java - 如何在java中更新小时？

Question

我用java做了一个显示当前时间的时钟。我会确保时钟都以一分钟的间隔更新，从而更新控制台中的结果。我阅读使用线程，但我对这个主题不是很了解，谁能帮助我实现它？

import java.util.*;

public class Current
{
  public static void main(String[] args)
  {
      Calendar calendar = new GregorianCalendar();
      String hour;
      int time = calendar.get(Calendar.HOUR);
      int m = calendar.get(Calendar.MINUTE);
      int sec = calendar.get(Calendar.SECOND);

      if(calendar.get(Calendar.AM_PM) == 0)
          hour = "A.M.";
      else
          hour = "P.M.";
      System.out.println(time + ":" + m + ":" + sec + " " + hour);
  }
  }

     class Data
     {
     public static void main(String[] args)
     {
     Calendar cal = new GregorianCalendar();
     int day = cal.get(Calendar.DAY_OF_MONTH);
     int month = cal.get(Calendar.MONTH);
     int year = cal.get(Calendar.YEAR);
     System.out.println(day + "-" + (month + 1) + "-" + year);
     }
     }

Answer 1

public static void main(String[] args) {
    while (true) {
        try {
            Thread.sleep(60*1000); //one minute

            Calendar calendar = new GregorianCalendar();
            String hour;
            int time = calendar.get(Calendar.HOUR);
            int m = calendar.get(Calendar.MINUTE);
            int sec = calendar.get(Calendar.SECOND);

            if(calendar.get(Calendar.AM_PM) == 0)
                hour = "A.M.";
            else
                hour = "P.M.";
            System.out.println(time + ":" + m + ":" + sec + " " + hour);

        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}