Quelle Calendar.java Sprache: JAVA

/*
* Copyright (c) 1996, 2022, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/

/*
* (C) Copyright Taligent, Inc. 1996-1998 - All Rights Reserved
* (C) Copyright IBM Corp. 1996-1998 - All Rights Reserved
*
* The original version of this source code and documentation is copyrighted
* and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
* materials are provided under terms of a License Agreement between Taligent
* and Sun. This technology is protected by multiple US and International
* patents. This notice and attribution to Taligent may not be removed.
* Taligent is a registered trademark of Taligent, Inc.
*
*/

package java.util;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OptionalDataException;
import java.io.Serializable;
import java.security.AccessControlContext;
import java.security.AccessController;
import java.security.PermissionCollection;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.security.ProtectionDomain;
import java.text.DateFormat;
import java.text.DateFormatSymbols;
import java.time.Instant;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import sun.util.BuddhistCalendar;
import sun.util.calendar.ZoneInfo;
import sun.util.locale.provider.CalendarDataUtility;
import sun.util.locale.provider.LocaleProviderAdapter;
import sun.util.locale.provider.TimeZoneNameUtility;
import sun.util.spi.CalendarProvider;

/**
* The {@code Calendar} class is an abstract class that provides methods
* for converting between a specific instant in time and a set of {@link
* #fields calendar fields} such as {@code YEAR}, {@code MONTH},
* {@code DAY_OF_MONTH}, {@code HOUR}, and so on, and for
* manipulating the calendar fields, such as getting the date of the next
* week. An instant in time can be represented by a millisecond value that is
* an offset from the <a id="Epoch">Epoch</a>, January 1, 1970
* 00:00:00.000 GMT (Gregorian).
*
* The class also provides additional fields and methods for
* implementing a concrete calendar system outside the package. Those
* fields and methods are defined as {@code protected}.
*
* 
* Like other locale-sensitive classes, {@code Calendar} provides a
* class method, {@code getInstance}, for getting a generally useful
* object of this type. {@code Calendar}'s {@code getInstance} method
* returns a {@code Calendar} object whose
* calendar fields have been initialized with the current date and time:
* <blockquote>
* <pre>
* Calendar rightNow = Calendar.getInstance();
* </pre>
* </blockquote>
*
* A {@code Calendar} object can produce all the calendar field values
* needed to implement the date-time formatting for a particular language and
* calendar style (for example, Japanese-Gregorian, Japanese-Traditional).
* {@code Calendar} defines the range of values returned by
* certain calendar fields, as well as their meaning. For example,
* the first month of the calendar system has value <code>MONTH ==
* JANUARY</code> for all calendars. Other values are defined by the
* concrete subclass, such as {@code ERA}. See individual field
* documentation and subclass documentation for details.
*
* <h2>Getting and Setting Calendar Field Values</h2>
*
* The calendar field values can be set by calling the {@code set}
* methods. Any field values set in a {@code Calendar} will not be
* interpreted until it needs to calculate its time value (milliseconds from
* the Epoch) or values of the calendar fields. Calling the
* {@code get}, {@code getTimeInMillis}, {@code getTime},
* {@code add} and {@code roll} involves such calculation.
*
* <h3>Leniency</h3>
*
* {@code Calendar} has two modes for interpreting the calendar
* fields, lenient and non-lenient. When a
* {@code Calendar} is in lenient mode, it accepts a wider range of
* calendar field values than it produces. When a {@code Calendar}
* recomputes calendar field values for return by {@code get()}, all of
* the calendar fields are normalized. For example, a lenient
* {@code GregorianCalendar} interprets {@code MONTH == JANUARY},
* {@code DAY_OF_MONTH == 32} as February 1.
*
* When a {@code Calendar} is in non-lenient mode, it throws an
* exception if there is any inconsistency in its calendar fields. For
* example, a {@code GregorianCalendar} always produces
* {@code DAY_OF_MONTH} values between 1 and the length of the month. A
* non-lenient {@code GregorianCalendar} throws an exception upon
* calculating its time or calendar field values if any out-of-range field
* value has been set.
*
* <h3><a id="first_week">First Week</a></h3>
*
* {@code Calendar} 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 or the
* locale itself when a {@code Calendar} is constructed. If the designated
* locale contains "fw" and/or "rg" <a href="./Locale.html#def_locale_extension">
* Unicode extensions</a>, the first day of the week will be obtained according to
* those extensions. If both "fw" and "rg" are specified, the value from the "fw"
* extension supersedes the implicit one from the "rg" extension.
* They may also be specified explicitly through the methods for setting their
* values.
*
* When setting or getting the {@code WEEK_OF_MONTH} or
* {@code WEEK_OF_YEAR} fields, {@code Calendar} 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()} and containing at least
* {@code getMinimalDaysInFirstWeek()} 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()} may be
* different. For example, a specific {@code Calendar} subclass may
* designate the week before week 1 of a year as week <code>n</code> of
* the previous year.
*
* <h3>Calendar Fields Resolution</h3>
*
* When computing a date and time from the calendar fields, there
* may be insufficient information for the computation (such as only
* year and month with no day of month), or there may be inconsistent
* information (such as Tuesday, July 15, 1996 (Gregorian) -- July 15,
* 1996 is actually a Monday). {@code Calendar} will resolve
* calendar field values to determine the date and time in the
* following way.
*
* <a id="resolution">If there is any conflict in calendar field values,
* {@code Calendar} gives priorities to calendar fields that have been set
* more recently.</a> The following are the default combinations of the
* calendar fields. The most recent combination, as determined by the
* most recently set single field, will be used.
*
* <a id="date_resolution">For the date fields</a>:
* <blockquote>
* <pre>
* YEAR + MONTH + DAY_OF_MONTH
* YEAR + MONTH + WEEK_OF_MONTH + DAY_OF_WEEK
* YEAR + MONTH + DAY_OF_WEEK_IN_MONTH + DAY_OF_WEEK
* YEAR + DAY_OF_YEAR
* YEAR + DAY_OF_WEEK + WEEK_OF_YEAR
* </pre></blockquote>
*
* <a id="time_resolution">For the time of day fields</a>:
* <blockquote>
* <pre>
* HOUR_OF_DAY
* AM_PM + HOUR
* </pre></blockquote>
*
* If there are any calendar fields whose values haven't been set in the selected
* field combination, {@code Calendar} uses their default values. The default
* value of each field may vary by concrete calendar systems. For example, in
* {@code GregorianCalendar}, the default of a field is the same as that
* of the start of the Epoch: i.e., {@code YEAR = 1970}, <code>MONTH =
* JANUARY</code>, {@code DAY_OF_MONTH = 1}, etc.
*
* 
* Note: There are certain possible ambiguities in
* interpretation of certain singular times, which are resolved in the
* following ways:
* <ol>
* <li> 23:59 is the last minute of the day and 00:00 is the first
* minute of the next day. Thus, 23:59 on Dec 31, 1999 < 00:00 on
* Jan 1, 2000 < 00:01 on Jan 1, 2000.
*
* <li> Although historically not precise, midnight also belongs to "am",
* and noon belongs to "pm", so on the same day,
* 12:00 am (midnight) < 12:01 am, and 12:00 pm (noon) < 12:01 pm
* </ol>
*
* 
* 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.
*
* <h3>Field Manipulation</h3>
*
* The calendar fields can be changed using three methods:
* {@code set()}, {@code add()}, and {@code roll()}.
*
* {@code set(f, value)} changes calendar field
* {@code f} to {@code value}. In addition, it sets an
* internal member variable to indicate that calendar field {@code f} has
* been changed. Although calendar field {@code f} is changed immediately,
* the calendar's time value in milliseconds is not recomputed until the next call to
* {@code get()}, {@code getTime()}, {@code getTimeInMillis()},
* {@code add()}, or {@code roll()} is made. Thus, multiple calls to
* {@code set()} do not trigger multiple, unnecessary
* computations. As a result of changing a calendar field using
* {@code set()}, other calendar fields may also change, depending on the
* calendar field, the calendar field value, and the calendar system. In addition,
* {@code get(f)} will not necessarily return {@code value} set by
* the call to the {@code set} method
* after the calendar fields have been recomputed. The specifics are determined by
* the concrete calendar class.
*
* Example: Consider a {@code GregorianCalendar}
* originally set to August 31, 1999. Calling <code>set(Calendar.MONTH,
* Calendar.SEPTEMBER)</code> sets the date to September 31,
* 1999. This is a temporary internal representation that resolves to
* October 1, 1999 if {@code getTime()} is then called. However, a
* call to {@code set(Calendar.DAY_OF_MONTH, 30)} before the call to
* {@code getTime()} sets the date to September 30, 1999, since
* no recomputation occurs after {@code set()} itself.
*
* {@code add(f, delta)} adds {@code delta}
* to field {@code f}. This is equivalent to calling <code>set(f,
* get(f) + delta)</code> with two adjustments:
*
* <blockquote>
* Add rule 1. The value of field {@code f}
* after the call minus the value of field {@code f} before the
* call is {@code delta}, modulo any overflow that has occurred in
* field {@code f}. 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.
*
* Add rule 2. 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} is changed or other constraints, such as time zone
* offset changes, 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} is a smaller field than
* {@code DAY_OF_MONTH}. 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.
* </blockquote>
*
* In addition, unlike {@code set()}, {@code add()} forces
* an immediate recomputation of the calendar's milliseconds and all
* fields.
*
* Example: Consider a {@code GregorianCalendar}
* originally set to August 31, 1999. Calling <code>add(Calendar.MONTH,
* 13)</code> sets the calendar to September 30, 2000. Add rule
* 1 sets the {@code MONTH} field to September, since
* adding 13 months to August gives September of the next year. Since
* {@code DAY_OF_MONTH} cannot be 31 in September in a
* {@code GregorianCalendar}, add rule 2 sets the
* {@code DAY_OF_MONTH} to 30, the closest possible value. Although
* it is a smaller field, {@code DAY_OF_WEEK} is not adjusted by
* rule 2, since it is expected to change when the month changes in a
* {@code GregorianCalendar}.
*
* {@code roll(f, delta)} adds
* {@code delta} to field {@code f} without changing larger
* fields. This is equivalent to calling {@code add(f, delta)} with
* the following adjustment:
*
* <blockquote>
* Roll rule. Larger fields are unchanged after the
* call. A larger field represents a larger unit of
* time. {@code DAY_OF_MONTH} is a larger field than
* {@code HOUR}.
* </blockquote>
*
* Example: See {@link java.util.GregorianCalendar#roll(int, int)}.
*
* Usage model. To motivate the behavior of
* {@code add()} and {@code roll()}, consider a user interface
* component with increment and decrement buttons for the month, day, and
* year, and an underlying {@code GregorianCalendar}. 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()}, 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()} or {@code roll()}, depending on whether larger
* fields should be affected, the user interface can behave as most users
* will intuitively expect.
*
* @see java.lang.System#currentTimeMillis()
* @see Date
* @see GregorianCalendar
* @see TimeZone
* @see java.text.DateFormat
* @author Mark Davis, David Goldsmith, Chen-Lieh Huang, Alan Liu
* @since 1.1
*/
public abstract class Calendar implements Serializable, Cloneable, Comparable<Calendar> {

