/*
* Copyright 1996-2007 Sun Microsystems, Inc. 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. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
/*
* (C) Copyright Taligent, Inc. 1996-1998 - All Rights Reserved
* (C) Copyright IBM Corp. 1996-1998 - All Rights Reserved
*
* The original version of this source code and documentation is copyrighted
* and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
* materials are provided under terms of a License Agreement between Taligent
* and Sun. This technology is protected by multiple US and International
* patents. This notice and attribution to Taligent may not be removed.
* Taligent is a registered trademark of Taligent, Inc.
*
*/
package java.util;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.security.AccessController;
import java.security.PrivilegedExceptionAction;
import java.text.DateFormat;
import java.text.DateFormatSymbols;
import sun.util.BuddhistCalendar;
import sun.util.calendar.ZoneInfo;
import sun.util.resources.LocaleData;
/**
* The <code>Calendar</code> 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>, <code>MONTH</code>,
* <code>DAY_OF_MONTH</code>, <code>HOUR</code>, 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 name="Epoch"><em>Epoch</em></a>, January 1, 1970
* 00:00:00.000 GMT (Gregorian).
*
* <p>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</code>.
*
* <p>
* Like other locale-sensitive classes, <code>Calendar</code> provides a
* class method, <code>getInstance</code>, for getting a generally useful
* object of this type. <code>Calendar</code>'s <code>getInstance</code> method
* returns a <code>Calendar</code> object whose
* calendar fields have been initialized with the current date and time:
* <blockquote>
* <pre>
* Calendar rightNow = Calendar.getInstance();
* </pre>
* </blockquote>
*
* <p>A <code>Calendar</code> object can produce all the 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</code> 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</code>. See individual field
* documentation and subclass documentation for details.
*
* <h4>Getting and Setting Calendar Field Values</h4>
*
* <p>The calendar field values can be set by calling the <code>set</code>
* methods. Any field values set in a <code>Calendar</code> 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>, <code>getTimeInMillis</code>, <code>getTime</code>,
* <code>add</code> and <code>roll</code> involves such calculation.
*
* <h4>Leniency</h4>
*
* <p><code>Calendar</code> has two modes for interpreting the calendar
* fields, <em>lenient</em> and <em>non-lenient</em>. When a
* <code>Calendar</code> is in lenient mode, it accepts a wider range of
* calendar field values than it produces. When a <code>Calendar</code>
* recomputes calendar field values for return by <code>get()</code>, all of
* the calendar fields are normalized. For example, a lenient
* <code>GregorianCalendar</code> interprets <code>MONTH == JANUARY</code>,
* <code>DAY_OF_MONTH == 32</code> as February 1.
* <p>When a <code>Calendar</code> is in non-lenient mode, it throws an
* exception if there is any inconsistency in its calendar fields. For
* example, a <code>GregorianCalendar</code> always produces
* <code>DAY_OF_MONTH</code> values between 1 and the length of the month. A
* non-lenient <code>GregorianCalendar</code> throws an exception upon
* calculating its time or calendar field values if any out-of-range field
* value has been set.
*
* <h4>First Week</h4>
*
* <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 methods for setting their values.
*
* <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 <code><i>n</i></code> of
* the previous year.
*
* <h4>Calendar Fields Resolution</h4>
*
* 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</code> will resolve
* calendar field values to determine the date and time in the
* following way.
*
* <p>If there is any conflict in calendar field values,
* <code>Calendar</code> gives priorities to calendar fields that have been set
* more recently. 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.
*
* <p><a name="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 name="time_resolution">For the time of day fields</a>:
* <blockquote>
* <pre>
* HOUR_OF_DAY
* AM_PM + HOUR
* </pre></blockquote>
*
* <p>If there are any calendar fields whose values haven't been set in the selected
* field combination, <code>Calendar</code> uses their default values. The default
* value of each field may vary by concrete calendar systems. For example, in
* <code>GregorianCalendar</code>, the default of a field is the same as that
* of the start of the Epoch: i.e., <code>YEAR = 1970</code>, <code>MONTH =
* JANUARY</code>, <code>DAY_OF_MONTH = 1</code>, etc.
*
* <p>
* <strong>Note:</strong> There are certain possible ambiguities in
* interpretation of certain singular times, which are resolved in the
* following ways:
* <ol>
* <li> 23:59 is the last minute of the day and 00:00 is the first
* minute of the next day. Thus, 23:59 on Dec 31, 1999 < 00:00 on
* Jan 1, 2000 < 00:01 on Jan 1, 2000.
*
* <li> Although historically not precise, midnight also belongs to "am",
* and noon belongs to "pm", so on the same day,
* 12:00 am (midnight) < 12:01 am, and 12:00 pm (noon) < 12:01 pm
* </ol>
*
* <p>
* The date or time format strings are not part of the definition of a
* calendar, as those must be modifiable or overridable by the user at
* runtime. Use {@link DateFormat}
* to format dates.
*
* <h4>Field Manipulation</h4>
*
* The calendar 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 calendar field
* <code>f</code> to <code>value</code>. In addition, it sets an
* internal member variable to indicate that calendar field <code>f</code> has
* been changed. Although calendar field <code>f</code> is changed immediately,
* the calendar's time value in milliseconds is not recomputed until the next call to
* <code>get()</code>, <code>getTime()</code>, <code>getTimeInMillis()</code>,
* <code>add()</code>, or <code>roll()</code> is made. Thus, multiple calls to
* <code>set()</code> do not trigger multiple, unnecessary
* computations. As a result of changing a calendar field using
* <code>set()</code>, other calendar fields may also change, depending on the
* calendar field, the calendar field value, and the calendar system. In addition,
* <code>get(f)</code> will not necessarily return <code>value</code> set by
* the call to the <code>set</code> method
* after the calendar 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 date 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 date 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 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</code> is a smaller field than
* <code>DAY_OF_MONTH</code>. No adjustment is made to smaller fields
* that are not expected to be invariant. The calendar system
* determines what fields are expected to be invariant.</p>
* </blockquote>
*
* <p>In addition, unlike <code>set()</code>, <code>add()</code> forces
* an immediate recomputation of the calendar's milliseconds and all
* fields.</p>
*
* <p><em>Example</em>: Consider a <code>GregorianCalendar</code>
* originally set to August 31, 1999. Calling <code>add(Calendar.MONTH,
* 13)</code> sets the calendar to September 30, 2000. <strong>Add rule
* 1</strong> sets the <code>MONTH</code> field to September, since
* adding 13 months to August gives September of the next year. Since
* <code>DAY_OF_MONTH</code> cannot be 31 in September in a
* <code>GregorianCalendar</code>, <strong>add rule 2</strong> sets the
* <code>DAY_OF_MONTH</code> to 30, the closest possible value. Although
* it is a smaller field, <code>DAY_OF_WEEK</code> is not adjusted by
* rule 2, since it is expected to change when the month changes in a
* <code>GregorianCalendar</code>.</p>
*
* <p><strong><code>roll(f, delta)</code></strong> adds
* <code>delta</code> to field <code>f</code> without changing larger
* fields. This is equivalent to calling <code>add(f, delta)</code> with
* the following adjustment:</p>
*
* <blockquote>
* <p><strong>Roll rule</strong>. Larger fields are unchanged after the
* call. A larger field represents a larger unit of
* time. <code>DAY_OF_MONTH</code> is a larger field than
* <code>HOUR</code>.</p>
* </blockquote>
*
* <p><em>Example</em>: See {@link java.util.GregorianCalendar#roll(int, int)}.
*
* <p><strong>Usage model</strong>. To motivate the behavior of
* <code>add()</code> and <code>roll()</code>, consider a user interface
* component with increment and decrement buttons for the month, day, and
* year, and an underlying <code>GregorianCalendar</code>. If the
* interface reads January 31, 1999 and the user presses the month
* increment button, what should it read? If the underlying
* implementation uses <code>set()</code>, it might read March 3, 1999. A
* better result would be February 28, 1999. Furthermore, if the user
* presses the month increment button again, it should read March 31,
* 1999, not March 28, 1999. By saving the original date and using either
* <code>add()</code> or <code>roll()</code>, depending on whether larger
* fields should be affected, the user interface can behave as most users
* will intuitively expect.</p>
*
* @see java.lang.System#currentTimeMillis()
* @see Date
* @see GregorianCalendar
* @see TimeZone
* @see java.text.DateFormat
* @version 1.95, 05/05/07
* @author Mark Davis, David Goldsmith, Chen-Lieh Huang, Alan Liu
* @since JDK1.1
*/
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</code> and <code>set</code> indicating the
* era, e.g., AD or BC in the Julian calendar. This is a calendar-specific
* value; see subclass documentation.
*
* @see GregorianCalendar#AD
* @see GregorianCalendar#BC
*/
public final static int ERA = 0;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* year. This is a calendar-specific value; see subclass documentation.
*/
public final static int YEAR = 1;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* month. This is a calendar-specific value. The first month of
* the year in the Gregorian and Julian calendars is
* <code>JANUARY</code> which is 0; the last depends on the number
* of months in a year.
*
* @see #JANUARY
* @see #FEBRUARY
* @see #MARCH
* @see #APRIL
* @see #MAY
* @see #JUNE
* @see #JULY
* @see #AUGUST
* @see #SEPTEMBER
* @see #OCTOBER
* @see #NOVEMBER
* @see #DECEMBER
* @see #UNDECIMBER
*/
public final static int MONTH = 2;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* week number within the current year. The first week of the year, as
* defined by <code>getFirstDayOfWeek()</code> and
* <code>getMinimalDaysInFirstWeek()</code>, has value 1. Subclasses define
* the value of <code>WEEK_OF_YEAR</code> for days before the first week of
* the year.
