# TemporalAmount

public interface **TemporalAmount**

|---|---|---|
| Known Indirect Subclasses [ChronoPeriod](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/chrono/ChronoPeriod.html), [Duration](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/Duration.html), [Period](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/Period.html) |---|---| | [ChronoPeriod](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/chrono/ChronoPeriod.html) | A date-based amount of time, such as '3 years, 4 months and 5 days' in an arbitrary chronology, intended for advanced globalization use cases. | | [Duration](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/Duration.html) | A time-based amount of time, such as '34.5 seconds'. | | [Period](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/Period.html) | A date-based amount of time in the ISO-8601 calendar system, such as '2 years, 3 months and 4 days'. | |||

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 `https://developers.google.com/j2objc/javadoc/jre/reference/java/time/temporal/TemporalUnit.html` to
`long`, exposed via `https://developers.google.com/j2objc/javadoc/jre/reference/java/time/temporal/TemporalAmount.html#getUnits()` and `https://developers.google.com/j2objc/javadoc/jre/reference/java/time/temporal/TemporalAmount.html#get(java.time.temporal.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.
`https://developers.google.com/j2objc/javadoc/jre/reference/java/time/Period.html` is a date-based implementation, storing years, months and days.
`https://developers.google.com/j2objc/javadoc/jre/reference/java/time/Duration.html` 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](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/temporal/Temporal.html) | [addTo](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/temporal/TemporalAmount.html#addTo(java.time.temporal.Temporal))([Temporal](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/temporal/Temporal.html) temporal) Adds to the specified temporal object. |
| abstract long | [get](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/temporal/TemporalAmount.html#get(java.time.temporal.TemporalUnit))([TemporalUnit](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/temporal/TemporalUnit.html) unit) Returns the value of the requested unit. |
| abstract [List](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/List.html)\<[TemporalUnit](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/temporal/TemporalUnit.html)\> | [getUnits](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/temporal/TemporalAmount.html#getUnits())() Returns the list of units uniquely defining the value of this TemporalAmount. |
| abstract [Temporal](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/temporal/Temporal.html) | [subtractFrom](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/temporal/TemporalAmount.html#subtractFrom(java.time.temporal.Temporal))([Temporal](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/temporal/Temporal.html) temporal) Subtracts this object from the specified temporal object. |

## Public Methods

#### public abstract [Temporal](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/temporal/Temporal.html)
**addTo**
([Temporal](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/temporal/Temporal.html) 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 `https://developers.google.com/j2objc/javadoc/jre/reference/java/time/temporal/Temporal.html#plus(java.time.temporal.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.

<br />

##### 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](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/DateTimeException.html) | if unable to add |
| [ArithmeticException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/ArithmeticException.html) | if numeric overflow occurs |
|---|---|

#### public abstract long
**get**
([TemporalUnit](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/temporal/TemporalUnit.html) unit)

Returns the value of the requested unit.
The units returned from `https://developers.google.com/j2objc/javadoc/jre/reference/java/time/temporal/TemporalAmount.html#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](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/DateTimeException.html) | if a value for the unit cannot be obtained |
| [UnsupportedTemporalTypeException](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/temporal/UnsupportedTemporalTypeException.html) | if the `unit` is not supported |
|---|---|

#### public abstract [List](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/List.html)\<[TemporalUnit](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/temporal/TemporalUnit.html)\>
**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](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/temporal/Temporal.html)
**subtractFrom**
([Temporal](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/temporal/Temporal.html) 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 `https://developers.google.com/j2objc/javadoc/jre/reference/java/time/temporal/Temporal.html#minus(java.time.temporal.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.

<br />

##### 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](https://developers.google.com/j2objc/javadoc/jre/reference/java/time/DateTimeException.html) | if unable to subtract |
| [ArithmeticException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/ArithmeticException.html) | if numeric overflow occurs |
|---|---|