Package javax.measure.spi

Interface QuantityFactory<Q extends Quantity<Q>>

Type Parameters:

Q - the type of the Quantity result

public interface QuantityFactory<Q extends Quantity<Q>>

Represents a factory that accepts Number and Unit arguments to create Quantity results.

Since:

1.0

Version:

1.4, December 18, 2018

Author:

Werner Keil, Otavio Santana

See Also:

Wikipedia: Factory method pattern, Quantity, Unit

Method Summary

Modifier and Type	Method	Description
Quantity<Q>	create(Number value, Unit<Q> unit)	Returns the quantity for the specified number stated in the specified unit.
Quantity<Q>	create(Number value, Unit<Q> unit, Quantity.Scale scale)	Returns the quantity for the specified number stated in the specified unit and scale.
Unit<Q>	getSystemUnit()	Returns the system unit for quantities produced by this factory or null if unknown.

Method Detail

create

Quantity<Q> create(Number value,
                   Unit<Q> unit,
                   Quantity.Scale scale)

Returns the quantity for the specified number stated in the specified unit and scale.

Parameters:

value - the numeric value stated in the specified unit

unit - the unit

scale - The ABSOLUTE / RELATIVE scale of this quantity

Returns:

the corresponding quantity

Since:

2.0

create

Quantity<Q> create(Number value,
                   Unit<Q> unit)

Returns the quantity for the specified number stated in the specified unit.

Parameters:

value - the numeric value stated in the specified unit

unit - the unit

Returns:

the corresponding quantity

getSystemUnit

Unit<Q> getSystemUnit()

Returns the system unit for quantities produced by this factory or null if unknown.

Because the system unit is unique by quantity type, it can be be used to identify the quantity given the unit. For example:

     static boolean isAngularSpeed(Unit<?> unit) {
         return unit.getSystemUnit().equals(RADIAN.divide(SECOND));
     }
     assert isAngularSpeed(REVOLUTION.divide(MINUTE)); // Returns true.
 

Returns:

the system unit for this factory.

See Also:

Unit.getSystemUnit()