java - How does the Date type get the 'YY-MM-DD'?

You can do it by the below code.

public void getCurrentTimeStampInYYMMDDFormat() {
    String date = new SimpleDateFormat("yy-MM-dd").format(new Date());
}

If you are using JDK8 then, you can also do it like this:

public void getCurrentTimeStampInYYMMDDFormat() {
    String date = LocalDateTime.now()
       .format(DateTimeFormatter.ofPattern("yy-MM-dd"));
}