 // Data flow in Calendar
 // ---------------------

 // The current time is represented in two ways by Calendar: as UTC
 // milliseconds from the epoch (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
 // in the class documentation.

 // 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() or setTimeInMillis(),
 // 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} and {@code set} indicating the
 * era, e.g., AD or BC in the Julian calendar. This is a calendar-specific
 * value; see subclass documentation.
 *
 * @see GregorianCalendar#AD
 * @see GregorianCalendar#BC
 */
 public static final int ERA = 0;

 /**
 * Field number for {@code get} and {@code set} indicating the
 * year. This is a calendar-specific value; see subclass documentation.
 */
 public static final int YEAR = 1;

 /**
 * Field number for {@code get} and {@code set} indicating the
 * month. This is a calendar-specific value. The first month of
 * the year in the Gregorian and Julian calendars is
 * {@code JANUARY} which is 0; the last depends on the number
 * of months in a year.
 *
 * @see #JANUARY
 * @see #FEBRUARY
 * @see #MARCH
 * @see #APRIL
 * @see #MAY
 * @see #JUNE
 * @see #JULY
 * @see #AUGUST
 * @see #SEPTEMBER
 * @see #OCTOBER
 * @see #NOVEMBER
 * @see #DECEMBER
 * @see #UNDECIMBER
 */
 public static final int MONTH = 2;

 /**
 * Field number for {@code get} and {@code set} indicating the
 * week number within the current year. The first week of the year, as
 * defined by {@code getFirstDayOfWeek()} and
 * {@code getMinimalDaysInFirstWeek()}, has value 1. Subclasses define
 * the value of {@code WEEK_OF_YEAR} for days before the first week of
 * the year.
 *
 * @see #getFirstDayOfWeek
 * @see #getMinimalDaysInFirstWeek
 */
 public static final int WEEK_OF_YEAR = 3;

 /**
 * Field number for {@code get} and {@code set} indicating the
 * week number within the current month. The first week of the month, as
 * defined by {@code getFirstDayOfWeek()} and
 * {@code getMinimalDaysInFirstWeek()}, has value 1. Subclasses define
 * the value of {@code WEEK_OF_MONTH} for days before the first week of
 * the month.
 *
 * @see #getFirstDayOfWeek
 * @see #getMinimalDaysInFirstWeek
 */
 public static final int WEEK_OF_MONTH = 4;

