+ * {@code LocalDate} is an immutable date-time object that represents a date, + * often viewed as year-month-day. Other date fields, such as day-of-year, + * day-of-week and week-of-year, can also be accessed. + * For example, the value "2nd October 2007" can be stored in a {@code LocalDate}. + *
+ * This class does not store or represent a time or time-zone. + * Instead, it is a description of the date, as used for birthdays. + * It cannot represent an instant on the time-line without additional information + * such as an offset or time-zone. + *
+ * 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. + * + *
+ * This is a value-based + * class; use of identity-sensitive operations (including reference equality + * ({@code ==}), identity hash code, or synchronization) on instances of + * {@code LocalDate} may have unpredictable results and should be avoided. + * The {@code equals} method should be used for comparisons. + * + * @implSpec + * This class is immutable and thread-safe. + * + * @since 1.8 + */ +public final class LocalDate + implements Temporal, TemporalAdjuster, ChronoLocalDate, Serializable { + + /** + * The minimum supported {@code LocalDate}, '-999999999-01-01'. + * This could be used by an application as a "far past" date. + */ + public static final LocalDate MIN = LocalDate.of(Year.MIN_VALUE, 1, 1); + /** + * The maximum supported {@code LocalDate}, '+999999999-12-31'. + * This could be used by an application as a "far future" date. + */ + public static final LocalDate MAX = LocalDate.of(Year.MAX_VALUE, 12, 31); + + /** + * Serialization version. + */ + private static final long serialVersionUID = 2942565459149668126L; + /** + * The number of days in a 400 year cycle. + */ + private static final int DAYS_PER_CYCLE = 146097; + /** + * The number of days from year zero to year 1970. + * There are five 400 year cycles from year zero to 2000. + * There are 7 leap years from 1970 to 2000. + */ + static final long DAYS_0000_TO_1970 = (DAYS_PER_CYCLE * 5L) - (30L * 365L + 7L); + + /** + * The year. + */ + private final int year; + /** + * The month-of-year. + */ + private final short month; + /** + * The day-of-month. + */ + private final short day; + + //----------------------------------------------------------------------- + /** + * Obtains the current date from the system clock in the default time-zone. + *
+ * This will query the {@link Clock#systemDefaultZone() system clock} in the default + * time-zone to obtain the current date. + *
+ * Using this method will prevent the ability to use an alternate clock for testing + * because the clock is hard-coded. + * + * @return the current date using the system clock and default time-zone, not null + */ + public static LocalDate now() { + return now(Clock.systemDefaultZone()); + } + + /** + * Obtains the current date from the system clock in the specified time-zone. + *
+ * This will query the {@link Clock#system(ZoneId) system clock} to obtain the current date. + * Specifying the time-zone avoids dependence on the default time-zone. + *
+ * 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 date using the system clock, not null + */ + public static LocalDate now(ZoneId zone) { + return now(Clock.system(zone)); + } + + /** + * Obtains the current date from the specified clock. + *
+ * This will query the specified clock to obtain the current date - today. + * 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 date, not null + */ + public static LocalDate now(Clock clock) { + Objects.requireNonNull(clock, "clock"); + // inline to avoid creating object and Instant checks + final Instant now = clock.instant(); // called once + ZoneOffset offset = clock.getZone().getRules().getOffset(now); + long epochSec = now.getEpochSecond() + offset.getTotalSeconds(); // overflow caught later + long epochDay = Math.floorDiv(epochSec, SECONDS_PER_DAY); + return LocalDate.ofEpochDay(epochDay); + } + + //----------------------------------------------------------------------- + /** + * Obtains an instance of {@code LocalDate} from a year, month and day. + *
+ * This returns a {@code LocalDate} with the specified year, month and day-of-month. + * The day must be valid for the year and month, otherwise an exception will be thrown. + * + * @param year the year to represent, from MIN_YEAR to MAX_YEAR + * @param month the month-of-year to represent, not null + * @param dayOfMonth the day-of-month to represent, from 1 to 31 + * @return the local date, not null + * @throws DateTimeException if the value of any field is out of range, + * or if the day-of-month is invalid for the month-year + */ + public static LocalDate of(int year, Month month, int dayOfMonth) { + YEAR.checkValidValue(year); + Objects.requireNonNull(month, "month"); + DAY_OF_MONTH.checkValidValue(dayOfMonth); + return create(year, month.getValue(), dayOfMonth); + } + + /** + * Obtains an instance of {@code LocalDate} from a year, month and day. + *
+ * This returns a {@code LocalDate} with the specified year, month and day-of-month. + * The day must be valid for the year and month, otherwise an exception will be thrown. + * + * @param year the year to represent, from MIN_YEAR to MAX_YEAR + * @param month the month-of-year to represent, from 1 (January) to 12 (December) + * @param dayOfMonth the day-of-month to represent, from 1 to 31 + * @return the local date, not null + * @throws DateTimeException if the value of any field is out of range, + * or if the day-of-month is invalid for the month-year + */ + public static LocalDate of(int year, int month, int dayOfMonth) { + YEAR.checkValidValue(year); + MONTH_OF_YEAR.checkValidValue(month); + DAY_OF_MONTH.checkValidValue(dayOfMonth); + return create(year, month, dayOfMonth); + } + + //----------------------------------------------------------------------- + /** + * Obtains an instance of {@code LocalDate} from a year and day-of-year. + *
+ * This returns a {@code LocalDate} with the specified year and day-of-year. + * The day-of-year must be valid for the year, otherwise an exception will be thrown. + * + * @param year the year to represent, from MIN_YEAR to MAX_YEAR + * @param dayOfYear the day-of-year to represent, from 1 to 366 + * @return the local date, not null + * @throws DateTimeException if the value of any field is out of range, + * or if the day-of-year is invalid for the year + */ + public static LocalDate ofYearDay(int year, int dayOfYear) { + YEAR.checkValidValue(year); + DAY_OF_YEAR.checkValidValue(dayOfYear); + boolean leap = IsoChronology.INSTANCE.isLeapYear(year); + if (dayOfYear == 366 && leap == false) { + throw new DateTimeException("Invalid date 'DayOfYear 366' as '" + year + "' is not a leap year"); + } + Month moy = Month.of((dayOfYear - 1) / 31 + 1); + int monthEnd = moy.firstDayOfYear(leap) + moy.length(leap) - 1; + if (dayOfYear > monthEnd) { + moy = moy.plus(1); + } + int dom = dayOfYear - moy.firstDayOfYear(leap) + 1; + return new LocalDate(year, moy.getValue(), dom); + } + + //----------------------------------------------------------------------- + /** + * Obtains an instance of {@code LocalDate} from the epoch day count. + *
+ * This returns a {@code LocalDate} with the specified epoch-day. + * The {@link ChronoField#EPOCH_DAY EPOCH_DAY} is a simple incrementing count + * of days where day 0 is 1970-01-01. Negative numbers represent earlier days. + * + * @param epochDay the Epoch Day to convert, based on the epoch 1970-01-01 + * @return the local date, not null + * @throws DateTimeException if the epoch day exceeds the supported date range + */ + public static LocalDate ofEpochDay(long epochDay) { + long zeroDay = epochDay + DAYS_0000_TO_1970; + // find the march-based year + zeroDay -= 60; // adjust to 0000-03-01 so leap day is at end of four year cycle + long adjust = 0; + if (zeroDay < 0) { + // adjust negative years to positive for calculation + long adjustCycles = (zeroDay + 1) / DAYS_PER_CYCLE - 1; + adjust = adjustCycles * 400; + zeroDay += -adjustCycles * DAYS_PER_CYCLE; + } + long yearEst = (400 * zeroDay + 591) / DAYS_PER_CYCLE; + long doyEst = zeroDay - (365 * yearEst + yearEst / 4 - yearEst / 100 + yearEst / 400); + if (doyEst < 0) { + // fix estimate + yearEst--; + doyEst = zeroDay - (365 * yearEst + yearEst / 4 - yearEst / 100 + yearEst / 400); + } + yearEst += adjust; // reset any negative year + int marchDoy0 = (int) doyEst; + + // convert march-based values back to january-based + int marchMonth0 = (marchDoy0 * 5 + 2) / 153; + int month = (marchMonth0 + 2) % 12 + 1; + int dom = marchDoy0 - (marchMonth0 * 306 + 5) / 10 + 1; + yearEst += marchMonth0 / 10; + + // check year now we are certain it is correct + int year = YEAR.checkValidIntValue(yearEst); + return new LocalDate(year, month, dom); + } + + //----------------------------------------------------------------------- + /** + * Obtains an instance of {@code LocalDate} from a temporal object. + *
