YearHalf.java
/*
* Copyright (c) 2007-present, Stephen Colebourne & Michael Nascimento Santos
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* * Neither the name of JSR-310 nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.threeten.extra;
import static java.time.temporal.ChronoField.ERA;
import static java.time.temporal.ChronoField.YEAR;
import static java.time.temporal.ChronoField.YEAR_OF_ERA;
import static java.time.temporal.ChronoUnit.CENTURIES;
import static java.time.temporal.ChronoUnit.DECADES;
import static java.time.temporal.ChronoUnit.ERAS;
import static java.time.temporal.ChronoUnit.MILLENNIA;
import static java.time.temporal.ChronoUnit.YEARS;
import static org.threeten.extra.TemporalFields.DAY_OF_HALF;
import static org.threeten.extra.TemporalFields.HALF_OF_YEAR;
import static org.threeten.extra.TemporalFields.HALF_YEARS;
import java.io.Serializable;
import java.time.Clock;
import java.time.DateTimeException;
import java.time.LocalDate;
import java.time.Month;
import java.time.Period;
import java.time.Year;
import java.time.ZoneId;
import java.time.chrono.Chronology;
import java.time.chrono.IsoChronology;
import java.time.format.DateTimeFormatter;
import java.time.format.DateTimeFormatterBuilder;
import java.time.format.DateTimeParseException;
import java.time.format.SignStyle;
import java.time.temporal.ChronoField;
import java.time.temporal.ChronoUnit;
import java.time.temporal.Temporal;
import java.time.temporal.TemporalAccessor;
import java.time.temporal.TemporalAdjuster;
import java.time.temporal.TemporalAmount;
import java.time.temporal.TemporalField;
import java.time.temporal.TemporalQueries;
import java.time.temporal.TemporalQuery;
import java.time.temporal.TemporalUnit;
import java.time.temporal.UnsupportedTemporalTypeException;
import java.time.temporal.ValueRange;
import java.util.Objects;
import java.util.stream.LongStream;
import java.util.stream.Stream;
import org.joda.convert.FromString;
import org.joda.convert.ToString;
/**
* A year-half in the ISO-8601 calendar system, such as {@code 2007-H2}.
* <p>
* {@code YearHalf} is an immutable date-time object that represents the combination
* of a year and a half-year. Any field that can be derived from a year and a half-year can be obtained.
* A half is defined by {@link Half} - H1 and H2.
* H1 is January to June, H2 is July to December.
* <p>
* This class does not store or represent a day, time or time-zone.
* For example, the value "2nd half 2007" can be stored in a {@code YearHalf}.
* <p>
* The ISO-8601 calendar system is the modern civil calendar system used today
* in most of the world. It is equivalent to the proleptic Gregorian calendar
* system, in which today's rules for leap years are applied for all time.
* For most applications written today, the ISO-8601 rules are entirely suitable.
* However, any application that makes use of historical dates, and requires them
* to be accurate will find the ISO-8601 approach unsuitable.
* Note that the ISO-8601 standard does not define or refer to halves.
*
* <h3>Implementation Requirements:</h3>
* This class is immutable and thread-safe.
* <p>
* This class must be treated as a value type. Do not synchronize, rely on the
* identity hash code or use the distinction between equals() and ==.
*/
public final class YearHalf
implements Temporal, TemporalAdjuster, Comparable<YearHalf>, Serializable {
/**
* Serialization version.
*/
private static final long serialVersionUID = 782467825761518L;
/**
* Parser.
*/
private static final DateTimeFormatter PARSER = new DateTimeFormatterBuilder()
.parseCaseInsensitive()
.appendValue(YEAR, 4, 10, SignStyle.EXCEEDS_PAD)
.appendLiteral('-')
.appendLiteral('H')
.appendValue(HALF_OF_YEAR, 1)
.toFormatter();
/**
* The year.
*/
private final int year;
/**
* The half-of-year, not null.
*/
private final Half half;
//-----------------------------------------------------------------------
/**
* Obtains the current year-half from the system clock in the default time-zone.
* <p>
* This will query the {@link java.time.Clock#systemDefaultZone() system clock} in the default
* time-zone to obtain the current year-half.
* The zone and offset will be set based on the time-zone in the clock.
* <p>
* Using this method will prevent the ability to use an alternate clock for testing
* because the clock is hard-coded.
*
* @return the current year-half using the system clock and default time-zone, not null
*/
public static YearHalf now() {
return now(Clock.systemDefaultZone());
}
/**
* Obtains the current year-half from the system clock in the specified time-zone.
* <p>
* This will query the {@link Clock#system(java.time.ZoneId) system clock} to obtain the current year-half.
* Specifying the time-zone avoids dependence on the default time-zone.
* <p>
* Using this method will prevent the ability to use an alternate clock for testing
* because the clock is hard-coded.
*
* @param zone the zone ID to use, not null
* @return the current year-half using the system clock, not null
*/
public static YearHalf now(ZoneId zone) {
return now(Clock.system(zone));
}
/**
* Obtains the current year-half from the specified clock.
* <p>
* This will query the specified clock to obtain the current year-half.
* Using this method allows the use of an alternate clock for testing.
* The alternate clock may be introduced using {@link Clock dependency injection}.
