4) to Adar (month #6). The
* {@link HebrewCalendar#roll HebrewCalendar.roll} method takes this into account,
* so that rolling the month of Shevat by one gives the proper result (Adar) in a
* non-leap year.
* <p>
* @param field the calendar field to roll.
* @param amount the amount by which the field should be rolled.
*
* @exception IllegalArgumentException if the field is invalid or refers
* to a field that cannot be handled by this method.
* @see #roll(int, boolean)
* @see #add
* @stable ICU 2.0
*/
public void roll(int field, int amount) {
if (amount == 0) {
return; // Nothing to do
}
complete();
switch (field) {
case DAY_OF_MONTH:
case AM_PM:
case MINUTE:
case SECOND:
case MILLISECOND:
case MILLISECONDS_IN_DAY:
case ERA:
// These are the standard roll instructions. These work for all
// simple cases, that is, cases in which the limits are fixed, such
// as the hour, the day of the month, and the era.
{
int min = getActualMinimum(field);
int max = getActualMaximum(field);
int gap = max - min + 1;
int value = internalGet(field) + amount;
value = (value - min) % gap;
if (value < 0) {
value += gap;
}
value += min;
set(field, value);
return;
}
case HOUR:
case HOUR_OF_DAY:
// Rolling the hour is difficult on the ONSET and CEASE days of
// daylight savings. For example, if the change occurs at
// 2 AM, we have the following progression:
// ONSET: 12 Std -> 1 Std -> 3 Dst -> 4 Dst
// CEASE: 12 Dst -> 1 Dst -> 1 Std -> 2 Std
// To get around this problem we don't use fields; we manipulate
// the time in millis directly.
{
// Assume min == 0 in calculations below
long start = getTimeInMillis();
int oldHour = internalGet(field);
int max = getMaximum(field);
int newHour = (oldHour + amount) % (max + 1);
if (newHour < 0) {
newHour += max + 1;
}
setTimeInMillis(start + ONE_HOUR * (newHour - oldHour));
return;
}
case MONTH:
// Rolling the month involves both pinning the final value
// and adjusting the DAY_OF_MONTH if necessary. We only adjust the
// DAY_OF_MONTH if, after updating the MONTH field, it is illegal.
// E.g., <jan31>.roll(MONTH, 1) -> <feb28> or <feb29>.
{
int max = getActualMaximum(MONTH);
int mon = (internalGet(MONTH) + amount) % (max+1);
if (mon < 0) {
mon += (max + 1);
}
set(MONTH, mon);
// Keep the day of month in range. We don't want to spill over
// into the next month; e.g., we don't want jan31 + 1 mo -> feb31 ->
// mar3.
pinField(DAY_OF_MONTH);
return;
}
case YEAR:
case YEAR_WOY:
case EXTENDED_YEAR:
// Rolling the year can involve pinning the DAY_OF_MONTH.
set(field, internalGet(field) + amount);
pinField(MONTH);
pinField(DAY_OF_MONTH);
return;
case WEEK_OF_MONTH:
{
// This is tricky, because during the roll we may have to shift
// to a different day of the week. For example:
// s m t w r f s
// 1 2 3 4 5
// 6 7 8 9 10 11 12
// When rolling from the 6th or 7th back one week, we go to the
// 1st (assuming that the first partial week counts). The same
// thing happens at the end of the month.
// The other tricky thing is that we have to figure out whether
// the first partial week actually counts or not, based on the
// minimal first days in the week. And we have to use the
// correct first day of the week to delineate the week
// boundaries.
// Here's our algorithm. First, we find the real boundaries of
// the month. Then we discard the first partial week if it
// doesn't count in this locale. Then we fill in the ends with
// phantom days, so that the first partial week and the last
// partial week are full weeks. We then have a nice square
// block of weeks. We do the usual rolling within this block,
// as is done elsewhere in this method. If we wind up on one of
// the phantom days that we added, we recognize this and pin to
// the first or the last day of the month. Easy, eh?
// Normalize the DAY_OF_WEEK so that 0 is the first day of the week
// in this locale. We have dow in 0..6.
int dow = internalGet(DAY_OF_WEEK) - getFirstDayOfWeek();
if (dow < 0) dow += 7;
// Find the day of the week (normalized for locale) for the first
// of the month.
int fdm = (dow - internalGet(DAY_OF_MONTH) + 1) % 7;
if (fdm < 0) fdm += 7;
// Get the first day of the first full week of the month,
// including phantom days, if any. Figure out if the first week
// counts or not; if it counts, then fill in phantom days. If
// not, advance to the first real full week (skip the partial week).
int start;
if ((7 - fdm) < getMinimalDaysInFirstWeek())
start = 8 - fdm; // Skip the first partial week
else
start = 1 - fdm; // This may be zero or negative
// Get the day of the week (normalized for locale) for the last
// day of the month.
int monthLen = getActualMaximum(DAY_OF_MONTH);
int ldm = (monthLen - internalGet(DAY_OF_MONTH) + dow) % 7;
// We know monthLen >= DAY_OF_MONTH so we skip the += 7 step here.
// Get the limit day for the blocked-off rectangular month; that
// is, the day which is one past the last day of the month,
// after the month has already been filled in with phantom days
// to fill out the last week. This day has a normalized DOW of 0.
int limit = monthLen + 7 - ldm;
// Now roll between start and (limit - 1).
int gap = limit - start;
int day_of_month = (internalGet(DAY_OF_MONTH) + amount*7 -
start) % gap;
if (day_of_month < 0) day_of_month += gap;
day_of_month += start;
// Finally, pin to the real start and end of the month.
if (day_of_month < 1) day_of_month = 1;
if (day_of_month > monthLen) day_of_month = monthLen;
// Set the DAY_OF_MONTH. We rely on the fact that this field
// takes precedence over everything else (since all other fields
// are also set at this point). If this fact changes (if the
// disambiguation algorithm changes) then we will have to unset
// the appropriate fields here so that DAY_OF_MONTH is attended
// to.
set(DAY_OF_MONTH, day_of_month);
return;
}
case WEEK_OF_YEAR:
{
// This follows the outline of WEEK_OF_MONTH, except it applies
// to the whole year. Please see the comment for WEEK_OF_MONTH
// for general notes.
// Normalize the DAY_OF_WEEK so that 0 is the first day of the week
// in this locale. We have dow in 0..6.
int dow = internalGet(DAY_OF_WEEK) - getFirstDayOfWeek();
if (dow < 0) dow += 7;
// Find the day of the week (normalized for locale) for the first
// of the year.
int fdy = (dow - internalGet(DAY_OF_YEAR) + 1) % 7;
if (fdy < 0) fdy += 7;
// Get the first day of the first full week of the year,
// including phantom days, if any. Figure out if the first week
// counts or not; if it counts, then fill in phantom days. If
// not, advance to the first real full week (skip the partial week).
int start;
if ((7 - fdy) < getMinimalDaysInFirstWeek())
start = 8 - fdy; // Skip the first partial week
else
start = 1 - fdy; // This may be zero or negative
// Get the day of the week (normalized for locale) for the last
// day of the year.
int yearLen = getActualMaximum(DAY_OF_YEAR);
int ldy = (yearLen - internalGet(DAY_OF_YEAR) + dow) % 7;
// We know yearLen >= DAY_OF_YEAR so we skip the += 7 step here.
// Get the limit day for the blocked-off rectangular year; that
// is, the day which is one past the last day of the year,
// after the year has already been filled in with phantom days
// to fill out the last week. This day has a normalized DOW of 0.
int limit = yearLen + 7 - ldy;
// Now roll between start and (limit - 1).
int gap = limit - start;
int day_of_year = (internalGet(DAY_OF_YEAR) + amount*7 -
start) % gap;
if (day_of_year < 0) day_of_year += gap;
day_of_year += start;
// Finally, pin to the real start and end of the month.
if (day_of_year < 1) day_of_year = 1;
if (day_of_year > yearLen) day_of_year = yearLen;
// Make sure that the year and day of year are attended to by
// clearing other fields which would normally take precedence.
// If the disambiguation algorithm is changed, this section will
// have to be updated as well.
set(DAY_OF_YEAR, day_of_year);
clear(MONTH);
return;
}
case DAY_OF_YEAR:
{
// Roll the day of year using millis. Compute the millis for
// the start of the year, and get the length of the year.
long delta = amount * ONE_DAY; // Scale up from days to millis
long min2 = time - (internalGet(DAY_OF_YEAR) - 1) * ONE_DAY;
int yearLength = getActualMaximum(DAY_OF_YEAR);
time = (time + delta - min2) % (yearLength*ONE_DAY);
if (time < 0) time += yearLength*ONE_DAY;
setTimeInMillis(time + min2);
return;
}
case DAY_OF_WEEK:
case DOW_LOCAL:
{
// Roll the day of week using millis. Compute the millis for
// the start of the week, using the first day of week setting.
// Restrict the millis to [start, start+7days).
long delta = amount * ONE_DAY; // Scale up from days to millis
// Compute the number of days before the current day in this
// week. This will be a value 0..6.
int leadDays = internalGet(field);
leadDays -= (field == DAY_OF_WEEK) ? getFirstDayOfWeek() : 1;
if (leadDays < 0) leadDays += 7;
long min2 = time - leadDays * ONE_DAY;
time = (time + delta - min2) % ONE_WEEK;
if (time < 0) time += ONE_WEEK;
setTimeInMillis(time + min2);
return;
}
case DAY_OF_WEEK_IN_MONTH:
{
// Roll the day of week in the month using millis. Determine
// the first day of the week in the month, and then the last,
// and then roll within that range.
long delta = amount * ONE_WEEK; // Scale up from weeks to millis
// Find the number of same days of the week before this one
// in this month.
int preWeeks = (internalGet(DAY_OF_MONTH) - 1) / 7;
// Find the number of same days of the week after this one
// in this month.
int postWeeks = (getActualMaximum(DAY_OF_MONTH) -
internalGet(DAY_OF_MONTH)) / 7;
// From these compute the min and gap millis for rolling.
long min2 = time - preWeeks * ONE_WEEK;
long gap2 = ONE_WEEK * (preWeeks + postWeeks + 1); // Must add 1!
// Roll within this range
time = (time + delta - min2) % gap2;
if (time < 0) time += gap2;
setTimeInMillis(time + min2);
return;
}
case JULIAN_DAY:
set(field, internalGet(field) + amount);
return;
default:
// Other fields cannot be rolled by this method
throw new IllegalArgumentException("Calendar.roll(" + fieldName(field) +
") not supported");
}
}
/**
* Add a signed amount to a specified field, using this calendar's rules.
* For example, to add three days to the current date, you can call
* <code>add(Calendar.DATE, 3)</code>.
* <p>
* When adding to certain fields, the values of other fields may conflict and
* need to be changed. For example, when adding one to the {@link #MONTH MONTH} field
* for the Gregorian date 1/31/96, the {@link #DAY_OF_MONTH DAY_OF_MONTH} field
* must be adjusted so that the result is 2/29/96 rather than the invalid
* 2/31/96.
* <p>
* The <code>com.ibm.icu.util.Calendar</code> implementation of this method is able to add to
* all fields except for {@link #ERA ERA}, {@link #DST_OFFSET DST_OFFSET},
* and {@link #ZONE_OFFSET ZONE_OFFSET}. Subclasses may, of course, add support for
* additional fields in their overrides of <code>add</code>.
* <p>
* <b>Note:</b> You should always use <tt>roll</tt> and <tt>add</tt> rather
* than attempting to perform arithmetic operations directly on the fields
* of a <tt>Calendar</tt>. It is quite possible for <tt>Calendar</tt> subclasses
* to have fields with non-linear behavior, for example missing months
* or days during non-leap years. The subclasses' <tt>add</tt> and <tt>roll</tt>
* methods will take this into account, while simple arithmetic manipulations
* may give invalid results.