 /**
 * Field number for {@code get} and {@code set} indicating the
 * day of the month. This is a synonym for {@code DAY_OF_MONTH}.
 * The first day of the month has value 1.
 *
 * @see #DAY_OF_MONTH
 */
 public static final int DATE = 5;

 /**
 * Field number for {@code get} and {@code set} indicating the
 * day of the month. This is a synonym for {@code DATE}.
 * The first day of the month has value 1.
 *
 * @see #DATE
 */
 public static final int DAY_OF_MONTH = 5;

 /**
 * Field number for {@code get} and {@code set} indicating the day
 * number within the current year. The first day of the year has value 1.
 */
 public static final int DAY_OF_YEAR = 6;

 /**
 * Field number for {@code get} and {@code set} indicating the day
 * of the week. This field takes values {@code SUNDAY},
 * {@code MONDAY}, {@code TUESDAY}, {@code WEDNESDAY},
 * {@code THURSDAY}, {@code FRIDAY}, and {@code SATURDAY}.
 *
 * @see #SUNDAY
 * @see #MONDAY
 * @see #TUESDAY
 * @see #WEDNESDAY
 * @see #THURSDAY
 * @see #FRIDAY
 * @see #SATURDAY
 */
 public static final int DAY_OF_WEEK = 7;

 /**
 * Field number for {@code get} and {@code set} indicating the
 * ordinal number of the day of the week within the current month. Together
 * with the {@code DAY_OF_WEEK} field, this uniquely specifies a day
 * within a month. Unlike {@code WEEK_OF_MONTH} and
 * {@code WEEK_OF_YEAR}, this field's value does not depend on
 * {@code getFirstDayOfWeek()} or
 * {@code getMinimalDaysInFirstWeek()}. {@code DAY_OF_MONTH 1}
 * through {@code 7} always correspond to <code>DAY_OF_WEEK_IN_MONTH
 * 1</code>; {@code 8} through {@code 14} correspond to
 * {@code DAY_OF_WEEK_IN_MONTH 2}, and so on.
 * {@code DAY_OF_WEEK_IN_MONTH 0} indicates the week before
 * {@code DAY_OF_WEEK_IN_MONTH 1}. 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}. 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} will overlap
 * {@code DAY_OF_WEEK_IN_MONTH 5} and the end of {@code 4}.
 *
 * @see #DAY_OF_WEEK
 * @see #WEEK_OF_MONTH
 */
 public static final int DAY_OF_WEEK_IN_MONTH = 8;

 /**
 * Field number for {@code get} and {@code set} indicating
 * whether the {@code HOUR} is before or after noon.
 * E.g., at 10:04:15.250 PM the {@code AM_PM} is {@code PM}.
 *
 * @see #AM
 * @see #PM
 * @see #HOUR
 */
 public static final int AM_PM = 9;

 /**
 * Field number for {@code get} and {@code set} indicating the
 * hour of the morning or afternoon. {@code HOUR} is used for the
 * 12-hour clock (0 - 11). Noon and midnight are represented by 0, not by 12.
 * E.g., at 10:04:15.250 PM the {@code HOUR} is 10.
 *
 * @see #AM_PM
 * @see #HOUR_OF_DAY
 */
 public static final int HOUR = 10;

 /**
 * Field number for {@code get} and {@code set} indicating the
 * hour of the day. {@code HOUR_OF_DAY} is used for the 24-hour clock.
 * E.g., at 10:04:15.250 PM the {@code HOUR_OF_DAY} is 22.
 *
 * @see #HOUR
 */
 public static final int HOUR_OF_DAY = 11;

 /**
 * Field number for {@code get} and {@code set} indicating the
 * minute within the hour.
 * E.g., at 10:04:15.250 PM the {@code MINUTE} is 4.
 */
 public static final int MINUTE = 12;

 /**
 * Field number for {@code get} and {@code set} indicating the
 * second within the minute.
 * E.g., at 10:04:15.250 PM the {@code SECOND} is 15.
 */
 public static final int SECOND = 13;

 /**
 * Field number for {@code get} and {@code set} indicating the
 * millisecond within the second.
 * E.g., at 10:04:15.250 PM the {@code MILLISECOND} is 250.
 */
 public static final int MILLISECOND = 14;

 /**
 * Field number for {@code get} and {@code set}
 * indicating the raw offset from GMT in milliseconds.
 * 
 * This field reflects the correct GMT offset value of the time
 * zone of this {@code Calendar} if the
 * {@code TimeZone} implementation subclass supports
 * historical GMT offset changes.
 */
 public static final int ZONE_OFFSET = 15;

 /**
 * Field number for {@code get} and {@code set} indicating the
 * daylight saving offset in milliseconds.
 * 
 * This field reflects the correct daylight saving offset value of
 * the time zone of this {@code Calendar} if the
 * {@code TimeZone} implementation subclass supports
 * historical Daylight Saving Time schedule changes.
 */
 public static final int DST_OFFSET = 16;

 /**
 * The number of distinct fields recognized by {@code get} and {@code set}.
 * Field numbers range from {@code 0..FIELD_COUNT-1}.
 */
 public static final int FIELD_COUNT = 17;

 /**
 * Value of the {@link #DAY_OF_WEEK} field indicating
 * Sunday.
 */
 public static final int SUNDAY = 1;

 /**
 * Value of the {@link #DAY_OF_WEEK} field indicating
 * Monday.
 */
 public static final int MONDAY = 2;

 /**
 * Value of the {@link #DAY_OF_WEEK} field indicating
 * Tuesday.
 */
 public static final int TUESDAY = 3;

 /**
 * Value of the {@link #DAY_OF_WEEK} field indicating
 * Wednesday.
 */
 public static final int WEDNESDAY = 4;

 /**
 * Value of the {@link #DAY_OF_WEEK} field indicating
 * Thursday.
 */
 public static final int THURSDAY = 5;

 /**
 * Value of the {@link #DAY_OF_WEEK} field indicating
 * Friday.
 */
 public static final int FRIDAY = 6;

 /**
 * Value of the {@link #DAY_OF_WEEK} field indicating
 * Saturday.
 */
 public static final int SATURDAY = 7;

 /**
 * Value of the {@link #MONTH} field indicating the
 * first month of the year in the Gregorian and Julian calendars.
 */
 public static final int JANUARY = 0;

 /**
 * Value of the {@link #MONTH} field indicating the
 * second month of the year in the Gregorian and Julian calendars.
 */
 public static final int FEBRUARY = 1;

 /**
 * Value of the {@link #MONTH} field indicating the
 * third month of the year in the Gregorian and Julian calendars.
 */
 public static final int MARCH = 2;

 /**
 * Value of the {@link #MONTH} field indicating the
 * fourth month of the year in the Gregorian and Julian calendars.
 */
 public static final int APRIL = 3;

 /**
 * Value of the {@link #MONTH} field indicating the
 * fifth month of the year in the Gregorian and Julian calendars.
 */
 public static final int MAY = 4;