+ * This obtains a local date 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 LocalDate}. + *
+ * The conversion uses the {@link TemporalQueries#localDate()} query, which relies + * on extracting the {@link ChronoField#EPOCH_DAY EPOCH_DAY} field. + *
+ * This method matches the signature of the functional interface {@link TemporalQuery} + * allowing it to be used as a query via method reference, {@code LocalDate::from}. + * + * @param temporal the temporal object to convert, not null + * @return the local date, not null + * @throws DateTimeException if unable to convert to a {@code LocalDate} + */ + public static LocalDate from(TemporalAccessor temporal) { + Objects.requireNonNull(temporal, "temporal"); + LocalDate date = temporal.query(TemporalQueries.localDate()); + if (date == null) { + throw new DateTimeException("Unable to obtain LocalDate from TemporalAccessor: " + + temporal + " of type " + temporal.getClass().getName()); + } + return date; + } + + //----------------------------------------------------------------------- + /** + * Obtains an instance of {@code LocalDate} from a text string such as {@code 2007-12-03}. + *
+ * The string must represent a valid date and is parsed using + * {@link java.time.format.DateTimeFormatter#ISO_LOCAL_DATE}. + * + * @param text the text to parse such as "2007-12-03", not null + * @return the parsed local date, not null + * @throws DateTimeParseException if the text cannot be parsed + */ + public static LocalDate parse(CharSequence text) { + return parse(text, DateTimeFormatter.ISO_LOCAL_DATE); + } + + /** + * Obtains an instance of {@code LocalDate} from a text string using a specific formatter. + *
+ * The text is parsed using the formatter, returning a date. + * + * @param text the text to parse, not null + * @param formatter the formatter to use, not null + * @return the parsed local date, not null + * @throws DateTimeParseException if the text cannot be parsed + */ + public static LocalDate parse(CharSequence text, DateTimeFormatter formatter) { + Objects.requireNonNull(formatter, "formatter"); + return formatter.parse(text, LocalDate::from); + } + + //----------------------------------------------------------------------- + /** + * Creates a local date from the year, month and day fields. + * + * @param year the year to represent, validated from MIN_YEAR to MAX_YEAR + * @param month the month-of-year to represent, from 1 to 12, validated + * @param dayOfMonth the day-of-month to represent, validated from 1 to 31 + * @return the local date, not null + * @throws DateTimeException if the day-of-month is invalid for the month-year + */ + private static LocalDate create(int year, int month, int dayOfMonth) { + if (dayOfMonth > 28) { + int dom = 31; + switch (month) { + case 2: + dom = (IsoChronology.INSTANCE.isLeapYear(year) ? 29 : 28); + break; + case 4: + case 6: + case 9: + case 11: + dom = 30; + break; + } + if (dayOfMonth > dom) { + if (dayOfMonth == 29) { + throw new DateTimeException("Invalid date 'February 29' as '" + year + "' is not a leap year"); + } else { + throw new DateTimeException("Invalid date '" + Month.of(month).name() + " " + dayOfMonth + "'"); + } + } + } + return new LocalDate(year, month, dayOfMonth); + } + + /** + * Resolves the date, resolving days past the end of month. + * + * @param year the year to represent, validated from MIN_YEAR to MAX_YEAR + * @param month the month-of-year to represent, validated from 1 to 12 + * @param day the day-of-month to represent, validated from 1 to 31 + * @return the resolved date, not null + */ + private static LocalDate resolvePreviousValid(int year, int month, int day) { + switch (month) { + case 2: + day = Math.min(day, IsoChronology.INSTANCE.isLeapYear(year) ? 29 : 28); + break; + case 4: + case 6: + case 9: + case 11: + day = Math.min(day, 30); + break; + } + return new LocalDate(year, month, day); + } + + /** + * Constructor, previously validated. + * + * @param year the year to represent, from MIN_YEAR to MAX_YEAR + * @param month the month-of-year to represent, not null + * @param dayOfMonth the day-of-month to represent, valid for year-month, from 1 to 31 + */ + private LocalDate(int year, int month, int dayOfMonth) { + this.year = year; + this.month = (short) month; + this.day = (short) dayOfMonth; + } + + //----------------------------------------------------------------------- + /** + * Checks if the specified field is supported. + *
+ * This checks if this date 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. + *
+ * If the field is a {@link ChronoField} then the query is implemented here. + * The supported fields are: + *
+ * 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 date, false if not + */ + @Override // override for Javadoc + public boolean isSupported(TemporalField field) { + return ChronoLocalDate.super.isSupported(field); + } + + /** + * Checks if the specified unit is supported. + *
+ * This checks if the specified unit can be added to, or subtracted from, this date. + * If false, then calling the {@link #plus(long, TemporalUnit)} and + * {@link #minus(long, TemporalUnit) minus} methods will throw an exception. + *
+ * If the unit is a {@link ChronoUnit} then the query is implemented here. + * The supported units are: + *
+ * 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 // override for Javadoc + public boolean isSupported(TemporalUnit unit) { + return ChronoLocalDate.super.isSupported(unit); + } + + //----------------------------------------------------------------------- + /** + * Gets the range of valid values for the specified field. + *
+ * The range object expresses the minimum and maximum valid values for a field. + * This date 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. + *
+ * 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}. + *
+ * 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 instanceof ChronoField) { + ChronoField f = (ChronoField) field; + if (f.isDateBased()) { + switch (f) { + case DAY_OF_MONTH: return ValueRange.of(1, lengthOfMonth()); + case DAY_OF_YEAR: return ValueRange.of(1, lengthOfYear()); + case ALIGNED_WEEK_OF_MONTH: return ValueRange.of(1, getMonth() == Month.FEBRUARY && isLeapYear() == false ? 4 : 5); + case YEAR_OF_ERA: + return (getYear() <= 0 ? ValueRange.of(1, Year.MAX_VALUE + 1) : ValueRange.of(1, Year.MAX_VALUE)); + } + return field.range(); + } + throw new UnsupportedTemporalTypeException("Unsupported field: " + field); + } + return field.rangeRefinedBy(this); + } + + /** + * Gets the value of the specified field from this date as an {@code int}. + *
+ * This queries this date for the value of 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. + *
+ * 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 date, except {@code EPOCH_DAY} and {@code PROLEPTIC_MONTH} + * which are too large to fit in an {@code int} and throw an {@code UnsupportedTemporalTypeException}. + * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}. + *
+ * 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 // override for Javadoc and performance + public int get(TemporalField field) { + if (field instanceof ChronoField) { + return get0(field); + } + return ChronoLocalDate.super.get(field); + } + + /** + * Gets the value of the specified field from this date as a {@code long}. + *
+ * This queries this date for the value of 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. + *
+ * 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 date. + * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}. + *