* <p>
* <b>Subclassing:</b><br>
* This implementation of <code>add</code> assumes that the behavior of the
* field is continuous between its minimum and maximum, which are found by
* calling {@link #getActualMinimum getActualMinimum} and
* {@link #getActualMaximum getActualMaximum}.
* For such fields, simple arithmetic operations are sufficient to
* perform the add.
* <p>
* Subclasses that have fields for which this assumption of continuity breaks
* down must overide <code>add</code> to handle those fields specially.
* For example, in the Hebrew calendar the month "Adar I"
* only occurs in leap years; in other years the calendar jumps from
* Shevat (month #4) to Adar (month #6). The
* {@link HebrewCalendar#add HebrewCalendar.add} method takes this into account,
* so that adding one month
* to a date in Shevat gives the proper result (Adar) in a non-leap year.
* <p>
* @param field the time field.
* @param amount the amount to add to the field.
*
* @exception IllegalArgumentException if the field is invalid or refers
* to a field that cannot be handled by this method.
* @see #roll(int, int)
* @stable ICU 2.0
*/
public void add(int field, int amount) {
if (amount == 0) {
return; // Do nothing!
}
// We handle most fields in the same way. The algorithm is to add
// a computed amount of millis to the current millis. The only
// wrinkle is with DST -- for some fields, like the DAY_OF_MONTH,
// we don't want the HOUR to shift due to changes in DST. If the
// result of the add operation is to move from DST to Standard, or
// vice versa, we need to adjust by an hour forward or back,
// respectively. For such fields we set keepHourInvariant to true.
// We only adjust the DST for fields larger than an hour. For
// fields smaller than an hour, we cannot adjust for DST without
// causing problems. for instance, if you add one hour to April 5,
// 1998, 1:00 AM, in PST, the time becomes "2:00 AM PDT" (an
// illegal value), but then the adjustment sees the change and
// compensates by subtracting an hour. As a result the time
// doesn't advance at all.
// For some fields larger than a day, such as a MONTH, we pin the
// DAY_OF_MONTH. This allows <March 31>.add(MONTH, 1) to be
// <April 30>, rather than <April 31> => <May 1>.
long delta = amount; // delta in ms
boolean keepHourInvariant = true;
switch (field) {
case ERA:
set(field, get(field) + amount);
pinField(ERA);
return;
case YEAR:
case EXTENDED_YEAR:
case YEAR_WOY:
case MONTH:
set(field, get(field) + amount);
pinField(DAY_OF_MONTH);
return;
case WEEK_OF_YEAR:
case WEEK_OF_MONTH:
case DAY_OF_WEEK_IN_MONTH:
delta *= ONE_WEEK;
break;
case AM_PM:
delta *= 12 * ONE_HOUR;
break;
case DAY_OF_MONTH:
case DAY_OF_YEAR:
case DAY_OF_WEEK:
case DOW_LOCAL:
case JULIAN_DAY:
delta *= ONE_DAY;
break;
case HOUR_OF_DAY:
case HOUR:
delta *= ONE_HOUR;
keepHourInvariant = false;
break;
case MINUTE:
delta *= ONE_MINUTE;
keepHourInvariant = false;
break;
case SECOND:
delta *= ONE_SECOND;
keepHourInvariant = false;
break;
case MILLISECOND:
case MILLISECONDS_IN_DAY:
keepHourInvariant = false;
break;
default:
throw new IllegalArgumentException("Calendar.add(" + fieldName(field) +
") not supported");
}
// In order to keep the hour invariant (for fields where this is
// appropriate), record the DST_OFFSET before and after the add()
// operation. If it has changed, then adjust the millis to
// compensate.
int dst = 0;
int hour = 0;
if (keepHourInvariant) {
dst = get(DST_OFFSET);
hour = internalGet(HOUR_OF_DAY);
}
setTimeInMillis(getTimeInMillis() + delta);
if (keepHourInvariant) {
dst -= get(DST_OFFSET);
if (dst != 0) {
// We have done an hour-invariant adjustment but the
// DST offset has altered. We adjust millis to keep
// the hour constant. In cases such as midnight after
// a DST change which occurs at midnight, there is the
// danger of adjusting into a different day. To avoid
// this we make the adjustment only if it actually
// maintains the hour.
long t = time;
setTimeInMillis(time + dst);
if (get(HOUR_OF_DAY) != hour) {
setTimeInMillis(t);
}
}
}
}
/**
* Return the name of this calendar in the language of the given locale.
* @stable ICU 2.0
*/
public String getDisplayName(Locale loc) {
return this.getClass().getName();
}
/**
* Return the name of this calendar in the language of the given locale.
* @stable ICU 3.2
*/
public String getDisplayName(ULocale loc) {
return this.getClass().getName();
}
/**
* Compares the times (in millis) represented by two
* <code>Calendar</code> objects.
*
* @param that the <code>Calendar</code> to compare to this.
* @return <code>0</code> if the time represented by
* this <code>Calendar</code> is equal to the time represented
* by that <code>Calendar</code>, a value less than
* <code>0</code> if the time represented by this is before
* the time represented by that, and a value greater than
* <code>0</code> if the time represented by this
* is after the time represented by that.
* @throws NullPointerException if that
* <code>Calendar</code> is null.
* @throws IllegalArgumentException if the time of that
* <code>Calendar</code> can't be obtained because of invalid
* calendar values.
* @stable ICU 3.4
*/
public int compareTo(Calendar that) {
long v = getTimeInMillis() - that.getTimeInMillis();
return v < 0 ? -1 : (v > 0 ? 1 : 0);
}
/**
* Implement comparable API as a convenience override of
* {@link #compareTo(Calendar)}.
* @stable ICU 3.4
*/
public int compareTo(Object that) {
return compareTo((Calendar)that);
}
//-------------------------------------------------------------------------
// Interface for creating custon DateFormats for different types of Calendars
//-------------------------------------------------------------------------
/**
* Return a <code>DateFormat</code> appropriate to this calendar.
* Subclasses wishing to specialize this behavior should override
* <code>handleGetDateFormat()</code>
* @see #handleGetDateFormat
* @stable ICU 2.0
*/
public DateFormat getDateTimeFormat(int dateStyle, int timeStyle, Locale loc) {
return formatHelper(this, ULocale.forLocale(loc), dateStyle, timeStyle);
}
/**
* Return a <code>DateFormat</code> appropriate to this calendar.
* Subclasses wishing to specialize this behavior should override
* <code>handleGetDateFormat()</code>
* @see #handleGetDateFormat
* @stable ICU 3.2
*/
public DateFormat getDateTimeFormat(int dateStyle, int timeStyle, ULocale loc) {
return formatHelper(this, loc, dateStyle, timeStyle);
}
/**
* Create a <code>DateFormat</code> appropriate to this calendar.
* This is a framework method for subclasses to override. This method
* is responsible for creating the calendar-specific DateFormat and
* DateFormatSymbols objects as needed.
* @param pattern the pattern, specific to the <code>DateFormat</code>
* subclass
* @param locale the locale for which the symbols should be drawn
* @return a <code>DateFormat</code> appropriate to this calendar
* @stable ICU 2.0
*/
protected DateFormat handleGetDateFormat(String pattern, Locale locale) {
return handleGetDateFormat(pattern, null, ULocale.forLocale(locale));
}
/**
* Create a <code>DateFormat</code> appropriate to this calendar.
* This is a framework method for subclasses to override. This method
* is responsible for creating the calendar-specific DateFormat and
* DateFormatSymbols objects as needed.
* @param pattern the pattern, specific to the <code>DateFormat</code>
* subclass
* @param locale the locale for which the symbols should be drawn
* @return a <code>DateFormat</code> appropriate to this calendar
* @stable ICU 2.0
*/
protected DateFormat handleGetDateFormat(String pattern, String override, Locale locale) {
return handleGetDateFormat(pattern, override, ULocale.forLocale(locale));
}
/**
* Create a <code>DateFormat</code> appropriate to this calendar.
* This is a framework method for subclasses to override. This method
* is responsible for creating the calendar-specific DateFormat and
* DateFormatSymbols objects as needed.
* @param pattern the pattern, specific to the <code>DateFormat</code>
* subclass
* @param locale the locale for which the symbols should be drawn
* @return a <code>DateFormat</code> appropriate to this calendar
* @stable ICU 2.0
*/
protected DateFormat handleGetDateFormat(String pattern, ULocale locale) {
return handleGetDateFormat(pattern, null, locale);
}
/**
* Create a <code>DateFormat</code> appropriate to this calendar.
* This is a framework method for subclasses to override. This method
* is responsible for creating the calendar-specific DateFormat and
* DateFormatSymbols objects as needed.
* @param pattern the pattern, specific to the <code>DateFormat</code>
* subclass
* @param locale the locale for which the symbols should be drawn
* @return a <code>DateFormat</code> appropriate to this calendar
* @draft ICU 3.2 (retain)
* @provisional This API might change or be removed in a future release.
*/
protected DateFormat handleGetDateFormat(String pattern, String override, ULocale locale) {
FormatConfiguration fmtConfig = new FormatConfiguration();
fmtConfig.pattern = pattern;
fmtConfig.override = override;
fmtConfig.formatData = new DateFormatSymbols(this, locale);
fmtConfig.loc = locale;
fmtConfig.cal = this;
return SimpleDateFormat.getInstance(fmtConfig);
}
// date format pattern cache
private static final ICUCache PATTERN_CACHE = new SimpleCache();
// final fallback patterns
private static final String[] DEFAULT_PATTERNS = {
"HH:mm:ss z",
"HH:mm:ss z",
"HH:mm:ss",
"HH:mm",
"EEEE, yyyy MMMM dd",
"yyyy MMMM d",
"yyyy MMM d",
"yy/MM/dd",
"{1} {0}",
"{1} {0}",
"{1} {0}",
"{1} {0}",
"{1} {0}"
};
static private DateFormat formatHelper(Calendar cal, ULocale loc, int dateStyle, int timeStyle) {
PatternData patternData = PatternData.make(cal, loc);
String override = null;
// Resolve a pattern for the date/time style
String pattern = null;
if ((timeStyle >= 0) && (dateStyle >= 0)) {
pattern = MessageFormat.format(patternData.getDateTimePattern(dateStyle),
new Object[] {patternData.patterns[timeStyle], patternData.patterns[dateStyle + 4]});
// Might need to merge the overrides from the date and time into a single override string
// TODO: Right now we are forcing the date's override into the time style.
if ( patternData.overrides != null ) {
String dateOverride = patternData.overrides[dateStyle + 4];
String timeOverride = patternData.overrides[timeStyle];
override = mergeOverrideStrings(patternData.patterns[dateStyle+4],patternData.patterns[timeStyle],dateOverride,timeOverride);
}
} else if (timeStyle >= 0) {
pattern = patternData.patterns[timeStyle];
if ( patternData.overrides != null ) {
override = patternData.overrides[timeStyle];
}
} else if (dateStyle >= 0) {
pattern = patternData.patterns[dateStyle + 4];
if ( patternData.overrides != null ) {
override = patternData.overrides[dateStyle + 4];
}
} else {
throw new IllegalArgumentException("No date or time style specified");
}
DateFormat result = cal.handleGetDateFormat(pattern, override, loc);
result.setCalendar(cal);
return result;
}
static class PatternData {
// TODO make this even more object oriented
private String[] patterns;
private String[] overrides;
public PatternData(String[] patterns, String[] overrides) {
this.patterns = patterns;
this.overrides = overrides;
}
private String getDateTimePattern(int dateStyle) {
int glueIndex = 8;
if (patterns.length >= 13) {
glueIndex += (dateStyle + 1);
}
final String dateTimePattern = patterns[glueIndex];
return dateTimePattern;
}
private static PatternData make(Calendar cal, ULocale loc) {
// First, try to get a pattern from PATTERN_CACHE
String key = loc.toString() + cal.getType();
PatternData patternData = (PatternData) PATTERN_CACHE.get(key);
if (patternData == null) {
// Cache missed. Get one from bundle
try {
CalendarData calData = new CalendarData(loc, cal.getType());
patternData = new PatternData(calData.getDateTimePatterns(), calData.getOverrides());
} catch (MissingResourceException e) {
patternData = new PatternData(DEFAULT_PATTERNS, null);
}
PATTERN_CACHE.put(key, patternData);
}
return patternData;
}
}
/**
* @internal
* @deprecated This API is ICU internal only.
