Interface Unit<Q extends Quantity<Q>>

All Known Implementing Classes:
Currency, StandardUnit
public interface Unit<Q extends Quantity<Q>>
A unit of measurement for a physical quantity.

Units define how quantities are measured and provide conversion between different units of the same dimension. Units are immutable and can be combined through multiplication and division to form derived units.

Example Usage:

Since:
1.0
Author:
Silvere Martin-Michiellot, Gemini AI (Google DeepMind)

  • Method Summary

    Modifier and Type
    Method
    Description
    default <R extends Quantity<R>>
    Unit<R>
    asType(Class<R> type)
    Casts this unit to a specific quantity type.
    default Unit<Q>
    divide(double factor)
    Returns a unit equal to this unit divided by the specified factor.
    Unit<?>
    divide(Unit<?> other)
    Returns the quotient of this unit by another unit.
    default UnitConverter
    getConverterFrom(Unit<Q> sourceUnit)
    Returns a converter from the target unit to this unit.
    UnitConverter
    getConverterTo(Unit<Q> targetUnit)
    Returns a converter to convert values from this unit to the target unit.
    Dimension
    getDimension()
    Returns the dimension of this unit.
    String
    getName()
    Returns the human-readable name for this unit (e.g., "meter", "kilogram").
    String
    getSymbol()
    Returns the symbol for this unit (e.g., "m", "kg", "s").
    default Unit<?>
    inverse()
    Returns the inverse of this unit.
    boolean
    isBaseUnit()
    Checks if this is a base SI unit (meter, kilogram, second, etc.).
    default boolean
    isCompatible(Unit<?> other)
    Checks if this unit is compatible with another unit.
    Unit<Q>
    multiply(double factor)
    Returns a unit equal to this unit multiplied by the specified factor.
    Unit<?>
    multiply(Unit<?> other)
    Returns the product of this unit with another unit.
    Unit<?>
    pow(int exponent)
    Returns this unit raised to the specified power.
    Unit<?>
    sqrt()
    Returns the square root of this unit.

  • Method Details

    • getSymbol

      String getSymbol()
      Returns the symbol for this unit (e.g., "m", "kg", "s").

      Symbols follow UCUM (Unified Code for Units of Measure) conventions where possible.

      Returns:
      the unit symbol

    • getName

      String getName()
      Returns the human-readable name for this unit (e.g., "meter", "kilogram").
      Returns:
      the unit name

    • getDimension

      Dimension getDimension()
      Returns the dimension of this unit.

      The dimension describes the physical nature of the quantity (e.g., length, mass, time) as a combination of base SI dimensions.

      Returns:
      the dimension

    • getConverterTo

      UnitConverter getConverterTo(Unit<Q> targetUnit)
      Returns a converter to convert values from this unit to the target unit.

      Both units must have compatible dimensions.

      Parameters:
      targetUnit - the target unit
      Returns:
      a converter from this unit to the target
      Throws:
      IllegalArgumentException - if units are incompatible

    • getConverterFrom

      default UnitConverter getConverterFrom(Unit<Q> sourceUnit)
      Returns a converter from the target unit to this unit.

      This is the inverse of getConverterTo(Unit).

      Parameters:
      sourceUnit - the source unit
      Returns:
      a converter from the source unit to this unit

    • multiply

      Unit<Q> multiply(double factor)
      Returns a unit equal to this unit multiplied by the specified factor.

      For example, METER.multiply(1000) gives kilometer.

      Parameters:
      factor - the multiplier
      Returns:
      the scaled unit

    • divide

      default Unit<Q> divide(double factor)
      Returns a unit equal to this unit divided by the specified factor.

      For example, METER.divide(100) gives centimeter.

      Parameters:
      factor - the divisor
      Returns:
      the scaled unit

    • multiply

      Unit<?> multiply(Unit<?> other)
      Returns the product of this unit with another unit.

      For example, multiplying Length by Length gives Area.

      Parameters:
      other - the unit to multiply with
      Returns:
      the product unit

    • divide

      Unit<?> divide(Unit<?> other)
      Returns the quotient of this unit by another unit.

      For example, dividing Length by Time gives Velocity.

      Parameters:
      other - the unit to divide by
      Returns:
      the quotient unit

    • pow

      Unit<?> pow(int exponent)
      Returns this unit raised to the specified power.

      For example, METER.pow(2) gives square meters (area).

      Parameters:
      exponent - the exponent
      Returns:
      the unit raised to the power

    • asType

      default <R extends Quantity<R>> Unit<R> asType(Class<R> type)
      Casts this unit to a specific quantity type.

      This is primarily used for type safety when creating derived units. For example, casting J/K to Entropy type.

      Type Parameters:
      R - the target quantity type
      Parameters:
      type - the target quantity class
      Returns:
      this unit cast to the target type

    • inverse

      default Unit<?> inverse()
      Returns the inverse of this unit.

      For example, the inverse of Time is Frequency (1/s = Hz).

      Returns:
      the inverse unit

    • sqrt

      Unit<?> sqrt()
      Returns the square root of this unit.

      The dimension exponents must all be even.

      Returns:
      the square root unit
      Throws:
      IllegalArgumentException - if square root is undefined

    • isCompatible

      default boolean isCompatible(Unit<?> other)
      Checks if this unit is compatible with another unit.

      Units are compatible if they have the same dimension, allowing conversion between them.

      Parameters:
      other - the other unit
      Returns:
      true if units are compatible

    • isBaseUnit

      boolean isBaseUnit()
      Checks if this is a base SI unit (meter, kilogram, second, etc.).
      Returns:
      true if this is a base unit