java如何將毫秒數轉為相應的年月日格式

public static void main(String[] args) {
Date date = new Date();
Long time = date.getTime();
System.out.println(time);

Date d = new Date(time);
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
System.out.println(sdf.format(d));
}