*/
public static String getDateTimePattern(Calendar cal, ULocale uLocale, int dateStyle) {
PatternData patternData = PatternData.make(cal, uLocale);
return patternData.getDateTimePattern(dateStyle);
}
private static String mergeOverrideStrings( String datePattern, String timePattern, String dateOverride, String timeOverride ) {
if ( dateOverride == null && timeOverride == null ) {
return null;
}
if ( dateOverride == null ) {
return expandOverride(timePattern,timeOverride);
}
if ( timeOverride == null ) {
return expandOverride(datePattern,dateOverride);
}
if ( dateOverride.equals(timeOverride) ) {
return dateOverride;
}
return (expandOverride(datePattern,dateOverride)+";"+expandOverride(timePattern,timeOverride));
}
private static final char QUOTE = '\'';
private static String expandOverride(String pattern, String override) {
if (override.indexOf('=') >= 0) {
return override;
}
boolean inQuotes = false;
char prevChar = ' ';
StringBuffer result = new StringBuffer();
StringCharacterIterator it = new StringCharacterIterator(pattern);
for (char c = it.first(); c!= StringCharacterIterator.DONE; c = it.next()) {
if ( c == QUOTE ) {
inQuotes = !inQuotes;
prevChar = c;
continue;
}
if ( !inQuotes && c != prevChar ) {
if (result.length() > 0) {
result.append(";");
}
result.append(c);
result.append("=");
result.append(override);
}
prevChar = c;
}
return result.toString();
}
/**
* An instance of FormatConfiguration represents calendar specific
* date format configuration and used for calling the ICU private
* SimpleDateFormat factory method.
*
* @internal
* @deprecated This API is ICU internal only.
*/
public static class FormatConfiguration {
private String pattern;
private String override;
private DateFormatSymbols formatData;
private Calendar cal;
private ULocale loc;
// Only Calendar can instantiate
private FormatConfiguration() {
}
/**
* Gets the pattern string
* @return the format pattern string
* @internal
* @deprecated This API is ICU internal only.
*/
public String getPatternString() {
return pattern;
}
public String getOverrideString() {
return override;
}
/**
* Gets the calendar
* @return the calendar
* @internal
* @deprecated This API is ICU internal only.
*/
public Calendar getCalendar() {
return cal;
}
/**
* Gets the locale
* @return the locale
* @internal
* @deprecated This API is ICU internal only.
*/
public ULocale getLocale() {
return loc;
}
/**
* Gets the format symbols
* @return the format symbols
* @internal
* @deprecated This API is ICU internal only.
*/
public DateFormatSymbols getDateFormatSymbols() {
return formatData;
}
}
//-------------------------------------------------------------------------
// Protected utility methods for use by subclasses. These are very handy
// for implementing add, roll, and computeFields.
//-------------------------------------------------------------------------
/**
* Adjust the specified field so that it is within
* the allowable range for the date to which this calendar is set.
* For example, in a Gregorian calendar pinning the {@link #DAY_OF_MONTH DAY_OF_MONTH}
* field for a calendar set to April 31 would cause it to be set
* to April 30.
* <p>
* <b>Subclassing:</b>
* <br>
* This utility method is intended for use by subclasses that need to implement
* their own overrides of {@link #roll roll} and {@link #add add}.
* <p>
* <b>Note:</b>
* <code>pinField</code> is implemented in terms of
* {@link #getActualMinimum getActualMinimum}
* and {@link #getActualMaximum getActualMaximum}. If either of those methods uses
* a slow, iterative algorithm for a particular field, it would be
* unwise to attempt to call <code>pinField</code> for that field. If you
* really do need to do so, you should override this method to do
* something more efficient for that field.
* <p>
* @param field The calendar field whose value should be pinned.
*
* @see #getActualMinimum
* @see #getActualMaximum
* @stable ICU 2.0
*/
protected void pinField(int field) {
int max = getActualMaximum(field);
int min = getActualMinimum(field);
if (fields[field] > max) {
set(field, max);
} else if (fields[field] < min) {
set(field, min);
}
}
/**
* Return the week number of a day, within a period. This may be the week number in
* a year or the week number in a month. Usually this will be a value >= 1, but if
* some initial days of the period are excluded from week 1, because
* {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek} is > 1, then
* the week number will be zero for those
* initial days. This method requires the day number and day of week for some
* known date in the period in order to determine the day of week
* on the desired day.
* <p>
* <b>Subclassing:</b>
* <br>
* This method is intended for use by subclasses in implementing their
* {@link #computeTime computeTime} and/or {@link #computeFields computeFields} methods.
* It is often useful in {@link #getActualMinimum getActualMinimum} and
* {@link #getActualMaximum getActualMaximum} as well.
* <p>
* This variant is handy for computing the week number of some other
* day of a period (often the first or last day of the period) when its day
* of the week is not known but the day number and day of week for some other
* day in the period (e.g. the current date) <em>is</em> known.
* <p>
* @param desiredDay The {@link #DAY_OF_YEAR DAY_OF_YEAR} or
* {@link #DAY_OF_MONTH DAY_OF_MONTH} whose week number is desired.
* Should be 1 for the first day of the period.
*
* @param dayOfPeriod The {@link #DAY_OF_YEAR DAY_OF_YEAR}
* or {@link #DAY_OF_MONTH DAY_OF_MONTH} for a day in the period whose
* {@link #DAY_OF_WEEK DAY_OF_WEEK} is specified by the
* <code>dayOfWeek</code> parameter.
* Should be 1 for first day of period.
*
* @param dayOfWeek The {@link #DAY_OF_WEEK DAY_OF_WEEK} for the day
* corresponding to the <code>dayOfPeriod</code> parameter.
* 1-based with 1=Sunday.
*
* @return The week number (one-based), or zero if the day falls before
* the first week because
* {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek}
* is more than one.
* @stable ICU 2.0
*/
protected int weekNumber(int desiredDay, int dayOfPeriod, int dayOfWeek)
{
// Determine the day of the week of the first day of the period
// in question (either a year or a month). Zero represents the
// first day of the week on this calendar.
int periodStartDayOfWeek = (dayOfWeek - getFirstDayOfWeek() - dayOfPeriod + 1) % 7;
if (periodStartDayOfWeek < 0) periodStartDayOfWeek += 7;
// Compute the week number. Initially, ignore the first week, which
// may be fractional (or may not be). We add periodStartDayOfWeek in
// order to fill out the first week, if it is fractional.
int weekNo = (desiredDay + periodStartDayOfWeek - 1)/7;
// If the first week is long enough, then count it. If
// the minimal days in the first week is one, or if the period start
// is zero, we always increment weekNo.
if ((7 - periodStartDayOfWeek) >= getMinimalDaysInFirstWeek()) ++weekNo;
return weekNo;
}
/**
* Return the week number of a day, within a period. This may be the week number in
* a year, or the week number in a month. Usually this will be a value >= 1, but if
* some initial days of the period are excluded from week 1, because
* {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek} is > 1,
* then the week number will be zero for those
* initial days. This method requires the day of week for the given date in order to
* determine the result.
* <p>
* <b>Subclassing:</b>
* <br>
* This method is intended for use by subclasses in implementing their
* {@link #computeTime computeTime} and/or {@link #computeFields computeFields} methods.
* It is often useful in {@link #getActualMinimum getActualMinimum} and
* {@link #getActualMaximum getActualMaximum} as well.
* <p>
* @param dayOfPeriod The {@link #DAY_OF_YEAR DAY_OF_YEAR} or
* {@link #DAY_OF_MONTH DAY_OF_MONTH} whose week number is desired.
* Should be 1 for the first day of the period.
*
* @param dayOfWeek The {@link #DAY_OF_WEEK DAY_OF_WEEK} for the day
* corresponding to the <code>dayOfPeriod</code> parameter.
* 1-based with 1=Sunday.
*
* @return The week number (one-based), or zero if the day falls before
* the first week because
* {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek}
* is more than one.
* @stable ICU 2.0
*/
protected final int weekNumber(int dayOfPeriod, int dayOfWeek)
{
return weekNumber(dayOfPeriod, dayOfPeriod, dayOfWeek);
}
//-------------------------------------------------------------------------
// Constants
//-------------------------------------------------------------------------
/**
* [NEW]
* Return the difference between the given time and the time this
* calendar object is set to. If this calendar is set
* <em>before</em> the given time, the returned value will be
* positive. If this calendar is set <em>after</em> the given
* time, the returned value will be negative. The
* <code>field</code> parameter specifies the units of the return
* value. For example, if <code>fieldDifference(when,
* Calendar.MONTH)</code> returns 3, then this calendar is set to
* 3 months before <code>when</code>, and possibly some additional
* time less than one month.
*
* <p>As a side effect of this call, this calendar is advanced
* toward <code>when</code> by the given amount. That is, calling
* this method has the side effect of calling <code>add(field,
* n)</code>, where <code>n</code> is the return value.
*
* <p>Usage: To use this method, call it first with the largest
* field of interest, then with progressively smaller fields. For
* example:
*
* <pre>
* int y = cal.fieldDifference(when, Calendar.YEAR);
* int m = cal.fieldDifference(when, Calendar.MONTH);
* int d = cal.fieldDifference(when, Calendar.DATE);</pre>
*
* computes the difference between <code>cal</code> and
* <code>when</code> in years, months, and days.
*
* <p>Note: <code>fieldDifference()</code> is
* <em>asymmetrical</em>. That is, in the following code:
*
* <pre>
* cal.setTime(date1);
* int m1 = cal.fieldDifference(date2, Calendar.MONTH);
* int d1 = cal.fieldDifference(date2, Calendar.DATE);
* cal.setTime(date2);
* int m2 = cal.fieldDifference(date1, Calendar.MONTH);
* int d2 = cal.fieldDifference(date1, Calendar.DATE);</pre>
*
* one might expect that <code>m1 == -m2 && d1 == -d2</code>.
* However, this is not generally the case, because of
* irregularities in the underlying calendar system (e.g., the
* Gregorian calendar has a varying number of days per month).
*
* @param when the date to compare this calendar's time to
* @param field the field in which to compute the result
* @return the difference, either positive or negative, between
* this calendar's time and <code>when</code>, in terms of
* <code>field</code>.
* @stable ICU 2.0
*/
public int fieldDifference(Date when, int field) {
int min = 0;
long startMs = getTimeInMillis();
long targetMs = when.getTime();
// Always add from the start millis. This accomodates
// operations like adding years from February 29, 2000 up to
// February 29, 2004. If 1, 1, 1, 1 is added to the year
// field, the DOM gets pinned to 28 and stays there, giving an
// incorrect DOM difference of 1. We have to add 1, reset, 2,
// reset, 3, reset, 4.
if (startMs < targetMs) {
int max = 1;
// Find a value that is too large
for (;;) {
setTimeInMillis(startMs);
add(field, max);
long ms = getTimeInMillis();
if (ms == targetMs) {
return max;
} else if (ms > targetMs) {
break;
} else {
max <<= 1;
if (max < 0) {
// Field difference too large to fit into int
throw new RuntimeException();
}
}
}
// Do a binary search
while ((max - min) > 1) {
int t = (min + max) / 2;
setTimeInMillis(startMs);
add(field, t);
long ms = getTimeInMillis();
if (ms == targetMs) {
return t;
} else if (ms > targetMs) {
max = t;
} else {
min = t;
}
}
} else if (startMs > targetMs) {
if (false) {
// This works, and makes the code smaller, but costs
// an extra object creation and an extra couple cycles
// of calendar computation.
setTimeInMillis(targetMs);
min = -fieldDifference(new Date(startMs), field);
}
int max = -1;
// Find a value that is too small
for (;;) {
setTimeInMillis(startMs);
add(field, max);
long ms = getTimeInMillis();
if (ms == targetMs) {
return max;
} else if (ms < targetMs) {
break;
} else {
max <<= 1;
if (max == 0) {
// Field difference too large to fit into int
throw new RuntimeException();
}
}
}
// Do a binary search
while ((min - max) > 1) {
int t = (min + max) / 2;
setTimeInMillis(startMs);
add(field, t);
long ms = getTimeInMillis();
if (ms == targetMs) {
return t;
} else if (ms < targetMs) {
max = t;
} else {
min = t;
}
}
}
// Set calendar to end point
setTimeInMillis(startMs);
add(field, min);
return min;
}
/**
* Sets the time zone with the given time zone value.
