java中如何將String類型的日期轉換成數值及計算

             Date date = new Date();
             DateFormat format;
                      format = DateFormat.getDateInstance(DateFormat.MEDIUM, Locale.CHINA);
                      String nowdate = format.format(date); 
                      SimpleDateFormat datetemp = new SimpleDateFormat("yyyy-MM-dd");
                      Date temp1 = datetemp.parse(nowdate);
                      Date temp2 = datetemp.parse("2007-05-19"); 

            int sec = temp1.getTime()-temp2.getTime();

得到的sec是微秒值，如果想得到差距的天數，請將 sec/1000/60/60/24即可。