+ * 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 instanceof ChronoField) { + if (field == EPOCH_DAY) { + return toEpochDay(); + } + if (field == PROLEPTIC_MONTH) { + return getProlepticMonth(); + } + return get0(field); + } + return field.getFrom(this); + } + + private int get0(TemporalField field) { + switch ((ChronoField) field) { + case DAY_OF_WEEK: return getDayOfWeek().getValue(); + case ALIGNED_DAY_OF_WEEK_IN_MONTH: return ((day - 1) % 7) + 1; + case ALIGNED_DAY_OF_WEEK_IN_YEAR: return ((getDayOfYear() - 1) % 7) + 1; + case DAY_OF_MONTH: return day; + case DAY_OF_YEAR: return getDayOfYear(); + case EPOCH_DAY: throw new UnsupportedTemporalTypeException("Invalid field 'EpochDay' for get() method, use getLong() instead"); + case ALIGNED_WEEK_OF_MONTH: return ((day - 1) / 7) + 1; + case ALIGNED_WEEK_OF_YEAR: return ((getDayOfYear() - 1) / 7) + 1; + case MONTH_OF_YEAR: return month; + case PROLEPTIC_MONTH: throw new UnsupportedTemporalTypeException("Invalid field 'ProlepticMonth' for get() method, use getLong() instead"); + case YEAR_OF_ERA: return (year >= 1 ? year : 1 - year); + case YEAR: return year; + case ERA: return (year >= 1 ? 1 : 0); + } + throw new UnsupportedTemporalTypeException("Unsupported field: " + field); + } + + private long getProlepticMonth() { + return (year * 12L + month - 1); + } + + //----------------------------------------------------------------------- + /** + * Gets the chronology of this date, which is the ISO calendar system. + *
+ * The {@code Chronology} represents the calendar system in use. + * 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. + * + * @return the ISO chronology, not null + */ + @Override + public IsoChronology getChronology() { + return IsoChronology.INSTANCE; + } + + /** + * Gets the era applicable at this date. + *
+ * The official ISO-8601 standard does not define eras, however {@code IsoChronology} does. + * It defines two eras, 'CE' from year one onwards and 'BCE' from year zero backwards. + * Since dates before the Julian-Gregorian cutover are not in line with history, + * the cutover between 'BCE' and 'CE' is also not aligned with the commonly used + * eras, often referred to using 'BC' and 'AD'. + *
+ * Users of this class should typically ignore this method as it exists primarily + * to fulfill the {@link ChronoLocalDate} contract where it is necessary to support + * the Japanese calendar system. + *
+ * The returned era will be a singleton capable of being compared with the constants + * in {@link IsoChronology} using the {@code ==} operator. + * + * @return the {@code IsoChronology} era constant applicable at this date, not null + */ + @Override // override for Javadoc + public Era getEra() { + return ChronoLocalDate.super.getEra(); + } + + /** + * Gets the year field. + *
+ * This method returns the primitive {@code int} value for the year. + *
+ * The year returned by this method is proleptic as per {@code get(YEAR)}. + * To obtain the year-of-era, use {@code get(YEAR_OF_ERA)}. + * + * @return the year, from MIN_YEAR to MAX_YEAR + */ + public int getYear() { + return year; + } + + /** + * Gets the month-of-year field from 1 to 12. + *
+ * This method returns the month as an {@code int} from 1 to 12. + * Application code is frequently clearer if the enum {@link Month} + * is used by calling {@link #getMonth()}. + * + * @return the month-of-year, from 1 to 12 + * @see #getMonth() + */ + public int getMonthValue() { + return month; + } + + /** + * Gets the month-of-year field using the {@code Month} enum. + *
+ * This method returns the enum {@link Month} for the month. + * 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 Month#getValue() int value}. + * + * @return the month-of-year, not null + * @see #getMonthValue() + */ + public Month getMonth() { + return Month.of(month); + } + + /** + * Gets the day-of-month field. + *
+ * This method returns the primitive {@code int} value for the day-of-month. + * + * @return the day-of-month, from 1 to 31 + */ + public int getDayOfMonth() { + return day; + } + + /** + * Gets the day-of-year field. + *
+ * This method returns the primitive {@code int} value for the day-of-year. + * + * @return the day-of-year, from 1 to 365, or 366 in a leap year + */ + public int getDayOfYear() { + return getMonth().firstDayOfYear(isLeapYear()) + day - 1; + } + + /** + * Gets the day-of-week field, which is an enum {@code DayOfWeek}. + *
+ * This method returns the enum {@link DayOfWeek} for the day-of-week. + * 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 DayOfWeek#getValue() int value}. + *
+ * Additional information can be obtained from the {@code DayOfWeek}. + * This includes textual names of the values. + * + * @return the day-of-week, not null + */ + public DayOfWeek getDayOfWeek() { + int dow0 = (int)Math.floorMod(toEpochDay() + 3, 7); + return DayOfWeek.of(dow0 + 1); + } + + //----------------------------------------------------------------------- + /** + * Checks if the year is a leap year, according to the ISO proleptic + * calendar system rules. + *
+ * 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. + *
+ * 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. + *
+ * 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 + */ + @Override // override for Javadoc and performance + public boolean isLeapYear() { + return IsoChronology.INSTANCE.isLeapYear(year); + } + + /** + * Returns the length of the month represented by this date. + *
+ * This returns the length of the month in days. + * For example, a date in January would return 31. + * + * @return the length of the month in days + */ + @Override + public int lengthOfMonth() { + switch (month) { + case 2: + return (isLeapYear() ? 29 : 28); + case 4: + case 6: + case 9: + case 11: + return 30; + default: + return 31; + } + } + + /** + * Returns the length of the year represented by this date. + *
+ * This returns the length of the year in days, either 365 or 366. + * + * @return 366 if the year is leap, 365 otherwise + */ + @Override // override for Javadoc and performance + public int lengthOfYear() { + return (isLeapYear() ? 366 : 365); + } + + //----------------------------------------------------------------------- + /** + * Returns an adjusted copy of this date. + *
+ * This returns a {@code LocalDate}, based on this one, with the date adjusted. + * The adjustment takes place using the specified adjuster strategy object. + * Read the documentation of the adjuster to understand what adjustment will be made. + *
+ * A simple adjuster might simply set the one of the fields, such as the year field. + * A more complex adjuster might set the date to the last day of the month. + *
+ * A selection of common adjustments is provided in + * {@link java.time.temporal.TemporalAdjusters TemporalAdjusters}. + * These include finding the "last day of the month" and "next Wednesday". + * Key date-time classes also implement the {@code TemporalAdjuster} interface, + * such as {@link Month} and {@link java.time.MonthDay MonthDay}. + * The adjuster is responsible for handling special cases, such as the varying + * lengths of month and leap years. + *
+ * For example this code returns a date on the last day of July: + *
+ * import static java.time.Month.*; + * import static java.time.temporal.TemporalAdjusters.*; + * + * result = localDate.with(JULY).with(lastDayOfMonth()); + *+ *
+ * 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. + *
+ * This instance is immutable and unaffected by this method call. + * + * @param adjuster the adjuster to use, not null + * @return a {@code LocalDate} 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 LocalDate with(TemporalAdjuster adjuster) { + // optimizations + if (adjuster instanceof LocalDate) { + return (LocalDate) adjuster; + } + return (LocalDate) adjuster.adjustInto(this); + } + + /** + * Returns a copy of this date with the specified field set to a new value. + *
+ * This returns a {@code LocalDate}, 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, month or day-of-month. + * If it is not possible to set the value, because the field is not supported or for + * some other reason, an exception is thrown. + *