*
* @see #getFirstDayOfWeek
* @see #getMinimalDaysInFirstWeek
*/
public final static int WEEK_OF_YEAR = 3;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* week number within the current month. The first week of the month, as
* defined by <code>getFirstDayOfWeek()</code> and
* <code>getMinimalDaysInFirstWeek()</code>, has value 1. Subclasses define
* the value of <code>WEEK_OF_MONTH</code> for days before the first week of
* the month.
*
* @see #getFirstDayOfWeek
* @see #getMinimalDaysInFirstWeek
*/
public final static int WEEK_OF_MONTH = 4;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* day of the month. This is a synonym for <code>DAY_OF_MONTH</code>.
* The first day of the month has value 1.
*
* @see #DAY_OF_MONTH
*/
public final static int DATE = 5;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* day of the month. This is a synonym for <code>DATE</code>.
* The first day of the month has value 1.
*
* @see #DATE
*/
public final static int DAY_OF_MONTH = 5;
/**
* Field number for <code>get</code> and <code>set</code> indicating the day
* number within the current year. The first day of the year has value 1.
*/
public final static int DAY_OF_YEAR = 6;
/**
* Field number for <code>get</code> and <code>set</code> indicating the day
* of the week. This field takes values <code>SUNDAY</code>,
* <code>MONDAY</code>, <code>TUESDAY</code>, <code>WEDNESDAY</code>,
* <code>THURSDAY</code>, <code>FRIDAY</code>, and <code>SATURDAY</code>.
*
* @see #SUNDAY
* @see #MONDAY
* @see #TUESDAY
* @see #WEDNESDAY
* @see #THURSDAY
* @see #FRIDAY
* @see #SATURDAY
*/
public final static int DAY_OF_WEEK = 7;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* ordinal number of the day of the week within the current month. Together
* with the <code>DAY_OF_WEEK</code> field, this uniquely specifies a day
* within a month. Unlike <code>WEEK_OF_MONTH</code> and
* <code>WEEK_OF_YEAR</code>, this field's value does <em>not</em> depend on
* <code>getFirstDayOfWeek()</code> or
* <code>getMinimalDaysInFirstWeek()</code>. <code>DAY_OF_MONTH 1</code>
* through <code>7</code> always correspond to <code>DAY_OF_WEEK_IN_MONTH
* 1</code>; <code>8</code> through <code>14</code> correspond to
* <code>DAY_OF_WEEK_IN_MONTH 2</code>, and so on.
* <code>DAY_OF_WEEK_IN_MONTH 0</code> indicates the week before
* <code>DAY_OF_WEEK_IN_MONTH 1</code>. Negative values count back from the
* end of the month, so the last Sunday of a month is specified as
* <code>DAY_OF_WEEK = SUNDAY, DAY_OF_WEEK_IN_MONTH = -1</code>. Because
* negative values count backward they will usually be aligned differently
* within the month than positive values. For example, if a month has 31
* days, <code>DAY_OF_WEEK_IN_MONTH -1</code> will overlap
* <code>DAY_OF_WEEK_IN_MONTH 5</code> and the end of <code>4</code>.
*
* @see #DAY_OF_WEEK
* @see #WEEK_OF_MONTH
*/
public final static int DAY_OF_WEEK_IN_MONTH = 8;
/**
* Field number for <code>get</code> and <code>set</code> indicating
* whether the <code>HOUR</code> is before or after noon.
* E.g., at 10:04:15.250 PM the <code>AM_PM</code> is <code>PM</code>.
*
* @see #AM
* @see #PM
* @see #HOUR
*/
public final static int AM_PM = 9;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* hour of the morning or afternoon. <code>HOUR</code> is used for the
* 12-hour clock (0 - 11). Noon and midnight are represented by 0, not by 12.
* E.g., at 10:04:15.250 PM the <code>HOUR</code> is 10.
*
* @see #AM_PM
* @see #HOUR_OF_DAY
*/
public final static int HOUR = 10;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* hour of the day. <code>HOUR_OF_DAY</code> is used for the 24-hour clock.
* E.g., at 10:04:15.250 PM the <code>HOUR_OF_DAY</code> is 22.
*
* @see #HOUR
*/
public final static int HOUR_OF_DAY = 11;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* minute within the hour.
* E.g., at 10:04:15.250 PM the <code>MINUTE</code> is 4.
*/
public final static int MINUTE = 12;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* second within the minute.
* E.g., at 10:04:15.250 PM the <code>SECOND</code> is 15.
*/
public final static int SECOND = 13;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* millisecond within the second.
* E.g., at 10:04:15.250 PM the <code>MILLISECOND</code> is 250.
*/
public final static int MILLISECOND = 14;
/**
* Field number for <code>get</code> and <code>set</code>
* indicating the raw offset from GMT in milliseconds.
* <p>
* This field reflects the correct GMT offset value of the time
* zone of this <code>Calendar</code> if the
* <code>TimeZone</code> implementation subclass supports
* historical GMT offset changes.
*/
public final static int ZONE_OFFSET = 15;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* daylight savings offset in milliseconds.
* <p>
* This field reflects the correct daylight saving offset value of
* the time zone of this <code>Calendar</code> if the
* <code>TimeZone</code> implementation subclass supports
* historical Daylight Saving Time schedule changes.
*/
public final static int DST_OFFSET = 16;
/**
* The number of distinct fields recognized by <code>get</code> and <code>set</code>.
* Field numbers range from <code>0..FIELD_COUNT-1</code>.
*/
public final static int FIELD_COUNT = 17;
/**
* Value of the {@link #DAY_OF_WEEK} field indicating
* Sunday.
*/
public final static int SUNDAY = 1;
/**
* Value of the {@link #DAY_OF_WEEK} field indicating
* Monday.
*/
public final static int MONDAY = 2;
/**
* Value of the {@link #DAY_OF_WEEK} field indicating
* Tuesday.
*/
public final static int TUESDAY = 3;
/**
* Value of the {@link #DAY_OF_WEEK} field indicating
* Wednesday.
*/
public final static int WEDNESDAY = 4;
/**
* Value of the {@link #DAY_OF_WEEK} field indicating
* Thursday.
*/
public final static int THURSDAY = 5;
/**
* Value of the {@link #DAY_OF_WEEK} field indicating
* Friday.
*/
public final static int FRIDAY = 6;
/**
* Value of the {@link #DAY_OF_WEEK} field indicating
* Saturday.
*/
public final static int SATURDAY = 7;
/**
* Value of the {@link #MONTH} field indicating the
* first month of the year in the Gregorian and Julian calendars.
*/
public final static int JANUARY = 0;
/**
* Value of the {@link #MONTH} field indicating the
* second month of the year in the Gregorian and Julian calendars.
*/
public final static int FEBRUARY = 1;
/**
* Value of the {@link #MONTH} field indicating the
* third month of the year in the Gregorian and Julian calendars.
*/
public final static int MARCH = 2;
/**
* Value of the {@link #MONTH} field indicating the
* fourth month of the year in the Gregorian and Julian calendars.
*/
public final static int APRIL = 3;
/**
* Value of the {@link #MONTH} field indicating the
* fifth month of the year in the Gregorian and Julian calendars.
*/
public final static int MAY = 4;
/**
* Value of the {@link #MONTH} field indicating the
* sixth month of the year in the Gregorian and Julian calendars.
*/
public final static int JUNE = 5;
/**
* Value of the {@link #MONTH} field indicating the
* seventh month of the year in the Gregorian and Julian calendars.
*/
public final static int JULY = 6;
/**
* Value of the {@link #MONTH} field indicating the
* eighth month of the year in the Gregorian and Julian calendars.
*/
public final static int AUGUST = 7;
/**
* Value of the {@link #MONTH} field indicating the
* ninth month of the year in the Gregorian and Julian calendars.
*/
public final static int SEPTEMBER = 8;
/**
* Value of the {@link #MONTH} field indicating the
* tenth month of the year in the Gregorian and Julian calendars.
*/
public final static int OCTOBER = 9;
/**
* Value of the {@link #MONTH} field indicating the
* eleventh month of the year in the Gregorian and Julian calendars.
*/
public final static int NOVEMBER = 10;
/**
* Value of the {@link #MONTH} field indicating the
* twelfth month of the year in the Gregorian and Julian calendars.
*/
public final static int DECEMBER = 11;
/**
* Value of the {@link #MONTH} field indicating the
* thirteenth month of the year. Although <code>GregorianCalendar</code>
* does not use this value, lunar calendars do.
*/
public final static int UNDECIMBER = 12;
/**
* Value of the {@link #AM_PM} field indicating the
* period of the day from midnight to just before noon.
*/
public final static int AM = 0;
/**
* Value of the {@link #AM_PM} field indicating the
* period of the day from noon to just before midnight.
*/
public final static 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
* @see #LONG
* @since 1.6
*/
public static final int ALL_STYLES = 0;
/**
* A style specifier for {@link #getDisplayName(int, int, Locale)
* getDisplayName} and {@link #getDisplayNames(int, int, Locale)
* getDisplayNames} indicating a short name, such as "Jan".
*
* @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} indicating a long name, such as "January".
*
* @see #SHORT
* @since 1.6
*/
public static final int LONG = 2;
// 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</code> integers, with index values
* <code>ERA</code> through <code>DST_OFFSET</code>.
* @serial
*/
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</code> booleans, with index values
* <code>ERA</code> through <code>DST_OFFSET</code>.
* @serial
*/
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.
*/
transient private int stamp[];
/**
* The currently set time for this calendar, expressed in milliseconds after
* January 1, 1970, 0:00:00 GMT.
* @see #isTimeSet
* @serial
*/
protected long time;
/**
* True if then the value of <code>time</code> is valid.
* The time is made invalid by a change to an item of <code>field[]</code>.
* @see #time
* @serial
*/
protected boolean isTimeSet;
/**
* True if <code>fields[]</code> are in sync with the currently set time.
