System.currentTimeMillis() 返回从GMT 1970年1月1日00:00:00开始到当前时刻的毫秒数
时间戳是时间开始计时的点,因为1970年是UNIX操作系统正式发布的时间,所以也称 UNIX时间戳(UNIX epoch)
public class ShowCurrentTime {// 显示当前时间
public static void main(String[] arg) {
long totalMilliseconds = System.currentTimeMillis();
long totalSeconds = totalMilliseconds / 1000;
long currentSecond = totalSeconds % 60;
long totalMinutes = totalSeconds / 60;
long currentMinute = totalMinutes % 60;
long totalHours = totalMinutes / 60;
long currentHour = totalHours % 24;
System.out.println("Current time is " + currentHour + " : " + currentMinute + " : " + currentSecond + " GMT");
}
}