GregorianCalendar类的应用——当前月日历打印

 1 import java.text.DateFormatSymbols;
 2 import java.util.Calendar;
 3 import java.util.GregorianCalendar;
 4 import java.util.Locale;
 5 
 6 public class CalenderTest {
 7 
 8     /**
 9      * 本程序是打印一个当前月历的示例
      * 
      * @Version 1.6 2009/10/7
      * @author Eduardo
      */
     public static void main(String[] args) {
         //将本地区设置为美国地区,为了输出英文星期格式
         Locale.setDefault(Locale.US);
         //构造一个日历对象
         GregorianCalendar d = new GregorianCalendar();
         
         int today =d.get(Calendar.DAY_OF_MONTH);//today为获取当前的日
         int month=d.get(Calendar.MONTH);//month为获取当前的月
         //将d设置为本月1号
         d.set(Calendar.DAY_OF_MONTH,1);
         
         int weekday=d.get(Calendar.DAY_OF_WEEK);//weekday为获取本月1号为星期几
         //firstDayOfWeek为获取本地区的起始日
         int firstDayOfWeek=d.getFirstDayOfWeek();
         
         /*进行缩进,将日历对象的日减一,知道一个星期的第一天位置*/
         int indent=0;//记录缩进几次
         while(weekday!=firstDayOfWeek)
         {
             indent++;
             d.add(Calendar.DAY_OF_MONTH, -1);//当前日期提前一天
             weekday=d.get(Calendar.DAY_OF_WEEK);//获取当前日期为星期几
         }
         
         /*打印星期缩写字符串*/
         String[] weekdayNames=new DateFormatSymbols().getShortWeekdays();//输出表示星期的方式为缩写
         do
         {
             System.out.printf("%4s",weekdayNames[weekday]);
             d.add(Calendar.DAY_OF_MONTH,1);//日期增1移动
             weekday=d.get(Calendar.DAY_OF_WEEK);//获取当前日期为星期几
         }
         while(weekday!=firstDayOfWeek);
         System.out.println();
 
         /*本月1号前的日期补位空格*/
         for(int i=1;i<=indent;i++)
             System.out.print("    ");
         
         /*进行打印日期,当日日期后用*注释,直到d进入下一个月停止打印*/
         d.set(Calendar.DAY_OF_MONTH, 1);//将d设置为本月1号        
         do
         {
             int day=d.get(Calendar.DAY_OF_MONTH);
             System.out.printf("%3d", day);
             
             if(day==today)System.out.print("*");
             else System.out.print(" ");
             
             d.add(Calendar.DAY_OF_MONTH, 1);
             weekday=d.get(Calendar.DAY_OF_WEEK);
             if(weekday==firstDayOfWeek)System.out.println();//weekday为星期的第一天则换行打印
         }
         while(d.get(Calendar.MONTH)==month);
         
         if(weekday!=firstDayOfWeek)System.out.println();
     
     }
 
 }
 

 样例输出：