The technical principles of the measured unit API framework in the Java class library

The technical principle of the measurement unit API framework in the Java class library When developing Java applications, measurement unit conversion and calculation often need to be performed.In order to simplify this process and provide a unified measurement unit, the Java class library provides a measurement unit API framework. The technical principle of the measurement unit API framework in the Java class library is based on the following key concepts: 1. Measurement units: The measurement unit is a unit that describes the physical quantity. For example, the unit of length can be rice (M), and the unit of quality can be a kg (KG).The API framework of the measurement unit defines a set of predetermined measurement units, and how to combine and transform it. 2. Numerical Values: The value represents the specific measurement result, such as 2.5 meters in length and 500 grams.The measurement unit API framework uses numerical objects to store and operate value.These objects can perform basic mathematical operations, such as addition, subtraction, multiplication and removal. 3. The combination of numerical and unit: The combination of value and measurement unit can create a quantitative object that represents the physical quantity.The quantity object is the core concept of the measurement of the unit framework. It encapsulates the relationship between the value and the unit, and provides a method for common calculation of these quantities. Example of code using measurement unit API framework: import javax.measure.Quantity; import javax.measure.quantity.Length; import javax.measure.unit.SI; import tech.units.indriya.quantity.Quantities; public class MeasurementExample { public static void main(String[] args) { // Create a quantitative object with a length of 2.5 meters Quantity<Length> length = Quantities.getQuantity(2.5, SI.METER); // Convert the quantitative object to different units Quantity<Length> lengthInCentimeters = length.to(SI.CENTIMETER); Quantity<Length> lengthInInches = length.to(NonSI.INCH); // Execute the mathematical operation between the measurement of the measurement Quantity<Length> combinedLength = length.add(lengthInCentimeters); // Output results System.out.println("Length: " + length); System.out.println("Length in Centimeters: " + lengthInCentimeters); System.out.println("Length in Inches: " + lengthInInches); System.out.println("Combined Length: " + combinedLength); } } In the above example, we first created a quantitative object with a length of 2.5 meters.Then, use the to () method to convert it to centimeter and inch units.Finally, we execute the addition of length and length (represented by centimeters).By using the measurement unit API framework, we can easily perform unit conversion and numerical calculations without manually writing tedious conversion codes. Summary: The measured unit API framework in the Java class library provides a way to simplify the conversion and calculation of the measurement unit.It uses measurement units, numerical and quantitative objects to represent and operate physical quantity.The use of this framework makes the processing unit more simple and reliable, reduce errors and increase the readability and maintenance of the code.