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/*
* This file is available under and governed by the GNU General Public
* License version 2 only, as published by the Free Software Foundation.
* However, the following notice accompanied the original version of this
* file:
*
* Copyright (c) 2012, Stephen Colebourne & Michael Nascimento Santos
*
* All rights reserved.
*
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package java.time.temporal;
import static java.time.temporal.ChronoField.EPOCH_DAY;
import static java.time.temporal.ChronoUnit.DAYS;
import static java.time.temporal.ChronoUnit.FOREVER;
import java.time.DateTimeException;
import java.time.chrono.ChronoLocalDate;
import java.time.chrono.Chronology;
import java.time.format.ResolverStyle;
import java.util.Map;
/**
* A set of date fields that provide access to Julian Days.
*
* The Julian Day is a standard way of expressing date and time commonly used in the scientific community.
* It is expressed as a decimal number of whole days where days start at midday.
* This class represents variations on Julian Days that count whole days from midnight.
*
* The fields are implemented relative to {@link ChronoField#EPOCH_DAY EPOCH_DAY}.
* The fields are supported, and can be queried and set if {@code EPOCH_DAY} is available.
* The fields work with all chronologies.
*
* @implSpec
* This is an immutable and thread-safe class.
*
* @since 1.8
*/
public final class JulianFields {
/**
* The offset from Julian to EPOCH DAY.
*/
private static final long JULIAN_DAY_OFFSET = 2440588L;
/**
* Julian Day field.
*
* This is an integer-based version of the Julian Day Number.
* Julian Day is a well-known system that represents the count of whole days since day 0,
* which is defined to be January 1, 4713 BCE in the Julian calendar, and -4713-11-24 Gregorian.
* The field has "JulianDay" as 'name', and 'DAYS' as 'baseUnit'.
* The field always refers to the local date-time, ignoring the offset or zone.
*
* For date-times, 'JULIAN_DAY.getFrom()' assumes the same value from
* midnight until just before the next midnight.
* When 'JULIAN_DAY.adjustInto()' is applied to a date-time, the time of day portion remains unaltered.
* 'JULIAN_DAY.adjustInto()' and 'JULIAN_DAY.getFrom()' only apply to {@code Temporal} objects that
* can be converted into {@link ChronoField#EPOCH_DAY}.
* An {@link UnsupportedTemporalTypeException} is thrown for any other type of object.
*
* In the resolving phase of parsing, a date can be created from a Julian Day field.
* In {@linkplain ResolverStyle#STRICT strict mode} and {@linkplain ResolverStyle#SMART smart mode}
* the Julian Day value is validated against the range of valid values.
* In {@linkplain ResolverStyle#LENIENT lenient mode} no validation occurs.
*
*
Astronomical and Scientific Notes
* The standard astronomical definition uses a fraction to indicate the time-of-day,
* thus 3.25 would represent the time 18:00, since days start at midday.
* This implementation uses an integer and days starting at midnight.
* The integer value for the Julian Day Number is the astronomical Julian Day value at midday
* of the date in question.
* This amounts to the astronomical Julian Day, rounded to an integer {@code JDN = floor(JD + 0.5)}.
*
*
* | ISO date | Julian Day Number | Astronomical Julian Day |
* | 1970-01-01T00:00 | 2,440,588 | 2,440,587.5 |
* | 1970-01-01T06:00 | 2,440,588 | 2,440,587.75 |
* | 1970-01-01T12:00 | 2,440,588 | 2,440,588.0 |
* | 1970-01-01T18:00 | 2,440,588 | 2,440,588.25 |
* | 1970-01-02T00:00 | 2,440,589 | 2,440,588.5 |
* | 1970-01-02T06:00 | 2,440,589 | 2,440,588.75 |
* | 1970-01-02T12:00 | 2,440,589 | 2,440,589.0 |
*
*
* Julian Days are sometimes taken to imply Universal Time or UTC, but this
* implementation always uses the Julian Day number for the local date,
* regardless of the offset or time-zone.
*/
public static final TemporalField JULIAN_DAY = Field.JULIAN_DAY;
/**
* Modified Julian Day field.
*
* This is an integer-based version of the Modified Julian Day Number.
* Modified Julian Day (MJD) is a well-known system that counts days continuously.
* It is defined relative to astronomical Julian Day as {@code MJD = JD - 2400000.5}.
* Each Modified Julian Day runs from midnight to midnight.
* The field always refers to the local date-time, ignoring the offset or zone.
*
* For date-times, 'MODIFIED_JULIAN_DAY.getFrom()' assumes the same value from
* midnight until just before the next midnight.
* When 'MODIFIED_JULIAN_DAY.adjustInto()' is applied to a date-time, the time of day portion remains unaltered.
* 'MODIFIED_JULIAN_DAY.adjustInto()' and 'MODIFIED_JULIAN_DAY.getFrom()' only apply to {@code Temporal} objects
* that can be converted into {@link ChronoField#EPOCH_DAY}.
* An {@link UnsupportedTemporalTypeException} is thrown for any other type of object.
*
* This implementation is an integer version of MJD with the decimal part rounded to floor.
*
* In the resolving phase of parsing, a date can be created from a Modified Julian Day field.
