javax.measure.quantity
Interface Quantity

All Known Subinterfaces:
Acceleration, AmountOfSubstance, Angle, AngularAcceleration, AngularVelocity, Area, CatalyticActivity, DataAmount, DataRate, Dimensionless, Duration, DynamicViscosity, ElectricCapacitance, ElectricCharge, ElectricConductance, ElectricCurrent, ElectricInductance, ElectricPotential, ElectricResistance, Energy, Force, Frequency, Illuminance, KinematicViscosity, Length, LuminousFlux, LuminousIntensity, MagneticFlux, MagneticFluxDensity, Mass, MassFlowRate, Money, Power, Pressure, RadiationDoseAbsorbed, RadiationDoseEffective, RadioactiveActivity, SolidAngle, Temperature, Torque, Velocity, Volume, VolumetricDensity, VolumetricFlowRate

public interface Quantity

This interface represents any type of quantitative properties or attributes of thing. Mass, time, distance, heat, and angular separation are among the familiar examples of quantitative properties.

Distinct quantities have usually different physical dimensions; although it is not required nor necessary, for example Torque and Energy have same dimension but are of different nature (vector for torque, scalar for energy).

See Also:
Wikipedia: Quantity, Wikipedia: Dimensional Analysis