Detailed explanation of the API framework technical principles in the Java class library (in-deptH Explanation of the Technical Principles of the Measurement Units API Framework in Java Class Libraries)

Detailed explanation of the technical principle of the measurement unit API framework in the Java class library Introduction: When developing Java applications, the measurement unit often needs to be converted or operated to meet various business needs.To simplify this process, the Java class library provides a measurement unit API framework, which provides a flexible and scalable way to process the conversion and calculations of the measurement unit.This article will introduce the technical principles of the API framework of the degree unit in detail and provide the corresponding Java code example. Overview: The API framework of the measurement unit is a powerful library introduced by the Java 8 and above versions.It aims to provide a consistent and type security mechanism to deal with the unit.This framework consists of three main components: unit, measurement and converter. unit: The unit is the basic element in the API framework of the unit.Each unit has a named entity and is used to represent a certain amount of standards, such as length, quality, temperature, etc.In the API framework of the measurement unit, the unit is implemented as an implementation class of the `Unit` interface.The implementation of many common measurement units in the Java library, such as `Meter`,` Kilogram` and so on. measure: Measure is a combination of a value and unit, which is used to represent the actual value of a certain measurement standard.In the API framework of the measurement unit, the measurement class is implemented as an implementation class of the `Measurement` interface.The interface provides a set of operations to perform basic mathematical operations, such as addition, subtraction and multiplication.For example, you can use the `MeaSurement` interface to represent a measure of 10 meters in length. converter: The converter is another important component in the API framework of the unit.The converter is used to convert between different measurement units.In the API framework of the measurement unit, the converter is implemented as an implementation class of the `UnitconVerter` interface.This interface defines a set of conversion methods for conversion operations between different units. principle: The core principle of the measurement unit API framework is to model the measurement with the relationship between the unit into a hierarchical structure.In this level structure, there is a conversion ratio between each unit and the benchmark unit.For example, in the length unit, rice is usually the benchmark unit, while the units such as centimeters and feet have a conversion ratio relative to rice. The measurement unit API framework uses a converter to handle the conversion between different units.The converter is included between the unit and is used to convey the measurement.When the unit conversion is carried out, the API will properly calculate the measurement according to the conversion ratio between the unit. The following is a simple example. Demonstration of how to use the measured unit API framework for unit conversion: // Create a length unit Unit<Length> meter = SI.METER; Unit<Length> centimeter = SI.CENTIMETER; // Create a measure of 1 meter in length Measurement<Length> measurement = Measurement.of(1, meter); // Convert the measure from rice to centimeter Measurement<Length> convertedMeasurement = measurement.to(centimeter); // The measuring value after the output conversion System.out.println (convertedMeAsurement.getValue ()); // Output results: 100 In the above code, first created a length unit `meter` and` Centimeter`, and then create a measurement` with a length of 1 meter.Next, use the `TO ()" method to convert the measurement from rice to centimeter, and save the result in the `ConvertedMeaSurement`.Finally, obtain the conversion of the conversion value through the `GetValue ()` method, and output it to the console. in conclusion: The API framework of the measurement unit provides a convenient and easy -to -use way to process the conversion and calculations of the unit.It models a hierarchical structure by modeling the relationship between the measurement and the unit, and uses a converter to convert the unit.Using the measured unit API framework, developers can more easily perform the unit operation of the unit, which improves the readability and maintenance of the code. Please note that due to the limitation of the length of the article, the above examples only show a small part of the API framework of the measurement unit.Developers can understand and use the API framework of the measurement unit by consulting the official documentation of Java and using related APIs.