public interface TemporalAmount
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
.
Modifier and Type | Method and Description |
---|---|
Temporal |
addTo(Temporal temporal)
Adds to the specified temporal object.
|
long |
get(TemporalUnit unit)
Returns the value of the requested unit.
|
List<TemporalUnit> |
getUnits()
Returns the list of units uniquely defining the value of this TemporalAmount.
|
Temporal |
subtractFrom(Temporal temporal)
Subtracts this object from the specified temporal object.
|
long get(TemporalUnit unit)
getUnits()
uniquely define the
value of the TemporalAmount
. A value must be returned
for each unit listed in getUnits
.unit
- the TemporalUnit
for which to return the valueDateTimeException
- if a value for the unit cannot be obtainedUnsupportedTemporalTypeException
- if the unit
is not supportedList<TemporalUnit> getUnits()
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.TemporalUnits
; not nullTemporal addTo(Temporal temporal)
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 Temporal.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.temporal
- the temporal object to add the amount to, not nullDateTimeException
- if unable to addArithmeticException
- if numeric overflow occursTemporal subtractFrom(Temporal temporal)
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 Temporal.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.temporal
- the temporal object to subtract the amount from, not nullDateTimeException
- if unable to subtractArithmeticException
- if numeric overflow occursDracula Javadoc Sample, Made with Allan Im.