Java 时间格式转换

貌似java里面么有ToString()的时间类型格式，想格式时间还得自己写个函数

public class SimpleDateFormatDemo {

    public  static String dateToString(Date d,String format){
        return  new SimpleDateFormat(format).format(d);
    }

    public static Date stringToDate(String d,String format) throws ParseException {
        return new SimpleDateFormat(format).parse(d);
    }

    public static void main(String[] args) throws ParseException {
        Scanner scanner = new Scanner(System.in);
        System.out.println("当前日期：" + dateToString(new Date(), "yyyy-MM-dd HH:mm:ss"));
        String birth = scanner.nextLine();
        //计算你活了多少天了
        System.out.println("请输入你的生日,格式yyyy-MM-dd");
        Date date =stringToDate(birth,"yyyy-MM-dd");
        long time=date.getTime(); //获得date的毫秒形式
        long day= (new Date().getTime()-time)/1000/60/60/24;
        System.out.println(day);
    }
}