*
* @param clock the clock to use, not null
* @return the current year-half, not null
*/
public static YearHalf now(Clock clock) {
final LocalDate now = LocalDate.now(clock); // called once
return YearHalf.of(now.getYear(), Half.from(now.getMonth()));
}
//-----------------------------------------------------------------------
/**
* Obtains an instance of {@code YearHalf} from a year and half.
*
* @param year the year to represent, not null
* @param half the half-of-year to represent, not null
* @return the year-half, not null
*/
public static YearHalf of(Year year, Half half) {
return of(year.getValue(), half);
}
/**
* Obtains an instance of {@code YearHalf} from a year and half.
*
* @param year the year to represent, not null
* @param half the half-of-year to represent, from 1 to 2
* @return the year-half, not null
* @throws DateTimeException if the half value is invalid
*/
public static YearHalf of(Year year, int half) {
return of(year.getValue(), Half.of(half));
}
/**
* Obtains an instance of {@code YearHalf} from a year and half.
*
* @param year the year to represent, from MIN_YEAR to MAX_YEAR
* @param half the half-of-year to represent, not null
* @return the year-half, not null
* @throws DateTimeException if the year value is invalid
*/
public static YearHalf of(int year, Half half) {
YEAR.checkValidValue(year);
Objects.requireNonNull(half, "half");
return new YearHalf(year, half);
}
/**
* Obtains an instance of {@code YearHalf} from a year and half.
*
* @param year the year to represent, from MIN_YEAR to MAX_YEAR
* @param half the half-of-year to represent, from 1 to 2
* @return the year-half, not null
* @throws DateTimeException if either field value is invalid
*/
public static YearHalf of(int year, int half) {
YEAR.checkValidValue(year);
return new YearHalf(year, Half.of(half));
}
//-----------------------------------------------------------------------
/**
* Obtains an instance of {@code YearHalf} from a temporal object.
* <p>
* This obtains a year-half based on the specified temporal.
* A {@code TemporalAccessor} represents an arbitrary set of date and time information,
* which this factory converts to an instance of {@code YearHalf}.
* <p>
* The conversion extracts the {@link ChronoField#YEAR YEAR} and
* {@link TemporalFields#HALF_OF_YEAR HALF_OF_YEAR} fields.
* The extraction is only permitted if the temporal object has an ISO
* chronology, or can be converted to a {@code LocalDate}.
* <p>
* This method matches the signature of the functional interface {@link TemporalQuery}
* allowing it to be used in queries via method reference, {@code YearHalf::from}.
*
* @param temporal the temporal object to convert, not null
* @return the year-half, not null
* @throws DateTimeException if unable to convert to a {@code YearHalf}
*/
public static YearHalf from(TemporalAccessor temporal) {
if (temporal instanceof YearHalf) {
return (YearHalf) temporal;
}
Objects.requireNonNull(temporal, "temporal");
try {
TemporalAccessor adjusted =
!IsoChronology.INSTANCE.equals(Chronology.from(temporal)) ? LocalDate.from(temporal) : temporal;
// need to use getLong() as JDK Parsed class get() doesn't work properly
int year = Math.toIntExact(adjusted.getLong(YEAR));
int hoy = Math.toIntExact(adjusted.getLong(HALF_OF_YEAR));
return of(year, hoy);
} catch (DateTimeException ex) {
throw new DateTimeException("Unable to obtain YearHalf from TemporalAccessor: " +
temporal + " of type " + temporal.getClass().getName(), ex);
}
}
//-----------------------------------------------------------------------
/**
* Obtains an instance of {@code YearHalf} from a text string such as {@code 2007-H2}.
* <p>
* The string must represent a valid year-half.
* The format must be {@code uuuu-'Q'Q} where the 'Q' is case insensitive.
* Years outside the range 0000 to 9999 must be prefixed by the plus or minus symbol.
*
* @param text the text to parse such as "2007-H2", not null
* @return the parsed year-half, not null
* @throws DateTimeParseException if the text cannot be parsed
*/
@FromString
public static YearHalf parse(CharSequence text) {
return parse(text, PARSER);
}
/**
* Obtains an instance of {@code YearHalf} from a text string using a specific formatter.
* <p>
* The text is parsed using the formatter, returning a year-half.
*
* @param text the text to parse, not null
* @param formatter the formatter to use, not null
* @return the parsed year-half, not null
* @throws DateTimeParseException if the text cannot be parsed
*/
public static YearHalf parse(CharSequence text, DateTimeFormatter formatter) {
Objects.requireNonNull(formatter, "formatter");
return formatter.parse(text, YearHalf::from);
}
//-----------------------------------------------------------------------
/**
* Constructor.
*
* @param year the year to represent, validated from MIN_YEAR to MAX_YEAR
* @param half the half-of-year to represent, validated not null
*/
private YearHalf(int year, Half half) {
this.year = year;
this.half = half;
}
/**
* Validates the input.
*
* @return the valid object, not null
*/
private Object readResolve() {
return of(year, half);
}
/**
* Returns a copy of this year-half with the new year and half, checking
* to see if a new object is in fact required.
*
* @param newYear the year to represent, validated from MIN_YEAR to MAX_YEAR
* @param newHalf the half-of-year to represent, validated not null
* @return the year-half, not null
*/
private YearHalf with(int newYear, Half newHalf) {
if (year == newYear && half == newHalf) {
return this;
}
return new YearHalf(newYear, newHalf);
}
//-----------------------------------------------------------------------
/**
* Checks if the specified field is supported.
* <p>
* This checks if this year-half can be queried for the specified field.
