In -depth understanding of the API framework of the measurement unit in the Java class library
In -depth understanding of the API framework of the measurement unit in the Java class library
The API framework in the Java class library is a powerful and practical tool. It provides developers with a simple way to handle the conversion and calculations between various measurement units.In this article, we will explore the API framework in the JAVA class library and display its usage through the Java code example.
First, what is the measurement unit API framework?
The API framework of the measurement unit is a powerful library introduced by Java 8. It provides a set of classes and methods through the javax.measure package to process the conversion between the unit and it.The framework (SI) based on international science, technology and trade regulations defines a set of common measurement units and allows developers to define their own measurement units.
2. The characteristics of the measurement unit API framework
1. Strong type Security: The API framework of the measurement unit uses a strong type system, which ensures the safety conversion and calculation of the unit through type inference and runtime inspection.
2. Scalability: Developers can easily define their own measurement units and conduct custom -defined unit conversion and calculations.
3. Standardization: The API framework of the measurement unit follows the international unit system (SI), providing a set of common measurement units to make developers more convenient when dealing with different types of measurement.
4. Support formatting output: The API framework of the measurement unit provides the function of formatting output, so that the developer can display the measurement results in a specified format, such as retaining decimal digits or display unit symbols.
3. Example of the use of the API framework of the unit
The use of several examples will be used to demonstrate the use of the API framework of the unit API:
1. Create a measurement object with a length of 10 meters and convert it to centimeter:
import javax.measure.Quantity;
import javax.measure.quantity.Length;
import javax.measure.unit.SI;
public class MeasurementExample {
public static void main(String[] args) {
Quantity<Length> length = QuantityUtil.create(10, SI.METER);
Quantity<Length> convertedLength = QuantityUtil.convert(length, SI.CENTIMETER);
System.out.println (convertedLength); // The output result is 1000 cm
}
}
2. Convert the temperature from the degree Celsius to Hua's:
import javax.measure.Quantity;
import javax.measure.quantity.Temperature;
import javax.measure.unit.NonSI;
import javax.measure.unit.SI;
public class MeasurementExample {
public static void main(String[] args) {
Quantity<Temperature> celsiusTemperature = QuantityUtil.create(25, SI.CELSIUS);
Quantity<Temperature> fahrenheitTemperature = QuantityUtil.convert(celsiusTemperature, NonSI.FAHRENHEIT);
System.out.println (FahrenheitTemperature); // The output result is 77 ° f
}
}
3. Basic calculations of the measurement object, such as the addition and subtraction of length:
import javax.measure.Quantity;
import javax.measure.quantity.Length;
import javax.measure.unit.SI;
public class MeasurementExample {
public static void main(String[] args) {
Quantity<Length> length1 = QuantityUtil.create(5, SI.METER);
Quantity<Length> length2 = QuantityUtil.create(3, SI.METER);
Quantity<Length> sum = QuantityUtil.add(length1, length2);
Quantity<Length> difference = QuantityUtil.subtract(length1, length2);
System.out.println (SUM); // The output result is 8 m
System.out.println (Difference); // The output result is 2 m
}
}
Fourth, summary
The API framework in the Java class library provides developers with a convenient way to handle the conversion and calculations between various measurement units.Its strong types of security, scalability and standardization enable developers to deal with various types of measurement more efficiently.Through the introduction and example code of this article, it is believed that readers have a deeper understanding of the API framework in the Java class library, and can be flexibly used in actual development.