+ * In some cases, changing the specified field can cause the resulting date to become invalid, + * such as changing the month from 31st January to February would make the day-of-month invalid. + * In cases like this, the field is responsible for resolving the date. Typically it will choose + * the previous valid date, which would be the last valid day of February in this example. + *
+ * If the field is a {@link ChronoField} then the adjustment is implemented here. + * The supported fields behave as follows: + *
+ * In all cases, if the new value is outside the valid range of values for the field + * then a {@code DateTimeException} will be thrown. + *
+ * All other {@code ChronoField} instances will throw an {@code UnsupportedTemporalTypeException}. + *
+ * 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. + *
+ * 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 LocalDate} 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 LocalDate with(TemporalField field, long newValue) { + if (field instanceof ChronoField) { + ChronoField f = (ChronoField) field; + f.checkValidValue(newValue); + switch (f) { + case DAY_OF_WEEK: return plusDays(newValue - getDayOfWeek().getValue()); + case ALIGNED_DAY_OF_WEEK_IN_MONTH: return plusDays(newValue - getLong(ALIGNED_DAY_OF_WEEK_IN_MONTH)); + case ALIGNED_DAY_OF_WEEK_IN_YEAR: return plusDays(newValue - getLong(ALIGNED_DAY_OF_WEEK_IN_YEAR)); + case DAY_OF_MONTH: return withDayOfMonth((int) newValue); + case DAY_OF_YEAR: return withDayOfYear((int) newValue); + case EPOCH_DAY: return LocalDate.ofEpochDay(newValue); + case ALIGNED_WEEK_OF_MONTH: return plusWeeks(newValue - getLong(ALIGNED_WEEK_OF_MONTH)); + case ALIGNED_WEEK_OF_YEAR: return plusWeeks(newValue - getLong(ALIGNED_WEEK_OF_YEAR)); + case MONTH_OF_YEAR: return withMonth((int) newValue); + case PROLEPTIC_MONTH: return plusMonths(newValue - getProlepticMonth()); + case YEAR_OF_ERA: return withYear((int) (year >= 1 ? newValue : 1 - newValue)); + case YEAR: return withYear((int) newValue); + case ERA: return (getLong(ERA) == newValue ? this : withYear(1 - year)); + } + throw new UnsupportedTemporalTypeException("Unsupported field: " + field); + } + return field.adjustInto(this, newValue); + } + + //----------------------------------------------------------------------- + /** + * Returns a copy of this {@code LocalDate} with the year altered. + *
+ * If the day-of-month is invalid for the year, it will be changed to the last valid day of the month. + *
+ * This instance is immutable and unaffected by this method call. + * + * @param year the year to set in the result, from MIN_YEAR to MAX_YEAR + * @return a {@code LocalDate} based on this date with the requested year, not null + * @throws DateTimeException if the year value is invalid + */ + public LocalDate withYear(int year) { + if (this.year == year) { + return this; + } + YEAR.checkValidValue(year); + return resolvePreviousValid(year, month, day); + } + + /** + * Returns a copy of this {@code LocalDate} with the month-of-year altered. + *
+ * If the day-of-month is invalid for the year, it will be changed to the last valid day of the month. + *
+ * This instance is immutable and unaffected by this method call. + * + * @param month the month-of-year to set in the result, from 1 (January) to 12 (December) + * @return a {@code LocalDate} based on this date with the requested month, not null + * @throws DateTimeException if the month-of-year value is invalid + */ + public LocalDate withMonth(int month) { + if (this.month == month) { + return this; + } + MONTH_OF_YEAR.checkValidValue(month); + return resolvePreviousValid(year, month, day); + } + + /** + * Returns a copy of this {@code LocalDate} with the day-of-month altered. + *
+ * If the resulting date is invalid, an exception is thrown. + *
+ * This instance is immutable and unaffected by this method call. + * + * @param dayOfMonth the day-of-month to set in the result, from 1 to 28-31 + * @return a {@code LocalDate} based on this date with the requested day, not null + * @throws DateTimeException if the day-of-month value is invalid, + * or if the day-of-month is invalid for the month-year + */ + public LocalDate withDayOfMonth(int dayOfMonth) { + if (this.day == dayOfMonth) { + return this; + } + return of(year, month, dayOfMonth); + } + + /** + * Returns a copy of this {@code LocalDate} with the day-of-year altered. + *
+ * If the resulting date is invalid, an exception is thrown. + *
+ * This instance is immutable and unaffected by this method call. + * + * @param dayOfYear the day-of-year to set in the result, from 1 to 365-366 + * @return a {@code LocalDate} based on this date with the requested day, not null + * @throws DateTimeException if the day-of-year value is invalid, + * or if the day-of-year is invalid for the year + */ + public LocalDate withDayOfYear(int dayOfYear) { + if (this.getDayOfYear() == dayOfYear) { + return this; + } + return ofYearDay(year, dayOfYear); + } + + //----------------------------------------------------------------------- + /** + * Returns a copy of this date with the specified amount added. + *
+ * This returns a {@code LocalDate}, 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. + *
+ * 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. + *
+ * This instance is immutable and unaffected by this method call. + * + * @param amountToAdd the amount to add, not null + * @return a {@code LocalDate} based on this date with the addition made, not null + * @throws DateTimeException if the addition cannot be made + * @throws ArithmeticException if numeric overflow occurs + */ + @Override + public LocalDate plus(TemporalAmount amountToAdd) { + if (amountToAdd instanceof Period) { + Period periodToAdd = (Period) amountToAdd; + return plusMonths(periodToAdd.toTotalMonths()).plusDays(periodToAdd.getDays()); + } + Objects.requireNonNull(amountToAdd, "amountToAdd"); + return (LocalDate) amountToAdd.addTo(this); + } + + /** + * Returns a copy of this date with the specified amount added. + *
+ * This returns a {@code LocalDate}, 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. + *
+ * In some cases, adding the amount can cause the resulting date to become invalid. + * For example, adding one month to 31st January would result in 31st February. + * In cases like this, the unit is responsible for resolving the date. + * Typically it will choose the previous valid date, which would be the last valid + * day of February in this example. + *
+ * If the field is a {@link ChronoUnit} then the addition is implemented here. + * The supported fields behave as follows: + *
+ * All other {@code ChronoUnit} instances will throw an {@code UnsupportedTemporalTypeException}. + *
+ * 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. + *
+ * 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 LocalDate} based on this date 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 LocalDate plus(long amountToAdd, TemporalUnit unit) { + if (unit instanceof ChronoUnit) { + ChronoUnit f = (ChronoUnit) unit; + switch (f) { + case DAYS: return plusDays(amountToAdd); + case WEEKS: return plusWeeks(amountToAdd); + case MONTHS: return plusMonths(amountToAdd); + 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)); + } + throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit); + } + return unit.addTo(this, amountToAdd); + } + + //----------------------------------------------------------------------- + /** + * Returns a copy of this {@code LocalDate} with the specified number of years added. + *
+ * This method adds the specified amount to the years field in three steps: + *
+ * For example, 2008-02-29 (leap year) plus one year would result in the + * invalid date 2009-02-29 (standard year). Instead of returning an invalid + * result, the last valid day of the month, 2009-02-28, is selected instead. + *
+ * This instance is immutable and unaffected by this method call. + * + * @param yearsToAdd the years to add, may be negative + * @return a {@code LocalDate} based on this date with the years added, not null + * @throws DateTimeException if the result exceeds the supported date range + */ + public LocalDate plusYears(long yearsToAdd) { + if (yearsToAdd == 0) { + return this; + } + int newYear = YEAR.checkValidIntValue(year + yearsToAdd); // safe overflow + return resolvePreviousValid(newYear, month, day); + } + + /** + * Returns a copy of this {@code LocalDate} with the specified number of months added. + *
