java Date類型 增加x天與當前時間進行比較

   //java date類型 增加x天與當前時間進行比較
            Date createDate = xxx;
            Calendar cal = Calendar.getInstance();
            cal.setTime(createDate);
            //增加x天
            cal.add(Calendar.DAY_OF_MONTH, 7);
            //Calendar轉爲Date類型
            createDate=cal.getTime();
            Date nowDate = new Date();
            _true = nowDate.compareTo(createDate)<=0;
            boolean before = nowDate.before(createDate);