 /**
 * Value of the {@link #MONTH} field indicating the
 * sixth month of the year in the Gregorian and Julian calendars.
 */
 public static final int JUNE = 5;

 /**
 * Value of the {@link #MONTH} field indicating the
 * seventh month of the year in the Gregorian and Julian calendars.
 */
 public static final int JULY = 6;

 /**
 * Value of the {@link #MONTH} field indicating the
 * eighth month of the year in the Gregorian and Julian calendars.
 */
 public static final int AUGUST = 7;

 /**
 * Value of the {@link #MONTH} field indicating the
 * ninth month of the year in the Gregorian and Julian calendars.
 */
 public static final int SEPTEMBER = 8;

 /**
 * Value of the {@link #MONTH} field indicating the
 * tenth month of the year in the Gregorian and Julian calendars.
 */
 public static final int OCTOBER = 9;

 /**
 * Value of the {@link #MONTH} field indicating the
 * eleventh month of the year in the Gregorian and Julian calendars.
 */
 public static final int NOVEMBER = 10;

 /**
 * Value of the {@link #MONTH} field indicating the
 * twelfth month of the year in the Gregorian and Julian calendars.
 */
 public static final int DECEMBER = 11;

 /**
 * Value of the {@link #MONTH} field indicating the
 * thirteenth month of the year. Although {@code GregorianCalendar}
 * does not use this value, lunar calendars do.
 */
 public static final int UNDECIMBER = 12;

 /**
 * Value of the {@link #AM_PM} field indicating the
 * period of the day from midnight to just before noon.
 */
 public static final int AM = 0;

 /**
 * Value of the {@link #AM_PM} field indicating the
 * period of the day from noon to just before midnight.
 */
 public static final int PM = 1;

 /**
 * A style specifier for {@link #getDisplayNames(int, int, Locale)
 * getDisplayNames} indicating names in all styles, such as
 * "January" and "Jan".
 *
 * @see #SHORT_FORMAT
 * @see #LONG_FORMAT
 * @see #SHORT_STANDALONE
 * @see #LONG_STANDALONE
 * @see #SHORT
 * @see #LONG
 * @since 1.6
 */
 public static final int ALL_STYLES = 0;

 static final int STANDALONE_MASK = 0x8000;

 /**
 * A style specifier for {@link #getDisplayName(int, int, Locale)
 * getDisplayName} and {@link #getDisplayNames(int, int, Locale)
 * getDisplayNames} equivalent to {@link #SHORT_FORMAT}.
 *
 * @see #SHORT_STANDALONE
 * @see #LONG
 * @since 1.6
 */
 public static final int SHORT = 1;

 /**
 * A style specifier for {@link #getDisplayName(int, int, Locale)
 * getDisplayName} and {@link #getDisplayNames(int, int, Locale)
 * getDisplayNames} equivalent to {@link #LONG_FORMAT}.
 *
 * @see #LONG_STANDALONE
 * @see #SHORT
 * @since 1.6
 */
 public static final int LONG = 2;

 /**
 * A style specifier for {@link #getDisplayName(int, int, Locale)
 * getDisplayName} and {@link #getDisplayNames(int, int, Locale)
 * getDisplayNames} indicating a narrow name used for format. Narrow names
 * are typically single character strings, such as "M" for Monday.
 *
 * @see #NARROW_STANDALONE
 * @see #SHORT_FORMAT
 * @see #LONG_FORMAT
 * @since 1.8
 */
 public static final int NARROW_FORMAT = 4;

 /**
 * A style specifier for {@link #getDisplayName(int, int, Locale)
 * getDisplayName} and {@link #getDisplayNames(int, int, Locale)
 * getDisplayNames} indicating a narrow name independently. Narrow names
 * are typically single character strings, such as "M" for Monday.
 *
 * @see #NARROW_FORMAT
 * @see #SHORT_STANDALONE
 * @see #LONG_STANDALONE
 * @since 1.8
 */
 public static final int NARROW_STANDALONE = NARROW_FORMAT | STANDALONE_MASK;

 /**
 * A style specifier for {@link #getDisplayName(int, int, Locale)
 * getDisplayName} and {@link #getDisplayNames(int, int, Locale)
 * getDisplayNames} indicating a short name used for format.
 *
 * @see #SHORT_STANDALONE
 * @see #LONG_FORMAT
 * @see #LONG_STANDALONE
 * @since 1.8
 */
 public static final int SHORT_FORMAT = 1;

 /**
 * A style specifier for {@link #getDisplayName(int, int, Locale)
 * getDisplayName} and {@link #getDisplayNames(int, int, Locale)
 * getDisplayNames} indicating a long name used for format.
 *
 * @see #LONG_STANDALONE
 * @see #SHORT_FORMAT
 * @see #SHORT_STANDALONE
 * @since 1.8
 */
 public static final int LONG_FORMAT = 2;

 /**
 * A style specifier for {@link #getDisplayName(int, int, Locale)
 * getDisplayName} and {@link #getDisplayNames(int, int, Locale)
 * getDisplayNames} indicating a short name used independently,
 * such as a month abbreviation as calendar headers.
 *
 * @see #SHORT_FORMAT
 * @see #LONG_FORMAT
 * @see #LONG_STANDALONE
 * @since 1.8
 */
 public static final int SHORT_STANDALONE = SHORT | STANDALONE_MASK;

 /**
 * A style specifier for {@link #getDisplayName(int, int, Locale)
 * getDisplayName} and {@link #getDisplayNames(int, int, Locale)
 * getDisplayNames} indicating a long name used independently,
 * such as a month name as calendar headers.
 *
 * @see #LONG_FORMAT
 * @see #SHORT_FORMAT
 * @see #SHORT_STANDALONE
 * @since 1.8
 */
 public static final int LONG_STANDALONE = LONG | STANDALONE_MASK;

 // Internal notes:
 // Calendar contains two kinds of time representations: current "time" in
 // milliseconds, and a set of calendar "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 calendar field values for the currently set time for this calendar.
 * This is an array of {@code FIELD_COUNT} integers, with index values
 * {@code ERA} through {@code DST_OFFSET}.
 * @serial
 */
 @SuppressWarnings("ProtectedField")
 protected int fields[];

 /**
 * The flags which tell if a specified calendar field for the calendar is set.
 * A new object has no fields set. After the first call to a method
 * which generates the fields, they all remain set after that.
 * This is an array of {@code FIELD_COUNT} booleans, with index values
 * {@code ERA} through {@code DST_OFFSET}.
 * @serial
 */
 @SuppressWarnings("ProtectedField")
 protected boolean isSet[];

 /**
 * Pseudo-time-stamps which specify when each field was set. There
 * are two special values, UNSET and COMPUTED. 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 #isTimeSet
 * @serial
 */
 @SuppressWarnings("ProtectedField")
 protected long time;

