javax.measure.unit

Class BaseUnit<Q extends Quantity>

java.lang.Object

javax.measure.unit.Unit<Q>

javax.measure.unit.BaseUnit<Q>

All Implemented Interfaces:

Serializable

public class BaseUnit<Q extends Quantity>
extends Unit<Q>

This class represents the building blocks on top of which all others units are created. Base units are typically dimensionally independent. The actual unit dimension is determinated by the current model. For example using the standard model, SI.CANDELA has the dimension of watt:[code] // Standard model. BaseUnit METER = new BaseUnit("m"); BaseUnit CANDELA = new BaseUnit("cd"); System.out.println(METER.getDimension()); System.out.println(CANDELA.getDimension()); > [L] > [L]²·[M]/[T]³ [/code]

This class represents the "standard base units" which includes SI base units and possibly others user-defined base units. It does not represent the base units of any specific SystemOfUnits (they would have be base units accross all possible systems otherwise).

Version:

3.1, April 22, 2006

Author:

Jean-Marie Dautelle

See Also:

Wikipedia: SI base unit, Serialized Form

Field Summary

Fields inherited from class javax.measure.unit.Unit

ONE

Constructor Summary

Constructors

Constructor and Description
BaseUnit(String symbol) Creates a base unit having the specified symbol.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(Object that) Indicates if this base unit is considered equals to the specified object (both are base units with equal symbol, standard dimension and standard transform).
Unit<? super Q>	getStandardUnit() Returns the base unit, alternate unit or product of base units and alternate units this unit is derived from.
String	getSymbol() Returns the unique symbol for this base unit.
int	hashCode() Returns the hash code for this unit.
UnitConverter	toStandardUnit() Returns the converter from this unit to its system unit.

Methods inherited from class javax.measure.unit.Unit

alternate, asType, compound, divide, divide, divide, getConverterTo, getDimension, inverse, isCompatible, isStandardUnit, plus, pow, root, times, times, times, toString, transform, valueOf

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

BaseUnit

public BaseUnit(String symbol)

Creates a base unit having the specified symbol.

Parameters:

symbol - the symbol of this base unit.

Throws:

IllegalArgumentException - if the specified symbol is associated to a different unit.

Method Detail

getSymbol

public final String getSymbol()

Returns the unique symbol for this base unit.

Returns:

this base unit symbol.

equals

public boolean equals(Object that)

Indicates if this base unit is considered equals to the specified object (both are base units with equal symbol, standard dimension and standard transform).

Specified by:

equals in class Unit<Q extends Quantity>

Parameters:

that - the object to compare for equality.

Returns:

true if this and that are considered equals; falseotherwise.

hashCode

public int hashCode()

Description copied from class: Unit

Returns the hash code for this unit.

Specified by:

hashCode in class Unit<Q extends Quantity>

Returns:

this unit hashcode value.

getStandardUnit

public Unit<? super Q> getStandardUnit()

Description copied from class: Unit

Returns the base unit, alternate unit or product of base units and alternate units this unit is derived from. The standard unit identifies the "type" of quantity for which this unit is employed. For example:[code] boolean isAngularVelocity(Unit u) { return u.getStandardUnit().equals(RADIAN.divide(SECOND)); } assert(REVOLUTION.divide(MINUTE).isAngularVelocity()); [/code]

Note: Having the same system unit is not sufficient to ensure that a converter exists between the two units (e.g. °C/m and K/m).

Specified by:

getStandardUnit in class Unit<Q extends Quantity>

Returns:

the system unit this unit is derived from.

toStandardUnit

public UnitConverter toStandardUnit()

Description copied from class: Unit

Returns the converter from this unit to its system unit.

Specified by:

toStandardUnit in class Unit<Q extends Quantity>

Returns:

this.getConverterTo(this.getSystemUnit())