* If false, then calling the {@link #range(TemporalField) range},
* {@link #get(TemporalField) get} and {@link #with(TemporalField, long)}
* methods will throw an exception.
* <p>
* If the field is a {@link ChronoField} then the query is implemented here.
* The supported fields are:
* <ul>
* <li>{@code HALF_OF_YEAR}
* <li>{@code YEAR_OF_ERA}
* <li>{@code YEAR}
* <li>{@code ERA}
* </ul>
* All other {@code ChronoField} instances will return false.
* <p>
* If the field is not a {@code ChronoField}, then the result of this method
* is obtained by invoking {@code TemporalField.isSupportedBy(TemporalAccessor)}
* passing {@code this} as the argument.
* Whether the field is supported is determined by the field.
*
* @param field the field to check, null returns false
* @return true if the field is supported on this year-half, false if not
*/
@Override
public boolean isSupported(TemporalField field) {
if (field == HALF_OF_YEAR) {
return true;
} else if (field instanceof ChronoField) {
return field == YEAR || field == YEAR_OF_ERA || field == ERA;
}
return field != null && field.isSupportedBy(this);
}
/**
* Checks if the specified unit is supported.
* <p>
* This checks if the specified unit can be added to, or subtracted from, this year-half.
* If false, then calling the {@link #plus(long, TemporalUnit)} and
* {@link #minus(long, TemporalUnit) minus} methods will throw an exception.
* <p>
* If the unit is a {@link ChronoUnit} then the query is implemented here.
* The supported units are:
* <ul>
* <li>{@code HALF_YEARS}
* <li>{@code YEARS}
* <li>{@code DECADES}
* <li>{@code CENTURIES}
* <li>{@code MILLENNIA}
* <li>{@code ERAS}
* </ul>
* All other {@code ChronoUnit} instances will return false.
* <p>
* If the unit is not a {@code ChronoUnit}, then the result of this method
* is obtained by invoking {@code TemporalUnit.isSupportedBy(Temporal)}
* passing {@code this} as the argument.
* Whether the unit is supported is determined by the unit.
*
* @param unit the unit to check, null returns false
* @return true if the unit can be added/subtracted, false if not
*/
@Override
public boolean isSupported(TemporalUnit unit) {
if (unit == HALF_YEARS) {
return true;
} else if (unit instanceof ChronoUnit) {
return unit == YEARS || unit == DECADES || unit == CENTURIES || unit == MILLENNIA || unit == ERAS;
}
return unit != null && unit.isSupportedBy(this);
}
//-----------------------------------------------------------------------
/**
* Gets the range of valid values for the specified field.
* <p>
* The range object expresses the minimum and maximum valid values for a field.
* This year-half is used to enhance the accuracy of the returned range.
* If it is not possible to return the range, because the field is not supported
* or for some other reason, an exception is thrown.
* <p>
* If the field is a {@link ChronoField} then the query is implemented here.
* The {@link #isSupported(TemporalField) supported fields} will return
* appropriate range instances.
* All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
* <p>
* If the field is not a {@code ChronoField}, then the result of this method
* is obtained by invoking {@code TemporalField.rangeRefinedBy(TemporalAccessor)}
* passing {@code this} as the argument.
* Whether the range can be obtained is determined by the field.
*
* @param field the field to query the range for, not null
* @return the range of valid values for the field, not null
* @throws DateTimeException if the range for the field cannot be obtained
* @throws UnsupportedTemporalTypeException if the field is not supported
*/
@Override
public ValueRange range(TemporalField field) {
if (field == HALF_OF_YEAR) {
return HALF_OF_YEAR.range();
}
if (field == YEAR_OF_ERA) {
return (getYear() <= 0 ? ValueRange.of(1, Year.MAX_VALUE + 1) : ValueRange.of(1, Year.MAX_VALUE));
}
return Temporal.super.range(field);
}
/**
* Gets the value of the specified field from this year-half as an {@code int}.
* <p>
* This queries this year-half for the value for the specified field.
* The returned value will always be within the valid range of values for the field.
* If it is not possible to return the value, because the field is not supported
* or for some other reason, an exception is thrown.
* <p>
* If the field is a {@link ChronoField} then the query is implemented here.
* The {@link #isSupported(TemporalField) supported fields} will return valid
* values based on this year-half,.
* All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
* <p>
* If the field is not a {@code ChronoField}, then the result of this method
* is obtained by invoking {@code TemporalField.getFrom(TemporalAccessor)}
* passing {@code this} as the argument. Whether the value can be obtained,
* and what the value represents, is determined by the field.
*
* @param field the field to get, not null
* @return the value for the field
* @throws DateTimeException if a value for the field cannot be obtained or
* the value is outside the range of valid values for the field
* @throws UnsupportedTemporalTypeException if the field is not supported or
* the range of values exceeds an {@code int}
* @throws ArithmeticException if numeric overflow occurs
*/
@Override
public int get(TemporalField field) {
if (field == HALF_OF_YEAR) {
return half.getValue();
} else if (field instanceof ChronoField) {
switch ((ChronoField) field) {
case YEAR_OF_ERA:
return (year < 1 ? 1 - year : year);
case YEAR:
return year;
case ERA:
return (year < 1 ? 0 : 1);
default:
throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
}
}
return Temporal.super.get(field);
}
/**
* Gets the value of the specified field from this year-half as a {@code long}.
