闰年

3、自定义一方法，用于返回某一年某一月的天数（要求用switch语句实现），即对于给定的年和月计算天数。提示：能被4整除且不能为100整除，或者能被400整除的年是闰年 。

import java.util.*;
import java.io.*;

class Day{ 
 private int year;
 private int month;
  
 Day(int year,int month){
  this.year=year;
  this.month=month;
 }
 
 int getYear(){
  return year;
 }
 
 int getMonth(){
  return month;
 }
 
 boolean isLeapYear(int year){
  if(((year % 4==0) &&(year % 100!=0)) ||(year % 400==0))
   return true;
  else
   return false;
 }
}

class InputData{
 static String s="";
 
 static void input() {
  BufferedReader bu = new BufferedReader(new InputStreamReader(System.in));
     try {
      s = bu.readLine();
     }
     catch (IOException e) {
      
     }
    }
     
    static int getInt() {
     input();
     return Integer.parseInt(s); //将字符组成的字符串s转化为整型数据后返回
   }
}

class DayTest{
 public static void main(String[] args){  
  int year,month;
       
  System.out.print("Input the year:");
  year=InputData.getInt();
  System.out.print("Input the month:");
  month=InputData.getInt();
  
  Day d=new Day(year,month);
  
  switch(d.getMonth())
  {
   case 1:
   case 3:
   case 5: 
   case 7:
   case 8:
   case 10:
   case 12: System.out.println(d.getYear()+"."+d.getMonth()+" has 31 days.");
      break;
   case 4:
   case 6:
   case 9:
   case 11: System.out.println(d.getYear()+"."+d.getMonth()+" has 30 days.");
      break;
   case 2:  if(d.isLeapYear(d.getYear())){
       System.out.println(d.getYear()+"."+d.getMonth()+" has 29 days.");
       break;
      }
      else{
       System.out.println(d.getYear()+"."+d.getMonth()+" has 28 days.");
      break;
      }
   default: System.out.println("Wrong! Please input the right month!");
  } 
 }
}