 /**
 * True if then the value of {@code time} is valid.
 * The time is made invalid by a change to an item of {@code field[]}.
 * @see #time
 * @serial
 */
 @SuppressWarnings("ProtectedField")
 protected boolean isTimeSet;

 /**
 * True if {@code fields[]} 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}.
 * @serial
 */
 @SuppressWarnings("ProtectedField")
 protected boolean areFieldsSet;

 /**
 * True if all fields have been set.
 * @serial
 */
 transient boolean areAllFieldsSet;

 /**
 * {@code True} if this calendar allows out-of-range field values during computation
 * of {@code time} from {@code fields[]}.
 * @see #setLenient
 * @see #isLenient
 * @serial
 */
 private boolean lenient = true;

 /**
 * The {@code TimeZone} used by this calendar. {@code Calendar}
 * uses the time zone data to translate between locale and GMT time.
 * @serial
 */
 private TimeZone zone;

 /**
 * {@code True} if zone references to a shared TimeZone object.
 */
 private transient boolean sharedZone = false;

 /**
 * The first day of the week, with possible values {@code SUNDAY},
 * {@code MONDAY}, etc. This is a locale-dependent value.
 * @serial
 */
 private int firstDayOfWeek;

 /**
 * The number of days required for the first week in a month or year,
 * with possible values from 1 to 7. This is a locale-dependent value.
 * @serial
 */
 private int minimalDaysInFirstWeek;

 /**
 * Cache to hold the firstDayOfWeek and minimalDaysInFirstWeek
 * of a Locale.
 */
 private static final ConcurrentMap<Locale, int[]> cachedLocaleData
 = new ConcurrentHashMap<>(3);

 // Special values of stamp[]
 /**
 * The corresponding fields[] has no value.
 */
 private static final int UNSET = 0;

 /**
 * The value of the corresponding fields[] has been calculated internally.
 */
 private static final int COMPUTED = 1;

 /**
 * The value of the corresponding fields[] has been set externally. Stamp
 * values which are greater than 1 represents the (pseudo) time when the
 * corresponding fields[] value was set.
 */
 private static final int MINIMUM_USER_STAMP = 2;

 /**
 * The mask value that represents all of the fields.
 */
 static final int ALL_FIELDS = (1 << FIELD_COUNT) - 1;

 /**
 * The next available value for {@code stamp[]}, an internal array.
 * This actually should not be written out to the stream, and will probably
 * be removed from the stream in the near future. In the meantime,
 * a value of {@code MINIMUM_USER_STAMP} should be used.
 * @serial
 */
 private int nextStamp = MINIMUM_USER_STAMP;

 // the internal serial version which says which version was written
 // - 0 (default) for version up to JDK 1.1.5
 // - 1 for version from JDK 1.1.6, which writes a correct 'time' value
 // as well as compatible values for other fields. This is a
 // transitional format.
 // - 2 (not implemented yet) a future version, in which fields[],
 // areFieldsSet, and isTimeSet become transient, and isSet[] is
 // removed. In JDK 1.1.6 we write a format compatible with version 2.
 static final int currentSerialVersion = 1;

 /**
 * The version of the serialized data on the stream. Possible values:
 * <dl>
 * <dt>0 or not present on stream</dt>
 * <dd>
 * JDK 1.1.5 or earlier.
 * </dd>
 * <dt>1</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}
 * is written.
 * @serial
 * @since 1.1.6
 */
 private int serialVersionOnStream = currentSerialVersion;

 // Proclaim serialization compatibility with JDK 1.1
 @java.io.Serial
 static final long serialVersionUID = -1807547505821590642L;

 // Mask values for calendar fields
 @SuppressWarnings("PointlessBitwiseExpression")
 static final int ERA_MASK = (1 << ERA);
 static final int YEAR_MASK = (1 << YEAR);
 static final int MONTH_MASK = (1 << MONTH);
 static final int WEEK_OF_YEAR_MASK = (1 << WEEK_OF_YEAR);
 static final int WEEK_OF_MONTH_MASK = (1 << WEEK_OF_MONTH);
 static final int DAY_OF_MONTH_MASK = (1 << DAY_OF_MONTH);
 static final int DAY_OF_YEAR_MASK = (1 << DAY_OF_YEAR);
 static final int DAY_OF_WEEK_MASK = (1 << DAY_OF_WEEK);
 static final int DAY_OF_WEEK_IN_MONTH_MASK = (1 << DAY_OF_WEEK_IN_MONTH);
 static final int AM_PM_MASK = (1 << AM_PM);
 static final int HOUR_MASK = (1 << HOUR);
 static final int HOUR_OF_DAY_MASK = (1 << HOUR_OF_DAY);
 static final int MINUTE_MASK = (1 << MINUTE);
 static final int SECOND_MASK = (1 << SECOND);
 static final int MILLISECOND_MASK = (1 << MILLISECOND);
 static final int ZONE_OFFSET_MASK = (1 << ZONE_OFFSET);
 static final int DST_OFFSET_MASK = (1 << DST_OFFSET);

 /**
 * {@code Calendar.Builder} is used for creating a {@code Calendar} from
 * various date-time parameters.
 *
 * There are two ways to set a {@code Calendar} to a date-time value. One
 * is to set the instant parameter to a millisecond offset from the <a
 * href="Calendar.html#Epoch">Epoch</a>. The other is to set individual
 * field parameters, such as {@link Calendar#YEAR YEAR}, to their desired
 * values. These two ways can't be mixed. Trying to set both the instant and
 * individual fields will cause an {@link IllegalStateException} to be
 * thrown. However, it is permitted to override previous values of the
 * instant or field parameters.
 *
 * If no enough field parameters are given for determining date and/or
 * time, calendar specific default values are used when building a
 * {@code Calendar}. For example, if the {@link Calendar#YEAR YEAR} value
 * isn't given for the Gregorian calendar, 1970 will be used. If there are
 * any conflicts among field parameters, the <a
 * href="Calendar.html#resolution"> resolution rules</a> are applied.
 * Therefore, the order of field setting matters.
 *
 * In addition to the date-time parameters,
 * the {@linkplain #setLocale(Locale) locale},
 * {@linkplain #setTimeZone(TimeZone) time zone},
 * {@linkplain #setWeekDefinition(int, int) week definition}, and
 * {@linkplain #setLenient(boolean) leniency mode} parameters can be set.
 *
 * Examples
 * The following are sample usages. Sample code assumes that the
 * {@code Calendar} constants are statically imported.
 *
 * The following code produces a {@code Calendar} with date 2012-12-31
 * (Gregorian) because Monday is the first day of a week with the <a
 * href="GregorianCalendar.html#iso8601_compatible_setting"> ISO 8601
 * compatible week parameters</a>.
 * <pre>
 * Calendar cal = new Calendar.Builder().setCalendarType("iso8601")
 * .setWeekDate(2013, 1, MONDAY).build();</pre>
 * The following code produces a Japanese {@code Calendar} with date
 * 1989-01-08 (Gregorian), assuming that the default {@link Calendar#ERA ERA}
 * is Heisei that started on that day.
 * <pre>
 * Calendar cal = new Calendar.Builder().setCalendarType("japanese")
 * .setFields(YEAR, 1, DAY_OF_YEAR, 1).build();</pre>
 *
 * @since 1.8
 * @see Calendar#getInstance(TimeZone, Locale)
 * @see Calendar#fields
 */
 public static class Builder {
 private static final int NFIELDS = FIELD_COUNT + 1; // +1 for WEEK_YEAR
 private static final int WEEK_YEAR = FIELD_COUNT;

