java本地时间与UTC时间相互转换

DateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        try {
            Date date = format.parse("2013-03-20 17:47:09");
            System.out.println(date);
            //转换为UTC时间
            System.out.println(date.getTime()/1000);
            //UTC转换为日期
            System.out.println(format.format(new Date(Long.valueOf(1363837989)*1000)));
           
        } catch (ParseException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }