How to detect current Operation System of by "java.nio.file.spi.FileSystemProvider" class and "java.nio.file.FileSystems.getDefault()" method in Java

How to detect current of by "java.nio.file.spi.FileSystemProvider" class and "java.nio.file.FileSystems.getDefault()" method

import java.nio.file.FileSystems;
import java.nio.file.spi.FileSystemProvider;
import java.nio.file.FileSystem;

public class HelloWorld {
    public static void main(final String[] args) {
        final FileSystem fs=FileSystems.getDefault();
        final FileSystemProvider fsp=fs!=null?fs.provider():null;
        System.out.println(fsp!=null?fsp.getClass():null);
    }
}

Operating System	java.nio.file.spi.FileSystemProvider implementation
Microsoft Windows	sun.nio.fs.WindowsFileSystemProvider
Linux	sun.nio.fs.LinuxFileSystemProvider