* If false, then the next attempt to get the value of a field will
* force a recomputation of all fields from the current value of
* <code>time</code>.
* @serial
*/
protected boolean areFieldsSet;
/**
* True if all fields have been set.
* @serial
*/
transient boolean areAllFieldsSet;
/**
* <code>True</code> if this calendar allows out-of-range field values during computation
* of <code>time</code> from <code>fields[]</code>.
* @see #setLenient
* @see #isLenient
* @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;
/**
* <code>True</code> if zone references to a shared TimeZone object.
*/
transient private boolean sharedZone = false;
/**
* The first day of the week, with possible values <code>SUNDAY</code>,
* <code>MONDAY</code>, etc. This is a locale-dependent value.
* @serial
*/
private int firstDayOfWeek;
/**
* The number of days required for the first week in a month or year,
* with possible values from 1 to 7. This is a locale-dependent value.
* @serial
*/
private int minimalDaysInFirstWeek;
/**
* Cache to hold the firstDayOfWeek and minimalDaysInFirstWeek
* of a Locale.
*/
private static Hashtable<Locale, int[]> cachedLocaleData = new Hashtable<Locale, int[]>(
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[]</code>, an internal array.
* This actually should not be written out to the stream, and will probably
* be removed from the stream in the near future. In the meantime,
* a value of <code>MINIMUM_USER_STAMP</code> should be used.
* @serial
*/
private int nextStamp = MINIMUM_USER_STAMP;
// the internal serial version which says which version was written
// - 0 (default) for version up to JDK 1.1.5
// - 1 for version from JDK 1.1.6, which writes a correct 'time' value
// as well as compatible values for other fields. This is a
// transitional format.
// - 2 (not implemented yet) a future version, in which fields[],
// areFieldsSet, and isTimeSet become transient, and isSet[] is
// removed. In JDK 1.1.6 we write a format compatible with version 2.
static final int currentSerialVersion = 1;
/**
* The version of the serialized data on the stream. Possible values:
* <dl>
* <dt><b>0</b> or not present on stream</dt>
* <dd>
* JDK 1.1.5 or earlier.
* </dd>
* <dt><b>1</b></dt>
* <dd>
* JDK 1.1.6 or later. Writes a correct 'time' value
* as well as compatible values for other fields. This is a
* transitional format.
* </dd>
* </dl>
* When streaming out this class, the most recent format
* and the highest allowable <code>serialVersionOnStream</code>
* is written.
* @serial
* @since JDK1.1.6
*/
private int serialVersionOnStream = currentSerialVersion;
// Proclaim serialization compatibility with JDK 1.1
static final long serialVersionUID = -1807547505821590642L;
// Mask values for calendar fields
final static int ERA_MASK = (1 << ERA);
final static int YEAR_MASK = (1 << YEAR);
final static int MONTH_MASK = (1 << MONTH);
final static int WEEK_OF_YEAR_MASK = (1 << WEEK_OF_YEAR);
final static int WEEK_OF_MONTH_MASK = (1 << WEEK_OF_MONTH);
final static int DAY_OF_MONTH_MASK = (1 << DAY_OF_MONTH);
final static int DATE_MASK = DAY_OF_MONTH_MASK;
final static int DAY_OF_YEAR_MASK = (1 << DAY_OF_YEAR);
final static int DAY_OF_WEEK_MASK = (1 << DAY_OF_WEEK);
final static int DAY_OF_WEEK_IN_MONTH_MASK = (1 << DAY_OF_WEEK_IN_MONTH);
final static int AM_PM_MASK = (1 << AM_PM);
final static int HOUR_MASK = (1 << HOUR);
final static int HOUR_OF_DAY_MASK = (1 << HOUR_OF_DAY);
final static int MINUTE_MASK = (1 << MINUTE);
final static int SECOND_MASK = (1 << SECOND);
final static int MILLISECOND_MASK = (1 << MILLISECOND);
final static int ZONE_OFFSET_MASK = (1 << ZONE_OFFSET);
final static int DST_OFFSET_MASK = (1 << DST_OFFSET);
/**
* Constructs a Calendar with the default time zone
* and locale.
* @see TimeZone#getDefault
*/
protected Calendar() {
this (TimeZone.getDefaultRef(), Locale.getDefault());
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];
stamp = new int[FIELD_COUNT];
this .zone = zone;
setWeekCountData(aLocale);
}
/**
* Gets a calendar using the default time zone and locale. The
* <code>Calendar</code> returned is based on the current time
* in the default time zone with the default locale.
*
* @return a Calendar.
*/
public static Calendar getInstance() {
Calendar cal = createCalendar(TimeZone.getDefaultRef(), Locale
.getDefault());
cal.sharedZone = true;
return cal;
}
/**
* Gets a calendar using the specified time zone and default locale.
* The <code>Calendar</code> returned is based on the current time
* in the given time zone with the default locale.
*
* @param zone the time zone to use
* @return a Calendar.
*/
public static Calendar getInstance(TimeZone zone) {
return createCalendar(zone, Locale.getDefault());
}
/**
* Gets a calendar using the default time zone and specified locale.
* The <code>Calendar</code> returned is based on the current time
* in the default time zone with the given locale.
*
* @param aLocale the locale for the week data
* @return a Calendar.
*/
public static Calendar getInstance(Locale aLocale) {
Calendar cal = createCalendar(TimeZone.getDefaultRef(), aLocale);
cal.sharedZone = true;
return cal;
}
/**
* Gets a calendar with the specified time zone and locale.
* The <code>Calendar</code> returned is based on the current time
* in the given time zone with the given locale.
*
* @param zone the time zone to use
* @param aLocale the locale for the week data
* @return a Calendar.
*/
public static Calendar getInstance(TimeZone zone, Locale aLocale) {
return createCalendar(zone, aLocale);
}
private static Calendar createCalendar(TimeZone zone, Locale aLocale) {
// If the specified locale is a Thai locale, returns a BuddhistCalendar
// instance.
if ("th".equals(aLocale.getLanguage())
&& ("TH".equals(aLocale.getCountry()))) {
return new sun.util.BuddhistCalendar(zone, aLocale);
} else if ("JP".equals(aLocale.getVariant())
&& "JP".equals(aLocale.getCountry())
&& "ja".equals(aLocale.getLanguage())) {
return new JapaneseImperialCalendar(zone, aLocale);
}
// else create the default calendar
return new GregorianCalendar(zone, aLocale);
}
/**
* Returns an array of all locales for which the <code>getInstance</code>
* methods of this class can return localized instances.
* The array returned must contain at least a <code>Locale</code>
* instance equal to {@link java.util.Locale#US Locale.US}.
*
* @return An array of locales for which localized
* <code>Calendar</code> instances are available.
*/
public static synchronized Locale[] getAvailableLocales() {
return DateFormat.getAvailableLocales();
}
/**
* Converts the current calendar field values in {@link #fields fields[]}
* to the millisecond time value
* {@link #time}.
*
* @see #complete()
* @see #computeFields()
*/
protected abstract void computeTime();
/**
* Converts the current millisecond time value {@link #time}
* to calendar field values in {@link #fields fields[]}.
* This allows you to sync up the calendar 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
* {@link #complete()} method.
*
* @see #computeTime()
*/
protected abstract void computeFields();
/**
* Returns a <code>Date</code> object representing this
* <code>Calendar</code>'s time value (millisecond offset from the <a
* href="#Epoch">Epoch</a>").
*
* @return a <code>Date</code> representing the time value.
* @see #setTime(Date)
* @see #getTimeInMillis()
*/
public final Date getTime() {
return new Date(getTimeInMillis());
}
/**
* Sets this Calendar's time with the given <code>Date</code>.
* <p>
* Note: Calling <code>setTime()</code> with
* <code>Date(Long.MAX_VALUE)</code> or <code>Date(Long.MIN_VALUE)</code>
* may yield incorrect field values from <code>get()</code>.
*
* @param date the given Date.
* @see #getTime()
* @see #setTimeInMillis(long)
*/
public final void setTime(Date date) {
setTimeInMillis(date.getTime());
}
/**
* Returns this Calendar's time value in milliseconds.
*
* @return the current time as UTC milliseconds from the epoch.
* @see #getTime()
* @see #setTimeInMillis(long)
*/
public long getTimeInMillis() {
if (!isTimeSet) {
updateTime();
}
return time;
}
/**
* Sets this Calendar's current time from the given long value.
*
* @param millis the new time in UTC milliseconds from the epoch.
* @see #setTime(Date)
* @see #getTimeInMillis()
*/
public void setTimeInMillis(long millis) {
// If we don't need to recalculate the calendar field values,
// do nothing.
if (time == millis && isTimeSet && areFieldsSet
&& areAllFieldsSet && (zone instanceof ZoneInfo)
&& !((ZoneInfo) zone).isDirty()) {
return;
}
time = millis;
isTimeSet = true;
areFieldsSet = false;
computeFields();
areAllFieldsSet = areFieldsSet = true;
}
/**
* Returns the value of the given calendar field. In lenient mode,
* all calendar fields are normalized. In non-lenient mode, all
* calendar fields are validated and this method throws an
* exception if any calendar fields have out-of-range values. The
* normalization and validation are handled by the
* {@link #complete()} method, which process is calendar
* system dependent.
*
* @param field the given calendar field.
* @return the value for the given calendar field.
* @throws ArrayIndexOutOfBoundsException if the specified field is out of range
* (<code>field < 0 || field >= FIELD_COUNT</code>).
* @see #set(int,int)
* @see #complete()
*/
public int get(int field) {
complete();
return internalGet(field);
}
/**
* Returns the value of the given calendar field. This method does
* not involve normalization or validation of the field value.
*
* @param field the given calendar field.
* @return the value for the given calendar field.
* @see #get(int)
*/
protected final int internalGet(int field) {
return fields[field];
}
/**
* Sets the value of the given calendar field. This method does
* not affect any setting state of the field in this
* <code>Calendar</code> instance.
