Java Module java.base Package java.time Class Year（JDK11）

Field Detail

• MIN_VALUE

  public static final int MIN_VALUE

  The minimum supported year, '-999,999,999'.

  See Also:

  Constant Field Values

• MAX_VALUE

  public static final int MAX_VALUE

  The maximum supported year, '+999,999,999'.

  See Also:

  Constant Field Values

Method Detail

• now

  public static Year now()

  Obtains the current year from the system clock in the default time-zone.

  This will query the system clock in the default time-zone to obtain the current year.

  Using this method will prevent the ability to use an alternate clock for testing because the clock is hard-coded.

  Returns:

  the current year using the system clock and default time-zone, not null

• now

  public static Year now​(ZoneId zone)

  Obtains the current year from the system clock in the specified time-zone.

  This will query the system clock to obtain the current year. 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.

  Parameters:

  zone - the zone ID to use, not null

  Returns:

  the current year using the system clock, not null

• now

  public static Year now​(Clock clock)

  Obtains the current year from the specified clock.

  This will query the specified clock to obtain the current year. Using this method allows the use of an alternate clock for testing. The alternate clock may be introduced using dependency injection.

  Parameters:

  clock - the clock to use, not null

  Returns:

  the current year, not null

• of

  public static Year of​(int isoYear)

  Obtains an instance of Year.

  This method accepts a year value from the proleptic ISO calendar system.

  The year 2AD/CE is represented by 2.
  The year 1AD/CE is represented by 1.
  The year 1BC/BCE is represented by 0.
  The year 2BC/BCE is represented by -1.
  

  Parameters:

  isoYear - the ISO proleptic year to represent, from MIN_VALUE to MAX_VALUE

  Returns:

  the year, not null

  Throws:

  DateTimeException - if the field is invalid

• from

  public static Year from​(TemporalAccessor temporal)

  Obtains an instance of Year from a temporal object.

  This obtains a year based on the specified temporal. A TemporalAccessor represents an arbitrary set of date and time information, which this factory converts to an instance of Year.

  The conversion extracts the year field. The extraction is only permitted if the temporal object has an ISO chronology, or can be converted to a LocalDate.

  This method matches the signature of the functional interface TemporalQuery allowing it to be used as a query via method reference, Year::from.

  Parameters:

  temporal - the temporal object to convert, not null

  Returns:

  the year, not null

  Throws:

  DateTimeException - if unable to convert to a Year

• parse

  public static Year parse​(CharSequence text)

  Obtains an instance of Year from a text string such as 2007.

  The string must represent a valid year. Years outside the range 0000 to 9999 must be prefixed by the plus or minus symbol.

  Parameters:

  text - the text to parse such as "2007", not null

  Returns:

  the parsed year, not null

  Throws:

  DateTimeParseException - if the text cannot be parsed

• parse

  public static Year parse​(CharSequence text,
                           DateTimeFormatter formatter)

  Obtains an instance of Year from a text string using a specific formatter.

  The text is parsed using the formatter, returning a year.

  Parameters:

  text - the text to parse, not null

  formatter - the formatter to use, not null

  Returns:

  the parsed year, not null

  Throws:

  DateTimeParseException - if the text cannot be parsed

• isLeap

  public static boolean isLeap​(long year)

  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.

  Parameters:

  year - the year to check

  Returns:

  true if the year is leap, false otherwise

• getValue

  public int getValue()

  Gets the year value.

  The year returned by this method is proleptic as per get(YEAR).

  Returns:

  the year, MIN_VALUE to MAX_VALUE

• isSupported

  public boolean isSupported​(TemporalField field)

  Checks if the specified field is supported.

  This checks if this year can be queried for the specified field. If false, then calling the range, get and with(TemporalField, long) methods will throw an exception.

  If the field is a ChronoField then the query is implemented here. The supported fields are:

  • YEAR_OF_ERA
  • YEAR
  • ERA

  All other ChronoField instances will return false.

  If the field is not a ChronoField, then the result of this method is obtained by invoking TemporalField.isSupportedBy(TemporalAccessor) passing this as the argument. Whether the field is supported is determined by the field.

