给定两个日期获取时间差(天时分秒)

String fromDate = "2013-04-16 08:29:12";
        String toDate = "2013-04-20 09:44:29";
        DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        try {
            //前的时间 
            Date fd = df.parse(fromDate);
            //后的时间
            Date td = df.parse(toDate);
            //两时间差,精确到毫秒 
            long diff = td.getTime() - fd.getTime();
            long day = diff / 86400000;                         //以天数为单位取整
            long hour= diff % 86400000 / 3600000;               //以小时为单位取整
            long min = diff % 86400000 % 3600000 / 60000;       //以分钟为单位取整
            long seconds = diff % 86400000 % 3600000 % 60000 / 1000;   //以秒为单位取整
            //天时分秒
            System.out.println("两时间差---> " +day+"天"+hour+"小时"+min+"分"+seconds+"秒");            
        } catch (ParseException e) {
            e.printStackTrace();
        }

 结果：两时间差---> 4天1小时15分17秒