net.time4j.engine.StartOfDay Maven / Gradle / Ivy
/*
* -----------------------------------------------------------------------
* Copyright © 2013-2017 Meno Hochschild, Defines the start of a given calendar day relative to midnight in seconds.
*
* @author Meno Hochschild
* @since 3.5/4.3
* @doctags.spec All subclasses must be immutable.
*/
/*[deutsch]
* Definiert den Start eines Kalendertages relativ zu Mitternacht in Sekunden.
*
* @author Meno Hochschild
* @since 3.5/4.3
* @doctags.spec All subclasses must be immutable.
*/
public abstract class StartOfDay {
//~ Statische Felder/Initialisierungen --------------------------------
/**
* Default start of calendar day at midnight.
*/
/*[deutsch]
* Standardbeginn eines Kalendertages zu Mitternacht.
*/
public static final StartOfDay MIDNIGHT = new FixedStartOfDay(0);
/**
* Start of calendar day at 18:00 on previous day.
*/
/*[deutsch]
* Beginn eines Kalendertages zu 18 Uhr am Vortag.
*/
public static final StartOfDay EVENING = new FixedStartOfDay(-21600);
/**
* Start of calendar day at 06:00 in the morning.
*/
/*[deutsch]
* Beginn eines Kalendertages zu 6 Uhr morgens.
*/
public static final StartOfDay MORNING = new FixedStartOfDay(21600);
//~ Konstruktoren -------------------------------------------------
/**
* For immutable subclasss only.
*/
/*[deutsch]
* Nur für Subklassen, die immutable sind.
*/
protected StartOfDay() {
super();
}
//~ Methoden ------------------------------------------------------
/**
* Obtains the start of a calendar day relative to midnight in fixed seconds.
*
* A negative deviation is explicitly allowed and refers to the previous calendar day.
*
* @param deviation the deviation of start of day relative to midnight in seconds on the local timeline
* @return start of day
* @throws IllegalArgumentException if the argument is out of range {@code -43200 < deviation <= 43200}
* @since 3.5/4.3
*/
/*[deutsch]
* Definiert den Start des angegebenen Kalendertages relativ zu Mitternacht fest in Sekunden.
*
* Eine negative Abweichung ist ausdrücklich erlaubt und bezieht sich auf den Vortag.
*
* @param deviation the deviation of start of day relative to midnight in seconds on the local timeline
* @return start of day
* @throws IllegalArgumentException if the argument is out of range {@code -43200 < deviation <= 43200}
* @since 3.5/4.3
*/
public static StartOfDay ofFixedDeviation(int deviation) {
if (deviation == 0){
return MIDNIGHT;
} else if (deviation == -21600) {
return EVENING;
} else if ((deviation > 43200) || (deviation <= -43200)) {
throw new IllegalArgumentException("Start of day out of range: " + deviation);
}
return new FixedStartOfDay(deviation);
}
/**
* Obtains the start of a calendar day as determined by given date function.
*
* If the given function cannot determine a moment for a calendar day then
* an exception will be thrown. This method is most suitable for calendars whose
* days start on astronomical events like sunset. Example:
*
*
* HijriCalendar hijri = HijriCalendar.ofUmalqura(1436, 10, 2);
* SolarTime mekkaTime = SolarTime.ofLocation(21.4225, 39.826111);
* ZonalOffset saudiArabia = ZonalOffset.ofHours(OffsetSign.AHEAD_OF_UTC, 3);
* StartOfDay startOfDay = StartOfDay.definedBy(mekkaTime.sunset());
*
* // short after sunset (2015-07-17T19:05:40)
* System.out.println(
* hijri.atTime(19, 6).at(saudiArabia, startOfDay)); // 2015-07-17T19:06+03:00
*
* // short before sunset (2015-07-17T19:05:40)
* System.out.println(
* hijri.minus(CalendarDays.ONE).atTime(19, 5).at(saudiArabia, startOfDay)); // 2015-07-17T19:05+03:00
*
*
* @param generic type parameter indicating the time of the event
* @param event function which yields the relevant moment for a given calendar day
* @return start of day
* @since 3.34/4.29
*/
/*[deutsch]
* Liefert den Start eines Kalendertags, wie von der angegebenen Datumsfunktion bestimmt.
