Package javax.measure.quantity

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:
  • Interfaces
    Class
    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.