* @param value the given time zone.
* @stable ICU 2.0
*/
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.
* @stable ICU 2.0
*/
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 DateFormat#setLenient
* @stable ICU 2.0
*/
public void setLenient(boolean lenient)
{
this.lenient = lenient;
}
/**
* Tell whether date/time interpretation is to be lenient.
* @stable ICU 2.0
*/
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.
* @stable ICU 2.0
*/
public void setFirstDayOfWeek(int value)
{
if (firstDayOfWeek != value) {
if (value < SUNDAY || value > SATURDAY) {
throw new IllegalArgumentException("Invalid day of week");
}
firstDayOfWeek = value;
areFieldsSet = false;
}
}
/**
* Gets what the first day of the week is; e.g., Sunday in US,
* Monday in France.
* @return the first day of the week.
* @stable ICU 2.0
*/
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.
* @stable ICU 2.0
*/
public void setMinimalDaysInFirstWeek(int value)
{
// Values less than 1 have the same effect as 1; values greater
// than 7 have the same effect as 7. However, we normalize values
// so operator== and so forth work.
if (value < 1) {
value = 1;
} else if (value > 7) {
value = 7;
}
if (minimalDaysInFirstWeek != value) {
minimalDaysInFirstWeek = value;
areFieldsSet = false;
}
}
/**
* 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.
* @stable ICU 2.0
*/
public int getMinimalDaysInFirstWeek()
{
return minimalDaysInFirstWeek;
}
private static final int LIMITS[][] = {
// Minimum Greatest min Least max Greatest max
{/* */}, // ERA
{/* */}, // YEAR
{/* */}, // MONTH
{/* */}, // WEEK_OF_YEAR
{/* */}, // WEEK_OF_MONTH
{/* */}, // DAY_OF_MONTH
{/* */}, // DAY_OF_YEAR
{ 1, 1, 7, 7 }, // DAY_OF_WEEK
{/* */}, // DAY_OF_WEEK_IN_MONTH
{ 0, 0, 1, 1 }, // AM_PM
{ 0, 0, 11, 11 }, // HOUR
{ 0, 0, 23, 23 }, // HOUR_OF_DAY
{ 0, 0, 59, 59 }, // MINUTE
{ 0, 0, 59, 59 }, // SECOND
{ 0, 0, 999, 999 }, // MILLISECOND
{-12*ONE_HOUR, -12*ONE_HOUR, 12*ONE_HOUR, 12*ONE_HOUR }, // ZONE_OFFSET
{ 0, 0, 1*ONE_HOUR, 1*ONE_HOUR }, // DST_OFFSET
{/* */}, // YEAR_WOY
{ 1, 1, 7, 7 }, // DOW_LOCAL
{/* */}, // EXTENDED_YEAR
{ -0x7F000000, -0x7F000000, 0x7F000000, 0x7F000000 }, // JULIAN_DAY
{ 0, 0, 24*ONE_HOUR-1, 24*ONE_HOUR-1 }, // MILLISECONDS_IN_DAY
};
/**
* Subclass API for defining limits of different types.
* Subclasses must implement this method to return limits for the
* following fields:
*
* <pre>ERA
* YEAR
* MONTH
* WEEK_OF_YEAR
* WEEK_OF_MONTH
* DAY_OF_MONTH
* DAY_OF_YEAR
* DAY_OF_WEEK_IN_MONTH
* YEAR_WOY
* EXTENDED_YEAR</pre>
*
* @param field one of the above field numbers
* @param limitType one of <code>MINIMUM</code>, <code>GREATEST_MINIMUM</code>,
* <code>LEAST_MAXIMUM</code>, or <code>MAXIMUM</code>
* @stable ICU 2.0
*/
abstract protected int handleGetLimit(int field, int limitType);
/**
* Return a limit for a field.
* @param field the field, from 0..</code>getFieldCount()-1</code>
* @param limitType the type specifier for the limit
* @see #MINIMUM
* @see #GREATEST_MINIMUM
* @see #LEAST_MAXIMUM
* @see #MAXIMUM
* @stable ICU 2.0
*/
protected int getLimit(int field, int limitType) {
switch (field) {
case DAY_OF_WEEK:
case AM_PM:
case HOUR:
case HOUR_OF_DAY:
case MINUTE:
case SECOND:
case MILLISECOND:
case ZONE_OFFSET:
case DST_OFFSET:
case DOW_LOCAL:
case JULIAN_DAY:
case MILLISECONDS_IN_DAY:
return LIMITS[field][limitType];
case WEEK_OF_MONTH:
{
int limit;
if (limitType == MINIMUM) {
limit = getMinimalDaysInFirstWeek() == 1 ? 1 : 0;
} else if (limitType == GREATEST_MINIMUM){
limit = 1;
} else {
int minDaysInFirst = getMinimalDaysInFirstWeek();
int daysInMonth = handleGetLimit(DAY_OF_MONTH, limitType);
if (limitType == LEAST_MAXIMUM) {
limit = (daysInMonth + (7 - minDaysInFirst)) / 7;
} else { // limitType == MAXIMUM
limit = (daysInMonth + 6 + (7 - minDaysInFirst)) / 7;
}
}
return limit;
}
}
return handleGetLimit(field, limitType);
}
/**
* Limit type for <code>getLimit()</code> and <code>handleGetLimit()</code>
* indicating the minimum value that a field can take (least minimum).
* @see #getLimit
* @see #handleGetLimit
* @stable ICU 2.0
*/
protected static final int MINIMUM = 0;
/**
* Limit type for <code>getLimit()</code> and <code>handleGetLimit()</code>
* indicating the greatest minimum value that a field can take.
* @see #getLimit
* @see #handleGetLimit
* @stable ICU 2.0
*/
protected static final int GREATEST_MINIMUM = 1;
/**
* Limit type for <code>getLimit()</code> and <code>handleGetLimit()</code>
* indicating the least maximum value that a field can take.
* @see #getLimit
* @see #handleGetLimit
* @stable ICU 2.0
*/
protected static final int LEAST_MAXIMUM = 2;
/**
* Limit type for <code>getLimit()</code> and <code>handleGetLimit()</code>
* indicating the maximum value that a field can take (greatest maximum).
* @see #getLimit
* @see #handleGetLimit
* @stable ICU 2.0
*/
protected static final int MAXIMUM = 3;
/**
* 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.
* @stable ICU 2.0
*/
public final int getMinimum(int field) {
return getLimit(field, MINIMUM);
}
/**
* 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.
* @stable ICU 2.0
*/
public final int getMaximum(int field) {
return getLimit(field, MAXIMUM);
}
/**
* 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.
* @stable ICU 2.0
*/
public final int getGreatestMinimum(int field) {
return getLimit(field, GREATEST_MINIMUM);
}
/**
* 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.
* @stable ICU 2.0
*/
public final int getLeastMaximum(int field) {
return getLimit(field, LEAST_MAXIMUM);
}
//-------------------------------------------------------------------------
// Weekend support -- determining which days of the week are the weekend
// in a given locale
//-------------------------------------------------------------------------
/**
* Return whether the given day of the week is a weekday, a
* weekend day, or a day that transitions from one to the other,
* in this calendar system. If a transition occurs at midnight,
* then the days before and after the transition will have the
* type WEEKDAY or WEEKEND. If a transition occurs at a time
* other than midnight, then the day of the transition will have
* the type WEEKEND_ONSET or WEEKEND_CEASE. In this case, the
* method getWeekendTransition() will return the point of
* transition.
* @param dayOfWeek either SUNDAY, MONDAY, TUESDAY, WEDNESDAY,
* THURSDAY, FRIDAY, or SATURDAY
* @return either WEEKDAY, WEEKEND, WEEKEND_ONSET, or
* WEEKEND_CEASE
* @exception IllegalArgumentException if dayOfWeek is not
* between SUNDAY and SATURDAY, inclusive
* @see #WEEKDAY
* @see #WEEKEND
* @see #WEEKEND_ONSET
* @see #WEEKEND_CEASE
* @see #getWeekendTransition
* @see #isWeekend(Date)
* @see #isWeekend()
* @stable ICU 2.0
*/
public int getDayOfWeekType(int dayOfWeek) {
if (dayOfWeek < SUNDAY || dayOfWeek > SATURDAY) {
throw new IllegalArgumentException("Invalid day of week");
}
if (weekendOnset < weekendCease) {
if (dayOfWeek < weekendOnset || dayOfWeek > weekendCease) {
return WEEKDAY;
}
} else {
if (dayOfWeek > weekendCease && dayOfWeek < weekendOnset) {
return WEEKDAY;
}
}
if (dayOfWeek == weekendOnset) {
return (weekendOnsetMillis == 0) ? WEEKEND : WEEKEND_ONSET;
}
if (dayOfWeek == weekendCease) {
return (weekendCeaseMillis == 0) ? WEEKDAY : WEEKEND_CEASE;
}
return WEEKEND;
}
/**
* Return the time during the day at which the weekend begins or end in
* this calendar system. If getDayOfWeekType(dayOfWeek) ==
* WEEKEND_ONSET return the time at which the weekend begins. If
* getDayOfWeekType(dayOfWeek) == WEEKEND_CEASE return the time at
* which the weekend ends. If getDayOfWeekType(dayOfWeek) has some
* other value, then throw an exception.
* @param dayOfWeek either SUNDAY, MONDAY, TUESDAY, WEDNESDAY,
* THURSDAY, FRIDAY, or SATURDAY
* @return the milliseconds after midnight at which the
* weekend begins or ends
* @exception IllegalArgumentException if dayOfWeek is not
* WEEKEND_ONSET or WEEKEND_CEASE
* @see #getDayOfWeekType
* @see #isWeekend(Date)
* @see #isWeekend()
* @stable ICU 2.0
*/
public int getWeekendTransition(int dayOfWeek) {
if (dayOfWeek == weekendOnset) {
return weekendOnsetMillis;
} else if (dayOfWeek == weekendCease) {
return weekendCeaseMillis;
}
throw new IllegalArgumentException("Not weekend transition day");
}
/**
* Return true if the given date and time is in the weekend in
* this calendar system. Equivalent to calling setTime() followed
* by isWeekend(). Note: This method changes the time this
* calendar is set to.
* @param date the date and time
* @return true if the given date and time is part of the
* weekend
* @see #getDayOfWeekType
* @see #getWeekendTransition
* @see #isWeekend()
* @stable ICU 2.0
*/
public boolean isWeekend(Date date) {
setTime(date);
return isWeekend();
}
/**
* Return true if this Calendar's current date and time is in the
* weekend in this calendar system.
* @return true if the given date and time is part of the
* weekend
* @see #getDayOfWeekType
* @see #getWeekendTransition
* @see #isWeekend(Date)
* @stable ICU 2.0
*/
public boolean isWeekend() {
int dow = get(DAY_OF_WEEK);
int dowt = getDayOfWeekType(dow);
switch (dowt) {
case WEEKDAY:
return false;
case WEEKEND:
return true;
default: // That is, WEEKEND_ONSET or WEEKEND_CEASE
// Use internalGet() because the above call to get() populated
// all fields.
