Java 日期增加一天、一周、一月、三月和六月以及判断是否周末

1、日期增加指定日期

public String isWeekendOrHoliday(String date, Integer type) throws ParseException {
		DateFormat format = new SimpleDateFormat("yyyy-MM-dd");
		Date recorDate = format.parse(date);
        // 日历对象
		Calendar cal = Calendar.getInstance();
        // 日历对象设置Date
		cal.setTime(recorDate);
		switch (type) {
		case 1:
			// 日期添加:一周
			cal.set(Calendar.DAY_OF_MONTH, cal.get(Calendar.DAY_OF_MONTH)+7);
			break;
		case 2:
			// 日期添加:一个月
			cal.set(Calendar.MONTH,cal.get(Calendar.MONTH)+1);
			break;
		case 3:
			// 日期添加：三个月
			cal.set(Calendar.MONTH,cal.get(Calendar.MONTH)+3);
			break;
		case 4:
			// 日期添加:六个月
			cal.set(Calendar.MONTH,cal.get(Calendar.MONTH)+6);
			break;
		default:
			// 默认当天
		}
		if (cal.get(Calendar.DAY_OF_WEEK) == Calendar.SATURDAY || cal.get(Calendar.DAY_OF_WEEK) == Calendar.SUNDAY) {
			cal.set(Calendar.DATE, cal.get(Calendar.DAY_OF_MONTH)+1);
			recorDate = cal.getTime();
			date = format.format(recorDate);
			return isWeekendOrHolidaySub(date);
		}
		recorDate = cal.getTime();
		return format.format(recorDate);
	}

2、判断是否周末功能代码：

public String isWeekendOrHolidaySub(String date) throws ParseException {
		DateFormat format = new SimpleDateFormat("yyyy-MM-dd");
		Date recorDate = format.parse(date);
		Calendar cal = Calendar.getInstance();
		cal.setTime(recorDate);
		if (cal.get(Calendar.DAY_OF_WEEK) == Calendar.SATURDAY || cal.get(Calendar.DAY_OF_WEEK) == Calendar.SUNDAY) {
			cal.set(Calendar.DATE, cal.get(Calendar.DAY_OF_MONTH)+1);
			recorDate = cal.getTime();
			date = format.format(recorDate);
			return isWeekendOrHolidaySub(date);
		}
		return date;
	}