Java基础IO输入输出04

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Calendar对象

导语：

学习的目的：不是掌握对象的方法，而是要学会如何使用API、如何使用API中的对象实现一些小功能，方法只需简单记下用什么对象就可以了。

类Calendar

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/*
Calendar对象
另请参见：
DateFormat、Calendar、TimeZone
*/
import java.util.*;
import java.text.*;
class CalendarDemo {
    public static void main(String[] args){
        
        //方法一：
        Date d = new Date();
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy");
        String year =  sdf.format(d);//返回的是字符串，我想加一年或减一年比较麻烦
        System.out.println(year);
        
        //方法二：
        Calendar c = Calendar.getInstance();
        
        //用查表法来改写
        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"};
        int index = c.get(Calendar.MONTH);
        
        String[] weeks = {"","星期一","星期二","星期三","星期四","星期五","星期六","星期日"};
        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]);
        
        //一些方法
        Calendar c1 = Calendar.getInstance();
        //c1.set(2012,2,23);
        //时间量的偏移
        c1.add(Calendar.YEAR,4);//加4年
        printCalendar(c1);
    }
    
    public static void sop(Object obj){
        System.out.println(obj);
    }
    
    public static void printCalendar(Calendar c){
        //用查表法来改写
                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"};
                int index = c.get(Calendar.MONTH);
                
                String[] weeks = {"","星期一","星期二","星期三","星期四","星期五","星期六","星期日"};
                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]);
    }
}