// [Note: There should be a better way to get millis in day.
// For ICU4J, submit request for a MILLIS_IN_DAY field
// and a DAY_NUMBER field (could be Julian day #). - aliu]
int millisInDay = internalGet(MILLISECOND) + 1000 * (internalGet(SECOND) +
60 * (internalGet(MINUTE) + 60 * internalGet(HOUR_OF_DAY)));
int transition = getWeekendTransition(dow);
return (dowt == WEEKEND_ONSET)
? (millisInDay >= transition)
: (millisInDay < transition);
}
// (We can never reach this point.)
}
//-------------------------------------------------------------------------
// End of weekend support
//-------------------------------------------------------------------------
/**
* Overrides Cloneable
* @stable ICU 2.0
*/
public Object clone()
{
try {
Calendar other = (Calendar) super.clone();
other.fields = new int[fields.length];
other.stamp = new int[fields.length];
System.arraycopy(this.fields, 0, other.fields, 0, fields.length);
System.arraycopy(this.stamp, 0, other.stamp, 0, fields.length);
other.zone = (TimeZone) zone.clone();
return other;
}
catch (CloneNotSupportedException e) {
// this shouldn't happen, since we are Cloneable
throw new IllegalStateException();
}
}
/**
* 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.
* @stable ICU 2.0
*/
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<fields.length; ++i) {
buffer.append(',').append(fieldName(i)).append('=');
buffer.append(isSet(i) ? String.valueOf(fields[i]) : "?");
}
buffer.append(']');
return buffer.toString();
}
// =======================privates===============================
/**
* Internal class that holds cached locale data.
*/
private static class WeekData {
public int firstDayOfWeek;
public int minimalDaysInFirstWeek;
public int weekendOnset;
public int weekendOnsetMillis;
public int weekendCease;
public int weekendCeaseMillis;
public ULocale actualLocale;
public WeekData(int fdow, int mdifw,
int weekendOnset, int weekendOnsetMillis,
int weekendCease, int weekendCeaseMillis,
ULocale actualLoc) {
this.firstDayOfWeek = fdow;
this.minimalDaysInFirstWeek = mdifw;
this.actualLocale = actualLoc;
this.weekendOnset = weekendOnset;
this.weekendOnsetMillis = weekendOnsetMillis;
this.weekendCease = weekendCease;
this.weekendCeaseMillis = weekendCeaseMillis;
}
}
/**
* Set this calendar to contain week and weekend data for the given
* locale.
* @param locale the locale
*/
private void setWeekData(ULocale locale)
{
/* try to get the Locale data from the cache */
WeekData data = (WeekData) cachedLocaleData.get(locale);
if (data == null) { /* cache miss */
CalendarData calData = new CalendarData(locale, getType());
int[] dateTimeElements = calData.get("DateTimeElements").getIntVector();
int[] weekend = calData.get("weekend").getIntVector();
data = new WeekData(dateTimeElements[0],dateTimeElements[1],
weekend[0],
weekend[1],
weekend[2],
weekend[3],
calData.getULocale());
/* cache update */
cachedLocaleData.put(locale, data);
}
setFirstDayOfWeek(data.firstDayOfWeek);
setMinimalDaysInFirstWeek(data.minimalDaysInFirstWeek);
weekendOnset = data.weekendOnset;
weekendOnsetMillis = data.weekendOnsetMillis;
weekendCease = data.weekendCease;
weekendCeaseMillis = data.weekendCeaseMillis;
// TODO: determine the actual/valid locale
ULocale uloc = data.actualLocale;
setLocale(uloc, uloc);
}
/**
* 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;
areFieldsVirtuallySet = false;
}
/**
* Save the state of this object to a stream (i.e., serialize it).
*/
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) {}
}
// Write out the 1.1 FCS object.
stream.defaultWriteObject();
}
/**
* Reconstitute this object from a stream (i.e., deserialize it).
*/
private void readObject(ObjectInputStream stream)
throws IOException, ClassNotFoundException {
stream.defaultReadObject();
initInternal();
isTimeSet = true;
areFieldsSet = areAllFieldsSet = false;
areFieldsVirtuallySet = true; // cause fields to be recalculated if requested.
nextStamp = MINIMUM_USER_STAMP;
}
//----------------------------------------------------------------------
// Time -> Fields
//----------------------------------------------------------------------
/**
* Converts the current millisecond time value <code>time</code> to
* field values in <code>fields[]</code>. This synchronizes 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
* @stable ICU 2.0
*/
protected void computeFields() {
int offsets[] = new int[2];
getTimeZone().getOffset(time, false, offsets);
long localMillis = time + offsets[0] + offsets[1];
// Mark fields as set. Do this before calling handleComputeFields().
int mask = internalSetMask;
for (int i=0; i<fields.length; ++i) {
if ((mask & 1) == 0) {
stamp[i] = INTERNALLY_SET;
} else {
stamp[i] = UNSET;
}
mask >>= 1;
}
// We used to check for and correct extreme millis values (near
// Long.MIN_VALUE or Long.MAX_VALUE) here. Such values would cause
// overflows from positive to negative (or vice versa) and had to
// be manually tweaked. We no longer need to do this because we
// have limited the range of supported dates to those that have a
// Julian day that fits into an int. This allows us to implement a
// JULIAN_DAY field and also removes some inelegant code. - Liu
// 11/6/00
long days = floorDivide(localMillis, ONE_DAY);
fields[JULIAN_DAY] = (int) days + EPOCH_JULIAN_DAY;
computeGregorianAndDOWFields(fields[JULIAN_DAY]);
// Call framework method to have subclass compute its fields.
// These must include, at a minimum, MONTH, DAY_OF_MONTH,
// EXTENDED_YEAR, YEAR, DAY_OF_YEAR. This method will call internalSet(),
// which will update stamp[].
handleComputeFields(fields[JULIAN_DAY]);
// Compute week-related fields, based on the subclass-computed
// fields computed by handleComputeFields().
computeWeekFields();
// Compute time-related fields. These are indepent of the date and
// of the subclass algorithm. They depend only on the local zone
// wall milliseconds in day.
int millisInDay = (int) (localMillis - (days * ONE_DAY));
fields[MILLISECONDS_IN_DAY] = millisInDay;
fields[MILLISECOND] = millisInDay % 1000;
millisInDay /= 1000;
fields[SECOND] = millisInDay % 60;
millisInDay /= 60;
fields[MINUTE] = millisInDay % 60;
millisInDay /= 60;
fields[HOUR_OF_DAY] = millisInDay;
fields[AM_PM] = millisInDay / 12; // Assume AM == 0
fields[HOUR] = millisInDay % 12;
fields[ZONE_OFFSET] = offsets[0];
fields[DST_OFFSET] = offsets[1];
}
/**
* Compute the Gregorian calendar year, month, and day of month from
* the given Julian day. These values are not stored in fields, but in
* member variables gregorianXxx. Also compute the DAY_OF_WEEK and
* DOW_LOCAL fields.
*/
private final void computeGregorianAndDOWFields(int julianDay) {
computeGregorianFields(julianDay);
// Compute day of week: JD 0 = Monday
int dow = fields[DAY_OF_WEEK] = julianDayToDayOfWeek(julianDay);
// Calculate 1-based localized day of week
int dowLocal = dow - getFirstDayOfWeek() + 1;
if (dowLocal < 1) {
dowLocal += 7;
}
fields[DOW_LOCAL] = dowLocal;
}
/**
* Compute the Gregorian calendar year, month, and day of month from the
* Julian day. These values are not stored in fields, but in member
* variables gregorianXxx. They are used for time zone computations and by
* subclasses that are Gregorian derivatives. Subclasses may call this
* method to perform a Gregorian calendar millis->fields computation.
* To perform a Gregorian calendar fields->millis computation, call
* computeGregorianMonthStart().
* @see #computeGregorianMonthStart
* @stable ICU 2.0
*/
protected final void computeGregorianFields(int julianDay) {
int year, month, dayOfMonth, dayOfYear;
// The Gregorian epoch day is zero for Monday January 1, year 1.
long gregorianEpochDay = julianDay - JAN_1_1_JULIAN_DAY;
// Here we convert from the day number to the multiple radix
// representation. We use 400-year, 100-year, and 4-year cycles.
// For example, the 4-year cycle has 4 years + 1 leap day; giving
// 1461 == 365*4 + 1 days.
int[] rem = new int[1];
int n400 = floorDivide(gregorianEpochDay, 146097, rem); // 400-year cycle length
int n100 = floorDivide(rem[0], 36524, rem); // 100-year cycle length
int n4 = floorDivide(rem[0], 1461, rem); // 4-year cycle length
int n1 = floorDivide(rem[0], 365, rem);
year = 400*n400 + 100*n100 + 4*n4 + n1;
dayOfYear = rem[0]; // zero-based day of year
if (n100 == 4 || n1 == 4) {
dayOfYear = 365; // Dec 31 at end of 4- or 400-yr cycle
} else {
++year;
}
boolean isLeap = ((year&0x3) == 0) && // equiv. to (year%4 == 0)
(year%100 != 0 || year%400 == 0);
int correction = 0;
int march1 = isLeap ? 60 : 59; // zero-based DOY for March 1
if (dayOfYear >= march1) correction = isLeap ? 1 : 2;
month = (12 * (dayOfYear + correction) + 6) / 367; // zero-based month
dayOfMonth = dayOfYear -
GREGORIAN_MONTH_COUNT[month][isLeap?3:2] + 1; // one-based DOM
gregorianYear = year;
gregorianMonth = month; // 0-based already
gregorianDayOfMonth = dayOfMonth; // 1-based already
gregorianDayOfYear = dayOfYear + 1; // Convert from 0-based to 1-based
}
/**
* Compute the fields WEEK_OF_YEAR, YEAR_WOY, WEEK_OF_MONTH,
* DAY_OF_WEEK_IN_MONTH, and DOW_LOCAL from EXTENDED_YEAR, YEAR,
* DAY_OF_WEEK, and DAY_OF_YEAR. The latter fields are computed by the
* subclass based on the calendar system.
*
* <p>The YEAR_WOY field is computed simplistically. It is equal to YEAR
* most of the time, but at the year boundary it may be adjusted to YEAR-1
* or YEAR+1 to reflect the overlap of a week into an adjacent year. In
* this case, a simple increment or decrement is performed on YEAR, even
* though this may yield an invalid YEAR value. For instance, if the YEAR
* is part of a calendar system with an N-year cycle field CYCLE, then
* incrementing the YEAR may involve incrementing CYCLE and setting YEAR
* back to 0 or 1. This is not handled by this code, and in fact cannot be
* simply handled without having subclasses define an entire parallel set of
* fields for fields larger than or equal to a year. This additional
* complexity is not warranted, since the intention of the YEAR_WOY field is
* to support ISO 8601 notation, so it will typically be used with a
* proleptic Gregorian calendar, which has no field larger than a year.
*/
private final void computeWeekFields() {
int eyear = fields[EXTENDED_YEAR];
int dayOfWeek = fields[DAY_OF_WEEK];
int dayOfYear = fields[DAY_OF_YEAR];
// WEEK_OF_YEAR start
// Compute the week of the year. For the Gregorian calendar, valid week
// numbers run from 1 to 52 or 53, depending on the year, the first day
// of the week, and the minimal days in the first week. For other
// calendars, the valid range may be different -- it depends on the year
// length. Days at the start of the year may fall into the last week of
// the previous year; days at the end of the year may fall into the
// first week of the next year. ASSUME that the year length is less than
// 7000 days.
int yearOfWeekOfYear = eyear;
int relDow = (dayOfWeek + 7 - getFirstDayOfWeek()) % 7; // 0..6
int relDowJan1 = (dayOfWeek - dayOfYear + 7001 - getFirstDayOfWeek()) % 7; // 0..6
int woy = (dayOfYear - 1 + relDowJan1) / 7; // 0..53
if ((7 - relDowJan1) >= getMinimalDaysInFirstWeek()) {
++woy;
}
// Adjust for weeks at the year end that overlap into the previous or
// next calendar year.
if (woy == 0) {
// We are the last week of the previous year.