*
* @throws IndexOutOfBoundsException if the specified field is out of range
* (<code>field < 0 || field >= FIELD_COUNT</code>).
* @see #areFieldsSet
* @see #isTimeSet
* @see #areAllFieldsSet
* @see #set(int,int)
*/
final void internalSet(int field, int value) {
fields[field] = value;
}
/**
* Sets the given calendar field to the given value. The value is not
* interpreted by this method regardless of the leniency mode.
*
* @param field the given calendar field.
* @param value the value to be set for the given calendar field.
* @throws ArrayIndexOutOfBoundsException if the specified field is out of range
* (<code>field < 0 || field >= FIELD_COUNT</code>).
* in non-lenient mode.
* @see #set(int,int,int)
* @see #set(int,int,int,int,int)
* @see #set(int,int,int,int,int,int)
* @see #get(int)
*/
public void set(int field, int value) {
if (isLenient() && areFieldsSet && !areAllFieldsSet) {
computeFields();
}
internalSet(field, value);
isTimeSet = false;
areFieldsSet = false;
isSet[field] = true;
stamp[field] = nextStamp++;
if (nextStamp == Integer.MAX_VALUE) {
adjustStamp();
}
}
/**
* Sets the values for the calendar fields <code>YEAR</code>,
* <code>MONTH</code>, and <code>DAY_OF_MONTH</code>.
* Previous values of other calendar fields are retained. If this is not desired,
* call {@link #clear()} first.
*
* @param year the value used to set the <code>YEAR</code> calendar field.
* @param month the value used to set the <code>MONTH</code> calendar field.
* Month value is 0-based. e.g., 0 for January.
* @param date the value used to set the <code>DAY_OF_MONTH</code> calendar field.
* @see #set(int,int)
* @see #set(int,int,int,int,int)
* @see #set(int,int,int,int,int,int)
*/
public final void set(int year, int month, int date) {
set(YEAR, year);
set(MONTH, month);
set(DATE, date);
}
/**
* Sets the values for the calendar fields <code>YEAR</code>,
* <code>MONTH</code>, <code>DAY_OF_MONTH</code>,
* <code>HOUR_OF_DAY</code>, and <code>MINUTE</code>.
* Previous values of other fields are retained. If this is not desired,
* call {@link #clear()} first.
*
* @param year the value used to set the <code>YEAR</code> calendar field.
* @param month the value used to set the <code>MONTH</code> calendar field.
* Month value is 0-based. e.g., 0 for January.
* @param date the value used to set the <code>DAY_OF_MONTH</code> calendar field.
* @param hourOfDay the value used to set the <code>HOUR_OF_DAY</code> calendar field.
* @param minute the value used to set the <code>MINUTE</code> calendar field.
* @see #set(int,int)
* @see #set(int,int,int)
* @see #set(int,int,int,int,int,int)
*/
public final void set(int year, int month, int date, int hourOfDay,
int minute) {
set(YEAR, year);
set(MONTH, month);
set(DATE, date);
set(HOUR_OF_DAY, hourOfDay);
set(MINUTE, minute);
}
/**
* Sets the values for the fields <code>YEAR</code>, <code>MONTH</code>,
* <code>DAY_OF_MONTH</code>, <code>HOUR</code>, <code>MINUTE</code>, and
* <code>SECOND</code>.
* Previous values of other fields are retained. If this is not desired,
* call {@link #clear()} first.
*
* @param year the value used to set the <code>YEAR</code> calendar field.
* @param month the value used to set the <code>MONTH</code> calendar field.
* Month value is 0-based. e.g., 0 for January.
* @param date the value used to set the <code>DAY_OF_MONTH</code> calendar field.
* @param hourOfDay the value used to set the <code>HOUR_OF_DAY</code> calendar field.
* @param minute the value used to set the <code>MINUTE</code> calendar field.
* @param second the value used to set the <code>SECOND</code> calendar field.
* @see #set(int,int)
* @see #set(int,int,int)
* @see #set(int,int,int,int,int)
*/
public final void set(int year, int month, int date, int hourOfDay,
int minute, int second) {
set(YEAR, year);
set(MONTH, month);
set(DATE, date);
set(HOUR_OF_DAY, hourOfDay);
set(MINUTE, minute);
set(SECOND, second);
}
/**
* Sets all the calendar field values and the time value
* (millisecond offset from the <a href="#Epoch">Epoch</a>) of
* this <code>Calendar</code> undefined. This means that {@link
* #isSet(int) isSet()} will return <code>false</code> for all the
* calendar fields, and the date and time calculations will treat
* the fields as if they had never been set. A
* <code>Calendar</code> implementation class may use its specific
* default field values for date/time calculations. For example,
* <code>GregorianCalendar</code> uses 1970 if the
* <code>YEAR</code> field value is undefined.
*
* @see #clear(int)
*/
public final void clear() {
for (int i = 0; i < fields.length;) {
stamp[i] = fields[i] = 0; // UNSET == 0
isSet[i++] = false;
}
areAllFieldsSet = areFieldsSet = false;
isTimeSet = false;
}
/**
* Sets the given calendar field value and the time value
* (millisecond offset from the <a href="#Epoch">Epoch</a>) of
* this <code>Calendar</code> undefined. This means that {@link
* #isSet(int) isSet(field)} will return <code>false</code>, and
* the date and time calculations will treat the field as if it
* had never been set. A <code>Calendar</code> implementation
* class may use the field's specific default value for date and
* time calculations.
*
* <p>The {@link #HOUR_OF_DAY}, {@link #HOUR} and {@link #AM_PM}
* fields are handled independently and the <a
* href="#time_resolution">the resolution rule for the time of
* day</a> is applied. Clearing one of the fields doesn't reset
* the hour of day value of this <code>Calendar</code>. Use {@link
* #set(int,int) set(Calendar.HOUR_OF_DAY, 0)} to reset the hour
* value.
*
* @param field the calendar field to be cleared.
* @see #clear()
*/
public final void clear(int field) {
fields[field] = 0;
stamp[field] = UNSET;
isSet[field] = false;
areAllFieldsSet = areFieldsSet = false;
isTimeSet = false;
}
/**
* Determines if the given calendar field has a value set,
* including cases that the value has been set by internal fields
* calculations triggered by a <code>get</code> method call.
*
* @return <code>true</code> if the given calendar field has a value set;
* <code>false</code> otherwise.
*/
public final boolean isSet(int field) {
return stamp[field] != UNSET;
}
/**
* Returns the string representation of the calendar
* <code>field</code> value in the given <code>style</code> and
* <code>locale</code>. If no string representation is
* applicable, <code>null</code> is returned. This method calls
* {@link Calendar#get(int) get(field)} to get the calendar
* <code>field</code> value if the string representation is
* applicable to the given calendar <code>field</code>.
*
* <p>For example, if this <code>Calendar</code> is a
* <code>GregorianCalendar</code> and its date is 2005-01-01, then
* the string representation of the {@link #MONTH} field would be
* "January" in the long style in an English locale or "Jan" in
* the short style. However, no string representation would be
* available for the {@link #DAY_OF_MONTH} field, and this method
* would return <code>null</code>.
*
* <p>The default implementation supports the calendar fields for
* which a {@link DateFormatSymbols} has names in the given
* <code>locale</code>.
*
* @param field
* the calendar field for which the string representation
* is returned
* @param style
* the style applied to the string representation; one of
* {@link #SHORT} or {@link #LONG}.
* @param locale
* the locale for the string representation
* @return the string representation of the given
* <code>field</code> in the given <code>style</code>, or
* <code>null</code> if no string representation is
* applicable.
* @exception IllegalArgumentException
* if <code>field</code> or <code>style</code> is invalid,
* or if this <code>Calendar</code> is non-lenient and any
* of the calendar fields have invalid values
* @exception NullPointerException
* if <code>locale</code> is null
* @since 1.6
*/
public String getDisplayName(int field, int style, Locale locale) {
if (!checkDisplayNameParams(field, style, ALL_STYLES, LONG,
locale, ERA_MASK | MONTH_MASK | DAY_OF_WEEK_MASK
| AM_PM_MASK)) {
return null;
}
DateFormatSymbols symbols = DateFormatSymbols
.getInstance(locale);
String[] strings = getFieldStrings(field, style, symbols);
if (strings != null) {
int fieldValue = get(field);
if (fieldValue < strings.length) {
return strings[fieldValue];
}
}
return null;
}
/**
* Returns a <code>Map</code> containing all names of the calendar
* <code>field</code> in the given <code>style</code> and
* <code>locale</code> and their corresponding field values. For
* example, if this <code>Calendar</code> is a {@link
* GregorianCalendar}, the returned map would contain "Jan" to
* {@link #JANUARY}, "Feb" to {@link #FEBRUARY}, and so on, in the
* {@linkplain #SHORT short} style in an English locale.
*
* <p>The values of other calendar fields may be taken into
* account to determine a set of display names. For example, if
* this <code>Calendar</code> is a lunisolar calendar system and
* the year value given by the {@link #YEAR} field has a leap
* month, this method would return month names containing the leap
* month name, and month names are mapped to their values specific
* for the year.
*
* <p>The default implementation supports display names contained in
* a {@link DateFormatSymbols}. For example, if <code>field</code>
* is {@link #MONTH} and <code>style</code> is {@link
* #ALL_STYLES}, this method returns a <code>Map</code> containing
* all strings returned by {@link DateFormatSymbols#getShortMonths()}
* and {@link DateFormatSymbols#getMonths()}.
*
* @param field
* the calendar field for which the display names are returned
* @param style
* the style applied to the display names; one of {@link
* #SHORT}, {@link #LONG}, or {@link #ALL_STYLES}.
