TemporalAmount

public interface TemporalAmount
Known Indirect Subclasses

Framework-level interface defining an amount of time, such as "6 hours", "8 days" or "2 years and 3 months".

This is the base interface type for amounts of time. An amount is distinct from a date or time-of-day in that it is not tied to any specific point on the time-line.

The amount can be thought of as a Map of TemporalUnit to long, exposed via getUnits() and get(TemporalUnit). A simple case might have a single unit-value pair, such as "6 hours". A more complex case may have multiple unit-value pairs, such as "7 years, 3 months and 5 days".

There are two common implementations. Period is a date-based implementation, storing years, months and days. Duration is a time-based implementation, storing seconds and nanoseconds, but providing some access using other duration based units such as minutes, hours and fixed 24-hour days.

This interface is a framework-level interface that should not be widely used in application code. Instead, applications should create and pass around instances of concrete types, such as Period and Duration.

Public Method Summary

abstract Temporal
addTo(Temporal temporal)
Adds to the specified temporal object.
abstract long
get(TemporalUnit unit)
Returns the value of the requested unit.
abstract List<TemporalUnit>
getUnits()
Returns the list of units uniquely defining the value of this TemporalAmount.
abstract Temporal
subtractFrom(Temporal temporal)
Subtracts this object from the specified temporal object.

Public Methods

public abstract Temporal addTo (Temporal temporal)

Adds to the specified temporal object.

Adds the amount to the specified temporal object using the logic encapsulated in the implementing class.

There are two equivalent ways of using this method. The first is to invoke this method directly. The second is to use plus(TemporalAmount):

   // These two lines are equivalent, but the second approach is recommended
   dateTime = amount.addTo(dateTime);
   dateTime = dateTime.plus(adder);
 
It is recommended to use the second approach, plus(TemporalAmount), as it is a lot clearer to read in code.

Parameters
temporal the temporal object to add the amount to, not null
Returns
  • an object of the same observable type with the addition made, not null
Throws
DateTimeException if unable to add
ArithmeticException if numeric overflow occurs

public abstract long get (TemporalUnit unit)

Returns the value of the requested unit. The units returned from getUnits() uniquely define the value of the TemporalAmount. A value must be returned for each unit listed in getUnits.

Parameters
unit the TemporalUnit for which to return the value
Returns
  • the long value of the unit
Throws
DateTimeException if a value for the unit cannot be obtained
UnsupportedTemporalTypeException if the unit is not supported

public abstract List<TemporalUnit> getUnits ()

Returns the list of units uniquely defining the value of this TemporalAmount. The list of TemporalUnits is defined by the implementation class. The list is a snapshot of the units at the time getUnits is called and is not mutable. The units are ordered from longest duration to the shortest duration of the unit.

Returns
  • the List of TemporalUnits; not null

public abstract Temporal subtractFrom (Temporal temporal)

Subtracts this object from the specified temporal object.

Subtracts the amount from the specified temporal object using the logic encapsulated in the implementing class.

There are two equivalent ways of using this method. The first is to invoke this method directly. The second is to use minus(TemporalAmount):

   // these two lines are equivalent, but the second approach is recommended
   dateTime = amount.subtractFrom(dateTime);
   dateTime = dateTime.minus(amount);
 
It is recommended to use the second approach, minus(TemporalAmount), as it is a lot clearer to read in code.

Parameters
temporal the temporal object to subtract the amount from, not null
Returns
  • an object of the same observable type with the subtraction made, not null
Throws
DateTimeException if unable to subtract
ArithmeticException if numeric overflow occurs