java 判断日期是否是周末

public static String isWeekend(String bDate) throws ParseException {
        DateFormat format1 = new SimpleDateFormat("yyyy/MM/dd");
        Date bdate = format1.parse(bDate);
        Calendar cal = Calendar.getInstance();
        cal.setTime(bdate);
        if(cal.get(Calendar.DAY_OF_WEEK) == Calendar.SATURDAY || cal.get(Calendar.DAY_OF_WEEK) == Calendar.SUNDAY){
            return "OK";
        } else{
            return "NO";
        }

 }