* <p>
* This queries this year-half for the value for the specified field.
* If it is not possible to return the value, because the field is not supported
* or for some other reason, an exception is thrown.
* <p>
* If the field is a {@link ChronoField} then the query is implemented here.
* The {@link #isSupported(TemporalField) supported fields} will return valid
* values based on this year-half.
* All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
* <p>
* If the field is not a {@code ChronoField}, then the result of this method
* is obtained by invoking {@code TemporalField.getFrom(TemporalAccessor)}
* passing {@code this} as the argument. Whether the value can be obtained,
* and what the value represents, is determined by the field.
*
* @param field the field to get, not null
* @return the value for the field
* @throws DateTimeException if a value for the field cannot be obtained
* @throws UnsupportedTemporalTypeException if the field is not supported
* @throws ArithmeticException if numeric overflow occurs
*/
@Override
public long getLong(TemporalField field) {
if (field == HALF_OF_YEAR) {
return half.getValue();
} else if (field instanceof ChronoField) {
switch ((ChronoField) field) {
case YEAR_OF_ERA:
return (year < 1 ? 1 - year : year);
case YEAR:
return year;
case ERA:
return (year < 1 ? 0 : 1);
default:
throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
}
}
return field.getFrom(this);
}
private long getProlepticHalf() {
return year * 2L + (half.getValue() - 1);
}
//-----------------------------------------------------------------------
/**
* Gets the year field.
* <p>
* This method returns the primitive {@code int} value for the year.
* <p>
* The year returned by this method is proleptic as per {@code get(YEAR)}.
*
* @return the year, from MIN_YEAR to MAX_YEAR
*/
public int getYear() {
return year;
}
/**
* Gets the half-of-year field from 1 to 2.
* <p>
* This method returns the half as an {@code int} from 1 to 2.
* Application code is frequently clearer if the enum {@link Half}
* is used by calling {@link #getHalf()}.
*
* @return the half-of-year, from 1 to 2
* @see #getHalf()
*/
public int getHalfValue() {
return half.getValue();
}
/**
* Gets the half-of-year field using the {@code Half} enum.
* <p>
* This method returns the enum {@link Half} for the half.
* This avoids confusion as to what {@code int} values mean.
* If you need access to the primitive {@code int} value then the enum
* provides the {@link Half#getValue() int value}.
*
* @return the half-of-year, not null
* @see #getHalfValue()
*/
public Half getHalf() {
return half;
}
//-----------------------------------------------------------------------
/**
* Checks if the year is a leap year, according to the ISO proleptic
* calendar system rules.
* <p>
* This method applies the current rules for leap years across the whole time-line.
* In general, a year is a leap year if it is divisible by four without
* remainder. However, years divisible by 100, are not leap years, with
* the exception of years divisible by 400 which are.
* <p>
* For example, 1904 is a leap year it is divisible by 4.
* 1900 was not a leap year as it is divisible by 100, however 2000 was a
* leap year as it is divisible by 400.
* <p>
* The calculation is proleptic - applying the same rules into the far future and far past.
* This is historically inaccurate, but is correct for the ISO-8601 standard.
*
* @return true if the year is leap, false otherwise
*/
public boolean isLeapYear() {
return IsoChronology.INSTANCE.isLeapYear(year);
}
/**
* Checks if the day-of-half is valid for this year-half.
* <p>
* This method checks whether this year and half and the input day form
* a valid date.
*
* @param dayOfHalf the day-of-half to validate, from 1 to 181, 182 or 184, invalid value returns false
* @return true if the day is valid for this year-half
*/
public boolean isValidDay(int dayOfHalf) {
return dayOfHalf >= 1 && dayOfHalf <= lengthOfHalf();
}
/**
* Returns the length of the half, taking account of the year.
* <p>
* This returns the length of the half in days.
*
* @return the length of the half in days, 181, 182 or 184
*/
public int lengthOfHalf() {
return half.length(isLeapYear());
}
/**
* Returns the length of the year.
* <p>
* This returns the length of the year in days, either 365 or 366.
*
* @return 366 if the year is leap, 365 otherwise
*/
public int lengthOfYear() {
return (isLeapYear() ? 366 : 365);
}
//-----------------------------------------------------------------------
/**
* Returns an adjusted copy of this year-half.
* <p>
* This returns a {@code YearHalf} based on this one, with the year-half adjusted.
* The adjustment takes place using the specified adjuster strategy object.
* Read the documentation of the adjuster to understand what adjustment will be made.
* <p>
* A simple adjuster might simply set the one of the fields, such as the year field.
* A more complex adjuster might set the year-half to the next half that
* Halley's comet will pass the Earth.
* <p>
* The result of this method is obtained by invoking the
* {@link TemporalAdjuster#adjustInto(Temporal)} method on the
* specified adjuster passing {@code this} as the argument.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param adjuster the adjuster to use, not null
* @return a {@code YearHalf} based on {@code this} with the adjustment made, not null
* @throws DateTimeException if the adjustment cannot be made
* @throws ArithmeticException if numeric overflow occurs
*/
@Override
public YearHalf with(TemporalAdjuster adjuster) {
return (YearHalf) adjuster.adjustInto(this);
}
/**
* Returns a copy of this year-half with the specified field set to a new value.
* <p>
* This returns a {@code YearHalf} based on this one, with the value
* for the specified field changed.
* This can be used to change any supported field, such as the year or half.