  Specified by:

  isSupported in interface TemporalAccessor

  Parameters:

  field - the field to check, null returns false

  Returns:

  true if the field is supported on this year, false if not

• isSupported

  public boolean isSupported​(TemporalUnit unit)

  Checks if the specified unit is supported.

  This checks if the specified unit can be added to, or subtracted from, this year. If false, then calling the plus(long, TemporalUnit) and minus methods will throw an exception.

  If the unit is a ChronoUnit then the query is implemented here. The supported units are:

  • YEARS
  • DECADES
  • CENTURIES
  • MILLENNIA
  • ERAS

  All other ChronoUnit instances will return false.

  If the unit is not a ChronoUnit, then the result of this method is obtained by invoking TemporalUnit.isSupportedBy(Temporal) passing this as the argument. Whether the unit is supported is determined by the unit.

  Specified by:

  isSupported in interface Temporal

  Parameters:

  unit - the unit to check, null returns false

  Returns:

  true if the unit can be added/subtracted, false if not

• range

  public ValueRange range​(TemporalField field)

  Gets the range of valid values for the specified field.

  The range object expresses the minimum and maximum valid values for a field. This year 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 ChronoField then the query is implemented here. The supported fields will return appropriate range instances. All other ChronoField instances will throw an UnsupportedTemporalTypeException.

  If the field is not a ChronoField, then the result of this method is obtained by invoking TemporalField.rangeRefinedBy(TemporalAccessor) passing this as the argument. Whether the range can be obtained is determined by the field.

  Specified by:

  range in interface TemporalAccessor

  Parameters:

  field - the field to query the range for, not null

  Returns:

  the range of valid values for the field, not null

  Throws:

  DateTimeException - if the range for the field cannot be obtained

  UnsupportedTemporalTypeException - if the field is not supported

• get

  public int get​(TemporalField field)

  Gets the value of the specified field from this year as an int.

  This queries this year 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 ChronoField then the query is implemented here. The supported fields will return valid values based on this year. All other ChronoField instances will throw an UnsupportedTemporalTypeException.

  If the field is not a ChronoField, then the result of this method is obtained by invoking TemporalField.getFrom(TemporalAccessor) passing this as the argument. Whether the value can be obtained, and what the value represents, is determined by the field.

  Specified by:

  get in interface TemporalAccessor

  Parameters:

  field - the field to get, not null

  Returns:

  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

  UnsupportedTemporalTypeException - if the field is not supported or the range of values exceeds an int

  ArithmeticException - if numeric overflow occurs

• getLong

  public long getLong​(TemporalField field)

  Gets the value of the specified field from this year as a long.

  This queries this year 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 ChronoField then the query is implemented here. The supported fields will return valid values based on this year. All other ChronoField instances will throw an UnsupportedTemporalTypeException.

  If the field is not a ChronoField, then the result of this method is obtained by invoking TemporalField.getFrom(TemporalAccessor) passing this as the argument. Whether the value can be obtained, and what the value represents, is determined by the field.

  Specified by:

  getLong in interface TemporalAccessor

  Parameters:

  field - the field to get, not null

  Returns:

  the value for the field

  Throws:

  DateTimeException - if a value for the field cannot be obtained

  UnsupportedTemporalTypeException - if the field is not supported

  ArithmeticException - if numeric overflow occurs

• isLeap

  public boolean isLeap()

  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.

  Returns:

  true if the year is leap, false otherwise

• isValidMonthDay

  public boolean isValidMonthDay​(MonthDay monthDay)

  Checks if the month-day is valid for this year.

  This method checks whether this year and the input month and day form a valid date.

  Parameters:

  monthDay - the month-day to validate, null returns false

  Returns:

  true if the month and day are valid for this year

• length

  public int length()

  Gets the length of this year in days.

  Returns:

  the length of this year in days, 365 or 366

• with

  public Year with​(TemporalAdjuster adjuster)

  Returns an adjusted copy of this year.

  This returns a Year, based on this one, with the year adjusted. The adjustment takes place using the specified adjuster strategy object. Read the documentation of the adjuster to understand what adjustment will be made.

  The result of this method is obtained by invoking the TemporalAdjuster.adjustInto(Temporal) method on the specified adjuster passing this as the argument.

  This instance is immutable and unaffected by this method call.