// Check to see if we are in the last week; if so, we need
// to handle the case in which we are the first week of the
// next year.
int prevDoy = dayOfYear + handleGetYearLength(eyear - 1);
woy = weekNumber(prevDoy, dayOfWeek);
yearOfWeekOfYear--;
} else {
int lastDoy = handleGetYearLength(eyear);
// Fast check: For it to be week 1 of the next year, the DOY
// must be on or after L-5, where L is yearLength(), then it
// cannot possibly be week 1 of the next year:
// L-5 L
// doy: 359 360 361 362 363 364 365 001
// dow: 1 2 3 4 5 6 7
if (dayOfYear >= (lastDoy - 5)) {
int lastRelDow = (relDow + lastDoy - dayOfYear) % 7;
if (lastRelDow < 0) {
lastRelDow += 7;
}
if (((6 - lastRelDow) >= getMinimalDaysInFirstWeek()) &&
((dayOfYear + 7 - relDow) > lastDoy)) {
woy = 1;
yearOfWeekOfYear++;
}
}
}
fields[WEEK_OF_YEAR] = woy;
fields[YEAR_WOY] = yearOfWeekOfYear;
// WEEK_OF_YEAR end
int dayOfMonth = fields[DAY_OF_MONTH];
fields[WEEK_OF_MONTH] = weekNumber(dayOfMonth, dayOfWeek);
fields[DAY_OF_WEEK_IN_MONTH] = (dayOfMonth-1) / 7 + 1;
}
//----------------------------------------------------------------------
// Fields -> Time
//----------------------------------------------------------------------
/**
* Value to OR against resolve table field values for remapping.
* @see #resolveFields
* @stable ICU 2.0
*/
protected static final int RESOLVE_REMAP = 32;
// A power of 2 greater than or equal to MAX_FIELD_COUNT
// Default table for day in year
static final int[][][] DATE_PRECEDENCE = {
{
{ DAY_OF_MONTH },
{ WEEK_OF_YEAR, DAY_OF_WEEK },
{ WEEK_OF_MONTH, DAY_OF_WEEK },
{ DAY_OF_WEEK_IN_MONTH, DAY_OF_WEEK },
{ WEEK_OF_YEAR, DOW_LOCAL },
{ WEEK_OF_MONTH, DOW_LOCAL },
{ DAY_OF_WEEK_IN_MONTH, DOW_LOCAL },
{ DAY_OF_YEAR },
},
{
{ WEEK_OF_YEAR },
{ WEEK_OF_MONTH },
{ DAY_OF_WEEK_IN_MONTH },
{ RESOLVE_REMAP | DAY_OF_WEEK_IN_MONTH, DAY_OF_WEEK },
{ RESOLVE_REMAP | DAY_OF_WEEK_IN_MONTH, DOW_LOCAL },
},
};
static final int[][][] DOW_PRECEDENCE = {
{
{ DAY_OF_WEEK },
{ DOW_LOCAL },
},
};
/**
* Given a precedence table, return the newest field combination in
* the table, or -1 if none is found.
*
* <p>The precedence table is a 3-dimensional array of integers. It
* may be thought of as an array of groups. Each group is an array of
* lines. Each line is an array of field numbers. Within a line, if
* all fields are set, then the time stamp of the line is taken to be
* the stamp of the most recently set field. If any field of a line is
* unset, then the line fails to match. Within a group, the line with
* the newest time stamp is selected. The first field of the line is
* returned to indicate which line matched.
*
* <p>In some cases, it may be desirable to map a line to field that
* whose stamp is NOT examined. For example, if the best field is
* DAY_OF_WEEK then the DAY_OF_WEEK_IN_MONTH algorithm may be used. In
* order to do this, insert the value <code>REMAP_RESOLVE | F</code> at
* the start of the line, where <code>F</code> is the desired return
* field value. This field will NOT be examined; it only determines
* the return value if the other fields in the line are the newest.
*
* <p>If all lines of a group contain at least one unset field, then no
* line will match, and the group as a whole will fail to match. In
* that case, the next group will be processed. If all groups fail to
* match, then -1 is returned.
* @stable ICU 2.0
*/
protected int resolveFields(int[][][] precedenceTable) {
int bestField = -1;
for (int g=0; g<precedenceTable.length && bestField < 0; ++g) {
int[][] group = precedenceTable[g];
int bestStamp = UNSET;
linesInGroup:
for (int l=0; l<group.length; ++l) {
int[] line= group[l];
int lineStamp = UNSET;
// Skip over first entry if it is negative
for (int i=(line[0]>=RESOLVE_REMAP)?1:0; i<line.length; ++i) {
int s = stamp[line[i]];
// If any field is unset then don't use this line
if (s == UNSET) {
continue linesInGroup;
} else {
lineStamp = Math.max(lineStamp, s);
}
}
// Record new maximum stamp & field no.
if (lineStamp > bestStamp) {
bestStamp = lineStamp;
bestField = line[0]; // First field refers to entire line
}
}
}
return (bestField>=RESOLVE_REMAP)?(bestField&(RESOLVE_REMAP-1)):bestField;
}
/**
* Return the newest stamp of a given range of fields.
* @stable ICU 2.0
*/
protected int newestStamp(int first, int last, int bestStampSoFar) {
int bestStamp = bestStampSoFar;
for (int i=first; i<=last; ++i) {
if (stamp[i] > bestStamp) {
bestStamp = stamp[i];
}
}
return bestStamp;
}
/**
* Return the timestamp of a field.
* @stable ICU 2.0
*/
protected final int getStamp(int field) {
return stamp[field];
}
/**
* Return the field that is newer, either defaultField, or
* alternateField. If neither is newer or neither is set, return defaultField.
* @stable ICU 2.0
*/
protected int newerField(int defaultField, int alternateField) {
if (stamp[alternateField] > stamp[defaultField]) {
return alternateField;
}
return defaultField;
}
/**
* Ensure that each field is within its valid range by calling {@link
* #validateField(int)} on each field that has been set. This method
* should only be called if this calendar is not lenient.
* @see #isLenient
* @see #validateField(int)
* @stable ICU 2.0
*/
protected void validateFields() {
for (int field = 0; field < fields.length; field++) {
if (isSet(field)) {
validateField(field);
}
}
}
/**
* Validate a single field of this calendar. Subclasses should
* override this method to validate any calendar-specific fields.
* Generic fields can be handled by
* <code>Calendar.validateField()</code>.
* @see #validateField(int, int, int)
* @stable ICU 2.0
*/
protected void validateField(int field) {
int y;
switch (field) {
case DAY_OF_MONTH:
y = handleGetExtendedYear();
validateField(field, 1, handleGetMonthLength(y, internalGet(MONTH)));
break;
case DAY_OF_YEAR:
y = handleGetExtendedYear();
validateField(field, 1, handleGetYearLength(y));
break;
case DAY_OF_WEEK_IN_MONTH:
if (internalGet(field) == 0) {
throw new IllegalArgumentException("DAY_OF_WEEK_IN_MONTH cannot be zero");
}
validateField(field, getMinimum(field), getMaximum(field));
break;
default:
validateField(field, getMinimum(field), getMaximum(field));
break;
}
}
/**
* Validate a single field of this calendar given its minimum and
* maximum allowed value. If the field is out of range, throw a
* descriptive <code>IllegalArgumentException</code>. Subclasses may
* use this method in their implementation of {@link
* #validateField(int)}.
* @stable ICU 2.0
*/
protected final void validateField(int field, int min, int max) {
int value = fields[field];
if (value < min || value > max) {
throw new IllegalArgumentException(fieldName(field) +
'=' + value + ", valid range=" +
min + ".." + max);
}
}
/**
* Converts the current field values in <code>fields[]</code> to the
* millisecond time value <code>time</code>.
* @stable ICU 2.0
*/
protected void computeTime() {
if (!isLenient()) {
validateFields();
}
// Compute the Julian day
int julianDay = computeJulianDay();
long millis = julianDayToMillis(julianDay);
int millisInDay;
// We only use MILLISECONDS_IN_DAY if it has been set by the user.
// This makes it possible for the caller to set the calendar to a
// time and call clear(MONTH) to reset the MONTH to January. This
// is legacy behavior. Without this, clear(MONTH) has no effect,
// since the internally set JULIAN_DAY is used.
if (stamp[MILLISECONDS_IN_DAY] >= MINIMUM_USER_STAMP &&
newestStamp(AM_PM, MILLISECOND, UNSET) <= stamp[MILLISECONDS_IN_DAY]) {
millisInDay = internalGet(MILLISECONDS_IN_DAY);
} else {
millisInDay = computeMillisInDay();
}
// Compute the time zone offset and DST offset. There are two potential
// ambiguities here. We'll assume a 2:00 am (wall time) switchover time
// for discussion purposes here.
// 1. The transition into DST. Here, a designated time of 2:00 am - 2:59 am
// can be in standard or in DST depending. However, 2:00 am is an invalid
// representation (the representation jumps from 1:59:59 am Std to 3:00:00 am DST).
// We assume standard time, that is, 2:30 am is interpreted as 3:30 am DST.
// 2. The transition out of DST. Here, a designated time of 1:00 am - 1:59 am
// can be in standard or DST. Both are valid representations (the rep
// jumps from 1:59:59 DST to 1:00:00 Std).
// Again, we assume standard time, that is, 1:30 am is interpreted as 1:30 am Std.
// We use the TimeZone object, unless the user has explicitly set the ZONE_OFFSET
// or DST_OFFSET fields; then we use those fields.
if (stamp[ZONE_OFFSET] >= MINIMUM_USER_STAMP ||
stamp[DST_OFFSET] >= MINIMUM_USER_STAMP) {
millisInDay -= internalGet(ZONE_OFFSET) + internalGet(DST_OFFSET);
} else {
millisInDay -= computeZoneOffset(millis, millisInDay);
}
time = millis + millisInDay;
}
/**
* Compute the milliseconds in the day from the fields. This is a
* value from 0 to 23:59:59.999 inclusive, unless fields are out of
* range, in which case it can be an arbitrary value. This value
* reflects local zone wall time.
* @stable ICU 2.0
*/
protected int computeMillisInDay() {
// Do the time portion of the conversion.
int millisInDay = 0;
// Find the best set of fields specifying the time of day. There
// are only two possibilities here; the HOUR_OF_DAY or the
// AM_PM and the HOUR.
int hourOfDayStamp = stamp[HOUR_OF_DAY];
int hourStamp = Math.max(stamp[HOUR], stamp[AM_PM]);
int bestStamp = (hourStamp > hourOfDayStamp) ? hourStamp : hourOfDayStamp;
// Hours
if (bestStamp != UNSET) {
if (bestStamp == hourOfDayStamp) {
// Don't normalize here; let overflow bump into the next period.
// This is consistent with how we handle other fields.
millisInDay += internalGet(HOUR_OF_DAY);
} else {
// Don't normalize here; let overflow bump into the next period.
// This is consistent with how we handle other fields.
millisInDay += internalGet(HOUR);
millisInDay += 12 * internalGet(AM_PM); // Default works for unset AM_PM
}
}
// We use the fact that unset == 0; we start with millisInDay
// == HOUR_OF_DAY.
millisInDay *= 60;
millisInDay += internalGet(MINUTE); // now have minutes
millisInDay *= 60;
millisInDay += internalGet(SECOND); // now have seconds
millisInDay *= 1000;
millisInDay += internalGet(MILLISECOND); // now have millis
return millisInDay;
}
/**
* This method can assume EXTENDED_YEAR has been set.
* @param millis milliseconds of the date fields (local midnight millis)
* @param millisInDay milliseconds of the time fields; may be out
* or range.
