Package javax.measure.spi

Interface SystemOfUnitsService

public interface SystemOfUnitsService

This interface represents the service to obtain a system of units.

Common systems of units are "SI" (System International) or Metric system, "Imperial" (British), or "US" (US Customary).

Since:

1.0

Version:

1.8, April 3, 2023

Author:

Jean-Marie Dautelle, Werner Keil, Martin Desruisseaux

See Also:

Wikipedia: International System of Units

Method Summary

Modifier and Type	Method	Description
java.util.Collection<SystemOfUnits>	getAvailableSystemsOfUnits()	Gets a list with available systems for this SystemOfUnitsService.
default <P extends Prefix> java.util.Set<P>	getPrefixes(java.lang.Class<P> prefixType)	Returns a Set containing the values of a particular Prefix type.
SystemOfUnits	getSystemOfUnits()	Returns the default system of units.
SystemOfUnits	getSystemOfUnits(java.lang.String name)	Returns the system of units having the specified name or null if none is found.

Method Detail

getSystemOfUnits

SystemOfUnits getSystemOfUnits()

Returns the default system of units. Depending on the implementation this may be the International System of Units or another default system.

Returns:

the default system of units.

getSystemOfUnits

SystemOfUnits getSystemOfUnits(java.lang.String name)

Returns the system of units having the specified name or null if none is found.

Parameters:

name - the system of unit name.

Returns:

the system of units for the given name.

getAvailableSystemsOfUnits

java.util.Collection<SystemOfUnits> getAvailableSystemsOfUnits()

Gets a list with available systems for this SystemOfUnitsService.

Returns:

list of available systems of units, never null.

getPrefixes

default <P extends Prefix> java.util.Set<P> getPrefixes(java.lang.Class<P> prefixType)

Returns a Set containing the values of a particular Prefix type.

This method may be used to iterate over certain prefixes as follows:

    for(MetricPrefix mp : service.getPrefixes(MetricPrefix.class))
        System.out.println(p);
 

The default implementation assumes that prefixes of the given type are implemented as an enumeration. This is the case of the two default prefix implementations provided in JSR 385, namely MetricPrefix and BinaryPrefix. Implementors shall override this method if they provide prefixes implemented in a different way.

Type Parameters:

P - compile-time value of the prefixType argument

Parameters:

prefixType - the Prefix type

Returns:

a set containing the constant values of this Prefix type, in the order they're declared

Throws:

java.lang.ClassCastException - if the class is not compatible with the desired Prefix implementation or does not implement Prefix at all.

Since:

2.0