* If it is not possible to set the value, because the field is not supported or for
* some other reason, an exception is thrown.
* <p>
* If the field is a {@link ChronoField} then the adjustment is implemented here.
* The supported fields behave as follows:
* <ul>
* <li>{@code HALF_OF_YEAR} -
* Returns a {@code YearHalf} with the specified half-of-year.
* The year will be unchanged.
* <li>{@code YEAR_OF_ERA} -
* Returns a {@code YearHalf} with the specified year-of-era
* The half and era will be unchanged.
* <li>{@code YEAR} -
* Returns a {@code YearHalf} with the specified year.
* The half will be unchanged.
* <li>{@code ERA} -
* Returns a {@code YearHalf} with the specified era.
* The half and year-of-era will be unchanged.
* </ul>
* <p>
* In all cases, if the new value is outside the valid range of values for the field
* then a {@code DateTimeException} will be thrown.
* <p>
* All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}.
* <p>
* If the field is not a {@code ChronoField}, then the result of this method
* is obtained by invoking {@code TemporalField.adjustInto(Temporal, long)}
* passing {@code this} as the argument. In this case, the field determines
* whether and how to adjust the instant.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param field the field to set in the result, not null
* @param newValue the new value of the field in the result
* @return a {@code YearHalf} based on {@code this} with the specified field set, not null
* @throws DateTimeException if the field cannot be set
* @throws UnsupportedTemporalTypeException if the field is not supported
* @throws ArithmeticException if numeric overflow occurs
*/
@Override
public YearHalf with(TemporalField field, long newValue) {
if (field == HALF_OF_YEAR) {
return withHalf(HALF_OF_YEAR.range().checkValidIntValue(newValue, HALF_OF_YEAR));
} else if (field instanceof ChronoField) {
ChronoField f = (ChronoField) field;
f.checkValidValue(newValue);
switch (f) {
case YEAR_OF_ERA:
return withYear((int) (year < 1 ? 1 - newValue : newValue));
case YEAR:
return withYear((int) newValue);
case ERA:
return (getLong(ERA) == newValue ? this : withYear(1 - year));
default:
throw new UnsupportedTemporalTypeException("Unsupported field: " + field);
}
}
return field.adjustInto(this, newValue);
}
//-----------------------------------------------------------------------
/**
* Returns a copy of this {@code YearHalf} with the year altered.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param year the year to set in the returned year-half, from MIN_YEAR to MAX_YEAR
* @return a {@code YearHalf} based on this year-half with the requested year, not null
* @throws DateTimeException if the year value is invalid
*/
public YearHalf withYear(int year) {
YEAR.checkValidValue(year);
return with(year, half);
}
/**
* Returns a copy of this {@code YearHalf} with the half-of-year altered.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param half the half-of-year to set in the returned year-half, from 1 to 2
* @return a {@code YearHalf} based on this year-half with the requested half, not null
* @throws DateTimeException if the half-of-year value is invalid
*/
public YearHalf withHalf(int half) {
HALF_OF_YEAR.range().checkValidValue(half, HALF_OF_YEAR);
return with(year, Half.of(half));
}
//-----------------------------------------------------------------------
/**
* Returns a copy of this year-half with the specified amount added.
* <p>
* This returns a {@code YearHalf} based on this one, with the specified amount added.
* The amount is typically {@link Period} but may be any other type implementing
* the {@link TemporalAmount} interface.
* <p>
* The calculation is delegated to the amount object by calling
* {@link TemporalAmount#addTo(Temporal)}. The amount implementation is free
* to implement the addition in any way it wishes, however it typically
* calls back to {@link #plus(long, TemporalUnit)}. Consult the documentation
* of the amount implementation to determine if it can be successfully added.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param amountToAdd the amount to add, not null
* @return a {@code YearHalf} based on this year-half with the addition made, not null
* @throws DateTimeException if the addition cannot be made
* @throws ArithmeticException if numeric overflow occurs
*/
@Override
public YearHalf plus(TemporalAmount amountToAdd) {
return (YearHalf) amountToAdd.addTo(this);
}
/**
* Returns a copy of this year-half with the specified amount added.
* <p>
* This returns a {@code YearHalf} based on this one, with the amount
* in terms of the unit added. If it is not possible to add the amount, because the
* unit is not supported or for some other reason, an exception is thrown.
* <p>
* If the field is a {@link ChronoUnit} then the addition is implemented here.
* The supported fields behave as follows:
* <ul>
* <li>{@code HALF_YEARS} -
* Returns a {@code YearHalf} with the specified number of halves added.
* This is equivalent to {@link #plusHalves(long)}.
* <li>{@code YEARS} -
* Returns a {@code YearHalf} with the specified number of years added.
* This is equivalent to {@link #plusYears(long)}.
* <li>{@code DECADES} -
* Returns a {@code YearHalf} with the specified number of decades added.
* This is equivalent to calling {@link #plusYears(long)} with the amount
* multiplied by 10.
* <li>{@code CENTURIES} -
* Returns a {@code YearHalf} with the specified number of centuries added.
* This is equivalent to calling {@link #plusYears(long)} with the amount
* multiplied by 100.
* <li>{@code MILLENNIA} -
* Returns a {@code YearHalf} with the specified number of millennia added.
* This is equivalent to calling {@link #plusYears(long)} with the amount
* multiplied by 1,000.