* @param locale
* the locale for the display names
* @return a <code>Map</code> containing all display names in
* <code>style</code> and <code>locale</code> and their
* field values, or <code>null</code> if no display names
* are defined for <code>field</code>
* @exception IllegalArgumentException
* if <code>field</code> or <code>style</code> is invalid,
* or if this <code>Calendar</code> is non-lenient and any
* of the calendar fields have invalid values
* @exception NullPointerException
* if <code>locale</code> is null
* @since 1.6
*/
public Map<String, Integer> getDisplayNames(int field, int style,
Locale locale) {
if (!checkDisplayNameParams(field, style, ALL_STYLES, LONG,
locale, ERA_MASK | MONTH_MASK | DAY_OF_WEEK_MASK
| AM_PM_MASK)) {
return null;
}
// ALL_STYLES
if (style == ALL_STYLES) {
Map<String, Integer> shortNames = getDisplayNamesImpl(
field, SHORT, locale);
if (field == ERA || field == AM_PM) {
return shortNames;
}
Map<String, Integer> longNames = getDisplayNamesImpl(field,
LONG, locale);
if (shortNames == null) {
return longNames;
}
if (longNames != null) {
shortNames.putAll(longNames);
}
return shortNames;
}
// SHORT or LONG
return getDisplayNamesImpl(field, style, locale);
}
private Map<String, Integer> getDisplayNamesImpl(int field,
int style, Locale locale) {
DateFormatSymbols symbols = DateFormatSymbols
.getInstance(locale);
String[] strings = getFieldStrings(field, style, symbols);
if (strings != null) {
Map<String, Integer> names = new HashMap<String, Integer>();
for (int i = 0; i < strings.length; i++) {
if (strings[i].length() == 0) {
continue;
}
names.put(strings[i], i);
}
return names;
}
return null;
}
boolean checkDisplayNameParams(int field, int style, int minStyle,
int maxStyle, Locale locale, int fieldMask) {
if (field < 0 || field >= fields.length || style < minStyle
|| style > maxStyle) {
throw new IllegalArgumentException();
}
if (locale == null) {
throw new NullPointerException();
}
return isFieldSet(fieldMask, field);
}
private String[] getFieldStrings(int field, int style,
DateFormatSymbols symbols) {
String[] strings = null;
switch (field) {
case ERA:
strings = symbols.getEras();
break;
case MONTH:
strings = (style == LONG) ? symbols.getMonths() : symbols
.getShortMonths();
break;
case DAY_OF_WEEK:
strings = (style == LONG) ? symbols.getWeekdays() : symbols
.getShortWeekdays();
break;
case AM_PM:
strings = symbols.getAmPmStrings();
break;
}
return strings;
}
/**
* Fills in any unset fields in the calendar fields. First, the {@link
* #computeTime()} method is called if the time value (millisecond offset
* from the <a href="#Epoch">Epoch</a>) has not been calculated from
* calendar field values. Then, the {@link #computeFields()} method is
* called to calculate all calendar field values.
*/
protected void complete() {
if (!isTimeSet)
updateTime();
if (!areFieldsSet || !areAllFieldsSet) {
computeFields(); // fills in unset fields
areAllFieldsSet = areFieldsSet = true;
}
}
/**
* Returns whether the value of the specified calendar field has been set
* externally by calling one of the setter methods rather than by the
* internal time calculation.
*
* @return <code>true</code> if the field has been set externally,
* <code>false</code> otherwise.
* @exception IndexOutOfBoundsException if the specified
* <code>field</code> is out of range
* (<code>field < 0 || field >= FIELD_COUNT</code>).
* @see #selectFields()
* @see #setFieldsComputed(int)
*/
final boolean isExternallySet(int field) {
return stamp[field] >= MINIMUM_USER_STAMP;
}
/**
* Returns a field mask (bit mask) indicating all calendar fields that
* have the state of externally or internally set.
*
* @return a bit mask indicating set state fields
*/
final int getSetStateFields() {
int mask = 0;
for (int i = 0; i < fields.length; i++) {
if (stamp[i] != UNSET) {
mask |= 1 << i;
}
}
return mask;
}
/**
* Sets the state of the specified calendar fields to
* <em>computed</em>. This state means that the specified calendar fields
* have valid values that have been set by internal time calculation
* rather than by calling one of the setter methods.
*
* @param fieldMask the field to be marked as computed.
* @exception IndexOutOfBoundsException if the specified
* <code>field</code> is out of range
* (<code>field < 0 || field >= FIELD_COUNT</code>).
* @see #isExternallySet(int)
* @see #selectFields()
*/
final void setFieldsComputed(int fieldMask) {
if (fieldMask == ALL_FIELDS) {
for (int i = 0; i < fields.length; i++) {
stamp[i] = COMPUTED;
isSet[i] = true;
}
areFieldsSet = areAllFieldsSet = true;
} else {
for (int i = 0; i < fields.length; i++) {
if ((fieldMask & 1) == 1) {
stamp[i] = COMPUTED;
isSet[i] = true;
} else {
if (areAllFieldsSet && !isSet[i]) {
areAllFieldsSet = false;
}
}
fieldMask >>>= 1;
}
}
}
/**
* Sets the state of the calendar fields that are <em>not</em> specified
* by <code>fieldMask</code> to <em>unset</em>. If <code>fieldMask</code>
* specifies all the calendar fields, then the state of this
* <code>Calendar</code> becomes that all the calendar fields are in sync
* with the time value (millisecond offset from the Epoch).
*
* @param fieldMask the field mask indicating which calendar fields are in
* sync with the time value.
* @exception IndexOutOfBoundsException if the specified
* <code>field</code> is out of range
* (<code>field < 0 || field >= FIELD_COUNT</code>).
* @see #isExternallySet(int)
* @see #selectFields()
*/
final void setFieldsNormalized(int fieldMask) {
if (fieldMask != ALL_FIELDS) {
for (int i = 0; i < fields.length; i++) {
if ((fieldMask & 1) == 0) {
stamp[i] = fields[i] = 0; // UNSET == 0
isSet[i] = false;
}
fieldMask >>= 1;
}
}
// Some or all of the fields are in sync with the
// milliseconds, but the stamp values are not normalized yet.
areFieldsSet = true;
areAllFieldsSet = false;
}
/**
* Returns whether the calendar fields are partially in sync with the time
* value or fully in sync but not stamp values are not normalized yet.
*/
final boolean isPartiallyNormalized() {
return areFieldsSet && !areAllFieldsSet;
}
/**
* Returns whether the calendar fields are fully in sync with the time
* value.
*/
final boolean isFullyNormalized() {
return areFieldsSet && areAllFieldsSet;
}
/**
* Marks this Calendar as not sync'd.
*/
final void setUnnormalized() {
areFieldsSet = areAllFieldsSet = false;
}
/**
* Returns whether the specified <code>field</code> is on in the
* <code>fieldMask</code>.
*/
static final boolean isFieldSet(int fieldMask, int field) {
return (fieldMask & (1 << field)) != 0;
}
/**
* Returns a field mask indicating which calendar field values
* to be used to calculate the time value. The calendar fields are
* returned as a bit mask, each bit of which corresponds to a field, i.e.,
* the mask value of <code>field</code> is <code>(1 <<
* field)</code>. For example, 0x26 represents the <code>YEAR</code>,
* <code>MONTH</code>, and <code>DAY_OF_MONTH</code> fields (i.e., 0x26 is
* equal to
* <code>(1<<YEAR)|(1<<MONTH)|(1<<DAY_OF_MONTH))</code>.
*
* <p>This method supports the calendar fields resolution as described in
* the class description. If the bit mask for a given field is on and its
* field has not been set (i.e., <code>isSet(field)</code> is
* <code>false</code>), then the default value of the field has to be
* used, which case means that the field has been selected because the
* selected combination involves the field.
*
* @return a bit mask of selected fields
* @see #isExternallySet(int)
* @see #setInternallySetState(int)
*/
final int selectFields() {
// This implementation has been taken from the GregorianCalendar class.
// The YEAR field must always be used regardless of its SET
// state because YEAR is a mandatory field to determine the date
// and the default value (EPOCH_YEAR) may change through the
// normalization process.
int fieldMask = YEAR_MASK;
if (stamp[ERA] != UNSET) {
fieldMask |= ERA_MASK;
}
// Find the most recent group of fields specifying the day within
// the year. These may be any of the following combinations:
// MONTH + DAY_OF_MONTH
// MONTH + WEEK_OF_MONTH + DAY_OF_WEEK
// MONTH + DAY_OF_WEEK_IN_MONTH + DAY_OF_WEEK
// DAY_OF_YEAR
// WEEK_OF_YEAR + DAY_OF_WEEK
// We look for the most recent of the fields in each group to determine
// the age of the group. For groups involving a week-related field such
// as WEEK_OF_MONTH, DAY_OF_WEEK_IN_MONTH, or WEEK_OF_YEAR, both the
// week-related field and the DAY_OF_WEEK must be set for the group as a
// whole to be considered. (See bug 4153860 - liu 7/24/98.)
int dowStamp = stamp[DAY_OF_WEEK];
int monthStamp = stamp[MONTH];
int domStamp = stamp[DAY_OF_MONTH];
int womStamp = aggregateStamp(stamp[WEEK_OF_MONTH], dowStamp);
int dowimStamp = aggregateStamp(stamp[DAY_OF_WEEK_IN_MONTH],
dowStamp);
int doyStamp = stamp[DAY_OF_YEAR];
int woyStamp = aggregateStamp(stamp[WEEK_OF_YEAR], dowStamp);
int bestStamp = domStamp;
if (womStamp > bestStamp) {
bestStamp = womStamp;
}
if (dowimStamp > bestStamp) {
bestStamp = dowimStamp;
}
if (doyStamp > bestStamp) {
bestStamp = doyStamp;
}
if (woyStamp > bestStamp) {
bestStamp = woyStamp;
}
/* No complete combination exists. Look for WEEK_OF_MONTH,
* DAY_OF_WEEK_IN_MONTH, or WEEK_OF_YEAR alone. Treat DAY_OF_WEEK alone
* as DAY_OF_WEEK_IN_MONTH.
