日期与毫秒互转

// 日期转毫秒
SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddhhmmss");
long millionSeconds = sdf.parse("20120809030000").getTime();//毫秒
System.out.println(millionSeconds);

// 毫秒转日期
Calendar c = Calendar.getInstance();
c.setTimeInMillis(millionSeconds);
Date date = c.getTime();
System.out.println(sdf.format(date));