* <li>{@code ERAS} -
* Returns a {@code YearHalf} with the specified number of eras added.
* Only two eras are supported so the amount must be one, zero or minus one.
* If the amount is non-zero then the year is changed such that the year-of-era
* is unchanged.
* </ul>
* <p>
* All other {@code ChronoUnit} instances will throw an {@code UnsupportedTemporalTypeException}.
* <p>
* If the field is not a {@code ChronoUnit}, then the result of this method
* is obtained by invoking {@code TemporalUnit.addTo(Temporal, long)}
* passing {@code this} as the argument. In this case, the unit determines
* whether and how to perform the addition.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param amountToAdd the amount of the unit to add to the result, may be negative
* @param unit the unit of the amount to add, not null
* @return a {@code YearHalf} based on this year-half with the specified amount added, not null
* @throws DateTimeException if the addition cannot be made
* @throws UnsupportedTemporalTypeException if the unit is not supported
* @throws ArithmeticException if numeric overflow occurs
*/
@Override
public YearHalf plus(long amountToAdd, TemporalUnit unit) {
if (unit == HALF_YEARS) {
return plusHalves(amountToAdd);
} else if (unit instanceof ChronoUnit) {
switch ((ChronoUnit) unit) {
case YEARS:
return plusYears(amountToAdd);
case DECADES:
return plusYears(Math.multiplyExact(amountToAdd, 10));
case CENTURIES:
return plusYears(Math.multiplyExact(amountToAdd, 100));
case MILLENNIA:
return plusYears(Math.multiplyExact(amountToAdd, 1000));
case ERAS:
return with(ERA, Math.addExact(getLong(ERA), amountToAdd));
default:
throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
}
}
return unit.addTo(this, amountToAdd);
}
/**
* Returns a copy of this year-half with the specified period in years added.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param yearsToAdd the years to add, may be negative
* @return a {@code YearHalf} based on this year-half with the years added, not null
* @throws DateTimeException if the result exceeds the supported range
*/
public YearHalf plusYears(long yearsToAdd) {
if (yearsToAdd == 0) {
return this;
}
int newYear = YEAR.checkValidIntValue(year + yearsToAdd); // safe overflow
return with(newYear, half);
}
/**
* Returns a copy of this year-half with the specified period in halves added.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param halvesToAdd the halves to add, may be negative
* @return a {@code YearHalf} based on this year-half with the halves added, not null
* @throws DateTimeException if the result exceeds the supported range
*/
public YearHalf plusHalves(long halvesToAdd) {
if (halvesToAdd == 0) {
return this;
}
long halfCount = year * 2L + (half.getValue() - 1);
long calcHalves = halfCount + halvesToAdd; // safe overflow
int newYear = YEAR.checkValidIntValue(Math.floorDiv(calcHalves, 2));
int newHalf = (int) Math.floorMod(calcHalves, 2L) + 1;
return with(newYear, Half.of(newHalf));
}
//-----------------------------------------------------------------------
/**
* Returns a copy of this year-half with the specified amount subtracted.
* <p>
* This returns a {@code YearHalf} based on this one, with the specified amount subtracted.
* The amount is typically {@link Period} but may be any other type implementing
* the {@link TemporalAmount} interface.
* <p>
* The calculation is delegated to the amount object by calling
* {@link TemporalAmount#subtractFrom(Temporal)}. The amount implementation is free
* to implement the subtraction in any way it wishes, however it typically
* calls back to {@link #minus(long, TemporalUnit)}. Consult the documentation
* of the amount implementation to determine if it can be successfully subtracted.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param amountToSubtract the amount to subtract, not null
* @return a {@code YearHalf} based on this year-half with the subtraction made, not null
* @throws DateTimeException if the subtraction cannot be made
* @throws ArithmeticException if numeric overflow occurs
*/
@Override
public YearHalf minus(TemporalAmount amountToSubtract) {
return (YearHalf) amountToSubtract.subtractFrom(this);
}
/**
* Returns a copy of this year-half with the specified amount subtracted.
* <p>
* This returns a {@code YearHalf} based on this one, with the amount
* in terms of the unit subtracted. If it is not possible to subtract the amount,
* because the unit is not supported or for some other reason, an exception is thrown.
* <p>
* This method is equivalent to {@link #plus(long, TemporalUnit)} with the amount negated.
* See that method for a full description of how addition, and thus subtraction, works.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param amountToSubtract the amount of the unit to subtract from the result, may be negative
* @param unit the unit of the amount to subtract, not null
* @return a {@code YearHalf} based on this year-half with the specified amount subtracted, not null
* @throws DateTimeException if the subtraction cannot be made
* @throws UnsupportedTemporalTypeException if the unit is not supported
* @throws ArithmeticException if numeric overflow occurs
*/
@Override
public YearHalf minus(long amountToSubtract, TemporalUnit unit) {
return (amountToSubtract == Long.MIN_VALUE ? plus(Long.MAX_VALUE, unit).plus(1, unit) : plus(-amountToSubtract, unit));
}
/**
* Returns a copy of this year-half with the specified period in years subtracted.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param yearsToSubtract the years to subtract, may be negative
* @return a {@code YearHalf} based on this year-half with the years subtracted, not null
* @throws DateTimeException if the result exceeds the supported range
*/
public YearHalf minusYears(long yearsToSubtract) {
return (yearsToSubtract == Long.MIN_VALUE ? plusYears(Long.MAX_VALUE).plusYears(1) : plusYears(-yearsToSubtract));
}
/**
* Returns a copy of this year-half with the specified period in halves subtracted.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param halvesToSubtract the halves to subtract, may be negative
* @return a {@code YearHalf} based on this year-half with the halves subtracted, not null
* @throws DateTimeException if the result exceeds the supported range
*/
public YearHalf minusHalves(long halvesToSubtract) {
return (halvesToSubtract == Long.MIN_VALUE ? plusHalves(Long.MAX_VALUE).plusHalves(1) : plusHalves(-halvesToSubtract));
}
//-----------------------------------------------------------------------
/**
* Queries this year-half using the specified query.
