敲了一下午，代码比较乱，思路也比较乱，第一次敲这么长的java代码，总结起来就是欠练！！

package homework;

import java.io.*;

import java.lang.*;

import java.util.Scanner;

import java.util.*;

class year{

year_month_day m=new year_month_day();

void set(int y){

m.year=y;    m.day=1;

}

void year_method(){

int i=1;

for(i=1;i<=12;i++){

System.out.println(+m.year+"年" +i+"月");

m.month=i;   m.print();

}

}

}

class year_month_day{

int itag=0;

int year,month,day;

void set(int y,int m,int d)     {

year=y;      month=m;      day=d;     }

public int  isLeepyear(int year)     {

int m;

if((this.year % 4 == 0 && this.year % 100 != 0) || this.year % 400 == 0)

m=1;

else         m=0;

return m;    }

void print(){

itag=isLeepyear(year);

Calendar rili=Calendar.getInstance();

rili.set(year, month-1, 1);

System.out.println("日\t一\t 二\t 三\t 四\t 五\t 六");

int week=rili.get(Calendar.DAY_OF_WEEK)-1;

//System.out.println("week="+week);

String a[]=new String[week+31];

for(int i=0;i     {

a[i]="**";     }

int num=0;

if(itag==1&&month==2)

num=29;

else if(itag==0&&month==2)

num=28;

else if(month==1||month==3||month==5||month==7||month==8||month==10||month==12)

num=31;

else num=30;

for(int i=week,n=1;i ++)

{

if(n<9)       a[i]=String.valueOf(n)+" ";

else       a[i]=String.valueOf(n);      n++;

}

for(int i=0;i ++)

if(i%7==0){

System.out.println("");      }

if(a[i]==null)

a[i]=" ";

System.out.print(a[i]+"\t");     }

System.out.print("\n\n");    }  }

public class year_calendar {

public static void main(String[] args)

System.out.println("**************************");

System.out.println("*         中华万年历                   *");

System.out.println("*       请选择查询方法                 *");

System.out.println("*1.按年份检索      2.按年月日检索   *");

System.out.println("*3.退出系统                                        *");

System.out.println("**************************");

int n;   int year,month,day;

Scanner s = new Scanner(System.in);

n=s.nextInt();

switch(n){

case 1:         {

System.out.println("请输入要检索的年份:");

year=s.nextInt();

year d=new year();

d.set(year);

d.year_method();         break;           }

case 2:   {

System.out.println("请输入要检索的年月日:");

year=s.nextInt();

month=s.nextInt();

day=s.nextInt();

year_month_day t=new year_month_day();

t.set(year, month, day);

t.print();     break;   }

case 3:break;

}

}

}