//CalendarTest.java
import java.util.*;

public class CalendarTest
{  
   public static void main(String[] args)
   {  
      GregorianCalendar d = new GregorianCalendar();//定義d作為當前日期
      int today = d.get(Calendar.DAY_OF_MONTH);
      int month = d.get(Calendar.MONTH);
      d.set(Calendar.DAY_OF_MONTH, 1);// 設置當前日期d開始月份
      int weekday = d.get(Calendar.DAY_OF_WEEK);
      System.out.println("Sun Mon Tue Wed Thu Fri Sat");//打印日歷頭
      for (int i = Calendar.SUNDAY; i < weekday; i++ )//縮排日歷
         System.out.print("    ");
      do
      {  
         int day = d.get(Calendar.DAY_OF_MONTH);// 打印天
         if (day < 10) System.out.print(" ");
         System.out.print(day);
         if (day == today)// 做當前天的標記 *
            System.out.print("* ");
         else
            System.out.print("  ");
         if (weekday == Calendar.SATURDAY)// 逢星期六開始一個新的行
            System.out.println();
         d.add(Calendar.DAY_OF_MONTH, 1);//增加 d 到下一天
         weekday = d.get(Calendar.DAY_OF_WEEK);
      } 
      while (d.get(Calendar.MONTH) == month);
      if (weekday != Calendar.SUNDAY) // 當d 是下個月的第一天退出循環
         System.out.println();
   }
}