java代码获得周六或者周日的个数

java代码获得周六或者周日的个数

/**
	 * 查询日期间有几天一周中的某一天
	 * 日期格式 yyyy-MM-dd yyyy-MM-dd 1-7(表示周一到周日)
	 * @param startDate 准备查询的起始日期
	 * @param endDate 准备查询的结束日期
	 * @param dayOfWeek 准备查的一周中的某一天(准备查周几？)
	 * @return 包含所查周几的天数
	 * @throws ParseException 不支持跨年查询、不支持结束日期早于起始日期、周几输入错误等
	 */
	public static int getMondayNumber(Date startDate,Date endDate,int dayOfWeek) throws ParseException{
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
		int differenceDay = 0;
		//实例化起始和结束Calendar对象
		Calendar startCalendar = Calendar.getInstance();
		Calendar endCalendar = Calendar.getInstance();
		//分别设置Calendar对象的时间
		startCalendar.setTime(startDate);
		endCalendar.setTime(endDate);

		//定义起始日期和结束日期分别属于第几周
		int startWeek = startCalendar.get(Calendar.WEEK_OF_YEAR);
		int endWeek = endCalendar.get(Calendar.WEEK_OF_YEAR);

		//拿到起始日期是星期几
		int startDayOfWeek = startCalendar.get(Calendar.DAY_OF_WEEK);
		if(startDayOfWeek == 1)    {
			startDayOfWeek = 7;
			startWeek--;
		}else startDayOfWeek--;

		//拿到结束日期是星期几
		int endDayOfWeek = endCalendar.get(Calendar.DAY_OF_WEEK);
		if(endDayOfWeek == 1) {
			endDayOfWeek = 7;
			endWeek--;
		}else endDayOfWeek--;

		//计算相差的周数
		int differenceWeek = endWeek - startWeek;

		//开始计算
		if(startDayOfWeek <= dayOfWeek) {
			if(endDayOfWeek >= dayOfWeek)
				differenceDay = differenceWeek + 1;
		}else if(startDayOfWeek > dayOfWeek) {
			if(endDayOfWeek < dayOfWeek)
				differenceDay = differenceWeek-1;
		}else {
			differenceDay = differenceWeek;
		}
		return differenceDay;
	}