 private long instant;
 // Calendar.stamp[] (lower half) and Calendar.fields[] (upper half) combined
 private int[] fields;
 // Pseudo timestamp starting from MINIMUM_USER_STAMP.
 // (COMPUTED is used to indicate that the instant has been set.)
 private int nextStamp;
 // maxFieldIndex keeps the max index of fields which have been set.
 // (WEEK_YEAR is never included.)
 private int maxFieldIndex;
 private String type;
 private TimeZone zone;
 private boolean lenient = true;
 private Locale locale;
 private int firstDayOfWeek, minimalDaysInFirstWeek;

 /**
 * Constructs a {@code Calendar.Builder}.
 */
 public Builder() {
 }

 /**
 * Sets the instant parameter to the given {@code instant} value that is
 * a millisecond offset from <a href="Calendar.html#Epoch">the
 * Epoch</a>.
 *
 * @param instant a millisecond offset from the Epoch
 * @return this {@code Calendar.Builder}
 * @throws IllegalStateException if any of the field parameters have
 * already been set
 * @see Calendar#setTime(Date)
 * @see Calendar#setTimeInMillis(long)
 * @see Calendar#time
 */
 public Builder setInstant(long instant) {
 if (fields != null) {
 throw new IllegalStateException();
 }
 this.instant = instant;
 nextStamp = COMPUTED;
 return this;
 }

 /**
 * Sets the instant parameter to the {@code instant} value given by a
 * {@link Date}. This method is equivalent to a call to
 * {@link #setInstant(long) setInstant(instant.getTime())}.
 *
 * @param instant a {@code Date} representing a millisecond offset from
 * the Epoch
 * @return this {@code Calendar.Builder}
 * @throws NullPointerException if {@code instant} is {@code null}
 * @throws IllegalStateException if any of the field parameters have
 * already been set
 * @see Calendar#setTime(Date)
 * @see Calendar#setTimeInMillis(long)
 * @see Calendar#time
 */
 public Builder setInstant(Date instant) {
 return setInstant(instant.getTime()); // NPE if instant == null
 }

 /**
 * Sets the {@code field} parameter to the given {@code value}.
 * {@code field} is an index to the {@link Calendar#fields}, such as
 * {@link Calendar#DAY_OF_MONTH DAY_OF_MONTH}. Field value validation is
 * not performed in this method. Any out of range values are either
 * normalized in lenient mode or detected as an invalid value in
 * non-lenient mode when building a {@code Calendar}.
 *
 * @param field an index to the {@code Calendar} fields
 * @param value the field value
 * @return this {@code Calendar.Builder}
 * @throws IllegalArgumentException if {@code field} is invalid
 * @throws IllegalStateException if the instant value has already been set,
 * or if fields have been set too many
 * (approximately {@link Integer#MAX_VALUE}) times.
 * @see Calendar#set(int, int)
 */
 public Builder set(int field, int value) {
 // Note: WEEK_YEAR can't be set with this method.
 if (field < 0 || field >= FIELD_COUNT) {
 throw new IllegalArgumentException("field is invalid");
 }
 if (isInstantSet()) {
 throw new IllegalStateException("instant has been set");
 }
 allocateFields();
 internalSet(field, value);
 return this;
 }

 /**
 * Sets field parameters to their values given by
 * {@code fieldValuePairs} that are pairs of a field and its value.
 * For example,
 * <pre>
 * setFields(Calendar.YEAR, 2013,
 * Calendar.MONTH, Calendar.DECEMBER,
 * Calendar.DAY_OF_MONTH, 23);</pre>
 * is equivalent to the sequence of the following
 * {@link #set(int, int) set} calls:
 * <pre>
 * set(Calendar.YEAR, 2013)
 * .set(Calendar.MONTH, Calendar.DECEMBER)
 * .set(Calendar.DAY_OF_MONTH, 23);</pre>
 *
 * @param fieldValuePairs field-value pairs
 * @return this {@code Calendar.Builder}
 * @throws NullPointerException if {@code fieldValuePairs} is {@code null}
 * @throws IllegalArgumentException if any of fields are invalid,
 * or if {@code fieldValuePairs.length} is an odd number.
 * @throws IllegalStateException if the instant value has been set,
 * or if fields have been set too many (approximately
 * {@link Integer#MAX_VALUE}) times.
 */
 public Builder setFields(int... fieldValuePairs) {
 int len = fieldValuePairs.length;
 if ((len % 2) != 0) {
 throw new IllegalArgumentException();
 }
 if (isInstantSet()) {
 throw new IllegalStateException("instant has been set");
 }
 if ((nextStamp + len / 2) < 0) {
 throw new IllegalStateException("stamp counter overflow");
 }
 allocateFields();
 for (int i = 0; i < len; ) {
 int field = fieldValuePairs[i++];
 // Note: WEEK_YEAR can't be set with this method.
 if (field < 0 || field >= FIELD_COUNT) {
 throw new IllegalArgumentException("field is invalid");
 }
 internalSet(field, fieldValuePairs[i++]);
 }
 return this;
 }

 /**
 * Sets the date field parameters to the values given by {@code year},
 * {@code month}, and {@code dayOfMonth}. This method is equivalent to
 * a call to:
 * <pre>
 * setFields(Calendar.YEAR, year,
 * Calendar.MONTH, month,
 * Calendar.DAY_OF_MONTH, dayOfMonth);</pre>
 *
 * @param year the {@link Calendar#YEAR YEAR} value
 * @param month the {@link Calendar#MONTH MONTH} value
 * (the month numbering is 0-based).
 * @param dayOfMonth the {@link Calendar#DAY_OF_MONTH DAY_OF_MONTH} value
 * @return this {@code Calendar.Builder}
 */
 public Builder setDate(int year, int month, int dayOfMonth) {
 return setFields(YEAR, year, MONTH, month, DAY_OF_MONTH, dayOfMonth);
 }

