import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.attribute.FileOwnerAttributeView;
import java.nio.file.attribute.UserPrincipal;

public class FileOwner {

    public static void main(String[] args) throws IOException {
        Path path = Paths.get(System.getProperty("user.home"));
        FileOwnerAttributeView ownerAttributeView = Files.getFileAttributeView(path, FileOwnerAttributeView.class);
        UserPrincipal owner = ownerAttributeView.getOwner();
        System.out.println("owner name: " + owner.getName());
        System.out.println("owner UID: " + owner.hashCode());
        
    }

}

java.nio.file.attribute.UserPrincipalLookupService svc =  java.nio.file.FileSystems.getDefault().getUserPrincipalLookupService();
svc.lookupPrincipalByGroupName("staff").hashCode()
svc.lookupPrincipalByName("root").hashCode()

            svc.lookupPrincipalByName("root").hashCode();
            svc.lookupPrincipalByGroupName("staff").hashCode();

       User login: admin$
         User SID: S-1-5-21-2673944721-1503362698-616458971-500
Primary group SID: S-1-5-21-2673944721-1503362698-616458971-513

import com.sun.security.auth.module.NTSystem;
public class Test {
  public static void main(String[] args)
  {
    NTSystem nts = new NTSystem();
    System.out.println("       User login: " + nts.getName());
    System.out.println("         User SID: " + nts.getUserSID());
    System.out.println("Primary group SID: " + nts.getPrimaryGroupID());
  }
}

root/root
root/shell
shell/shell