Detailed explanation

Detailed explanation The measurement unit is a standard for measuring material characteristics, measurement and comparison in science, business and daily life.The Java class library provides a measured unit API, which can easily convert and calculate the unit.This article will introduce the use of the measurement unit API in the Java class library in detail, and provide relevant Java code examples. 1. Introduce the measured unit API First, in order to use the measured unit API, we need to import the corresponding library in the Java code.Before introducing the API of the measurement unit, make sure your Java version is 1.8 or higher.The following is an example of the code of importing the API of the measurement unit: import javax.measure.*; import javax.measure.quantity.*; import javax.measure.unit.*; 2. Create a measurement unit object Before using the measured unit API, we need to create the measurement unit object.Objectives are used to represent specific measurement units, such as length, quality, time, etc.The following is an example of the code for creating a measurement unit object: Unit <langth> Meter = si.meter; // Create a length unit object Unit <mass> kilogram = si.kilogram; // Create a quality unit object Unit <Time> Second = si.Second; // Create time unit object 3. Perform unit conversion The measurement unit API provides a method for unit conversion.We can use the `TO ()" method to convert a unit into another.The following is an example of code conversion of unit conversion: Unit<Length> foot = NonSI.FOOT; double meters = 2.5; double feet = meter.to(foot).convert(meters); System.out.println (meters + "meter is equal to" + Feet + "feet"); 4. Perform unit calculation The measurement unit API also provides some methods for unit computing, such as addition, subtraction, multiplication, etc.We can use these methods to calculate between units.The following is an example of code calculated by the unit: Unit<Mass> gram = NonSI.GRAM; double value1 = 500; double value2 = 0.25; double result = kilogram.multiply(value1).divide(gram).times(value2).doubleValue(); System.out.println (Value1 + "" + Value2 + "is equal to" + result + "grams"); 5. Custom metering unit In addition to using a predefined measurement unit, we can also customize the measurement unit.The measurement unit API allows us to customize new metering units according to needs.The following is an example of the code of the custom unit: Unit<Speed> kilometersPerHour = new ProductUnit<Speed>(SI.KILO(SI.METER).divide(SI.HOUR)); double speed = 120; System.out.println (Speed + "km/hour is equal to" + KilometersperHour.Convert (Speed) + "meter/second"); Summarize: This article introduces the use of the measurement unit API in the Java class library, and provides related Java code examples.By using the measured unit API, we can easily transform and calculate the unit to improve the readability and maintenance of the code.The measurement unit API has a wide range of application prospects in science, business and daily life.