*/
if (bestStamp == UNSET) {
womStamp = stamp[WEEK_OF_MONTH];
dowimStamp = Math
.max(stamp[DAY_OF_WEEK_IN_MONTH], dowStamp);
woyStamp = stamp[WEEK_OF_YEAR];
bestStamp = Math.max(Math.max(womStamp, dowimStamp),
woyStamp);
/* Treat MONTH alone or no fields at all as DAY_OF_MONTH. This may
* result in bestStamp = domStamp = UNSET if no fields are set,
* which indicates DAY_OF_MONTH.
*/
if (bestStamp == UNSET) {
bestStamp = domStamp = monthStamp;
}
}
if (bestStamp == domStamp
|| (bestStamp == womStamp && stamp[WEEK_OF_MONTH] >= stamp[WEEK_OF_YEAR])
|| (bestStamp == dowimStamp && stamp[DAY_OF_WEEK_IN_MONTH] >= stamp[WEEK_OF_YEAR])) {
fieldMask |= MONTH_MASK;
if (bestStamp == domStamp) {
fieldMask |= DAY_OF_MONTH_MASK;
} else {
assert (bestStamp == womStamp || bestStamp == dowimStamp);
if (dowStamp != UNSET) {
fieldMask |= DAY_OF_WEEK_MASK;
}
if (womStamp == dowimStamp) {
// When they are equal, give the priority to
// WEEK_OF_MONTH for compatibility.
if (stamp[WEEK_OF_MONTH] >= stamp[DAY_OF_WEEK_IN_MONTH]) {
fieldMask |= WEEK_OF_MONTH_MASK;
} else {
fieldMask |= DAY_OF_WEEK_IN_MONTH_MASK;
}
} else {
if (bestStamp == womStamp) {
fieldMask |= WEEK_OF_MONTH_MASK;
} else {
assert (bestStamp == dowimStamp);
if (stamp[DAY_OF_WEEK_IN_MONTH] != UNSET) {
fieldMask |= DAY_OF_WEEK_IN_MONTH_MASK;
}
}
}
}
} else {
assert (bestStamp == doyStamp || bestStamp == woyStamp || bestStamp == UNSET);
if (bestStamp == doyStamp) {
fieldMask |= DAY_OF_YEAR_MASK;
} else {
assert (bestStamp == woyStamp);
if (dowStamp != UNSET) {
fieldMask |= DAY_OF_WEEK_MASK;
}
fieldMask |= WEEK_OF_YEAR_MASK;
}
}
// 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 = aggregateStamp(stamp[HOUR], stamp[AM_PM]);
bestStamp = (hourStamp > hourOfDayStamp) ? hourStamp
: hourOfDayStamp;
// if bestStamp is still UNSET, then take HOUR or AM_PM. (See 4846659)
if (bestStamp == UNSET) {
bestStamp = Math.max(stamp[HOUR], stamp[AM_PM]);
}
// Hours
if (bestStamp != UNSET) {
if (bestStamp == hourOfDayStamp) {
fieldMask |= HOUR_OF_DAY_MASK;
} else {
fieldMask |= HOUR_MASK;
if (stamp[AM_PM] != UNSET) {
fieldMask |= AM_PM_MASK;
}
}
}
if (stamp[MINUTE] != UNSET) {
fieldMask |= MINUTE_MASK;
}
if (stamp[SECOND] != UNSET) {
fieldMask |= SECOND_MASK;
}
if (stamp[MILLISECOND] != UNSET) {
fieldMask |= MILLISECOND_MASK;
}
if (stamp[ZONE_OFFSET] >= MINIMUM_USER_STAMP) {
fieldMask |= ZONE_OFFSET_MASK;
}
if (stamp[DST_OFFSET] >= MINIMUM_USER_STAMP) {
fieldMask |= DST_OFFSET_MASK;
}
return fieldMask;
}
/**
* Returns the pseudo-time-stamp for two fields, given their
* individual pseudo-time-stamps. If either of the fields
* is unset, then the aggregate is unset. Otherwise, the
* aggregate is the later of the two stamps.
*/
private static final int aggregateStamp(int stamp_a, int stamp_b) {
if (stamp_a == UNSET || stamp_b == UNSET) {
return UNSET;
}
return (stamp_a > stamp_b) ? stamp_a : stamp_b;
}
/**
* Compares this <code>Calendar</code> to the specified
* <code>Object</code>. The result is <code>true</code> if and only if
* the argument is a <code>Calendar</code> object of the same calendar
* system that represents the same time value (millisecond offset from the
* <a href="#Epoch">Epoch</a>) under the same
* <code>Calendar</code> parameters as this object.
*
* <p>The <code>Calendar</code> parameters are the values represented
* by the <code>isLenient</code>, <code>getFirstDayOfWeek</code>,
* <code>getMinimalDaysInFirstWeek</code> and <code>getTimeZone</code>
* methods. If there is any difference in those parameters
* between the two <code>Calendar</code>s, this method returns
* <code>false</code>.
*
* <p>Use the {@link #compareTo(Calendar) compareTo} method to
* compare only the time values.
*
* @param obj the object to compare with.
* @return <code>true</code> if this object is equal to <code>obj</code>;
* <code>false</code> otherwise.
*/
public boolean equals(Object obj) {
if (this == obj)
return true;
try {
Calendar that = (Calendar) obj;
return compareTo(getMillisOf(that)) == 0
&& lenient == that.lenient
&& firstDayOfWeek == that.firstDayOfWeek
&& minimalDaysInFirstWeek == that.minimalDaysInFirstWeek
&& zone.equals(that.zone);
} catch (Exception e) {
// Note: GregorianCalendar.computeTime throws
// IllegalArgumentException if the ERA value is invalid
// even it's in lenient mode.
}
return false;
}
/**
* Returns a hash code for this calendar.
*
* @return a hash code value for this object.
* @since 1.2
*/
public int hashCode() {
// 'otheritems' represents the hash code for the previous versions.
int otheritems = (lenient ? 1 : 0) | (firstDayOfWeek << 1)
| (minimalDaysInFirstWeek << 4)
| (zone.hashCode() << 7);
long t = getMillisOf(this );
return (int) t ^ (int) (t >> 32) ^ otheritems;
}
/**
* Returns whether this <code>Calendar</code> represents a time
* before the time represented by the specified
* <code>Object</code>. This method is equivalent to:
* <pre><blockquote>
* compareTo(when) < 0
* </blockquote></pre>
* if and only if <code>when</code> is a <code>Calendar</code>
* instance. Otherwise, the method returns <code>false</code>.
*
* @param when the <code>Object</code> to be compared
* @return <code>true</code> if the time of this
* <code>Calendar</code> is before the time represented by
* <code>when</code>; <code>false</code> otherwise.
* @see #compareTo(Calendar)
*/
public boolean before(Object when) {
return when instanceof Calendar
&& compareTo((Calendar) when) < 0;
}
/**
* Returns whether this <code>Calendar</code> represents a time
* after the time represented by the specified
* <code>Object</code>. This method is equivalent to:
* <pre><blockquote>
* compareTo(when) > 0
* </blockquote></pre>
* if and only if <code>when</code> is a <code>Calendar</code>
* instance. Otherwise, the method returns <code>false</code>.
*
* @param when the <code>Object</code> to be compared
* @return <code>true</code> if the time of this <code>Calendar</code> is
* after the time represented by <code>when</code>; <code>false</code>
* otherwise.
* @see #compareTo(Calendar)
*/
public boolean after(Object when) {
return when instanceof Calendar
&& compareTo((Calendar) when) > 0;
}
/**
* Compares the time values (millisecond offsets from the <a
* href="#Epoch">Epoch</a>) represented by two
* <code>Calendar</code> objects.
*
* @param anotherCalendar the <code>Calendar</code> to be compared.
* @return the value <code>0</code> if the time represented by the argument
* is equal to the time represented by this <code>Calendar</code>; a value
* less than <code>0</code> if the time of this <code>Calendar</code> is
* before the time represented by the argument; and a value greater than
* <code>0</code> if the time of this <code>Calendar</code> is after the
* time represented by the argument.
* @exception NullPointerException if the specified <code>Calendar</code> is
* <code>null</code>.
* @exception IllegalArgumentException if the time value of the
* specified <code>Calendar</code> object can't be obtained due to
* any invalid calendar values.
* @since 1.5
*/
public int compareTo(Calendar anotherCalendar) {
return compareTo(getMillisOf(anotherCalendar));
}
/**
* Adds or subtracts the specified amount of time to the given calendar field,
* based on the calendar's rules. For example, to subtract 5 days from
* the current time of the calendar, you can achieve it by calling:
* <p><code>add(Calendar.DAY_OF_MONTH, -5)</code>.
*
* @param field the calendar field.
* @param amount the amount of date or time to be added to the field.
* @see #roll(int,int)
* @see #set(int,int)
*/
abstract public void add(int field, int amount);
/**
* Adds or subtracts (up/down) a single unit of time on the given time
* field without changing larger fields. For example, to roll the current
* date up by one day, you can achieve it by calling:
* <p>roll(Calendar.DATE, true).
* When rolling on the year or Calendar.YEAR field, it will roll the year
* value in the range between 1 and the value returned by calling
* <code>getMaximum(Calendar.YEAR)</code>.
* When rolling on the month or Calendar.MONTH field, other fields like
* date might conflict and, need to be changed. For instance,
* rolling the month on the date 01/31/96 will result in 02/29/96.
* When rolling on the hour-in-day or Calendar.HOUR_OF_DAY field, it will
* roll the hour value in the range between 0 and 23, which is zero-based.