* @return total zone offset (raw + DST) for the given moment
* @stable ICU 2.0
*/
protected int computeZoneOffset(long millis, int millisInDay) {
int offsets[] = new int[2];
zone.getOffset(millis + millisInDay, true, offsets);
return offsets[0] + offsets[1];
// Note: Because we pass in wall millisInDay, rather than
// standard millisInDay, we interpret "1:00 am" on the day
// of cessation of DST as "1:00 am Std" (assuming the time
// of cessation is 2:00 am).
}
/**
* Compute the Julian day number as specified by this calendar's fields.
* @stable ICU 2.0
*/
protected int computeJulianDay() {
// We want to see if any of the date fields is newer than the
// JULIAN_DAY. If not, then we use JULIAN_DAY. If so, then we do
// the normal resolution. We only use JULIAN_DAY if it has been
// set by the user. This makes it possible for the caller to set
// the calendar to a time and call clear(MONTH) to reset the MONTH
// to January. This is legacy behavior. Without this,
// clear(MONTH) has no effect, since the internally set JULIAN_DAY
// is used.
if (stamp[JULIAN_DAY] >= MINIMUM_USER_STAMP) {
int bestStamp = newestStamp(ERA, DAY_OF_WEEK_IN_MONTH, UNSET);
bestStamp = newestStamp(YEAR_WOY, EXTENDED_YEAR, bestStamp);
if (bestStamp <= stamp[JULIAN_DAY]) {
return internalGet(JULIAN_DAY);
}
}
int bestField = resolveFields(getFieldResolutionTable());
if (bestField < 0) {
bestField = DAY_OF_MONTH;
}
return handleComputeJulianDay(bestField);
}
/**
* Return the field resolution array for this calendar. Calendars that
* define additional fields or change the semantics of existing fields
* should override this method to adjust the field resolution semantics
* accordingly. Other subclasses should not override this method.
* @see #resolveFields
* @stable ICU 2.0
*/
protected int[][][] getFieldResolutionTable() {
return DATE_PRECEDENCE;
}
/**
* Return the Julian day number of day before the first day of the
* given month in the given extended year. Subclasses should override
* this method to implement their calendar system.
* @param eyear the extended year
* @param month the zero-based month, or 0 if useMonth is false
* @param useMonth if false, compute the day before the first day of
* the given year, otherwise, compute the day before the first day of
* the given month
* @return the Julian day number of the day before the first
* day of the given month and year
* @stable ICU 2.0
*/
abstract protected int handleComputeMonthStart(int eyear, int month,
boolean useMonth);
/**
* Return the extended year defined by the current fields. This will
* use the EXTENDED_YEAR field or the YEAR and supra-year fields (such
* as ERA) specific to the calendar system, depending on which set of
* fields is newer.
* @return the extended year
* @stable ICU 2.0
*/
abstract protected int handleGetExtendedYear();
// (The following method is not called because all existing subclasses
// override it. 2003-06-11 ICU 2.6 Alan)
///CLOVER:OFF
/**
* Return the number of days in the given month of the given extended
* year of this calendar system. Subclasses should override this
* method if they can provide a more correct or more efficient
* implementation than the default implementation in Calendar.
* @stable ICU 2.0
*/
protected int handleGetMonthLength(int extendedYear, int month) {
return handleComputeMonthStart(extendedYear, month+1, true) -
handleComputeMonthStart(extendedYear, month, true);
}
///CLOVER:ON
/**
* Return the number of days in the given extended year of this
* calendar system. Subclasses should override this method if they can
* provide a more correct or more efficient implementation than the
* default implementation in Calendar.
* @stable ICU 2.0
*/
protected int handleGetYearLength(int eyear) {
return handleComputeMonthStart(eyear+1, 0, false) -
handleComputeMonthStart(eyear, 0, false);
}
/**
* Subclasses that use additional fields beyond those defined in
* <code>Calendar</code> should override this method to return an
* <code>int[]</code> array of the appropriate length. The length
* must be at least <code>BASE_FIELD_COUNT</code> and no more than
* <code>MAX_FIELD_COUNT</code>.
* @stable ICU 2.0
*/
protected int[] handleCreateFields() {
return new int[BASE_FIELD_COUNT];
}
/**
* Subclasses may override this.
* Called by handleComputeJulianDay. Returns the default month (0-based) for the year,
* taking year and era into account. Defaults to 0 (JANUARY) for Gregorian.
* @param extendedYear the extendedYear, as returned by handleGetExtendedYear
* @return the default month
* @draft ICU 3.6 (retain)
* @provisional This API might change or be removed in a future release.
* @see #MONTH
*/
protected int getDefaultMonthInYear(int extendedYear) {
return Calendar.JANUARY;
}
/**
* Subclasses may override this.
* Called by handleComputeJulianDay. Returns the default day (1-based) for the month,
* taking currently-set year and era into account. Defaults to 1 for Gregorian.
* @param extendedYear the extendedYear, as returned by handleGetExtendedYear
* @param month the month, as returned by getDefaultMonthInYear
* @return the default day of the month
* @draft ICU 3.6 (retain)
* @provisional This API might change or be removed in a future release.
* @see #DAY_OF_MONTH
*/
protected int getDefaultDayInMonth(int extendedYear, int month) {
return 1;
}
/**
* Subclasses may override this. This method calls
* handleGetMonthLength() to obtain the calendar-specific month
* length.
* @stable ICU 2.0
*/
protected int handleComputeJulianDay(int bestField) {
boolean useMonth = (bestField == DAY_OF_MONTH ||
bestField == WEEK_OF_MONTH ||
bestField == DAY_OF_WEEK_IN_MONTH);
int year;
if (bestField == WEEK_OF_YEAR) {
// Nota Bene! It is critical that YEAR_WOY be used as the year here, if it is set.
// Otherwise, when WOY is the best field, the year may be wrong at the extreme limits of the year.
// If YEAR_WOY is not set then it will fall back.
// TODO: Should resolveField(YEAR_PRECEDENCE) be brought to bear?
year = internalGet(YEAR_WOY, handleGetExtendedYear());
} else {
year = handleGetExtendedYear();
}
internalSet(EXTENDED_YEAR, year);
int month = useMonth ? internalGet(MONTH, getDefaultMonthInYear(year)) : 0;
// Get the Julian day of the day BEFORE the start of this year.
// If useMonth is true, get the day before the start of the month.
int julianDay = handleComputeMonthStart(year, month, useMonth);
if (bestField == DAY_OF_MONTH) {
if(isSet(DAY_OF_MONTH)) {
return julianDay + internalGet(DAY_OF_MONTH, getDefaultDayInMonth(year, month));
} else {
return julianDay + getDefaultDayInMonth(year, month);
}
}
if (bestField == DAY_OF_YEAR) {
return julianDay + internalGet(DAY_OF_YEAR);
}
int firstDOW = getFirstDayOfWeek(); // Localized fdw
// At this point julianDay is the 0-based day BEFORE the first day of
// January 1, year 1 of the given calendar. If julianDay == 0, it
// specifies (Jan. 1, 1) - 1, in whatever calendar we are using (Julian
// or Gregorian).
// At this point we need to process the WEEK_OF_MONTH or
// WEEK_OF_YEAR, which are similar, or the DAY_OF_WEEK_IN_MONTH.
// First, perform initial shared computations. These locate the
// first week of the period.
// Get the 0-based localized DOW of day one of the month or year.
// Valid range 0..6.
int first = julianDayToDayOfWeek(julianDay + 1) - firstDOW;
if (first < 0) {
first += 7;
}
// Get zero-based localized DOW, valid range 0..6. This is the DOW
// we are looking for.
int dowLocal = 0;
switch (resolveFields(DOW_PRECEDENCE)) {
case DAY_OF_WEEK:
dowLocal = internalGet(DAY_OF_WEEK) - firstDOW;
break;
case DOW_LOCAL:
dowLocal = internalGet(DOW_LOCAL) - 1;
break;
}
dowLocal = dowLocal % 7;
if (dowLocal < 0) {
dowLocal += 7;
}
// Find the first target DOW (dowLocal) in the month or year.
// Actually, it may be just before the first of the month or year.
// It will be an integer from -5..7.
int date = 1 - first + dowLocal;
if (bestField == DAY_OF_WEEK_IN_MONTH) {
// Adjust the target DOW to be in the month or year.
if (date < 1) {
date += 7;
}
// The only trickiness occurs if the day-of-week-in-month is
// negative.
int dim = internalGet(DAY_OF_WEEK_IN_MONTH, 1);
if (dim >= 0) {
date += 7*(dim - 1);
} else {
// Move date to the last of this day-of-week in this month,
// then back up as needed. If dim==-1, we don't back up at
// all. If dim==-2, we back up once, etc. Don't back up
// past the first of the given day-of-week in this month.
// Note that we handle -2, -3, etc. correctly, even though
// values < -1 are technically disallowed.
int m = internalGet(MONTH, JANUARY);
int monthLength = handleGetMonthLength(year, m);
date += ((monthLength - date) / 7 + dim + 1) * 7;
}
} else {
// assert(bestField == WEEK_OF_MONTH || bestField == WEEK_OF_YEAR)
// Adjust for minimal days in first week
if ((7 - first) < getMinimalDaysInFirstWeek()) {
date += 7;
}
// Now adjust for the week number.
date += 7 * (internalGet(bestField) - 1);
}
return julianDay + date;
}
/**
* Compute the Julian day of a month of the Gregorian calendar.
* Subclasses may call this method to perform a Gregorian calendar
* fields->millis computation. To perform a Gregorian calendar
* millis->fields computation, call computeGregorianFields().
* @param year extended Gregorian year
* @param month zero-based Gregorian month
* @return the Julian day number of the day before the first
* day of the given month in the given extended year
* @see #computeGregorianFields
* @stable ICU 2.0
*/
protected int computeGregorianMonthStart(int year, int month) {
// If the month is out of range, adjust it into range, and
// modify the extended year value accordingly.
if (month < 0 || month > 11) {
int[] rem = new int[1];
year += floorDivide(month, 12, rem);
month = rem[0];
}
boolean isLeap = (year%4 == 0) && ((year%100 != 0) || (year%400 == 0));
int y = year - 1;
// This computation is actually ... + (JAN_1_1_JULIAN_DAY - 3) + 2.
// Add 2 because Gregorian calendar starts 2 days after Julian
// calendar.
int julianDay = 365*y + floorDivide(y, 4) - floorDivide(y, 100) +
floorDivide(y, 400) + JAN_1_1_JULIAN_DAY - 1;
// At this point julianDay indicates the day BEFORE the first day
// of January 1, <eyear> of the Gregorian calendar.
if (month != 0) {
julianDay += GREGORIAN_MONTH_COUNT[month][isLeap?3:2];
}
return julianDay;
}
//----------------------------------------------------------------------
// Subclass API
// For subclasses to override
//----------------------------------------------------------------------
// (The following method is not called because all existing subclasses
// override it. 2003-06-11 ICU 2.6 Alan)
///CLOVER:OFF
/**
* Subclasses may override this method to compute several fields
* specific to each calendar system. These are:
*
* <ul><li>ERA
* <li>YEAR
* <li>MONTH
* <li>DAY_OF_MONTH
* <li>DAY_OF_YEAR
* <li>EXTENDED_YEAR</ul>
*
* Subclasses can refer to the DAY_OF_WEEK and DOW_LOCAL fields, which
* will be set when this method is called. Subclasses can also call
* the getGregorianXxx() methods to obtain Gregorian calendar
* equivalents for the given Julian day.
*
* <p>In addition, subclasses should compute any subclass-specific
* fields, that is, fields from BASE_FIELD_COUNT to
* getFieldCount() - 1.
*
* <p>The default implementation in <code>Calendar</code> implements
* a pure proleptic Gregorian calendar.
