Date类

import java.util.*;

/*
两个练习：
1，获取任意年的二月有多少天。
    思路：根据指定年设置一个时间就是 
    c.set(year,2,1)//某一年的3月1日。
    c.add(Calenar.DAY_OF_MONTH,-1);//3月1日，往前推一天，就是2月最后一天。



2，获取昨天的现在这个时刻。
    c.add(Calenar.DAY_OF_MONTH,-1);


*/


class  CalendarDemo2
{
    public static void main(String[] args) 
    {

        Calendar c = Calendar.getInstance();

        //c.set(2012,2,23);

        c.add(Calendar.DAY_OF_MONTH,-18);
        
        printCalendar(c);
    }

    public static void printCalendar(Calendar c)
    {
        String[] mons = {"一月","二月","三月","四月"
                    ,"五月","六月","七月","八月"
                    ,"九月","十月","十一月","十二月"};


        String[] weeks = {
                        "","星期日","星期一","星期二","星期三","星期四","星期五","星期六",
                            };        
        int index = c.get(Calendar.MONTH);

        int index1 = c.get(Calendar.DAY_OF_WEEK);

        sop(c.get(Calendar.YEAR)+"年");
        //sop((c.get(Calendar.MONTH)+1)+"月");
        sop(mons[index]);
        sop(c.get(Calendar.DAY_OF_MONTH)+"日");
        //sop("星期"+c.get(Calendar.DAY_OF_WEEK));
        sop(weeks[index1]);
    }
    public static void sop(Object obj)
    {
        System.out.println(obj);
    }
}