  Specified by:

  with in interface Temporal

  Parameters:

  adjuster - the adjuster to use, not null

  Returns:

  a Year based on this with the adjustment made, not null

  Throws:

  DateTimeException - if the adjustment cannot be made

  ArithmeticException - if numeric overflow occurs

• with

  public Year with​(TemporalField field,
                   long newValue)

  Returns a copy of this year with the specified field set to a new value.

  This returns a Year, based on this one, with the value for the specified field changed. If it is not possible to set the value, because the field is not supported or for some other reason, an exception is thrown.

  If the field is a ChronoField then the adjustment is implemented here. The supported fields behave as follows:

  • YEAR_OF_ERA - Returns a Year with the specified year-of-era The era will be unchanged.
  • YEAR - Returns a Year with the specified year. This completely replaces the date and is equivalent to of(int).
  • ERA - Returns a Year with the specified era. The year-of-era will be unchanged.

  In all cases, if the new value is outside the valid range of values for the field then a DateTimeException will be thrown.

  All other ChronoField instances will throw an UnsupportedTemporalTypeException.

  If the field is not a ChronoField, then the result of this method is obtained by invoking TemporalField.adjustInto(Temporal, long) passing 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.

  Specified by:

  with in interface Temporal

  Parameters:

  field - the field to set in the result, not null

  newValue - the new value of the field in the result

  Returns:

  a Year based on this with the specified field set, not null

  Throws:

  DateTimeException - if the field cannot be set

  UnsupportedTemporalTypeException - if the field is not supported

  ArithmeticException - if numeric overflow occurs

• plus

  public Year plus​(TemporalAmount amountToAdd)

  Returns a copy of this year with the specified amount added.

  This returns a Year, based on this one, with the specified amount added. The amount is typically Period but may be any other type implementing the TemporalAmount interface.

  The calculation is delegated to the amount object by calling TemporalAmount.addTo(Temporal). The amount implementation is free to implement the addition in any way it wishes, however it typically calls back to 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.

  Specified by:

  plus in interface Temporal

  Parameters:

  amountToAdd - the amount to add, not null

  Returns:

  a Year based on this year with the addition made, not null

  Throws:

  DateTimeException - if the addition cannot be made

  ArithmeticException - if numeric overflow occurs

• plus

  public Year plus​(long amountToAdd,
                   TemporalUnit unit)

  Returns a copy of this year with the specified amount added.

  This returns a Year, 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.

  If the field is a ChronoUnit then the addition is implemented here. The supported fields behave as follows:

  • YEARS - Returns a Year with the specified number of years added. This is equivalent to plusYears(long).
  • DECADES - Returns a Year with the specified number of decades added. This is equivalent to calling plusYears(long) with the amount multiplied by 10.
  • CENTURIES - Returns a Year with the specified number of centuries added. This is equivalent to calling plusYears(long) with the amount multiplied by 100.
  • MILLENNIA - Returns a Year with the specified number of millennia added. This is equivalent to calling plusYears(long) with the amount multiplied by 1,000.
  • ERAS - Returns a Year 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.

  All other ChronoUnit instances will throw an UnsupportedTemporalTypeException.

  If the field is not a ChronoUnit, then the result of this method is obtained by invoking TemporalUnit.addTo(Temporal, long) passing 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.

  Specified by:

  plus in interface Temporal

  Parameters:

  amountToAdd - the amount of the unit to add to the result, may be negative

  unit - the unit of the amount to add, not null

  Returns:

  a Year based on this year with the specified amount added, not null

  Throws:

  DateTimeException - if the addition cannot be made

  UnsupportedTemporalTypeException - if the unit is not supported

  ArithmeticException - if numeric overflow occurs

• plusYears

  public Year plusYears​(long yearsToAdd)

  Returns a copy of this Year with the specified number of years added.

  This instance is immutable and unaffected by this method call.

  Parameters:

  yearsToAdd - the years to add, may be negative

  Returns:

  a Year based on this year with the years added, not null

  Throws:

  DateTimeException - if the result exceeds the supported range

• minus

  public Year minus​(TemporalAmount amountToSubtract)

  Returns a copy of this year with the specified amount subtracted.

