在java中要比較日期的前後

程式碼如下

				SimpleDateFormat sdf =   new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
				String beginTimeString="2017-03-24 08:00:00";

				String endTimeString="2017-03-27 08:00:00";

				String nowtimeString =sdf.format(new Date());
				Date beginTimeDate = sdf.parse( activitybeginTimeString );
				Date endTimeDate = sdf.parse( activityendTimeString );
				Date nowtimeTimeDate = sdf.parse( nowtimeString );
				System.out.println("活動開始時間"+beginTimeDate);
				System.out.println("活動結束時間"+endTimeDate);
				System.out.println("當前時間"+nowtimeTimeDate);
if ( (nowtimeTimeDate.before(activityendTimeDate))&&((nowtimeTimeDate.after(activitybeginTimeDate))) ){ 
					  System.out.println("活動期內");}else{
System.out.println("活動期外");
}