* This class is used by applications seeking to handle dates in non-ISO calendar systems. * For example, the Japanese, Minguo, Thai Buddhist and others. *
* {@code ChronoLocalDate} is built on the generic concepts of year, month and day. * The calendar system, represented by a {@link java.time.chrono.Chronology}, expresses the relationship between * the fields and this class allows the resulting date to be manipulated. *
* Note that not all calendar systems are suitable for use with this class. * For example, the Mayan calendar uses a system that bears no relation to years, months and days. *
* The API design encourages the use of {@code LocalDate} for the majority of the application. * This includes code to read and write from a persistent data store, such as a database, * and to send dates and times across a network. The {@code ChronoLocalDate} instance is then used * at the user interface level to deal with localized input/output. * *
Example:
*
* System.out.printf("Example()%n");
* // Enumerate the list of available calendars and print today for each
* Set<Chronology> chronos = Chronology.getAvailableChronologies();
* for (Chronology chrono : chronos) {
* ChronoLocalDate date = chrono.dateNow();
* System.out.printf(" %20s: %s%n", chrono.getID(), date.toString());
* }
*
* // Print the Hijrah date and calendar
* ChronoLocalDate date = Chronology.of("Hijrah").dateNow();
* int day = date.get(ChronoField.DAY_OF_MONTH);
* int dow = date.get(ChronoField.DAY_OF_WEEK);
* int month = date.get(ChronoField.MONTH_OF_YEAR);
* int year = date.get(ChronoField.YEAR);
* System.out.printf(" Today is %s %s %d-%s-%d%n", date.getChronology().getID(),
* dow, day, month, year);
*
* // Print today's date and the last day of the year
* ChronoLocalDate now1 = Chronology.of("Hijrah").dateNow();
* ChronoLocalDate first = now1.with(ChronoField.DAY_OF_MONTH, 1)
* .with(ChronoField.MONTH_OF_YEAR, 1);
* ChronoLocalDate last = first.plus(1, ChronoUnit.YEARS)
* .minus(1, ChronoUnit.DAYS);
* System.out.printf(" Today is %s: start: %s; end: %s%n", last.getChronology().getID(),
* first, last);
*
*
* The set of calendars is extensible by defining a subclass of {@link ChronoLocalDate} * to represent a date instance and an implementation of {@code Chronology} * to be the factory for the ChronoLocalDate subclass. *
*To permit the discovery of the additional calendar types the implementation of * {@code Chronology} must be registered as a Service implementing the {@code Chronology} interface * in the {@code META-INF/Services} file as per the specification of {@link java.util.ServiceLoader}. * The subclass must function according to the {@code Chronology} class description and must provide its * {@link java.time.chrono.Chronology#getId() chronlogy ID} and {@link Chronology#getCalendarType() calendar type}.
* * @implSpec * This abstract class must be implemented with care to ensure other classes operate correctly. * All implementations that can be instantiated must be final, immutable and thread-safe. * Subclasses should be Serializable wherever possible. * * @param* This adds the specified period in years to the date. * In some cases, adding years can cause the resulting date to become invalid. * If this occurs, then other fields, typically the day-of-month, will be adjusted to ensure * that the result is valid. Typically this will select the last valid day of the month. *
* This instance is immutable and unaffected by this method call. * * @param yearsToAdd the years to add, may be negative * @return a date based on this one with the years added, not null * @throws DateTimeException if the result exceeds the supported date range */ abstract D plusYears(long yearsToAdd); /** * Returns a copy of this date with the specified number of months added. *
* This adds the specified period in months to the date. * In some cases, adding months can cause the resulting date to become invalid. * If this occurs, then other fields, typically the day-of-month, will be adjusted to ensure * that the result is valid. Typically this will select the last valid day of the month. *
* This instance is immutable and unaffected by this method call. * * @param monthsToAdd the months to add, may be negative * @return a date based on this one with the months added, not null * @throws DateTimeException if the result exceeds the supported date range */ abstract D plusMonths(long monthsToAdd); /** * Returns a copy of this date with the specified number of weeks added. *
* This adds the specified period in weeks to the date. * In some cases, adding weeks can cause the resulting date to become invalid. * If this occurs, then other fields will be adjusted to ensure that the result is valid. *
* The default implementation uses {@link #plusDays(long)} using a 7 day week. *
* This instance is immutable and unaffected by this method call. * * @param weeksToAdd the weeks to add, may be negative * @return a date based on this one with the weeks added, not null * @throws DateTimeException if the result exceeds the supported date range */ D plusWeeks(long weeksToAdd) { return plusDays(Math.multiplyExact(weeksToAdd, 7)); } /** * Returns a copy of this date with the specified number of days added. *
* This adds the specified period in days to the date. *
* This instance is immutable and unaffected by this method call. * * @param daysToAdd the days to add, may be negative * @return a date based on this one with the days added, not null * @throws DateTimeException if the result exceeds the supported date range */ abstract D plusDays(long daysToAdd); //----------------------------------------------------------------------- /** * Returns a copy of this date with the specified number of years subtracted. *
* This subtracts the specified period in years to the date. * In some cases, subtracting years can cause the resulting date to become invalid. * If this occurs, then other fields, typically the day-of-month, will be adjusted to ensure * that the result is valid. Typically this will select the last valid day of the month. *
* The default implementation uses {@link #plusYears(long)}. *
* This instance is immutable and unaffected by this method call.
*
* @param yearsToSubtract the years to subtract, may be negative
* @return a date based on this one with the years subtracted, not null
* @throws DateTimeException if the result exceeds the supported date range
*/
@SuppressWarnings("unchecked")
D minusYears(long yearsToSubtract) {
return (yearsToSubtract == Long.MIN_VALUE ? ((ChronoLocalDateImpl
* This subtracts the specified period in months to the date.
* In some cases, subtracting months can cause the resulting date to become invalid.
* If this occurs, then other fields, typically the day-of-month, will be adjusted to ensure
* that the result is valid. Typically this will select the last valid day of the month.
*
* The default implementation uses {@link #plusMonths(long)}.
*
* This instance is immutable and unaffected by this method call.
*
* @param monthsToSubtract the months to subtract, may be negative
* @return a date based on this one with the months subtracted, not null
* @throws DateTimeException if the result exceeds the supported date range
*/
@SuppressWarnings("unchecked")
D minusMonths(long monthsToSubtract) {
return (monthsToSubtract == Long.MIN_VALUE ? ((ChronoLocalDateImpl
* This subtracts the specified period in weeks to the date.
* In some cases, subtracting weeks can cause the resulting date to become invalid.
* If this occurs, then other fields will be adjusted to ensure that the result is valid.
*
* The default implementation uses {@link #plusWeeks(long)}.
*
* This instance is immutable and unaffected by this method call.
*
* @param weeksToSubtract the weeks to subtract, may be negative
* @return a date based on this one with the weeks subtracted, not null
* @throws DateTimeException if the result exceeds the supported date range
*/
@SuppressWarnings("unchecked")
D minusWeeks(long weeksToSubtract) {
return (weeksToSubtract == Long.MIN_VALUE ? ((ChronoLocalDateImpl
* This subtracts the specified period in days to the date.
*
* The default implementation uses {@link #plusDays(long)}.
*
* This instance is immutable and unaffected by this method call.
*
* @param daysToSubtract the days to subtract, may be negative
* @return a date based on this one with the days subtracted, not null
* @throws DateTimeException if the result exceeds the supported date range
*/
@SuppressWarnings("unchecked")
D minusDays(long daysToSubtract) {
return (daysToSubtract == Long.MIN_VALUE ? ((ChronoLocalDateImpl