  This returns a Year, based on this one, with the specified amount subtracted. The amount is typically Period but may be any other type implementing the TemporalAmount interface.

  The calculation is delegated to the amount object by calling TemporalAmount.subtractFrom(Temporal). The amount implementation is free to implement the subtraction in any way it wishes, however it typically calls back to 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.

  Specified by:

  minus in interface Temporal

  Parameters:

  amountToSubtract - the amount to subtract, not null

  Returns:

  a Year based on this year with the subtraction made, not null

  Throws:

  DateTimeException - if the subtraction cannot be made

  ArithmeticException - if numeric overflow occurs

• minus

  public Year minus​(long amountToSubtract,
                    TemporalUnit unit)

  Returns a copy of this year with the specified amount subtracted.

  This returns a Year, 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 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.

  Specified by:

  minus in interface Temporal

  Parameters:

  amountToSubtract - the amount of the unit to subtract from the result, may be negative

  unit - the unit of the amount to subtract, not null

  Returns:

  a Year based on this year with the specified amount subtracted, not null

  Throws:

  DateTimeException - if the subtraction cannot be made

  UnsupportedTemporalTypeException - if the unit is not supported

  ArithmeticException - if numeric overflow occurs

• minusYears

  public Year minusYears​(long yearsToSubtract)

  Returns a copy of this Year with the specified number of years subtracted.

  This instance is immutable and unaffected by this method call.

  Parameters:

  yearsToSubtract - the years to subtract, may be negative

  Returns:

  a Year based on this year with the year subtracted, not null

  Throws:

  DateTimeException - if the result exceeds the supported range

• query

  public <R> R query​(TemporalQuery<R> query)

  Queries this year using the specified query.

  This queries this year using the specified query strategy object. The 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 TemporalQuery.queryFrom(TemporalAccessor) method on the specified query passing this as the argument.

  Specified by:

  query in interface TemporalAccessor

  Type Parameters:

  R - the type of the result

  Parameters:

  query - the query to invoke, not null

  Returns:

  the query result, null may be returned (defined by the query)

  Throws:

  DateTimeException - if unable to query (defined by the query)

  ArithmeticException - if numeric overflow occurs (defined by the query)

• adjustInto

  public Temporal adjustInto​(Temporal temporal)

  Adjusts the specified temporal object to have this year.

  This returns a temporal object of the same observable type as the input with the year changed to be the same as this.

  The adjustment is equivalent to using Temporal.with(TemporalField, long) passing ChronoField.YEAR as the field. If the specified temporal object does not use the ISO calendar system then a DateTimeException is thrown.

  In most cases, it is clearer to reverse the calling pattern by using Temporal.with(TemporalAdjuster):

     // these two lines are equivalent, but the second approach is recommended
     temporal = thisYear.adjustInto(temporal);
     temporal = temporal.with(thisYear);
   

  This instance is immutable and unaffected by this method call.

  Specified by:

  adjustInto in interface TemporalAdjuster

  Parameters:

  temporal - the target object to be adjusted, not null

  Returns:

  the adjusted object, not null

  Throws:

  DateTimeException - if unable to make the adjustment

  ArithmeticException - if numeric overflow occurs

• until

  public long until​(Temporal endExclusive,
                    TemporalUnit unit)

  Calculates the amount of time until another year in terms of the specified unit.

  This calculates the amount of time between two Year objects in terms of a single TemporalUnit. The start and end points are this and the specified year. The result will be negative if the end is before the start. The Temporal passed to this method is converted to a Year using from(TemporalAccessor). For example, the amount in decades between two year can be calculated using startYear.until(endYear, DECADES).

  The calculation returns a whole number, representing the number of complete units between the two years. For example, the amount in decades between 2012 and 2031 will only be one decade as it is one year short of two decades.

  There are two equivalent ways of using this method. The first is to invoke this method. The second is to use TemporalUnit.between(Temporal, Temporal):

     // these two lines are equivalent
     amount = start.until(end, YEARS);
     amount = YEARS.between(start, end);
   

  The choice should be made based on which makes the code more readable.

  The calculation is implemented in this method for ChronoUnit. The units YEARS, DECADES, CENTURIES, MILLENNIA and ERAS are supported. Other ChronoUnit values will throw an exception.

