public static void main(String[] args) {
    
    
    //13位的时间戳的三种方式
    long time1 = System.currentTimeMillis();

    long time2 = Calendar.getInstance().getTimeInMillis();

    long time3 = System.currentTimeMillis();

    //10位的时间戳的三种方式
    long time11 = System.currentTimeMillis() / 1000;

    long time12 = Calendar.getInstance().getTimeInMillis() / 1000;

    long time13 = System.currentTimeMillis() / 1000;

    System.out.println("time1:"+time1);
    System.out.println("time2:"+time2);
    System.out.println("time3:"+time3);
    System.out.println("time11:"+time11);
    System.out.println("time12:"+time12);
    System.out.println("time13:"+time13);
}