Java class library moderate unit API framework technical principle analysis

Analysis of technical principles of the API framework of Java Class Library API Framework Overview: In modern software development, the conversion and calculation of measurement units is a common and important task.In order to simplify code writing and improve the reuse, the Java class library introduced the API framework of the measurement unit.This article will analyze the technical principles of the framework and provide some Java code examples. 1 Introduction The API framework of the measurement unit is a standardized API provided by the Java class library to process the conversion, calculation and formatting of the measurement unit.The framework is based on the standards of the international unit system (SI), providing developers with a unified and easy -to -use method to handle conversion and calculations between different measurement units. 2. Technical principles The technical principle of the API framework of the measurement unit is based on the following main concepts: 2.1 numerical type The numerical type in the measurement unit API framework is a data structure that represents the value that represents the unit.It can contain various types such as integer and floating point numbers, and is associated with a specific measurement unit.Using numerical types, unit conversion, computing and formatting operations can be performed. 2.2 Unit type The unit type of the API framework of the measurement unit represents different measurement units.For example, the length can be represented by Meter or FOOT.Each unit type includes attributes such as identifiers, symbols, and conversion functions, which are used to define the characteristics and conversion rules of the unit. 2.3 unit system The unit system is a collection of unit types for organizing and managing various measurement units.The API framework in the Java class library provides some common unit systems, such as the international unit system (SI) and the US Custom unit system, so that developers can easily convert and calculate the conversion and calculation between units. 2.4 Unit conversion The API framework of the measurement unit can realize the unit conversion by defining the conversion rules between the unit.Each unit type can define its own conversion function to convert one unit into another.For example, a function converted to a feet can multiply the given meter by 3.28084 to get a foot number. 3. Example code Below is a simple example code that demonstrates how to use the measurement unit API framework for unit conversion and calculation: import javax.measure.*; import javax.measure.quantity.*; public class MeasurementExample { public static void main(String[] args) { Unit<Length> meter = SI.METER; Unit<Length> foot = NonSI.FOOT; // Convert: rice to feet double meters = 10; double feet = meter.getConverterTo(foot).convert(meters); System.out.println (meters + "meter =" + feet + "feet"); // Calculation: two lengths add double length1 = 5; double length2 = 7; double sum = meter.of(length1).plus(meter.of(length2)).getValue(); System.out.println (length1 + "rice +" + length2 + "rice =" + sum + "rice"); } } In the above sample code, we first define the types of rice and feet.Then, we use the `GetConverterto () method to convert the given rice number to a foot number and print the output result.Next, we used the `OF ()" method to create two length objects, and then use the `plus ()` method to add them and get the length value after the addition. Summarize: This article analyzes the technical principles of the API framework of the JAVA library mode, and provides a simple code example.Using this framework, developers can easily perform the conversion, calculation and formatting of the unit to improve the readability and reuse of the code.It is hoped that this article can help readers better understand and apply the API framework of the unit.