Java Metric Unit Conversion Library? [closed]

Answer 1

We created a library, UnitOf, for Java, JavaScript, and C# to easily perform these measurement conversions. There are are over 20 complete units of measure and conversions can be done in as little as one line.

//One liner
double x = new UnitOf.Mass().fromPounds(5).toKilograms(); //2.26796 returned as 5 pounds is 2.26796 kilograms

//Or as a variable
UnitOf.Length feet = new UnitOf.Length().fromFeet(5.5); //Instantiate UnitOf.Length and set "feet" as 5.5
double foo = feet.toInches(); //66 returned as 5.5 feet is 66 inches
double bar = feet.toMeters(); //1.6764 returned as 5.5 feet is 1.6764 meters

UnitOf also gives the ability to parse data types, convert to and from fractions, and even create your own custom UnitOf measurements.

Answer 2

Adding to the pile...

Unidata now publishes the java units conversion library from netcdf-java as a standalone package.

Answer 3

I have found Java Unit Conversion library at SourceForge, but I have not yet tried it (I will need similar funcionality in near future). It is licensed as BSD license. It might help.

Answer 4

there is a specific JSR 275 (javax.measure) with JScience as RI (Reference Implementation). For example converting 100 Miles to kilometers is easy as:

UnitConverter toKilometers = MILE.getConverterTo(KILOMETER);
double km = toKilometers.convert(Measure.valueOf(100, MILE).doubleValue(MILE));

(note that units are all type safe a compile-time, a killer feature imho)

The reverse can be easy:

UnitConverter toMiles1 = KILOMETER.getConverterTo(MILE);

or supereasy as:

UnitConverter toMiles2 = toKilometers.inverse();

NB imports:

import javax.measure.Measure;
import javax.measure.converter.UnitConverter;
import javax.measure.quantity.Length;
import static javax.measure.unit.NonSI.*;
import static javax.measure.unit.SI.*;