java关于时间差的计算

关于时间差的计算我总结了一下。

方法一：

DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

try
{
    Date d1 = df.parse("2008-03-26 13:31:40");
    Date d2 = df.parse("2008-01-02 11:30:24");
    long diff = d1.getTime() - d2.getTime();
    long days = diff / (1000 * 60 * 60 * 24);
}
catch (Exception e)
{
}

方法二：
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
   java.util.Date now = df.parse("2008-03-26 13:31:40");
   java.util.Date date=df.parse("2008-01-02 11:30:24");
   long l=now.getTime()-date.getTime();
   long day=l/(24*60*60*1000);
   long hour=(l/(60*60*1000)-day*24);
   long min=((l/(60*1000))-day*24*60-hour*60);
   long s=(l/1000-day*24*60*60-hour*60*60-min*60);
   System.out.println(""+day+"天"+hour+"小时"+min+"分"+s+"秒");

方法三：
SimpleDateFormat dfs = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
   java.util.Date begin=dfs.parse("2008-01-02 11:30:24");
   java.util.Date end = dfs.parse("2008-03-26 13:31:40");
   long between=(end.getTime()-begin.getTime())/1000;//除以1000是为了转换成秒

   long day1=between/(24*3600);
   long hour1=between%(24*3600)/3600;
   long minute1=between%3600/60;
   long second1=between%60/60;
   System.out.println(""+day1+"天"+hour1+"小时"+minute1+"分"+second1+"秒");