+ * This method adds the specified amount to the months field in three steps: + *
+ * For example, 2007-03-31 plus one month would result in the invalid date + * 2007-04-31. Instead of returning an invalid result, the last valid day + * of the month, 2007-04-30, is selected instead. + *
+ * This instance is immutable and unaffected by this method call. + * + * @param monthsToAdd the months to add, may be negative + * @return a {@code LocalDate} based on this date with the months added, not null + * @throws DateTimeException if the result exceeds the supported date range + */ + public LocalDate plusMonths(long monthsToAdd) { + if (monthsToAdd == 0) { + return this; + } + long monthCount = year * 12L + (month - 1); + long calcMonths = monthCount + monthsToAdd; // safe overflow + int newYear = YEAR.checkValidIntValue(Math.floorDiv(calcMonths, 12)); + int newMonth = (int)Math.floorMod(calcMonths, 12) + 1; + return resolvePreviousValid(newYear, newMonth, day); + } + + /** + * Returns a copy of this {@code LocalDate} with the specified number of weeks added. + *
+ * This method adds the specified amount in weeks to the days field incrementing + * the month and year fields as necessary to ensure the result remains valid. + * The result is only invalid if the maximum/minimum year is exceeded. + *
+ * For example, 2008-12-31 plus one week would result in 2009-01-07. + *
+ * This instance is immutable and unaffected by this method call. + * + * @param weeksToAdd the weeks to add, may be negative + * @return a {@code LocalDate} based on this date with the weeks added, not null + * @throws DateTimeException if the result exceeds the supported date range + */ + public LocalDate plusWeeks(long weeksToAdd) { + return plusDays(Math.multiplyExact(weeksToAdd, 7)); + } + + /** + * Returns a copy of this {@code LocalDate} with the specified number of days added. + *
+ * This method adds the specified amount to the days field incrementing the + * month and year fields as necessary to ensure the result remains valid. + * The result is only invalid if the maximum/minimum year is exceeded. + *
+ * For example, 2008-12-31 plus one day would result in 2009-01-01. + *
+ * This instance is immutable and unaffected by this method call. + * + * @param daysToAdd the days to add, may be negative + * @return a {@code LocalDate} based on this date with the days added, not null + * @throws DateTimeException if the result exceeds the supported date range + */ + public LocalDate plusDays(long daysToAdd) { + if (daysToAdd == 0) { + return this; + } + long mjDay = Math.addExact(toEpochDay(), daysToAdd); + return LocalDate.ofEpochDay(mjDay); + } + + //----------------------------------------------------------------------- + /** + * Returns a copy of this date with the specified amount subtracted. + *
+ * This returns a {@code LocalDate}, 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. + *
+ * 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. + *
+ * This instance is immutable and unaffected by this method call. + * + * @param amountToSubtract the amount to subtract, not null + * @return a {@code LocalDate} based on this date with the subtraction made, not null + * @throws DateTimeException if the subtraction cannot be made + * @throws ArithmeticException if numeric overflow occurs + */ + @Override + public LocalDate minus(TemporalAmount amountToSubtract) { + if (amountToSubtract instanceof Period) { + Period periodToSubtract = (Period) amountToSubtract; + return minusMonths(periodToSubtract.toTotalMonths()).minusDays(periodToSubtract.getDays()); + } + Objects.requireNonNull(amountToSubtract, "amountToSubtract"); + return (LocalDate) amountToSubtract.subtractFrom(this); + } + + /** + * Returns a copy of this date with the specified amount subtracted. + *
+ * This returns a {@code LocalDate}, 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. + *
+ * 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. + *
+ * 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 LocalDate} based on this date 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 LocalDate 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 {@code LocalDate} with the specified number of years subtracted. + *
+ * This method subtracts the specified amount from the years field in three steps: + *
+ * For example, 2008-02-29 (leap year) minus one year would result in the + * invalid date 2007-02-29 (standard year). Instead of returning an invalid + * result, the last valid day of the month, 2007-02-28, is selected instead. + *
+ * This instance is immutable and unaffected by this method call. + * + * @param yearsToSubtract the years to subtract, may be negative + * @return a {@code LocalDate} based on this date with the years subtracted, not null + * @throws DateTimeException if the result exceeds the supported date range + */ + public LocalDate minusYears(long yearsToSubtract) { + return (yearsToSubtract == Long.MIN_VALUE ? plusYears(Long.MAX_VALUE).plusYears(1) : plusYears(-yearsToSubtract)); + } + + /** + * Returns a copy of this {@code LocalDate} with the specified number of months subtracted. + *
+ * This method subtracts the specified amount from the months field in three steps: + *
+ * For example, 2007-03-31 minus one month would result in the invalid date + * 2007-02-31. Instead of returning an invalid result, the last valid day + * of the month, 2007-02-28, is selected instead. + *
+ * This instance is immutable and unaffected by this method call. + * + * @param monthsToSubtract the months to subtract, may be negative + * @return a {@code LocalDate} based on this date with the months subtracted, not null + * @throws DateTimeException if the result exceeds the supported date range + */ + public LocalDate minusMonths(long monthsToSubtract) { + return (monthsToSubtract == Long.MIN_VALUE ? plusMonths(Long.MAX_VALUE).plusMonths(1) : plusMonths(-monthsToSubtract)); + } + + /** + * Returns a copy of this {@code LocalDate} with the specified number of weeks subtracted. + *
+ * This method subtracts the specified amount in weeks from the days field decrementing + * the month and year fields as necessary to ensure the result remains valid. + * The result is only invalid if the maximum/minimum year is exceeded. + *
+ * For example, 2009-01-07 minus one week would result in 2008-12-31. + *
+ * This instance is immutable and unaffected by this method call. + * + * @param weeksToSubtract the weeks to subtract, may be negative + * @return a {@code LocalDate} based on this date with the weeks subtracted, not null + * @throws DateTimeException if the result exceeds the supported date range + */ + public LocalDate minusWeeks(long weeksToSubtract) { + return (weeksToSubtract == Long.MIN_VALUE ? plusWeeks(Long.MAX_VALUE).plusWeeks(1) : plusWeeks(-weeksToSubtract)); + } + + /** + * Returns a copy of this {@code LocalDate} with the specified number of days subtracted. + *
+ * This method subtracts the specified amount from the days field decrementing the + * month and year fields as necessary to ensure the result remains valid. + * The result is only invalid if the maximum/minimum year is exceeded. + *
+ * For example, 2009-01-01 minus one day would result in 2008-12-31. + *
+ * This instance is immutable and unaffected by this method call. + * + * @param daysToSubtract the days to subtract, may be negative + * @return a {@code LocalDate} based on this date with the days subtracted, not null + * @throws DateTimeException if the result exceeds the supported date range + */ + public LocalDate minusDays(long daysToSubtract) { + return (daysToSubtract == Long.MIN_VALUE ? plusDays(Long.MAX_VALUE).plusDays(1) : plusDays(-daysToSubtract)); + } + + //----------------------------------------------------------------------- + /** + * Queries this date using the specified query. + *
+ * This queries this date 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. + *
+ * 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
+ * This returns a temporal object of the same observable type as the input
+ * with the date changed to be the same as this.