* @stable ICU 2.0
*/
protected void handleComputeFields(int julianDay) {
internalSet(MONTH, getGregorianMonth());
internalSet(DAY_OF_MONTH, getGregorianDayOfMonth());
internalSet(DAY_OF_YEAR, getGregorianDayOfYear());
int eyear = getGregorianYear();
internalSet(EXTENDED_YEAR, eyear);
int era = GregorianCalendar.AD;
if (eyear < 1) {
era = GregorianCalendar.BC;
eyear = 1 - eyear;
}
internalSet(ERA, era);
internalSet(YEAR, eyear);
}
///CLOVER:ON
//----------------------------------------------------------------------
// Subclass API
// For subclasses to call
//----------------------------------------------------------------------
/**
* Return the extended year on the Gregorian calendar as computed by
* <code>computeGregorianFields()</code>.
* @see #computeGregorianFields
* @stable ICU 2.0
*/
protected final int getGregorianYear() {
return gregorianYear;
}
/**
* Return the month (0-based) on the Gregorian calendar as computed by
* <code>computeGregorianFields()</code>.
* @see #computeGregorianFields
* @stable ICU 2.0
*/
protected final int getGregorianMonth() {
return gregorianMonth;
}
/**
* Return the day of year (1-based) on the Gregorian calendar as
* computed by <code>computeGregorianFields()</code>.
* @see #computeGregorianFields
* @stable ICU 2.0
*/
protected final int getGregorianDayOfYear() {
return gregorianDayOfYear;
}
/**
* Return the day of month (1-based) on the Gregorian calendar as
* computed by <code>computeGregorianFields()</code>.
* @see #computeGregorianFields
* @stable ICU 2.0
*/
protected final int getGregorianDayOfMonth() {
return gregorianDayOfMonth;
}
/**
* Return the number of fields defined by this calendar. Valid field
* arguments to <code>set()</code> and <code>get()</code> are
* <code>0..getFieldCount()-1</code>.
* @stable ICU 2.0
*/
public final int getFieldCount() {
return fields.length;
}
/**
* Set a field to a value. Subclasses should use this method when
* computing fields. It sets the time stamp in the
* <code>stamp[]</code> array to <code>INTERNALLY_SET</code>. If a
* field that may not be set by subclasses is passed in, an
* <code>IllegalArgumentException</code> is thrown. This prevents
* subclasses from modifying fields that are intended to be
* calendar-system invariant.
* @stable ICU 2.0
*/
protected final void internalSet(int field, int value) {
if (((1 << field) & internalSetMask) == 0) {
throw new IllegalStateException("Subclass cannot set " +
fieldName(field));
}
fields[field] = value;
stamp[field] = INTERNALLY_SET;
}
private static final int[][] GREGORIAN_MONTH_COUNT = {
//len len2 st st2
{ 31, 31, 0, 0 }, // Jan
{ 28, 29, 31, 31 }, // Feb
{ 31, 31, 59, 60 }, // Mar
{ 30, 30, 90, 91 }, // Apr
{ 31, 31, 120, 121 }, // May
{ 30, 30, 151, 152 }, // Jun
{ 31, 31, 181, 182 }, // Jul
{ 31, 31, 212, 213 }, // Aug
{ 30, 30, 243, 244 }, // Sep
{ 31, 31, 273, 274 }, // Oct
{ 30, 30, 304, 305 }, // Nov
{ 31, 31, 334, 335 } // Dec
// len length of month
// len2 length of month in a leap year
// st days in year before start of month
// st2 days in year before month in leap year
};
/**
* Determines if the given year is a leap year. Returns true if the
* given year is a leap year.
* @param year the given year.
* @return true if the given year is a leap year; false otherwise.
* @stable ICU 2.0
*/
protected static final boolean isGregorianLeapYear(int year) {
return (year%4 == 0) && ((year%100 != 0) || (year%400 == 0));
}
/**
* Return the length of a month of the Gregorian calendar.
* @param y the extended year
* @param m the 0-based month number
* @return the number of days in the given month
* @stable ICU 2.0
*/
protected static final int gregorianMonthLength(int y, int m) {
return GREGORIAN_MONTH_COUNT[m][isGregorianLeapYear(y)?1:0];
}
/**
* Return the length of a previous month of the Gregorian calendar.
* @param y the extended year
* @param m the 0-based month number
* @return the number of days in the month previous to the given month
* @stable ICU 2.0
*/
protected static final int gregorianPreviousMonthLength(int y, int m) {
return (m > 0) ? gregorianMonthLength(y, m-1) : 31;
}
/**
* Divide two long integers, returning the floor of the quotient.
* <p>
* Unlike the built-in division, this is mathematically well-behaved.
* E.g., <code>-1/4</code> => 0
* but <code>floorDivide(-1,4)</code> => -1.
* @param numerator the numerator
* @param denominator a divisor which must be > 0
* @return the floor of the quotient.
* @stable ICU 2.0
*/
protected static final long floorDivide(long numerator, long denominator) {
// We do this computation in order to handle
// a numerator of Long.MIN_VALUE correctly
return (numerator >= 0) ?
numerator / denominator :
((numerator + 1) / denominator) - 1;
}
/**
* Divide two integers, returning the floor of the quotient.
* <p>
* Unlike the built-in division, this is mathematically well-behaved.
* E.g., <code>-1/4</code> => 0
* but <code>floorDivide(-1,4)</code> => -1.
* @param numerator the numerator
* @param denominator a divisor which must be > 0
* @return the floor of the quotient.
* @stable ICU 2.0
*/
protected static final int floorDivide(int numerator, int denominator) {
// We do this computation in order to handle
// a numerator of Integer.MIN_VALUE correctly
return (numerator >= 0) ?
numerator / denominator :
((numerator + 1) / denominator) - 1;
}
/**
* Divide two integers, returning the floor of the quotient, and
* the modulus remainder.
* <p>
* Unlike the built-in division, this is mathematically well-behaved.
* E.g., <code>-1/4</code> => 0 and <code>-1%4</code> => -1,
* but <code>floorDivide(-1,4)</code> => -1 with <code>remainder[0]</code> => 3.
* @param numerator the numerator
* @param denominator a divisor which must be > 0
* @param remainder an array of at least one element in which the value
* <code>numerator mod denominator</code> is returned. Unlike <code>numerator
* % denominator</code>, this will always be non-negative.
* @return the floor of the quotient.
* @stable ICU 2.0
*/
protected static final int floorDivide(int numerator, int denominator, int[] remainder) {
if (numerator >= 0) {
remainder[0] = numerator % denominator;
return numerator / denominator;
}
int quotient = ((numerator + 1) / denominator) - 1;
remainder[0] = numerator - (quotient * denominator);
return quotient;
}
/**
* Divide two integers, returning the floor of the quotient, and
* the modulus remainder.
* <p>
* Unlike the built-in division, this is mathematically well-behaved.
* E.g., <code>-1/4</code> => 0 and <code>-1%4</code> => -1,
* but <code>floorDivide(-1,4)</code> => -1 with <code>remainder[0]</code> => 3.
* @param numerator the numerator
* @param denominator a divisor which must be > 0
* @param remainder an array of at least one element in which the value
* <code>numerator mod denominator</code> is returned. Unlike <code>numerator
* % denominator</code>, this will always be non-negative.
* @return the floor of the quotient.
* @stable ICU 2.0
*/
protected static final int floorDivide(long numerator, int denominator, int[] remainder) {
if (numerator >= 0) {
remainder[0] = (int)(numerator % denominator);
return (int)(numerator / denominator);
}
int quotient = (int)(((numerator + 1) / denominator) - 1);
remainder[0] = (int)(numerator - (quotient * denominator));
return quotient;
}
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", "YEAR_WOY", "DOW_LOCAL", "EXTENDED_YEAR",
"JULIAN_DAY", "MILLISECONDS_IN_DAY",
};
/**
* Return a string name for a field, for debugging and exceptions.
* @stable ICU 2.0
*/
protected String fieldName(int field) {
try {
return FIELD_NAME[field];
} catch (ArrayIndexOutOfBoundsException e) {
return "Field " + field;
}
}
/**
* Converts time as milliseconds to Julian day.
* @param millis the given milliseconds.
* @return the Julian day number.
* @stable ICU 2.0
*/
protected static final int millisToJulianDay(long millis) {
return (int) (EPOCH_JULIAN_DAY + floorDivide(millis, ONE_DAY));
}
/**
* Converts Julian day to time as milliseconds.
* @param julian the given Julian day number.
* @return time as milliseconds.
* @stable ICU 2.0
*/
protected static final long julianDayToMillis(int julian) {
return (julian - EPOCH_JULIAN_DAY) * ONE_DAY;
}
/**
* Return the day of week, from SUNDAY to SATURDAY, given a Julian day.
* @stable ICU 2.0
*/
protected static final int julianDayToDayOfWeek(int julian) {
// If julian is negative, then julian%7 will be negative, so we adjust
// accordingly. Julian day 0 is Monday.
int dayOfWeek = (julian + MONDAY) % 7;
if (dayOfWeek < SUNDAY) {
dayOfWeek += 7;
}
return dayOfWeek;
}
/**
* Return the current milliseconds without recomputing.
* @stable ICU 2.0
*/
protected final long internalGetTimeInMillis() {
return time;
}
/**
* Return the current Calendar type.
* Note, in 3.0 this function will return 'gregorian' in Calendar to emulate legacy behavior
* @return type of calendar (gregorian, etc)
* @stable ICU 3.8
*/
public String getType() {
return "gregorian";
}
// -------- BEGIN ULocale boilerplate --------
/**
* Return the locale that was used to create this object, or null.
* This may may differ from the locale requested at the time of
* this object's creation. For example, if an object is created
* for locale <tt>en_US_CALIFORNIA</tt>, the actual data may be
* drawn from <tt>en</tt> (the <i>actual</i> locale), and
* <tt>en_US</tt> may be the most specific locale that exists (the
* <i>valid</i> locale).
*
* <p>Note: This method will be implemented in ICU 3.0; ICU 2.8
* contains a partial preview implementation. The * <i>actual</i>
* locale is returned correctly, but the <i>valid</i> locale is
* not, in most cases.
* @param type type of information requested, either {@link
* com.ibm.icu.util.ULocale#VALID_LOCALE} or {@link
* com.ibm.icu.util.ULocale#ACTUAL_LOCALE}.
* @return the information specified by <i>type</i>, or null if
* this object was not constructed from locale data.
* @see com.ibm.icu.util.ULocale
* @see com.ibm.icu.util.ULocale#VALID_LOCALE
* @see com.ibm.icu.util.ULocale#ACTUAL_LOCALE
* @draft ICU 2.8 (retain)
* @provisional This API might change or be removed in a future release.
*/
public final ULocale getLocale(ULocale.Type type) {
return type == ULocale.ACTUAL_LOCALE ?
this.actualLocale : this.validLocale;
}
/**
* Set information about the locales that were used to create this
* object. If the object was not constructed from locale data,
* both arguments should be set to null. Otherwise, neither
* should be null. The actual locale must be at the same level or
* less specific than the valid locale. This method is intended
* for use by factories or other entities that create objects of
* this class.
* @param valid the most specific locale containing any resource
* data, or null
* @param actual the locale containing data used to construct this
* object, or null
* @see com.ibm.icu.util.ULocale
* @see com.ibm.icu.util.ULocale#VALID_LOCALE
* @see com.ibm.icu.util.ULocale#ACTUAL_LOCALE
* @internal
*/
final void setLocale(ULocale valid, ULocale actual) {
// Change the following to an assertion later
if ((valid == null) != (actual == null)) {
///CLOVER:OFF
throw new IllegalArgumentException();
///CLOVER:ON
}
// Another check we could do is that the actual locale is at
// the same level or less specific than the valid locale.
this.validLocale = valid;
this.actualLocale = actual;
}
/**
* The most specific locale containing any resource data, or null.
* @see com.ibm.icu.util.ULocale
* @internal
*/
private ULocale validLocale;
/**
* The locale containing data used to construct this object, or
* null.
* @see com.ibm.icu.util.ULocale
* @internal
*/
private ULocale actualLocale;
// -------- END ULocale boilerplate --------
}