* In {@linkplain ResolverStyle#STRICT strict mode} and {@linkplain ResolverStyle#SMART smart mode}
* the Modified Julian Day value is validated against the range of valid values.
* In {@linkplain ResolverStyle#LENIENT lenient mode} no validation occurs.
*
*
Astronomical and Scientific Notes
*
* | ISO date | Modified Julian Day | Decimal MJD |
* | 1970-01-01T00:00 | 40,587 | 40,587.0 |
* | 1970-01-01T06:00 | 40,587 | 40,587.25 |
* | 1970-01-01T12:00 | 40,587 | 40,587.5 |
* | 1970-01-01T18:00 | 40,587 | 40,587.75 |
* | 1970-01-02T00:00 | 40,588 | 40,588.0 |
* | 1970-01-02T06:00 | 40,588 | 40,588.25 |
* | 1970-01-02T12:00 | 40,588 | 40,588.5 |
*
*
* Modified Julian Days are sometimes taken to imply Universal Time or UTC, but this
* implementation always uses the Modified Julian Day for the local date,
* regardless of the offset or time-zone.
*/
public static final TemporalField MODIFIED_JULIAN_DAY = Field.MODIFIED_JULIAN_DAY;
/**
* Rata Die field.
*
* Rata Die counts whole days continuously starting day 1 at midnight at the beginning of 0001-01-01 (ISO).
* The field always refers to the local date-time, ignoring the offset or zone.
*
* For date-times, 'RATA_DIE.getFrom()' assumes the same value from
* midnight until just before the next midnight.
* When 'RATA_DIE.adjustInto()' is applied to a date-time, the time of day portion remains unaltered.
* 'RATA_DIE.adjustInto()' and 'RATA_DIE.getFrom()' only apply to {@code Temporal} objects
* that can be converted into {@link ChronoField#EPOCH_DAY}.
* An {@link UnsupportedTemporalTypeException} is thrown for any other type of object.
*
* In the resolving phase of parsing, a date can be created from a Rata Die field.
* In {@linkplain ResolverStyle#STRICT strict mode} and {@linkplain ResolverStyle#SMART smart mode}
* the Rata Die value is validated against the range of valid values.
* In {@linkplain ResolverStyle#LENIENT lenient mode} no validation occurs.
*/
public static final TemporalField RATA_DIE = Field.RATA_DIE;
/**
* Restricted constructor.
*/
private JulianFields() {
throw new AssertionError("Not instantiable");
}
/**
* Implementation of JulianFields. Each instance is a singleton.
*/
private static enum Field implements TemporalField {
JULIAN_DAY("JulianDay", DAYS, FOREVER, JULIAN_DAY_OFFSET),
MODIFIED_JULIAN_DAY("ModifiedJulianDay", DAYS, FOREVER, 40587L),
RATA_DIE("RataDie", DAYS, FOREVER, 719163L);
private static final long serialVersionUID = -7501623920830201812L;
private final transient String name;
private final transient TemporalUnit baseUnit;
private final transient TemporalUnit rangeUnit;
private final transient ValueRange range;
private final transient long offset;
private Field(String name, TemporalUnit baseUnit, TemporalUnit rangeUnit, long offset) {
this.name = name;
this.baseUnit = baseUnit;
this.rangeUnit = rangeUnit;
this.range = ValueRange.of(-365243219162L + offset, 365241780471L + offset);
this.offset = offset;
}
//-----------------------------------------------------------------------
@Override
public TemporalUnit getBaseUnit() {
return baseUnit;
}
@Override
public TemporalUnit getRangeUnit() {
return rangeUnit;
}
@Override
public boolean isDateBased() {
return true;
}
@Override
public boolean isTimeBased() {
return false;
}
@Override
public ValueRange range() {
return range;
}
//-----------------------------------------------------------------------
@Override
public boolean isSupportedBy(TemporalAccessor temporal) {
return temporal.isSupported(EPOCH_DAY);
}
@Override
public ValueRange rangeRefinedBy(TemporalAccessor temporal) {
if (isSupportedBy(temporal) == false) {
throw new DateTimeException("Unsupported field: " + this);
}
return range();
}
@Override
public long getFrom(TemporalAccessor temporal) {
return temporal.getLong(EPOCH_DAY) + offset;
}
@SuppressWarnings("unchecked")
@Override
public R adjustInto(R temporal, long newValue) {
if (range().isValidValue(newValue) == false) {
throw new DateTimeException("Invalid value: " + name + " " + newValue);
}
return (R) temporal.with(EPOCH_DAY, Math.subtractExact(newValue, offset));
}
//-----------------------------------------------------------------------
@Override
public ChronoLocalDate resolve(
Map fieldValues, TemporalAccessor partialTemporal, ResolverStyle resolverStyle) {
long value = fieldValues.remove(this);
Chronology chrono = Chronology.from(partialTemporal);
if (resolverStyle == ResolverStyle.LENIENT) {
return chrono.dateEpochDay(Math.subtractExact(value, offset));
}
range().checkValidValue(value, this);
return chrono.dateEpochDay(value - offset);
}
//-----------------------------------------------------------------------
@Override
public String toString() {
return name;
}
}
}