  If the unit is not a ChronoUnit, then the result of this method is obtained by invoking TemporalUnit.between(Temporal, Temporal) passing this as the first argument and the converted input temporal as the second argument.

  This instance is immutable and unaffected by this method call.

  Specified by:

  until in interface Temporal

  Parameters:

  endExclusive - the end date, exclusive, which is converted to a Year, not null

  unit - the unit to measure the amount in, not null

  Returns:

  the amount of time between this year and the end year

  Throws:

  DateTimeException - if the amount cannot be calculated, or the end temporal cannot be converted to a Year

  UnsupportedTemporalTypeException - if the unit is not supported

  ArithmeticException - if numeric overflow occurs

• format

  public String format​(DateTimeFormatter formatter)

  Formats this year using the specified formatter.

  This year will be passed to the formatter to produce a string.

  Parameters:

  formatter - the formatter to use, not null

  Returns:

  the formatted year string, not null

  Throws:

  DateTimeException - if an error occurs during printing

• atDay

  public LocalDate atDay​(int dayOfYear)

  Combines this year with a day-of-year to create a LocalDate.

  This returns a LocalDate formed from this year and the specified day-of-year.

  The day-of-year value 366 is only valid in a leap year.

  Parameters:

  dayOfYear - the day-of-year to use, from 1 to 365-366

  Returns:

  the local date formed from this year and the specified date of year, not null

  Throws:

  DateTimeException - if the day of year is zero or less, 366 or greater or equal to 366 and this is not a leap year

• atMonth

  public YearMonth atMonth​(Month month)

  Combines this year with a month to create a YearMonth.

  This returns a YearMonth formed from this year and the specified month. All possible combinations of year and month are valid.

  This method can be used as part of a chain to produce a date:

    LocalDate date = year.atMonth(month).atDay(day);
   

  Parameters:

  month - the month-of-year to use, not null

  Returns:

  the year-month formed from this year and the specified month, not null

• atMonth

  public YearMonth atMonth​(int month)

  Combines this year with a month to create a YearMonth.

  This returns a YearMonth formed from this year and the specified month. All possible combinations of year and month are valid.

  This method can be used as part of a chain to produce a date:

    LocalDate date = year.atMonth(month).atDay(day);
   

  Parameters:

  month - the month-of-year to use, from 1 (January) to 12 (December)

  Returns:

  the year-month formed from this year and the specified month, not null

  Throws:

  DateTimeException - if the month is invalid

• atMonthDay

  public LocalDate atMonthDay​(MonthDay monthDay)

  Combines this year with a month-day to create a LocalDate.

  This returns a LocalDate formed from this year and the specified month-day.

  A month-day of February 29th will be adjusted to February 28th in the resulting date if the year is not a leap year.

  Parameters:

  monthDay - the month-day to use, not null

  Returns:

  the local date formed from this year and the specified month-day, not null

• compareTo

  public int compareTo​(Year other)

  Compares this year to another year.

  The comparison is based on the value of the year. It is "consistent with equals", as defined by Comparable.

  Specified by:

  compareTo in interface Comparable<Year>

  Parameters:

  other - the other year to compare to, not null

  Returns:

  the comparator value, negative if less, positive if greater

• isAfter

  public boolean isAfter​(Year other)

  Checks if this year is after the specified year.

  Parameters:

  other - the other year to compare to, not null

  Returns:

  true if this is after the specified year

• isBefore

  public boolean isBefore​(Year other)

  Checks if this year is before the specified year.

  Parameters:

  other - the other year to compare to, not null

  Returns:

  true if this point is before the specified year

• equals

  public boolean equals​(Object obj)

  Checks if this year is equal to another year.

  The comparison is based on the time-line position of the years.

  Overrides:

  equals in class Object

  Parameters:

  obj - the object to check, null returns false

  Returns:

  true if this is equal to the other year

  See Also:

  Object.hashCode(), HashMap

• hashCode

  public int hashCode()

  A hash code for this year.

  Overrides:

  hashCode in class Object

  Returns:

  a suitable hash code

  See Also:

  Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)

• toString

  public String toString()

  Outputs this year as a String.

  Overrides:

  toString in class Object

  Returns:

  a string representation of this year, not null