* <p>
* This queries this year-half using the specified query strategy object.
* The {@code TemporalQuery} object defines the logic to be used to
* obtain the result. Read the documentation of the query to understand
* what the result of this method will be.
* <p>
* The result of this method is obtained by invoking the
* {@link TemporalQuery#queryFrom(TemporalAccessor)} method on the
* specified query passing {@code this} as the argument.
*
* @param <R> the type of the result
* @param query the query to invoke, not null
* @return the query result, null may be returned (defined by the query)
* @throws DateTimeException if unable to query (defined by the query)
* @throws ArithmeticException if numeric overflow occurs (defined by the query)
*/
@SuppressWarnings("unchecked")
@Override
public <R> R query(TemporalQuery<R> query) {
if (query == TemporalQueries.chronology()) {
return (R) IsoChronology.INSTANCE;
} else if (query == TemporalQueries.precision()) {
return (R) HALF_YEARS;
}
return Temporal.super.query(query);
}
/**
* Adjusts the specified temporal object to have this year-half.
* <p>
* This returns a temporal object of the same observable type as the input
* with the year and half changed to be the same as this.
* <p>
* The adjustment is equivalent to using {@link Temporal#plus(long, TemporalUnit)}
* passing the number of halves to adjust by.
* If the specified temporal object does not use the ISO calendar system then
* a {@code DateTimeException} is thrown.
* <p>
* In most cases, it is clearer to reverse the calling pattern by using
* {@link Temporal#with(TemporalAdjuster)}:
* <pre>
* // these two lines are equivalent, but the second approach is recommended
* temporal = thisYearHalf.adjustInto(temporal);
* temporal = temporal.with(thisYearHalf);
* </pre>
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param temporal the target object to be adjusted, not null
* @return the adjusted object, not null
* @throws DateTimeException if unable to make the adjustment
* @throws ArithmeticException if numeric overflow occurs
*/
@Override
public Temporal adjustInto(Temporal temporal) {
if (Chronology.from(temporal).equals(IsoChronology.INSTANCE) == false) {
throw new DateTimeException("Adjustment only supported on ISO date-time");
}
long newProlepticHalf = getProlepticHalf();
long oldProlepticHalf = temporal.get(YEAR) * 2L + (temporal.get(HALF_OF_YEAR) - 1);
return temporal.plus(newProlepticHalf - oldProlepticHalf, HALF_YEARS);
}
/**
* Calculates the amount of time until another year-half in terms of the specified unit.
* <p>
* This calculates the amount of time between two {@code YearHalf}
* objects in terms of a single {@code TemporalUnit}.
* The start and end points are {@code this} and the specified year-half.
* The result will be negative if the end is before the start.
* The {@code Temporal} passed to this method is converted to a
* {@code YearHalf} using {@link #from(TemporalAccessor)}.
* For example, the period in years between two year-halves can be calculated
* using {@code startYearHalf.until(endYearHalf, YEARS)}.
* <p>
* The calculation returns a whole number, representing the number of
* complete units between the two year-halves.
* For example, the period in decades between 2012-H2 and 2032-H1
* will only be one decade as it is one half short of two decades.
* <p>
* There are two equivalent ways of using this method.
* The first is to invoke this method.
* The second is to use {@link TemporalUnit#between(Temporal, Temporal)}:
* <pre>
* // these two lines are equivalent
* amount = start.until(end, HALF_YEARS);
* amount = HALF_YEARS.between(start, end);
* </pre>
* The choice should be made based on which makes the code more readable.
* <p>
* The calculation is implemented in this method for {@link ChronoUnit}.
* The units {@code HALF_YEARS}, {@code YEARS}, {@code DECADES},
* {@code CENTURIES}, {@code MILLENNIA} and {@code ERAS} are supported.
* Other {@code ChronoUnit} values will throw an exception.
* <p>
* If the unit is not a {@code ChronoUnit}, then the result of this method
* is obtained by invoking {@code TemporalUnit.between(Temporal, Temporal)}
* passing {@code this} as the first argument and the converted input temporal
* as the second argument.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param endExclusive the end date, exclusive, which is converted to a {@code YearHalf}, not null
* @param unit the unit to measure the amount in, not null
* @return the amount of time between this year-half and the end year-half
* @throws DateTimeException if the amount cannot be calculated, or the end
* temporal cannot be converted to a {@code YearHalf}
* @throws UnsupportedTemporalTypeException if the unit is not supported
* @throws ArithmeticException if numeric overflow occurs
*/
@Override
public long until(Temporal endExclusive, TemporalUnit unit) {
YearHalf end = YearHalf.from(endExclusive);
long halvesUntil = end.getProlepticHalf() - getProlepticHalf(); // no overflow
if (unit == HALF_YEARS) {
return halvesUntil;
} else if (unit instanceof ChronoUnit) {
switch ((ChronoUnit) unit) {
case YEARS:
return halvesUntil / 2;
case DECADES:
return halvesUntil / 20;
case CENTURIES:
return halvesUntil / 200;
case MILLENNIA:
return halvesUntil / 2000;
case ERAS:
return end.getLong(ERA) - getLong(ERA);
default:
throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
}
}
return unit.between(this, end);
}
/**
* Returns a sequential ordered stream of year-half. The returned stream starts from this year-half
* (inclusive) and goes to {@code endExclusive} (exclusive) by an incremental step of 1 {@code HALF_YEARS}.
