docs/net.corda.core.contracts/Amount

Amount

data class Amount<T : Any>(val quantity: Long, val displayTokenSize: BigDecimal, val token: T) : Comparable<Amount<T>>

Amount represents a positive quantity of some token (currency, asset, etc.), measured in quantity of the smallest representable units. The nominal quantity represented by each individual token is equal to the displayTokenSize. The scale property of the displayTokenSize should correctly reflect the displayed decimal places and is used when rounding conversions from indicative/displayed amounts in BigDecimal to Amount occur via the Amount.fromDecimal method.

Amounts of different tokens do not mix and attempting to add or subtract two amounts of different currencies will throw IllegalArgumentException. Amounts may not be negative. Amounts are represented internally using a signed 64 bit value, therefore, the maximum expressable amount is 2^63 - 1 == Long.MAX_VALUE. Addition, subtraction and multiplication are overflow checked and will throw ArithmeticException if the operation would have caused integer overflow.

Parameters

the type of the token, for example Currency. T should implement TokenizableAssetInfo if automatic conversion to/from a display format is required.

Constructors

Amount

constructor(tokenQuantity: Long, token: T)

Automatic conversion constructor from number of tokens to an Amount using getDisplayTokenSize to determine the displayTokenSize.

constructor(quantity: Long, displayTokenSize: BigDecimal, token: T)

Types

Companion

object Companion

Properties

CASH

val Amount<Currency>.CASH: Cash.State

An extension property that lets you write 100.DOLLARS.CASH

displayTokenSize

val displayTokenSize: BigDecimal

the nominal display unit size of a single token, potentially with trailing decimal display places if the scale parameter is non-zero.

quantity

val quantity: Long

the number of tokens as a long value.

STATE

val Amount<Issued<Currency>>.STATE: Cash.State

An extension property that lets you get a cash state from an issued token, under the NULL_PARTY

token

val token: T

the type of token this is an amount of. This is usually a singleton.

Functions

issued by

infix fun Amount<Currency>.issued by(deposit: PartyAndReference): Amount<Issued<Currency>>

issuedBy

infix fun Amount<Currency>.issuedBy(deposit: PartyAndReference): Amount<Issued<Currency>>

minus

operator fun minus(other: Amount<T>): Amount<T>

A checked subtraction operator is supported to simplify netting of Amounts.

plus

operator fun plus(other: Amount<T>): Amount<T>

A checked addition operator is supported to simplify aggregation of Amounts. Mixing non-identical token types will throw IllegalArgumentException.

splitEvenly

fun splitEvenly(partitions: Int): List<Amount<T>>

This method provides a token conserving divide mechanism.

times

operator fun times(other: Int): Amount<T>

operator fun times(other: Long): Amount<T>

The multiplication operator is supported to allow easy calculation for multiples of a primitive Amount. Note this is not a conserving operation, so it may not always be correct modelling of proper token behaviour. N.B. Division is not supported as fractional tokens are not representable by an Amount.

toDecimal

fun toDecimal(): BigDecimal

Convert a currency Amount to a decimal representation. For example, with an amount with a quantity of "1234" GBP, returns "12.34". The precise representation is controlled by the display token size ( from getDisplayTokenSize), which determines the size of a single token and controls the trailing decimal places via its scale property. Note that currencies such as the Bahraini Dinar use 3 decimal places, and it must not be presumed that this converts amounts to 2 decimal places.

toString

open override fun toString(): String

Convert a currency Amount to a display string representation.

withoutIssuer

fun <T : Any> Amount<Issued<T>>.withoutIssuer(): Amount<T>

Strips the issuer and returns an Amount of the raw token directly. This is useful when you are mixing code that cares about specific issuers with code that will accept any, or which is imposing issuer constraints via some other mechanism and the additional type safety is not wanted.