获取星期几，周一到周日，返回1-7

Posted 2020-08-25 JLCUI

 public int getDayOfWeek(Date date) {
  Calendar c = Calendar.getInstance();
  c.setTime(date);
  int d = c.get(Calendar.DAY_OF_WEEK) - 1;
  if (d == 0) {
   return 7;
  }
  return d;
 }