 /**
 * Sets the time of day field parameters to the values given by
 * {@code hourOfDay}, {@code minute}, and {@code second}. This method is
 * equivalent to a call to:
 * <pre>
 * setTimeOfDay(hourOfDay, minute, second, 0);</pre>
 *
 * @param hourOfDay the {@link Calendar#HOUR_OF_DAY HOUR_OF_DAY} value
 * (24-hour clock)
 * @param minute the {@link Calendar#MINUTE MINUTE} value
 * @param second the {@link Calendar#SECOND SECOND} value
 * @return this {@code Calendar.Builder}
 */
 public Builder setTimeOfDay(int hourOfDay, int minute, int second) {
 return setTimeOfDay(hourOfDay, minute, second, 0);
 }

 /**
 * Sets the time of day field parameters to the values given by
 * {@code hourOfDay}, {@code minute}, {@code second}, and
 * {@code millis}. This method is equivalent to a call to:
 * <pre>
 * setFields(Calendar.HOUR_OF_DAY, hourOfDay,
 * Calendar.MINUTE, minute,
 * Calendar.SECOND, second,
 * Calendar.MILLISECOND, millis);</pre>
 *
 * @param hourOfDay the {@link Calendar#HOUR_OF_DAY HOUR_OF_DAY} value
 * (24-hour clock)
 * @param minute the {@link Calendar#MINUTE MINUTE} value
 * @param second the {@link Calendar#SECOND SECOND} value
 * @param millis the {@link Calendar#MILLISECOND MILLISECOND} value
 * @return this {@code Calendar.Builder}
 */
 public Builder setTimeOfDay(int hourOfDay, int minute, int second, int millis) {
 return setFields(HOUR_OF_DAY, hourOfDay, MINUTE, minute,
 SECOND, second, MILLISECOND, millis);
 }

 /**
 * Sets the week-based date parameters to the values with the given
 * date specifiers - week year, week of year, and day of week.
 *
 * If the specified calendar doesn't support week dates, the
 * {@link #build() build} method will throw an {@link IllegalArgumentException}.
 *
 * @param weekYear the week year
 * @param weekOfYear the week number based on {@code weekYear}
 * @param dayOfWeek the day of week value: one of the constants
 * for the {@link Calendar#DAY_OF_WEEK DAY_OF_WEEK} field:
 * {@link Calendar#SUNDAY SUNDAY}, ..., {@link Calendar#SATURDAY SATURDAY}.
 * @return this {@code Calendar.Builder}
 * @see Calendar#setWeekDate(int, int, int)
 * @see Calendar#isWeekDateSupported()
 */
 public Builder setWeekDate(int weekYear, int weekOfYear, int dayOfWeek) {
 allocateFields();
 internalSet(WEEK_YEAR, weekYear);
 internalSet(WEEK_OF_YEAR, weekOfYear);
 internalSet(DAY_OF_WEEK, dayOfWeek);
 return this;
 }

 /**
 * Sets the time zone parameter to the given {@code zone}. If no time
 * zone parameter is given to this {@code Calendar.Builder}, the
 * {@linkplain TimeZone#getDefault() default
 * {@code TimeZone}} will be used in the {@link #build() build}
 * method.
 *
 * @param zone the {@link TimeZone}
 * @return this {@code Calendar.Builder}
 * @throws NullPointerException if {@code zone} is {@code null}
 * @see Calendar#setTimeZone(TimeZone)
 */
 public Builder setTimeZone(TimeZone zone) {
 if (zone == null) {
 throw new NullPointerException();
 }
 this.zone = zone;
 return this;
 }

 /**
 * Sets the lenient mode parameter to the value given by {@code lenient}.
 * If no lenient parameter is given to this {@code Calendar.Builder},
 * lenient mode will be used in the {@link #build() build} method.
 *
 * @param lenient {@code true} for lenient mode;
 * {@code false} for non-lenient mode
 * @return this {@code Calendar.Builder}
 * @see Calendar#setLenient(boolean)
 */
 public Builder setLenient(boolean lenient) {
 this.lenient = lenient;
 return this;
 }

 /**
 * Sets the calendar type parameter to the given {@code type}. The
 * calendar type given by this method has precedence over any explicit
 * or implicit calendar type given by the
 * {@linkplain #setLocale(Locale) locale}.
 *
 * In addition to the available calendar types returned by the
 * {@link Calendar#getAvailableCalendarTypes() Calendar.getAvailableCalendarTypes}
 * method, {@code "gregorian"} and {@code "iso8601"} as aliases of
 * {@code "gregory"} can be used with this method.
 *
 * @param type the calendar type
 * @return this {@code Calendar.Builder}
 * @throws NullPointerException if {@code type} is {@code null}
 * @throws IllegalArgumentException if {@code type} is unknown
 * @throws IllegalStateException if another calendar type has already been set
 * @see Calendar#getCalendarType()
 * @see Calendar#getAvailableCalendarTypes()
 */
 public Builder setCalendarType(String type) {
 if (type.equals("gregorian")) { // NPE if type == null
 type = "gregory";
 }
 if (!Calendar.getAvailableCalendarTypes().contains(type)
 && !type.equals("iso8601")) {
 throw new IllegalArgumentException("unknown calendar type: " + type);
 }
 if (this.type == null) {
 this.type = type;
 } else {
 if (!this.type.equals(type)) {
 throw new IllegalStateException("calendar type override");
 }
 }
 return this;
 }

 /**
 * Sets the locale parameter to the given {@code locale}. If no locale
 * is given to this {@code Calendar.Builder}, the {@linkplain
 * Locale#getDefault(Locale.Category) default {@code Locale}}
 * for {@link Locale.Category#FORMAT} will be used.
 *
 * If no calendar type is explicitly given by a call to the
 * {@link #setCalendarType(String) setCalendarType} method,
 * the {@code Locale} value is used to determine what type of
 * {@code Calendar} to be built.
 *
 * If no week definition parameters are explicitly given by a call to
 * the {@link #setWeekDefinition(int,int) setWeekDefinition} method, the
 * {@code Locale}'s default values are used.
 *
 * @param locale the {@link Locale}
 * @throws NullPointerException if {@code locale} is {@code null}
 * @return this {@code Calendar.Builder}
 * @see Calendar#getInstance(Locale)
 */
 public Builder setLocale(Locale locale) {
 if (locale == null) {
 throw new NullPointerException();
 }
 this.locale = locale;
 return this;
 }

 /**
 * Sets the week definition parameters to the values given by
 * {@code firstDayOfWeek} and {@code minimalDaysInFirstWeek} that are
 * used to determine the <a href="Calendar.html#first_week">first
 * week</a> of a year. The parameters given by this method have
 * precedence over the default values given by the
 * {@linkplain #setLocale(Locale) locale}.
 *
 * @param firstDayOfWeek the first day of a week; one of
 * {@link Calendar#SUNDAY} to {@link Calendar#SATURDAY}
 * @param minimalDaysInFirstWeek the minimal number of days in the first
 * week (1..7)
 * @return this {@code Calendar.Builder}
 * @throws IllegalArgumentException if {@code firstDayOfWeek} or
 * {@code minimalDaysInFirstWeek} is invalid
 * @see Calendar#getFirstDayOfWeek()
 * @see Calendar#getMinimalDaysInFirstWeek()
 */
 public Builder setWeekDefinition(int firstDayOfWeek, int minimalDaysInFirstWeek) {
 if (!isValidWeekParameter(firstDayOfWeek)
 || !isValidWeekParameter(minimalDaysInFirstWeek)) {
 throw new IllegalArgumentException();
 }
 this.firstDayOfWeek = firstDayOfWeek;
 this.minimalDaysInFirstWeek = minimalDaysInFirstWeek;
 return this;
 }

