用示例在Java中打包 getImplementationVersion() 方法

Java.lang.Package 类的getImplementationVersion()方法用于获取该包的实现版本。该方法将包的实现版本作为字符串返回。
句法：

public String getImplementationVersion()

参数：此方法不接受任何参数。
返回值：此方法以字符串形式返回包的实现版本（如果已知）。否则返回 null
下面的程序演示了 getImplementationVersion() 方法。
示例 1：

Java

// Java program to demonstrate
// getImplementationVersion() method
 
public class Test {
    public static void main(String[] args)
    {
 
        // returns the Package object
        // for this package
        Package myPackage
            = Package.getPackage("java.lang");
 
        System.out.println(
            "Package represented by myPackage: "
            + myPackage.toString());
 
        // Get the implementation version of myPackage
        // using getImplementationVersion() method
        System.out.println(
            "Implementation version of myPackage: "
            + myPackage.getImplementationVersion());
    }
}

输出：

Package represented by myPackage: package java.lang, Java Platform API Specification, version 1.8
Implementation version of myPackage: 1.8.0_181

示例 2：

Java

// Java program to demonstrate
// getImplementationVersion() method
 
public class Test {
    public static void main(String[] args)
    {
 
        // returns the Package object
        // for this package
        Package myPackage
            = Package.getPackage("java.io");
 
        System.out.println(
            "Package represented by myPackage: "
            + myPackage.toString());
 
        // Get the name of myPackage
        // using getImplementationVersion() method
        System.out.println(
            "Implementation version of myPackage: "
            + myPackage.getImplementationVersion());
    }
}

输出：

Package represented by myPackage: package java.io, Java Platform API Specification, version 1.8
Implementation version of myPackage: 1.8.0_181

参考： https://docs.oracle.com/javase/9/docs/api/ Java/lang/Package.html#getImplementationVersion–