第一種方法：

/**
	 * 獲取當前日期是星期幾<br>
	 * 
	 * @param date
	 * @return 當前日期是星期幾
	 */
	public String getWeekOfDate(Date date) {
		String[] weekDays = { "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 w = cal.get(Calendar.DAY_OF_WEEK) - 1;
		if (w < 0)
			w = 0;
		return weekDays[w];
	}
 

Date date = new Date();
		SimpleDateFormat dateFm = new SimpleDateFormat("EEEE");
		String currSun = dateFm.format(date);
		System.out.println(currSun);