 /**
 * Returns a {@code Calendar} built from the parameters set by the
 * setter methods. The calendar type given by the {@link #setCalendarType(String)
 * setCalendarType} method or the {@linkplain #setLocale(Locale) locale} is
 * used to determine what {@code Calendar} to be created. If no explicit
 * calendar type is given, the locale's default calendar is created.
 *
 * If the calendar type is {@code "iso8601"}, the
 * {@linkplain GregorianCalendar#setGregorianChange(Date) Gregorian change date}
 * of a {@link GregorianCalendar} is set to {@code Date(Long.MIN_VALUE)}
 * to be the proleptic Gregorian calendar. Its week definition
 * parameters are also set to be <a
 * href="GregorianCalendar.html#iso8601_compatible_setting">compatible
 * with the ISO 8601 standard</a>. Note that the
 * {@link GregorianCalendar#getCalendarType() getCalendarType} method of
 * a {@code GregorianCalendar} created with {@code "iso8601"} returns
 * {@code "gregory"}.
 *
 * The default values are used for locale and time zone if these
 * parameters haven't been given explicitly.
 * 
 * If the locale contains the time zone with "tz"
 * <a href="Locale.html#def_locale_extension">Unicode extension</a>,
 * and time zone hasn't been given explicitly, time zone in the locale
 * is used.
 *
 * Any out of range field values are either normalized in lenient
 * mode or detected as an invalid value in non-lenient mode.
 *
 * @return a {@code Calendar} built with parameters of this {@code
 * Calendar.Builder}
 * @throws IllegalArgumentException if the calendar type is unknown, or
 * if any invalid field values are given in non-lenient mode, or
 * if a week date is given for the calendar type that doesn't
 * support week dates.
 * @see Calendar#getInstance(TimeZone, Locale)
 * @see Locale#getDefault(Locale.Category)
 * @see TimeZone#getDefault()
 */
 public Calendar build() {
 if (locale == null) {
 locale = Locale.getDefault();
 }
 if (zone == null) {
 zone = defaultTimeZone(locale);
 }
 if (type == null) {
 type = locale.getUnicodeLocaleType("ca");
 }
 if (type == null) {
 if (locale.getCountry() == "TH"
 && locale.getLanguage() == "th") {
 type = "buddhist";
 } else {
 type = "gregory";
 }
 }
 final Calendar cal = switch (type) {
 case "gregory" -> new GregorianCalendar(zone, locale, true);
 case "iso8601" -> {
 GregorianCalendar gcal = new GregorianCalendar(zone, locale, true);
 // make gcal a proleptic Gregorian
 gcal.setGregorianChange(new Date(Long.MIN_VALUE));
 // and week definition to be compatible with ISO 8601
 setWeekDefinition(MONDAY, 4);
 yield gcal;
 }
 case "buddhist" -> {
 var buddhistCalendar = new BuddhistCalendar(zone, locale);
 buddhistCalendar.clear();
 yield buddhistCalendar;
 }
 case "japanese" -> new JapaneseImperialCalendar(zone, locale, true);
 default -> throw new IllegalArgumentException("unknown calendar type: " + type);
 };
 cal.setLenient(lenient);
 if (firstDayOfWeek != 0) {
 cal.setFirstDayOfWeek(firstDayOfWeek);
 cal.setMinimalDaysInFirstWeek(minimalDaysInFirstWeek);
 }
 if (isInstantSet()) {
 cal.setTimeInMillis(instant);
 cal.complete();
 return cal;
 }

 if (fields != null) {
 boolean weekDate = isSet(WEEK_YEAR)
 && fields[WEEK_YEAR] > fields[YEAR];
 if (weekDate && !cal.isWeekDateSupported()) {
 throw new IllegalArgumentException("week date is unsupported by " + type);
 }

 // Set the fields from the min stamp to the max stamp so that
 // the fields resolution works in the Calendar.
 for (int stamp = MINIMUM_USER_STAMP; stamp < nextStamp; stamp++) {
 for (int index = 0; index <= maxFieldIndex; index++) {
 if (fields[index] == stamp) {
 cal.set(index, fields[NFIELDS + index]);
 break;
 }
 }
 }

 if (weekDate) {
 int weekOfYear = isSet(WEEK_OF_YEAR) ? fields[NFIELDS + WEEK_OF_YEAR] : 1;
 int dayOfWeek = isSet(DAY_OF_WEEK)
 ? fields[NFIELDS + DAY_OF_WEEK] : cal.getFirstDayOfWeek();
 cal.setWeekDate(fields[NFIELDS + WEEK_YEAR], weekOfYear, dayOfWeek);
 }
 cal.complete();
 }

 return cal;
 }

 private void allocateFields() {
 if (fields == null) {
 fields = new int[NFIELDS * 2];
 nextStamp = MINIMUM_USER_STAMP;
 maxFieldIndex = -1;
 }
 }

 private void internalSet(int field, int value) {
 fields[field] = nextStamp++;
 if (nextStamp < 0) {
 throw new IllegalStateException("stamp counter overflow");
 }
 fields[NFIELDS + field] = value;
 if (field > maxFieldIndex && field < WEEK_YEAR) {
 maxFieldIndex = field;
 }
 }

 private boolean isInstantSet() {
 return nextStamp == COMPUTED;
 }

 private boolean isSet(int index) {
 return fields != null && fields[index] > UNSET;
 }

 private boolean isValidWeekParameter(int value) {
 return value > 0 && value <= 7;
 }
 }

 /**
 * Constructs a Calendar with the default time zone
 * and the default {@link java.util.Locale.Category#FORMAT FORMAT}
 * locale.
 * @see TimeZone#getDefault
 */
 protected Calendar()
 {
 this(TimeZone.getDefaultRef(), Locale.getDefault(Locale.Category.FORMAT));
 sharedZone = true;
 }

 /**
 * Constructs a calendar with the specified time zone and locale.
 *
 * @param zone the time zone to use
 * @param aLocale the locale for the week data
 */
 protected Calendar(TimeZone zone, Locale aLocale)
 {
 fields = new int[FIELD_COUNT];
 isSet = new boolean[FIELD_COUNT];
--> --------------------

--> maximum size reached

--> --------------------

quality92%

¤ Dauer der Verarbeitung: 0.14 Sekunden (vorverarbeitet) ¤

Entwurf

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.