import java.io.File;
import java.util.Date;
public class Main {
public static void main(String[] args) throws Exception {
File fileToChange = new File("C:/myfile.txt");
Date filetime = new Date(fileToChange.lastModified());
System.out.println(filetime.toString());
System.out.println(fileToChange.setLastModified(System.currentTimeMillis()));
filetime = new Date(fileToChange.lastModified());
System.out.println(filetime.toString());
}
}