*
* Wenn die angegebene Funktion keinen Moment für ein Kalenderdatum ermitteln kann,
* wird eine Ausnahme geworfen. Diese Methode ist am besten für Kalender geeignet,
* deren Tage zu astronomischen Ereignissen wie einem Sonnenuntergang beginnen. Beispiel:
*
*
* HijriCalendar hijri = HijriCalendar.ofUmalqura(1436, 10, 2);
* SolarTime mekkaTime = SolarTime.ofLocation(21.4225, 39.826111);
* ZonalOffset saudiArabia = ZonalOffset.ofHours(OffsetSign.AHEAD_OF_UTC, 3);
* StartOfDay startOfDay = StartOfDay.definedBy(mekkaTime.sunset());
*
* // short after sunset (2015-07-17T19:05:40)
* System.out.println(
* hijri.atTime(19, 6).at(saudiArabia, startOfDay)); // 2015-07-17T19:06+03:00
*
* // short before sunset (2015-07-17T19:05:40)
* System.out.println(
* hijri.minus(CalendarDays.ONE).atTime(19, 5).at(saudiArabia, startOfDay)); // 2015-07-17T19:05+03:00
*
*
* @param generic type parameter indicating the time of the event
* @param event function which yields the relevant moment for a given calendar day
* @return start of day
* @since 3.34/4.29
*/
public static StartOfDay definedBy(ChronoFunction> event) {
return new FunctionalStartOfDay<>(event);
}
/**
* Yields the start of given calendar day relative to midnight in seconds.
*
* @param calendarDay calendar day
* @param tzid timezone identifier, helps to resolve an UTC-event like sunset to a local time
* @return nominal deviation of start of day relative to midnight in seconds on the local timeline
* @since 3.5/4.3
* @deprecated The signature will be changed in next major release such
* that the type {@code CalendarDate} will be used instead of {@code Calendrical}
*/
/*[deutsch]
* Definiert den Start des angegebenen Kalendertages relativ zu Mitternacht in Sekunden.
*
* @param calendarDay calendar day
* @param tzid timezone identifier, helps to resolve an UTC-event like sunset to a local time
* @return nominal deviation of start of day relative to midnight in seconds on the local timeline
* @since 3.5/4.3
* @deprecated The signature will be changed in next major release such
* that the type {@code CalendarDate} will be used instead of {@code Calendrical}
*/
@Deprecated
public abstract int getDeviation(
Calendrical calendarDay,
TZID tzid
);
//~ Innere Klassen ----------------------------------------------------
private static class FixedStartOfDay
extends StartOfDay {
//~ Instanzvariablen ------------------------------------------
private final int deviation;
//~ Konstruktoren ---------------------------------------------
private FixedStartOfDay(int deviation) {
super();
this.deviation = deviation;
}
//~ Methoden --------------------------------------------------
@Override
public int getDeviation(
Calendrical calendarDay,
TZID tzid
) {
return this.deviation;
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
} else if (obj instanceof FixedStartOfDay) {
FixedStartOfDay that = (FixedStartOfDay) obj;
return (this.deviation == that.deviation);
} else {
return false;
}
}
@Override
public int hashCode() {
return this.deviation;
}
@Override
public String toString() {
return "FixedStartOfDay[" + this.deviation + "]";
}
}
private static class FunctionalStartOfDay
extends StartOfDay {
//~ Instanzvariablen ------------------------------------------
private final ChronoFunction> event;
//~ Konstruktoren ---------------------------------------------
private FunctionalStartOfDay(ChronoFunction> event) {
super();
if (event == null) {
throw new NullPointerException("Missing event function.");
}
this.event = event;
}
//~ Methoden --------------------------------------------------
@Override
public int getDeviation(
Calendrical calendarDay,
TZID tzid
) {
Optional unixTime = this.event.apply(calendarDay);
if (unixTime.isPresent()) {
UnixTime ut = unixTime.get();
long local = ut.getPosixTime() - 2 * 365 * 86400 + Timezone.of(tzid).getOffset(ut).getIntegralAmount();
long midnight = calendarDay.getDaysSinceEpochUTC() * 86400;
int timeOfDay = MathUtils.safeCast(local - midnight);
return ((timeOfDay >= 43200) ? (timeOfDay - 86400) : timeOfDay);
} else {
throw new ChronoException("Cannot determine start of day: No event.");
}
}
}
}
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