* <p>
* This instance is immutable and unaffected by this method call.
*
* @param endExclusive the end year-half, exclusive, not null
* @return a sequential {@code Stream} for the range of {@code YearHalf} values
* @throws IllegalArgumentException if end year-half is before this year-half
*/
public Stream<YearHalf> halvesUntil(YearHalf endExclusive) {
if (endExclusive.isBefore(this)) {
throw new IllegalArgumentException(endExclusive + " < " + this);
}
long intervalLength = until(endExclusive, HALF_YEARS);
return LongStream.range(0, intervalLength).mapToObj(n -> plusHalves(n));
}
/**
* Formats this year-half using the specified formatter.
* <p>
* This year-half will be passed to the formatter to produce a string.
*
* @param formatter the formatter to use, not null
* @return the formatted year-half string, not null
* @throws DateTimeException if an error occurs during printing
*/
public String format(DateTimeFormatter formatter) {
Objects.requireNonNull(formatter, "formatter");
return formatter.format(this);
}
//-----------------------------------------------------------------------
/**
* Combines this year-half with a day-of-half to create a {@code LocalDate}.
* <p>
* This returns a {@code LocalDate} formed from this year-half and the specified day-of-half.
* <p>
* The day-of-half value must be valid for the year-half.
* <p>
* This method can be used as part of a chain to produce a date:
* <pre>
* LocalDate date = yearHalf.atDay(day);
* </pre>
*
* @param dayOfHalf the day-of-half to use, from 1 to 184
* @return the date formed from this year-half and the specified day, not null
* @throws DateTimeException if the day is invalid for the year-half
* @see #isValidDay(int)
*/
public LocalDate atDay(int dayOfHalf) {
ValueRange.of(1, lengthOfHalf()).checkValidValue(dayOfHalf, DAY_OF_HALF);
boolean leap = Year.isLeap(year);
Month month = half.firstMonth();
int dom = dayOfHalf;
while (dom > month.length(leap)) {
dom -= month.length(leap);
month = month.plus(1);
}
return LocalDate.of(year, month, dom);
}
/**
* Returns a {@code LocalDate} at the end of the half.
* <p>
* This returns a {@code LocalDate} based on this year-half.
* The day-of-half is set to the last valid day of the half, taking
* into account leap years.
* <p>
* This method can be used as part of a chain to produce a date:
* <pre>
* LocalDate date = year.atHalf(half).atEndOfHalf();
* </pre>
*
* @return the last valid date of this year-half, not null
*/
public LocalDate atEndOfHalf() {
Month month = half.firstMonth().plus(5);
return LocalDate.of(year, month, month.maxLength());
}
//-----------------------------------------------------------------------
/**
* Compares this year-half to another
* <p>
* The comparison is based first on the value of the year, then on the value of the half.
* It is "consistent with equals", as defined by {@link Comparable}.
*
* @param other the other year-half to compare to, not null
* @return the comparator value, negative if less, positive if greater
*/
@Override
public int compareTo(YearHalf other) {
int cmp = (year - other.year);
if (cmp == 0) {
cmp = half.compareTo(other.half);
}
return cmp;
}
/**
* Is this year-half after the specified year-half.
*
* @param other the other year-half to compare to, not null
* @return true if this is after the specified year-half
*/
public boolean isAfter(YearHalf other) {
return compareTo(other) > 0;
}
/**
* Is this year-half before the specified year-half.
*
* @param other the other year-half to compare to, not null
* @return true if this point is before the specified year-half
*/
public boolean isBefore(YearHalf other) {
return compareTo(other) < 0;
}
//-----------------------------------------------------------------------
/**
* Checks if this year-half is equal to another year-half.
* <p>
* The comparison is based on the time-line position of the year-halves.
*
* @param obj the object to check, null returns false
* @return true if this is equal to the other year-half
*/
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj instanceof YearHalf) {
YearHalf other = (YearHalf) obj;
return year == other.year && half == other.half;
}
return false;
}
/**
* A hash code for this year-half.
*
* @return a suitable hash code
*/
@Override
public int hashCode() {
return year ^ (half.getValue() << 28);
}
//-----------------------------------------------------------------------
/**
* Outputs this year-half as a {@code String}, such as {@code 2007-H2}.
*
* @return a string representation of this year-half, not null
*/
@Override
@ToString
public String toString() {
int absYear = Math.abs(year);
StringBuilder buf = new StringBuilder(10);
if (absYear < 1000) {
if (year < 0) {
buf.append(year - 10000).deleteCharAt(1);
} else {
buf.append(year + 10000).deleteCharAt(0);
}
} else {
if (year > 9999) {
buf.append('+');
}
buf.append(year);
}
return buf.append('-').append(half).toString();
}
}