java 日期转换

SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");        String start="2014-01-01 00:00:00";        long now = 0;        long times =0;        try {            now = times = sdf.parse(start).getTime();        } catch (ParseException e1) {            // TODO Auto-generated catch block            e1.printStackTrace();        }        System.out.println(times);         Date dNow=new Date(1389254798000L);         System.out.println("日期类型："+dNow.getTime());         System.out.println("日期类型："+dNow);

long sd=1389254798000L;//1389211598000//1389254798000Date dat=new Date(sd);  GregorianCalendar gc = new GregorianCalendar();   gc.setTime(dat);  java.text.SimpleDateFormat format = new java.text.SimpleDateFormat("yyyy-MM-dd hh:mm:ss");  String sb=format.format(gc.getTime());  System.out.println(sb);System.out.println("========^^^^^^^^^^^^^^^^^^^^======");

两种转换方式