+ *
+ * The adjustment is equivalent to using {@link Temporal#with(TemporalField, long)}
+ * passing {@link ChronoField#EPOCH_DAY} as the field.
+ *
+ * In most cases, it is clearer to reverse the calling pattern by using
+ * {@link Temporal#with(TemporalAdjuster)}:
+ *
+ * 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 // override for Javadoc
+ public Temporal adjustInto(Temporal temporal) {
+ return ChronoLocalDate.super.adjustInto(temporal);
+ }
+
+ /**
+ * Calculates the amount of time until another date in terms of the specified unit.
+ *
+ * This calculates the amount of time between two {@code LocalDate}
+ * objects in terms of a single {@code TemporalUnit}.
+ * The start and end points are {@code this} and the specified date.
+ * The result will be negative if the end is before the start.
+ * The {@code Temporal} passed to this method is converted to a
+ * {@code LocalDate} using {@link #from(TemporalAccessor)}.
+ * For example, the amount in days between two dates can be calculated
+ * using {@code startDate.until(endDate, DAYS)}.
+ *
+ * The calculation returns a whole number, representing the number of
+ * complete units between the two dates.
+ * For example, the amount in months between 2012-06-15 and 2012-08-14
+ * will only be one month as it is one day short of two months.
+ *
+ * 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)}:
+ *
+ * The calculation is implemented in this method for {@link ChronoUnit}.
+ * The units {@code DAYS}, {@code WEEKS}, {@code MONTHS}, {@code YEARS},
+ * {@code DECADES}, {@code CENTURIES}, {@code MILLENNIA} and {@code ERAS}
+ * are supported. Other {@code ChronoUnit} values will throw an exception.
+ *
+ * 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.
+ *
+ * This instance is immutable and unaffected by this method call.
+ *
+ * @param endExclusive the end date, exclusive, which is converted to a {@code LocalDate}, not null
+ * @param unit the unit to measure the amount in, not null
+ * @return the amount of time between this date and the end date
+ * @throws DateTimeException if the amount cannot be calculated, or the end
+ * temporal cannot be converted to a {@code LocalDate}
+ * @throws UnsupportedTemporalTypeException if the unit is not supported
+ * @throws ArithmeticException if numeric overflow occurs
+ */
+ @Override
+ public long until(Temporal endExclusive, TemporalUnit unit) {
+ LocalDate end = LocalDate.from(endExclusive);
+ if (unit instanceof ChronoUnit) {
+ switch ((ChronoUnit) unit) {
+ case DAYS: return daysUntil(end);
+ case WEEKS: return daysUntil(end) / 7;
+ case MONTHS: return monthsUntil(end);
+ case YEARS: return monthsUntil(end) / 12;
+ case DECADES: return monthsUntil(end) / 120;
+ case CENTURIES: return monthsUntil(end) / 1200;
+ case MILLENNIA: return monthsUntil(end) / 12000;
+ case ERAS: return end.getLong(ERA) - getLong(ERA);
+ }
+ throw new UnsupportedTemporalTypeException("Unsupported unit: " + unit);
+ }
+ return unit.between(this, end);
+ }
+
+ long daysUntil(LocalDate end) {
+ return end.toEpochDay() - toEpochDay(); // no overflow
+ }
+
+ private long monthsUntil(LocalDate end) {
+ long packed1 = getProlepticMonth() * 32L + getDayOfMonth(); // no overflow
+ long packed2 = end.getProlepticMonth() * 32L + end.getDayOfMonth(); // no overflow
+ return (packed2 - packed1) / 32;
+ }
+
+ /**
+ * Calculates the period between this date and another date as a {@code Period}.
+ *
+ * This calculates the period between two dates in terms of years, months and days.
+ * The start and end points are {@code this} and the specified date.
+ * The result will be negative if the end is before the start.
+ * The negative sign will be the same in each of year, month and day.
+ *
+ * The calculation is performed using the ISO calendar system.
+ * If necessary, the input date will be converted to ISO.
+ *
+ * The start date is included, but the end date is not.
+ * The period is calculated by removing complete months, then calculating
+ * the remaining number of days, adjusting to ensure that both have the same sign.
+ * The number of months is then normalized into years and months based on a 12 month year.
+ * A month is considered to be complete if the end day-of-month is greater
+ * than or equal to the start day-of-month.
+ * For example, from {@code 2010-01-15} to {@code 2011-03-18} is "1 year, 2 months and 3 days".
+ *
+ * There are two equivalent ways of using this method.
+ * The first is to invoke this method.
+ * The second is to use {@link Period#between(LocalDate, LocalDate)}:
+ *
+ * This date will be passed to the formatter to produce a string.
+ *
+ * @param formatter the formatter to use, not null
+ * @return the formatted date string, not null
+ * @throws DateTimeException if an error occurs during printing
+ */
+ @Override // override for Javadoc and performance
+ public String format(DateTimeFormatter formatter) {
+ Objects.requireNonNull(formatter, "formatter");
+ return formatter.format(this);
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Combines this date with a time to create a {@code LocalDateTime}.
+ *
+ * This returns a {@code LocalDateTime} formed from this date at the specified time.
+ * All possible combinations of date and time are valid.
+ *
+ * @param time the time to combine with, not null
+ * @return the local date-time formed from this date and the specified time, not null
+ */
+ @Override
+ public LocalDateTime atTime(LocalTime time) {
+ return LocalDateTime.of(this, time);
+ }
+
+ /**
+ * Combines this date with a time to create a {@code LocalDateTime}.
+ *
+ * This returns a {@code LocalDateTime} formed from this date at the
+ * specified hour and minute.
+ * The seconds and nanosecond fields will be set to zero.
+ * The individual time fields must be within their valid range.
+ * All possible combinations of date and time are valid.
+ *
+ * @param hour the hour-of-day to use, from 0 to 23
+ * @param minute the minute-of-hour to use, from 0 to 59
+ * @return the local date-time formed from this date and the specified time, not null
+ * @throws DateTimeException if the value of any field is out of range
+ */
+ public LocalDateTime atTime(int hour, int minute) {
+ return atTime(LocalTime.of(hour, minute));
+ }
+
+ /**
+ * Combines this date with a time to create a {@code LocalDateTime}.
+ *
+ * This returns a {@code LocalDateTime} formed from this date at the
+ * specified hour, minute and second.
+ * The nanosecond field will be set to zero.
+ * The individual time fields must be within their valid range.
+ * All possible combinations of date and time are valid.
+ *
+ * @param hour the hour-of-day to use, from 0 to 23
+ * @param minute the minute-of-hour to use, from 0 to 59
+ * @param second the second-of-minute to represent, from 0 to 59
+ * @return the local date-time formed from this date and the specified time, not null
+ * @throws DateTimeException if the value of any field is out of range
+ */
+ public LocalDateTime atTime(int hour, int minute, int second) {
+ return atTime(LocalTime.of(hour, minute, second));
+ }
+
+ /**
+ * Combines this date with a time to create a {@code LocalDateTime}.
+ *
+ * This returns a {@code LocalDateTime} formed from this date at the
+ * specified hour, minute, second and nanosecond.
+ * The individual time fields must be within their valid range.
+ * All possible combinations of date and time are valid.
+ *
+ * @param hour the hour-of-day to use, from 0 to 23
+ * @param minute the minute-of-hour to use, from 0 to 59
+ * @param second the second-of-minute to represent, from 0 to 59
+ * @param nanoOfSecond the nano-of-second to represent, from 0 to 999,999,999
+ * @return the local date-time formed from this date and the specified time, not null
+ * @throws DateTimeException if the value of any field is out of range
+ */
+ public LocalDateTime atTime(int hour, int minute, int second, int nanoOfSecond) {
+ return atTime(LocalTime.of(hour, minute, second, nanoOfSecond));
+ }
+
+ /**
+ * Combines this date with an offset time to create an {@code OffsetDateTime}.
+ *
+ * This returns an {@code OffsetDateTime} formed from this date at the specified time.
+ * All possible combinations of date and time are valid.
+ *
+ * @param time the time to combine with, not null
+ * @return the offset date-time formed from this date and the specified time, not null
+ */
+ public OffsetDateTime atTime(OffsetTime time) {
+ return OffsetDateTime.of(LocalDateTime.of(this, time.toLocalTime()), time.getOffset());
+ }
+
+ /**
+ * Combines this date with the time of midnight to create a {@code LocalDateTime}
+ * at the start of this date.
+ *
+ * This returns a {@code LocalDateTime} formed from this date at the time of
+ * midnight, 00:00, at the start of this date.
+ *
+ * @return the local date-time of midnight at the start of this date, not null
+ */
+ public LocalDateTime atStartOfDay() {
+ return LocalDateTime.of(this, LocalTime.MIDNIGHT);
+ }
+
+ /**
+ * Returns a zoned date-time from this date at the earliest valid time according
+ * to the rules in the time-zone.
+ *
+ * Time-zone rules, such as daylight savings, mean that not every local date-time
+ * is valid for the specified zone, thus the local date-time may not be midnight.
+ *
+ * In most cases, there is only one valid offset for a local date-time.
+ * In the case of an overlap, there are two valid offsets, and the earlier one is used,
+ * corresponding to the first occurrence of midnight on the date.
+ * In the case of a gap, the zoned date-time will represent the instant just after the gap.
+ *
+ * If the zone ID is a {@link ZoneOffset}, then the result always has a time of midnight.
+ *
+ * To convert to a specific time in a given time-zone call {@link #atTime(LocalTime)}
+ * followed by {@link LocalDateTime#atZone(ZoneId)}.
+ *
+ * @param zone the zone ID to use, not null
+ * @return the zoned date-time formed from this date and the earliest valid time for the zone, not null
+ */
+ public ZonedDateTime atStartOfDay(ZoneId zone) {
+ Objects.requireNonNull(zone, "zone");
+ // need to handle case where there is a gap from 11:30 to 00:30
+ // standard ZDT factory would result in 01:00 rather than 00:30
+ LocalDateTime ldt = atTime(LocalTime.MIDNIGHT);
+ if (zone instanceof ZoneOffset == false) {
+ ZoneRules rules = zone.getRules();
+ ZoneOffsetTransition trans = rules.getTransition(ldt);
+ if (trans != null && trans.isGap()) {
+ ldt = trans.getDateTimeAfter();
+ }
+ }
+ return ZonedDateTime.of(ldt, zone);
+ }
+
+ //-----------------------------------------------------------------------
+ @Override
+ public long toEpochDay() {
+ long y = year;
+ long m = month;
+ long total = 0;
+ total += 365 * y;
+ if (y >= 0) {
+ total += (y + 3) / 4 - (y + 99) / 100 + (y + 399) / 400;
+ } else {
+ total -= y / -4 - y / -100 + y / -400;
+ }
+ total += ((367 * m - 362) / 12);
+ total += day - 1;
+ if (m > 2) {
+ total--;
+ if (isLeapYear() == false) {
+ total--;
+ }
+ }
+ return total - DAYS_0000_TO_1970;
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Compares this date to another date.
+ *
+ * The comparison is primarily based on the date, from earliest to latest.
+ * It is "consistent with equals", as defined by {@link Comparable}.
+ *
+ * If all the dates being compared are instances of {@code LocalDate},
+ * then the comparison will be entirely based on the date.
+ * If some dates being compared are in different chronologies, then the
+ * chronology is also considered, see {@link java.time.chrono.ChronoLocalDate#compareTo}.
+ *
+ * @param other the other date to compare to, not null
+ * @return the comparator value, negative if less, positive if greater
+ */
+ @Override // override for Javadoc and performance
+ public int compareTo(ChronoLocalDate other) {
+ if (other instanceof LocalDate) {
+ return compareTo0((LocalDate) other);
+ }
+ return ChronoLocalDate.super.compareTo(other);
+ }
+
+ int compareTo0(LocalDate otherDate) {
+ int cmp = (year - otherDate.year);
+ if (cmp == 0) {
+ cmp = (month - otherDate.month);
+ if (cmp == 0) {
+ cmp = (day - otherDate.day);
+ }
+ }
+ return cmp;
+ }
+
+ /**
+ * Checks if this date is after the specified date.
+ *
+ * This checks to see if this date represents a point on the
+ * local time-line after the other date.
+ *
+ * This method only considers the position of the two dates on the local time-line.
+ * It does not take into account the chronology, or calendar system.
+ * This is different from the comparison in {@link #compareTo(ChronoLocalDate)},
+ * but is the same approach as {@link ChronoLocalDate#timeLineOrder()}.
+ *
+ * @param other the other date to compare to, not null
+ * @return true if this date is after the specified date
+ */
+ @Override // override for Javadoc and performance
+ public boolean isAfter(ChronoLocalDate other) {
+ if (other instanceof LocalDate) {
+ return compareTo0((LocalDate) other) > 0;
+ }
+ return ChronoLocalDate.super.isAfter(other);
+ }
+
+ /**
+ * Checks if this date is before the specified date.
