Package javax.measure.quantity

[OPTIONAL] Provides quantitative properties or attributes of thing such as mass, time, distance, heat, and angular separation. Quantities of different kinds are represented by sub-types of the Quantity interface.

Only quantities defined in the BIPM - SI Brochure are provided here. Users can create their own quantity types by extending the Quantity interface.

This package supports measurable quantities, which can be expressed as (Number, Unit) tuples. Those tuples are not necessarily used directly in numerically intensive code. They are more useful as meta-data converted to the application internal representation (for example double primitive type with the requirement to provide values in meters) before computation begins.

Quantity sub-types are also used as parameterized type to characterize generic classes and provide additional compile time check. This technique is used extensively by the Unit interface, but users can apply the same approach to their own classes. In the example below, Sensor, MyQuantity and Vector3D are user-defined classes:

// A general-purpose Sensor class used for temperature measurements:
Sensor<Temperature> sensor ...;
Temperature temp = sensor.getValue();

// A vector of velocity in a three-dimensional space.
Unit<Speed> = metrePerSecond = METRE.divide(SECOND);
Vector3D<Speed> aircraftSpeed = new Vector3D(200.0, 50.0, -0.5, metrePerSecond);

This package holds only the quantities required by the metric system.

Since:

1.0

Version:

2.8

Author:

Jean-Marie Dautelle, Werner Keil

See Also:

Wikipedia: International System of Units, Wikipedia: 2019 redefinition of the SI base units

Interface Summary

Interface	Description
Acceleration	Rate of change of velocity with respect to time.
AmountOfSubstance	Number of elementary entities (molecules, for example) of a substance.
Angle	Figure formed by two lines diverging from a common point.
Area	Extent of a planar region or of the surface of a solid measured in square units.
CatalyticActivity	Catalytic activity.
Dimensionless	Dimensionless quantity.
ElectricCapacitance	Electric capacitance.
ElectricCharge	Electric charge.
ElectricConductance	Electric conductance.
ElectricCurrent	Amount of electric charge flowing past a specified circuit point per unit time.
ElectricInductance	Electric inductance.
ElectricPotential	Electric potential or electromotive force.
ElectricResistance	Electric resistance.
Energy	Capacity of a physical system to do work.
Force	Quantity that tends to produce an acceleration of a body in the direction of its application.
Frequency	Number of times a specified phenomenon occurs within a specified interval.
Illuminance	Illuminance.
Length	Extent of something along its greatest dimension or the extent of space between two objects or places.
LuminousFlux	Luminous flux.
LuminousIntensity	Luminous flux density per solid angle as measured in a given direction relative to the emitting source.
MagneticFlux	Magnetic flux.
MagneticFluxDensity	Magnetic flux density.
Mass	Measure of the quantity of matter that a body or an object contains.
Power	Rate at which work is done.
Pressure	Force applied uniformly over a surface.
RadiationDoseAbsorbed	Amount of energy deposited per unit of mass.
RadiationDoseEffective	Effective (or "equivalent") dose of radiation received by a human or some other living organism.
Radioactivity	Radioactive activity.
SolidAngle	Angle formed by three or more planes intersecting at a common point.
Speed	Distance traveled divided by the time of travel.
Temperature	Degree of hotness or coldness of a body or an environment.
Time	Period of existence or persistence.
Volume	Amount of space occupied by a three-dimensional object or region of space.