*
* @param field the time field.
* @param up indicates if the value of the specified time field is to be
* rolled up or rolled down. Use true if rolling up, false otherwise.
* @see Calendar#add(int,int)
* @see Calendar#set(int,int)
*/
abstract public void roll(int field, boolean up);
/**
* Adds the specified (signed) amount to the specified calendar field
* without changing larger fields. A negative amount means to roll
* down.
*
* <p>NOTE: This default implementation on <code>Calendar</code> just repeatedly calls the
* version of {@link #roll(int,boolean) roll()} that rolls by one unit. This may not
* always do the right thing. For example, if the <code>DAY_OF_MONTH</code> field is 31,
* rolling through February will leave it set to 28. The <code>GregorianCalendar</code>
* version of this function takes care of this problem. Other subclasses
* should also provide overrides of this function that do the right thing.
*
* @param field the calendar field.
* @param amount the signed amount to add to the calendar <code>field</code>.
* @since 1.2
* @see #roll(int,boolean)
* @see #add(int,int)
* @see #set(int,int)
*/
public void roll(int field, int amount) {
while (amount > 0) {
roll(field, true);
amount--;
}
while (amount < 0) {
roll(field, false);
amount++;
}
}
/**
* Sets the time zone with the given time zone value.
*
* @param value the given time zone.
*/
public void setTimeZone(TimeZone value) {
zone = value;
sharedZone = false;
/* 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().
*/
areAllFieldsSet = areFieldsSet = false;
}
/**
* Gets the time zone.
*
* @return the time zone object associated with this calendar.
*/
public TimeZone getTimeZone() {
// If the TimeZone object is shared by other Calendar instances, then
// create a clone.
if (sharedZone) {
zone = (TimeZone) zone.clone();
sharedZone = false;
}
return zone;
}
/**
* Returns the time zone (without cloning).
*/
TimeZone getZone() {
return zone;
}
/**
* Sets the sharedZone flag to <code>shared</code>.
*/
void setZoneShared(boolean shared) {
sharedZone = shared;
}
/**
* Specifies 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 (non-lenient) interpretation, such dates will cause an exception to be
* thrown. The default is lenient.
*
* @param lenient <code>true</code> if the lenient mode is to be turned
* on; <code>false</code> if it is to be turned off.
* @see #isLenient()
* @see java.text.DateFormat#setLenient
*/
public void setLenient(boolean lenient) {
this .lenient = lenient;
}
/**
* Tells whether date/time interpretation is to be lenient.
*
* @return <code>true</code> if the interpretation mode of this calendar is lenient;
* <code>false</code> otherwise.
* @see #setLenient(boolean)
*/
public boolean isLenient() {
return lenient;
}
/**
* Sets what the first day of the week is; e.g., <code>SUNDAY</code> in the U.S.,
* <code>MONDAY</code> in France.
*
* @param value the given first day of the week.
* @see #getFirstDayOfWeek()
* @see #getMinimalDaysInFirstWeek()
*/
public void setFirstDayOfWeek(int value) {
if (firstDayOfWeek == value) {
return;
}
firstDayOfWeek = value;
invalidateWeekFields();
}
/**
* Gets what the first day of the week is; e.g., <code>SUNDAY</code> in the U.S.,
* <code>MONDAY</code> in France.
*
* @return the first day of the week.
* @see #setFirstDayOfWeek(int)
* @see #getMinimalDaysInFirstWeek()
*/
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 this 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.
* @see #getMinimalDaysInFirstWeek()
*/
public void setMinimalDaysInFirstWeek(int value) {
if (minimalDaysInFirstWeek == value) {
return;
}
minimalDaysInFirstWeek = value;
invalidateWeekFields();
}
/**
* Gets what the minimal days required in the first week of the year are;
* e.g., if the first week is defined as one that contains the first day
* of the first month of a year, this method returns 1. If
* the minimal days required must be a full week, this method
* returns 7.
*
* @return the minimal days required in the first week of the year.
* @see #setMinimalDaysInFirstWeek(int)
*/
public int getMinimalDaysInFirstWeek() {
return minimalDaysInFirstWeek;
}
/**
* Returns the minimum value for the given calendar field of this
* <code>Calendar</code> instance. The minimum value is defined as
* the smallest value returned by the {@link #get(int) get} method
* for any possible time value. The minimum value depends on
* calendar system specific parameters of the instance.
*
* @param field the calendar field.
* @return the minimum value for the given calendar field.
* @see #getMaximum(int)
* @see #getGreatestMinimum(int)
* @see #getLeastMaximum(int)
* @see #getActualMinimum(int)
* @see #getActualMaximum(int)
*/
abstract public int getMinimum(int field);
/**
* Returns the maximum value for the given calendar field of this
* <code>Calendar</code> instance. The maximum value is defined as
* the largest value returned by the {@link #get(int) get} method
* for any possible time value. The maximum value depends on
* calendar system specific parameters of the instance.
*
* @param field the calendar field.
* @return the maximum value for the given calendar field.
* @see #getMinimum(int)
* @see #getGreatestMinimum(int)
* @see #getLeastMaximum(int)
* @see #getActualMinimum(int)
* @see #getActualMaximum(int)
*/
abstract public int getMaximum(int field);
/**
* Returns the highest minimum value for the given calendar field
* of this <code>Calendar</code> instance. The highest minimum
* value is defined as the largest value returned by {@link
* #getActualMinimum(int)} for any possible time value. The
* greatest minimum value depends on calendar system specific
* parameters of the instance.
*
* @param field the calendar field.
* @return the highest minimum value for the given calendar field.
* @see #getMinimum(int)
* @see #getMaximum(int)
* @see #getLeastMaximum(int)
* @see #getActualMinimum(int)
* @see #getActualMaximum(int)
*/
abstract public int getGreatestMinimum(int field);
/**
* Returns the lowest maximum value for the given calendar field
* of this <code>Calendar</code> instance. The lowest maximum
* value is defined as the smallest value returned by {@link
* #getActualMaximum(int)} for any possible time value. The least
* maximum value depends on calendar system specific parameters of
* the instance. For example, a <code>Calendar</code> for the
* Gregorian calendar system returns 28 for the
* <code>DAY_OF_MONTH</code> field, because the 28th is the last
* day of the shortest month of this calendar, February in a
* common year.
*
* @param field the calendar field.
* @return the lowest maximum value for the given calendar field.
* @see #getMinimum(int)
* @see #getMaximum(int)
* @see #getGreatestMinimum(int)
* @see #getActualMinimum(int)
* @see #getActualMaximum(int)
*/
abstract public int getLeastMaximum(int field);
/**
* Returns the minimum value that the specified calendar field
* could have, given the time value of this <code>Calendar</code>.
*
* <p>The default implementation of this method uses an iterative
* algorithm to determine the actual minimum value for the
* calendar field. Subclasses should, if possible, override this
* with a more efficient implementation - in many cases, they can
* simply return <code>getMinimum()</code>.
*
* @param field the calendar field
* @return the minimum of the given calendar field for the time
* value of this <code>Calendar</code>
* @see #getMinimum(int)
* @see #getMaximum(int)
* @see #getGreatestMinimum(int)
* @see #getLeastMaximum(int)
* @see #getActualMaximum(int)
* @since 1.2
*/
public int getActualMinimum(int field) {
int fieldValue = getGreatestMinimum(field);
int endValue = getMinimum(field);
// if we know that the minimum value is always the same, just return it
if (fieldValue == endValue) {
return fieldValue;
}
// clone the calendar so we don't mess with the real one, and set it to
// accept anything for the field values
Calendar work = (Calendar) this .clone();
work.setLenient(true);
// now try each value from getLeastMaximum() to getMaximum() one by one until
// we get a value that normalizes to another value. The last value that
// normalizes to itself is the actual minimum for the current date
int result = fieldValue;
do {
work.set(field, fieldValue);
if (work.get(field) != fieldValue) {
break;
} else {
result = fieldValue;
fieldValue--;
}
} while (fieldValue >= endValue);
return result;
}
/**
* Returns the maximum value that the specified calendar field
* could have, given the time value of this
* <code>Calendar</code>. For example, the actual maximum value of
* the <code>MONTH</code> field is 12 in some years, and 13 in
* other years in the Hebrew calendar system.
*
* <p>The default implementation of this method uses an iterative
* algorithm to determine the actual maximum value for the
* calendar field. Subclasses should, if possible, override this
* with a more efficient implementation.
*
* @param field the calendar field
* @return the maximum of the given calendar field for the time
* value of this <code>Calendar</code>
* @see #getMinimum(int)
* @see #getMaximum(int)
* @see #getGreatestMinimum(int)
* @see #getLeastMaximum(int)
* @see #getActualMinimum(int)
* @since 1.2
*/
public int getActualMaximum(int field) {
int fieldValue = getLeastMaximum(field);
int endValue = getMaximum(field);
// if we know that the maximum value is always the same, just return it.
if (fieldValue == endValue) {
return fieldValue;
}
// clone the calendar so we don't mess with the real one, and set it to
// accept anything for the field values.
Calendar work = (Calendar) this .clone();
work.setLenient(true);
// if we're counting weeks, set the day of the week to Sunday. We know the
// last week of a month or year will contain the first day of the week.
if (field == WEEK_OF_YEAR || field == WEEK_OF_MONTH)
work.set(DAY_OF_WEEK, firstDayOfWeek);
// now try each value from getLeastMaximum() to getMaximum() one by one until
// we get a value that normalizes to another value. The last value that
// normalizes to itself is the actual maximum for the current date
int result = fieldValue;
do {
work.set(field, fieldValue);
if (work.get(field) != fieldValue) {
break;
} else {
result = fieldValue;
fieldValue++;
}
} while (fieldValue <= endValue);
return result;
}
/**
* Creates and returns a copy of this object.
*
* @return a copy of this object.
