Java는 지정된 날짜가 어떤 요일인지 결정합니다.

//根据日期取得星期几
	public static String getWeek(Date date){
		String[] weeks = {"星期日","星期一","星期二","星期三","星期四","星期五","星期六"};
		Calendar cal = Calendar.getInstance();
		cal.setTime(date);
		int week_index = cal.get(Calendar.DAY_OF_WEEK) - 1;
		if(week_index<0){
			week_index = 0;
		} 
		return weeks[week_index];
	}

//根据日期取得星期几
	public static String getWeek(Date date){ 
		SimpleDateFormat sdf = new SimpleDateFormat("EEEE");
		String week = sdf.format(date);
		return week;
	}