+ *
+ * This checks to see if this date represents a point on the
+ * local time-line before the other date.
+ *
+ * This method only considers the position of the two dates on the local time-line.
+ * It does not take into account the chronology, or calendar system.
+ * This is different from the comparison in {@link #compareTo(ChronoLocalDate)},
+ * but is the same approach as {@link ChronoLocalDate#timeLineOrder()}.
+ *
+ * @param other the other date to compare to, not null
+ * @return true if this date is before the specified date
+ */
+ @Override // override for Javadoc and performance
+ public boolean isBefore(ChronoLocalDate other) {
+ if (other instanceof LocalDate) {
+ return compareTo0((LocalDate) other) < 0;
+ }
+ return ChronoLocalDate.super.isBefore(other);
+ }
+
+ /**
+ * Checks if this date is equal to the specified date.
+ *
+ * This checks to see if this date represents the same point on the
+ * local time-line as the other date.
+ *
+ * This method only considers the position of the two dates on the local time-line.
+ * It does not take into account the chronology, or calendar system.
+ * This is different from the comparison in {@link #compareTo(ChronoLocalDate)}
+ * but is the same approach as {@link ChronoLocalDate#timeLineOrder()}.
+ *
+ * @param other the other date to compare to, not null
+ * @return true if this date is equal to the specified date
+ */
+ @Override // override for Javadoc and performance
+ public boolean isEqual(ChronoLocalDate other) {
+ if (other instanceof LocalDate) {
+ return compareTo0((LocalDate) other) == 0;
+ }
+ return ChronoLocalDate.super.isEqual(other);
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Checks if this date is equal to another date.
+ *
+ * Compares this {@code LocalDate} with another ensuring that the date is the same.
+ *
+ * Only objects of type {@code LocalDate} are compared, other types return false.
+ * To compare the dates of two {@code TemporalAccessor} instances, including dates
+ * in two different chronologies, use {@link ChronoField#EPOCH_DAY} as a comparator.
+ *
+ * @param obj the object to check, null returns false
+ * @return true if this is equal to the other date
+ */
+ @Override
+ public boolean equals(Object obj) {
+ if (this == obj) {
+ return true;
+ }
+ if (obj instanceof LocalDate) {
+ return compareTo0((LocalDate) obj) == 0;
+ }
+ return false;
+ }
+
+ /**
+ * A hash code for this date.
+ *
+ * @return a suitable hash code
+ */
+ @Override
+ public int hashCode() {
+ int yearValue = year;
+ int monthValue = month;
+ int dayValue = day;
+ return (yearValue & 0xFFFFF800) ^ ((yearValue << 11) + (monthValue << 6) + (dayValue));
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Outputs this date as a {@code String}, such as {@code 2007-12-03}.
+ *
+ * The output will be in the ISO-8601 format {@code uuuu-MM-dd}.
+ *
+ * @return a string representation of this date, not null
+ */
+ @Override
+ public String toString() {
+ int yearValue = year;
+ int monthValue = month;
+ int dayValue = day;
+ int absYear = Math.abs(yearValue);
+ StringBuilder buf = new StringBuilder(10);
+ if (absYear < 1000) {
+ if (yearValue < 0) {
+ buf.append(yearValue - 10000).deleteCharAt(1);
+ } else {
+ buf.append(yearValue + 10000).deleteCharAt(0);
+ }
+ } else {
+ if (yearValue > 9999) {
+ buf.append('+');
+ }
+ buf.append(yearValue);
+ }
+ return buf.append(monthValue < 10 ? "-0" : "-")
+ .append(monthValue)
+ .append(dayValue < 10 ? "-0" : "-")
+ .append(dayValue)
+ .toString();
+ }
+
+ //-----------------------------------------------------------------------
+ /**
+ * Writes the object using a
+ * dedicated serialized form.
+ * @serialData
+ *
+ * // these two lines are equivalent, but the second approach is recommended
+ * temporal = thisLocalDate.adjustInto(temporal);
+ * temporal = temporal.with(thisLocalDate);
+ *
+ *
+ * // these two lines are equivalent
+ * amount = start.until(end, MONTHS);
+ * amount = MONTHS.between(start, end);
+ *
+ * The choice should be made based on which makes the code more readable.
+ *
+ * // these two lines are equivalent
+ * period = start.until(end);
+ * period = Period.between(start, end);
+ *
+ * The choice should be made based on which makes the code more readable.
+ *
+ * @param endDateExclusive the end date, exclusive, which may be in any chronology, not null
+ * @return the period between this date and the end date, not null
+ */
+ @Override
+ public Period until(ChronoLocalDate endDateExclusive) {
+ LocalDate end = LocalDate.from(endDateExclusive);
+ long totalMonths = end.getProlepticMonth() - this.getProlepticMonth(); // safe
+ int days = end.day - this.day;
+ if (totalMonths > 0 && days < 0) {
+ totalMonths--;
+ LocalDate calcDate = this.plusMonths(totalMonths);
+ days = (int) (end.toEpochDay() - calcDate.toEpochDay()); // safe
+ } else if (totalMonths < 0 && days > 0) {
+ totalMonths++;
+ days -= end.lengthOfMonth();
+ }
+ long years = totalMonths / 12; // safe
+ int months = (int) (totalMonths % 12); // safe
+ return Period.of(Math.toIntExact(years), months, days);
+ }
+
+ /**
+ * Formats this date using the specified formatter.
+ *
+ * LocalDate a = LocalDate.of(2012, 6, 30);
+ * LocalDate b = LocalDate.of(2012, 7, 1);
+ * a.isAfter(b) == false
+ * a.isAfter(a) == false
+ * b.isAfter(a) == true
+ *
+ *
+ * LocalDate a = LocalDate.of(2012, 6, 30);
+ * LocalDate b = LocalDate.of(2012, 7, 1);
+ * a.isBefore(b) == true
+ * a.isBefore(a) == false
+ * b.isBefore(a) == false
+ *
+ *
+ * LocalDate a = LocalDate.of(2012, 6, 30);
+ * LocalDate b = LocalDate.of(2012, 7, 1);
+ * a.isEqual(b) == false
+ * a.isEqual(a) == true
+ * b.isEqual(a) == false
+ *
+ *
+ * out.writeByte(3); // identifies a LocalDate
+ * out.writeInt(year);
+ * out.writeByte(month);
+ * out.writeByte(day);
+ *
+ *
+ * @return the instance of {@code Ser}, not null
+ */
+ private Object writeReplace() {
+ return new Ser(Ser.LOCAL_DATE_TYPE, this);
+ }
+
+ /**
+ * Defend against malicious streams.
+ *
+ * @param s the stream to read
+ * @throws InvalidObjectException always
+ */
+ private void readObject(ObjectInputStream s) throws InvalidObjectException {
+ throw new InvalidObjectException("Deserialization via serialization delegate");
+ }
+
+ void writeExternal(DataOutput out) throws IOException {
+ out.writeInt(year);
+ out.writeByte(month);
+ out.writeByte(day);
+ }
+
+ static LocalDate readExternal(DataInput in) throws IOException {
+ int year = in.readInt();
+ int month = in.readByte();
+ int dayOfMonth = in.readByte();
+ return LocalDate.of(year, month, dayOfMonth);
+ }
+
+}