The technical analysis of the Java class library moderate unit API framework (Technical Principles Analysis of the Measurement Units API Framework in Java Class Libraries)

Analysis of the technical principles of the API framework of the Java class library mode In the development of Java, we often need to change and represent different measurement units.In order to simplify this process, the Java class library provides a measured unit API framework, so that developers can easily handle the unit conversion and representation.This article will analyze the technical principles of the API framework of this measurement unit and provide examples of Java code for better understanding. 1. Basic concept Before starting the technical principles of the API framework of the unit API, we first need to understand some basic concepts. -Mit (Unit): It means a standard for a certain amount or outline.For example, the length unit can be meter (Meter), and the weight unit may be kilograms. -Number: indicates the specific value of a certain measurement unit.For example, length is 10 meters and weighs 5 kg. -Mittype: indicates a set of a set of units with the same measurement type.For example, the length units can include rice, centimeters, divided rice, etc. -MitsyStytem: It means a group of related unit types and the relationship between the unit.For example, the international unit system (SI) is a commonly used unit system. 2. The structure of the API framework The API framework of the measurement unit is mainly composed of the following core components: -Init class: It is used to indicate a specific unit and provide methods related to value conversion and calculation.For example, 10 meters can be converted to centimeter through the Unit class. -Mittype: It is used to indicate a set of units with the same measurement type.For example, the types of length can include rice, centimeters, and meters.The unit type category provides methods related to the relationship between the unit and the unit. -MitsyStytem: It is used to represent a set of related unit types and the relationship between the unit.The unit system class provides related methods related to conversion, computing, and indicating. 3. Technical analysis The technical principles of the API framework of the measurement unit can basically be divided into the following steps: -D define unit and unit type: First of all, you need to define various units and units types, and provide them with corresponding classes and methods.These classes and methods can realize the relationship between the unit and the unit type through inheritance or interface implementation. -The implementation of unit conversion and calculation: Provide a conversion and calculation method for each unit class, so as to convert and calculate between different units.For example, a method of converting rice to centimeters can be provided for a length unit class. -Seng the unit type and unit system: According to business needs, organize the unit into different unit types and unit systems.You can use inheritance and combination to achieve the relationship between different units. -Sere the API interface: Finally, all the classes and methods are encapsulated as the API interface so that users can easily use these functions.The API interface can include methods such as unit conversion, computing and representation. 4. Java code example The following is a simple Java code example, which shows how to use the measured unit API framework for unit conversion: import javax.measure.*; import javax.measure.unit.*; public class UnitConversionExample { public static void main(String[] args) { // Define the unit type UnitType<Length> lengthType = UnitTypeImpl.LENGTH; // Definition unit Unit<Length> meter = SI.METER; Unit<Length> centimeter = SI.CENTIMETER; // Perform unit conversion Quantity<Length> lengthInMeter = Quantities.getQuantity(10, meter); Quantity<Length> lengthInCentimeter = lengthInMeter.to(centimeter); // Output conversion results System.out.println("Length in meter: " + lengthInMeter); System.out.println("Length in centimeter: " + lengthInCentimeter); } } In the above code, we first define the length type (lengthtype) and the meter and centimeter.Then, we use the method of measured the API framework of the unit to convert 10 meters to centimeter and output the conversion result. Summarize The API framework of the measurement unit provides convenient unit conversion and representations in the Java library.By defining the type of unit and unit and realizing the methods of conversion and calculation, developers can easily handle various measurement units.It is hoped that this article will help readers better understand and use this feature through the example code.