时间格式转换

public static void main(String[] args) throws ParseException {
        
        SimpleDateFormat sdf = new SimpleDateFormat("yy-MM-dd HH:mm:ss");// HH:24小时制
        String format2 = sdf.format(new Date());
        System.out.println(format2);//18-03-19 23:01:07
        
        SimpleDateFormat sdf2 = new SimpleDateFormat("yy-MM-dd");
        String str = sdf.format(new Date());//String类型时间：18-03-19 23:01:07
        System.out.println("String类型时间："+str);
        
        Timestamp ts = new Timestamp(new Date().getTime());
        System.out.println("TimeStamp:"+ts);//TimeStamp:2018-03-19 23:01:07.442

       // 将当前时间前移两小时   求前移两小时后的时间
        Long now = System.currentTimeMillis();//18-03-19 23:01:07
        Long time2  = 1000*60*60*2L;//前移两小时
        Long start = now -time2;
        Date date3 = new Date();
        date3.setTime(start);
        String format = sdf.format(date3);
        System.out.println(format);//18-03-19 21:01:07
        
    }