*/
public Object clone() {
try {
Calendar other = (Calendar) super .clone();
other.fields = new int[FIELD_COUNT];
other.isSet = new boolean[FIELD_COUNT];
other.stamp = new int[FIELD_COUNT];
for (int i = 0; i < FIELD_COUNT; i++) {
other.fields[i] = fields[i];
other.stamp[i] = stamp[i];
other.isSet[i] = isSet[i];
}
other.zone = (TimeZone) zone.clone();
return other;
} catch (CloneNotSupportedException e) {
// this shouldn't happen, since we are Cloneable
throw new InternalError();
}
}
private static final String[] FIELD_NAME = { "ERA", "YEAR",
"MONTH", "WEEK_OF_YEAR", "WEEK_OF_MONTH", "DAY_OF_MONTH",
"DAY_OF_YEAR", "DAY_OF_WEEK", "DAY_OF_WEEK_IN_MONTH",
"AM_PM", "HOUR", "HOUR_OF_DAY", "MINUTE", "SECOND",
"MILLISECOND", "ZONE_OFFSET", "DST_OFFSET" };
/**
* Returns the name of the specified calendar field.
*
* @param field the calendar field
* @return the calendar field name
* @exception IndexOutOfBoundsException if <code>field</code> is negative,
* equal to or greater then <code>FIELD_COUNT</code>.
*/
static final String getFieldName(int field) {
return FIELD_NAME[field];
}
/**
* Return a string representation of this calendar. This method
* is intended to be used only for debugging purposes, and the
* format of the returned string may vary between implementations.
* The returned string may be empty but may not be <code>null</code>.
*
* @return a string representation of this calendar.
*/
public String toString() {
// NOTE: BuddhistCalendar.toString() interprets the string
// produced by this method so that the Gregorian year number
// is substituted by its B.E. year value. It relies on
// "...,YEAR=<year>,..." or "...,YEAR=?,...".
StringBuilder buffer = new StringBuilder(800);
buffer.append(getClass().getName()).append('[');
appendValue(buffer, "time", isTimeSet, time);
buffer.append(",areFieldsSet=").append(areFieldsSet);
buffer.append(",areAllFieldsSet=").append(areAllFieldsSet);
buffer.append(",lenient=").append(lenient);
buffer.append(",zone=").append(zone);
appendValue(buffer, ",firstDayOfWeek", true,
(long) firstDayOfWeek);
appendValue(buffer, ",minimalDaysInFirstWeek", true,
(long) minimalDaysInFirstWeek);
for (int i = 0; i < FIELD_COUNT; ++i) {
buffer.append(',');
appendValue(buffer, FIELD_NAME[i], isSet(i),
(long) fields[i]);
}
buffer.append(']');
return buffer.toString();
}
// =======================privates===============================
private static final void appendValue(StringBuilder sb,
String item, boolean valid, long value) {
sb.append(item).append('=');
if (valid) {
sb.append(value);
} else {
sb.append('?');
}
}
/**
* Both firstDayOfWeek and minimalDaysInFirstWeek are locale-dependent.
* They are used to figure out the week count for a specific date for
* a given locale. These must be set when a Calendar is constructed.
* @param desiredLocale the given locale.
*/
private void setWeekCountData(Locale desiredLocale) {
/* try to get the Locale data from the cache */
int[] data = cachedLocaleData.get(desiredLocale);
if (data == null) { /* cache miss */
ResourceBundle bundle = LocaleData
.getCalendarData(desiredLocale);
data = new int[2];
data[0] = Integer.parseInt(bundle
.getString("firstDayOfWeek"));
data[1] = Integer.parseInt(bundle
.getString("minimalDaysInFirstWeek"));
cachedLocaleData.put(desiredLocale, data);
}
firstDayOfWeek = data[0];
minimalDaysInFirstWeek = data[1];
}
/**
* Recomputes the time and updates the status fields isTimeSet
* and areFieldsSet. Callers should check isTimeSet and only
* call this method if isTimeSet is false.
*/
private void updateTime() {
computeTime();
// The areFieldsSet and areAllFieldsSet values are no longer
// controlled here (as of 1.5).
isTimeSet = true;
}
private int compareTo(long t) {
long this Time = getMillisOf(this );
return (this Time > t) ? 1 : (this Time == t) ? 0 : -1;
}
private static final long getMillisOf(Calendar calendar) {
if (calendar.isTimeSet) {
return calendar.time;
}
Calendar cal = (Calendar) calendar.clone();
cal.setLenient(true);
return cal.getTimeInMillis();
}
/**
* Adjusts the stamp[] values before nextStamp overflow. nextStamp
* is set to the next stamp value upon the return.
*/
private final void adjustStamp() {
int max = MINIMUM_USER_STAMP;
int newStamp = MINIMUM_USER_STAMP;
for (;;) {
int min = Integer.MAX_VALUE;
for (int i = 0; i < stamp.length; i++) {
int v = stamp[i];
if (v >= newStamp && min > v) {
min = v;
}
if (max < v) {
max = v;
}
}
if (max != min && min == Integer.MAX_VALUE) {
break;
}
for (int i = 0; i < stamp.length; i++) {
if (stamp[i] == min) {
stamp[i] = newStamp;
}
}
newStamp++;
if (min == max) {
break;
}
}
nextStamp = newStamp;
}
/**
* Sets the WEEK_OF_MONTH and WEEK_OF_YEAR fields to new values with the
* new parameter value if they have been calculated internally.
*/
private void invalidateWeekFields() {
if (stamp[WEEK_OF_MONTH] != COMPUTED
&& stamp[WEEK_OF_YEAR] != COMPUTED) {
return;
}
// We have to check the new values of these fields after changing
// firstDayOfWeek and/or minimalDaysInFirstWeek. If the field values
// have been changed, then set the new values. (4822110)
Calendar cal = (Calendar) clone();
cal.setLenient(true);
cal.clear(WEEK_OF_MONTH);
cal.clear(WEEK_OF_YEAR);
if (stamp[WEEK_OF_MONTH] == COMPUTED) {
int weekOfMonth = cal.get(WEEK_OF_MONTH);
if (fields[WEEK_OF_MONTH] != weekOfMonth) {
fields[WEEK_OF_MONTH] = weekOfMonth;
}
}
if (stamp[WEEK_OF_YEAR] == COMPUTED) {
int weekOfYear = cal.get(WEEK_OF_YEAR);
if (fields[WEEK_OF_YEAR] != weekOfYear) {
fields[WEEK_OF_YEAR] = weekOfYear;
}
}
}
/**
* Save the state of this object to a stream (i.e., serialize it).
*
* Ideally, <code>Calendar</code> would only write out its state data and
* the current time, and not write any field data out, such as
* <code>fields[]</code>, <code>isTimeSet</code>, <code>areFieldsSet</code>,
* and <code>isSet[]</code>. <code>nextStamp</code> also should not be part
* of the persistent state. Unfortunately, this didn't happen before JDK 1.1
* shipped. To be compatible with JDK 1.1, we will always have to write out
* the field values and state flags. However, <code>nextStamp</code> can be
* removed from the serialization stream; this will probably happen in the
* near future.
*/
private void writeObject(ObjectOutputStream stream)
throws IOException {
// Try to compute the time correctly, for the future (stream
// version 2) in which we don't write out fields[] or isSet[].
if (!isTimeSet) {
try {
updateTime();
} catch (IllegalArgumentException e) {
}
}
// If this Calendar has a ZoneInfo, save it and set a
// SimpleTimeZone equivalent (as a single DST schedule) for
// backward compatibility.
TimeZone savedZone = null;
if (zone instanceof ZoneInfo) {
SimpleTimeZone stz = ((ZoneInfo) zone)
.getLastRuleInstance();
if (stz == null) {
stz = new SimpleTimeZone(zone.getRawOffset(), zone
.getID());
}
savedZone = zone;
zone = stz;
}
// Write out the 1.1 FCS object.
stream.defaultWriteObject();
// Write out the ZoneInfo object
// 4802409: we write out even if it is null, a temporary workaround
// the real fix for bug 4844924 in corba-iiop
stream.writeObject(savedZone);
if (savedZone != null) {
zone = savedZone;
}
}
/**
* Reconstitutes this object from a stream (i.e., deserialize it).
*/
private void readObject(ObjectInputStream stream)
throws IOException, ClassNotFoundException {
final ObjectInputStream input = stream;
input.defaultReadObject();
stamp = new int[FIELD_COUNT];
// Starting with version 2 (not implemented yet), we expect that
// fields[], isSet[], isTimeSet, and areFieldsSet may not be
// streamed out anymore. We expect 'time' to be correct.
if (serialVersionOnStream >= 2) {
isTimeSet = true;
if (fields == null)
fields = new int[FIELD_COUNT];
if (isSet == null)
isSet = new boolean[FIELD_COUNT];
} else if (serialVersionOnStream >= 0) {
for (int i = 0; i < FIELD_COUNT; ++i)
stamp[i] = isSet[i] ? COMPUTED : UNSET;
}
serialVersionOnStream = currentSerialVersion;
// If there's a ZoneInfo object, use it for zone.
try {
ZoneInfo zi = (ZoneInfo) AccessController
.doPrivileged(new PrivilegedExceptionAction() {
public Object run() throws Exception {
return input.readObject();
}
});
if (zi != null) {
zone = zi;
}
} catch (Exception e) {
}
// If the deserialized object has a SimpleTimeZone, try to
// replace it with a ZoneInfo equivalent (as of 1.4) in order
// to be compatible with the SimpleTimeZone-based
// implementation as much as possible.
if (zone instanceof SimpleTimeZone) {
String id = zone.getID();
TimeZone zi = TimeZone.getTimeZone(id);
if (zi != null && zi.hasSameRules(zone)
&& zi.getID().equals(id)) {
zone = zi;
}
}
}
}
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