1573495434 Long Date java 互轉

		Long a = 1447759915523l;
		SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
		Date date= new Date(a);
		String d = df.format(date);
		System.out.println("d = "+d);
		
		/*date轉long*/
		String dd = "2015-11-17 11:31:56";
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");// 2015-06-05 15:02:03
		Date dt = sdf.parse(dd);
		long time = dt.getTime();
		System.out.println("time = "+time);