/*
* Copyright 2000-2009 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.
*
* 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.
*/
package org.visage.runtime.date;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.MissingResourceException;
import java.util.ResourceBundle;
import java.util.Set;
import java.util.TimeZone;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
/**
* <code>CalendarSystem</code> is an abstract class that defines the
* programming interface to deal with calendar date and time.
*
* <p><code>CalendarSystem</code> instances are singletons. For
* example, there exists only one Gregorian calendar instance in the
* Java runtime environment. A singleton instance can be obtained
* calling one of the static factory methods.
*
* <h4>CalendarDate</h4>
*
* <p>For the methods in a <code>CalendarSystem</code> that manipulate
* a <code>CalendarDate</code>, <code>CalendarDate</code>s that have
* been created by the <code>CalendarSystem</code> must be
* specified. Otherwise, the methods throw an exception. This is
* because, for example, a Chinese calendar date can't be understood
* by the Hebrew calendar system.
*
* @see CalendarDate
* @author Masayoshi Okutsu
*/
/*
* Derived from JDK7 sun.util.calendar.
*/
abstract class CalendarSystem {
public abstract CalendarDate getCalendarDate();
/**
* Calculates calendar fields from the specified number of
* milliseconds since the Epoch, January 1, 1970 00:00:00 UTC
* (Gregorian). This method doesn't check overflow or underflow
* when adjusting the millisecond value (representing UTC) with
* the time zone offsets (i.e., the GMT offset and amount of
* daylight saving).
*
* @param millis the offset value in milliseconds from January 1,
* 1970 00:00:00 UTC (Gregorian).
* @return a <code>CalendarDate</code> instance that contains the
* calculated calendar field values.
*/
public abstract CalendarDate getCalendarDate(long millis);
public abstract CalendarDate getCalendarDate(long millis, CalendarDate date);
public abstract CalendarDate getCalendarDate(long millis, TimeZone zone);
/**
* Constructs a <code>CalendarDate</code> that is specific to this
* calendar system. All calendar fields have their initial
* values. The {@link TimeZone#getDefault() default time zone} is
* set to the instance.
*
* @return a <code>CalendarDate</code> instance that contains the initial
* calendar field values.
*/
public abstract CalendarDate newCalendarDate();
public abstract CalendarDate newCalendarDate(TimeZone zone);
/**
* Returns the number of milliseconds since the Epoch, January 1,
* 1970 00:00:00 UTC (Gregorian), represented by the specified
* <code>CalendarDate</code>.
*
* @param date the <code>CalendarDate</code> from which the time
* value is calculated
* @return the number of milliseconds since the Epoch.
*/
public abstract long getTime(CalendarDate date);
/**
* Returns the length in days of the specified year by
* <code>date</code>. This method does not perform the
* normalization with the specified <code>CalendarDate</code>. The
* <code>CalendarDate</code> must be normalized to get a correct
* value.
*/
public abstract int getYearLength(CalendarDate date);
/**
* Returns the number of months of the specified year. This method
* does not perform the normalization with the specified
* <code>CalendarDate</code>. The <code>CalendarDate</code> must
* be normalized to get a correct value.
*/
public abstract int getYearLengthInMonths(CalendarDate date);
/**
* Returns the length in days of the month specified by the calendar
* date. This method does not perform the normalization with the
* specified calendar date. The <code>CalendarDate</code> must
* be normalized to get a correct value.
*
* @param date the date from which the month value is obtained
* @return the number of days in the month
* @exception IllegalArgumentException if the specified calendar date
* doesn't have a valid month value in this calendar system.
*/
public abstract int getMonthLength(CalendarDate date); // no setter
/**
* Returns the length in days of a week in this calendar
* system. If this calendar system has multiple radix weeks, this
* method returns only one of them.
*/
public abstract int getWeekLength();
/**
* Returns a <code>CalendarDate</code> of the n-th day of week
* which is on, after or before the specified date. For example, the
* first Sunday in April 2002 (Gregorian) can be obtained as
* below:
*
* <pre><code>
* Gregorian cal = CalendarSystem.getGregorianCalendar();
* CalendarDate date = cal.newCalendarDate();
* date.setDate(2004, cal.APRIL, 1);
* CalendarDate firstSun = cal.getNthDayOfWeek(1, cal.SUNDAY, date);
* // firstSun represents April 4, 2004.
* </code></pre>
*
* This method returns a new <code>CalendarDate</code> instance
* and doesn't modify the original date.
*
* @param nth specifies the n-th one. A positive number specifies
* <em>on or after</em> the <code>date</code>. A non-positive number
* specifies <em>on or before</em> the <code>date</code>.
* @param dayOfWeek the day of week
* @param date the date
* @return the date of the nth <code>dayOfWeek</code> after
* or before the specified <code>CalendarDate</code>
*/
public abstract CalendarDate getNthDayOfWeek(int nth, int dayOfWeek,
CalendarDate date);
public abstract CalendarDate setTimeOfDay(CalendarDate date, int timeOfDay);
/**
* Checks whether the calendar fields specified by <code>date</code>
* represents a valid date and time in this calendar system. If the
* given date is valid, <code>date</code> is marked as <em>normalized</em>.
*
* @param date the <code>CalendarDate</code> to be validated
* @return <code>true</code> if all the calendar fields are consistent,
* otherwise, <code>false</code> is returned.
* @exception NullPointerException if the specified
* <code>date</code> is <code>null</code>
*/
public abstract boolean validate(CalendarDate date);
/**
* Normalizes calendar fields in the specified
* <code>date</code>. Also all {@link CalendarDate#FIELD_UNDEFINED
* undefined} fields are set to correct values. The actual
* normalization process is calendar system dependent.
*
* @param date the calendar date to be validated
* @return <code>true</code> if all fields have been normalized;
* <code>false</code> otherwise.
* @exception NullPointerException if the specified
* <code>date</code> is <code>null</code>
*/
public abstract boolean normalize(CalendarDate date);
}