初学者求大神帮助

菜鸟求大神帮助
import javax.swing.JOptionPane;
public class PC {
  public static void main(String[] args){  
  int option=0;
  do{
  String yearstring=JOptionPane.showInputDialog("请输入一个年份（如：2010）:");
  int year=Integer.parseInt(yearstring);
  String monthstring=JOptionPane.showInputDialog("请输入一个月份（如：8）：");
  int month=Integer.parseInt(monthstring);
  //JOptionPane.showMessageDialog(null,printmonth(year,month));
  System.out.println(printmonth(year,month));
  option=JOptionPane.showConfirmDialog(null,"countinue?");
  }while(option==JOptionPane.YES_OPTION);
  }
  static String printmonth(int year,int month){
  String printmonth=printmonthtitle(year,month);
  printmonth+=printmonthbody(year,month);
  return printmonth;
  }
  static String printmonthtitle(int year,int month){
  String printmonthtitle=" "+year+"年"+getmonthname(month)+"\n";
  printmonthtitle+="----------------------------------\n";
  printmonthtitle+=" SUN MON TUE WED THU FRI SAT \n";
  return printmonthtitle;
  }
  static String getmonthname(int month){
  String monthname=null;
  switch(month){
  case 1:monthname="1月";break;
  case 2:monthname="2月";break;
  case 3:monthname="3月";break;
  case 4:monthname="4月";break;
  case 5:monthname="5月";break;
  case 6:monthname="6月";break;
  case 7:monthname="7月";break;
  case 8:monthname="8月";break;
  case 9:monthname="9月";break;
  case 10:monthname="10月";break;
  case 11:monthname="11月";break;
  case 12:monthname="12月";
  }
  return monthname;
  }
  static String printmonthbody(int year,int month){
  int startday=getstarday(year,month);
  int numberofdaysinmonth=getnumberofdaysinmonth(year,month);
  String printmonthbody="";
  for(int i=0;i<startday;i++)printmonthbody+=" ";
  for(int i=1;i<=numberofdaysinmonth;i++){
  if(i<10)printmonthbody+=" "+i;
  else printmonthbody+=" "+i;
  if((i+startday)%7==0)printmonthbody+="\n";  
  }
  return printmonthbody;
  }
  static int getstarday(int year,int month){
  int stardayof1970=4;
  int totaldays=gettotaldays(year,month);
  return (totaldays+stardayof1970)%7;
  }
  static int gettotaldays(int year,int month){
  int total=0;
  for(int i=1970;i<year;i++){
  if(isleapyear(year))total+=366;
  else total+=365;
  }
  for(int i=1;i<month;i++)total+=getnumberofdaysinmonth(year,month);
  return total;
  }
  static int getnumberofdaysinmonth(int year,int month){
  int numberofdaysinmonth;
  if(month==1||month==3||month==5||month==7||month==8||month==10||month==12)  

numberofdaysinmonth=31;
  else if(month==4||month==6||month==9||month==11)
  numberofdaysinmonth=30;
  else numberofdaysinmonth=(isleapyear(year)?29:28);
  return numberofdaysinmonth;
  }
  static boolean isleapyear(int year){
  return year%400==0||(year%4==0&&year%100!=0);
  }
}

为什么我的输出结果总是与世界结果不同呢？（已知1970年1月1日为星期四，求其后的任意一年的某月的星期情况并图表打印）



[解决办法]
人家原来的代码符号java 命名规范，你改大小写严重影响可读性

Java code

import javax.swing.*;import java.util.Calendar;/** * Created by IntelliJ IDEA. * User: ioe_gaoyong * Date: 2011-9-28 * Time: 0:33:20 * To change this template use File | Settings | File Templates. * 这个类里面要自己设计排布的方法，自己画出一个日历 */public class PC2 {     public static void main(String[] args){        int option=0;        do{            String yearString= JOptionPane.showInputDialog("请输入一个年份（如：2010）:");            int year=Integer.parseInt(yearString);            String monthString=JOptionPane.showInputDialog("请输入一个月份（如：8）：");            int month=Integer.parseInt(monthString);//            JOptionPane.showMessageDialog(null,printMonth(year,month));            System.out.println(year+"年"+month+"月");//            printCalendar(2011,9);            printCalendar(year,month);            option=JOptionPane.showConfirmDialog(null,"countinue?");        }while(option==JOptionPane.YES_OPTION);    }    public static void printCalendar(int year,int month){        String printMonthTitle=" "+year+"年"+month+"月"+"\n";        printMonthTitle+="----------------------------------\n";        printMonthTitle+="SUN\tMON\tTUE\tWED\tTHU\tFRI\tSAT \n";        System.out.println(printMonthTitle);        Calendar c=Calendar.getInstance();        c.set(year,month-1,1);//现在的时间是该月的第一天        int firstDayOfWeek=c.get(Calendar.DAY_OF_WEEK);//这个月的1号是星期几        int sumDays=c.getMaximum(Calendar.DAY_OF_MONTH);//获得这个月总共多少天//        System.out.println(firstDayOfWeek);        for(int i=1;i<firstDayOfWeek;i++){                System.out.print("   \t");        }        if(firstDayOfWeek!=7){            System.out.print(1+"  \t");        }else{            System.out.println(1+"  \t");        }        for(int i=2;i<=sumDays;i++){             c.add(Calendar.DAY_OF_MONTH,1);             if(c.get(Calendar.DAY_OF_WEEK)==7){//如果是星期六                 System.out.println(i);             }else{                 if(i<=8){                     System.out.print(i+"  \t");                 }else{                     System.out.print(i+" \t");                 }             }        }    }    }