打印日历

import java.util.Scanner;
public class PrintCalendar {
    public static void main(String[] args){
        Scanner input = new Scanner(System.in);
        System.out.print("Enter full year(eg.2012): ");
        int year = input.nextInt();
        System.out.print("Enter month as number between 1 and 12: ");
        int month = input.nextInt();
        printMonth(year,month);
    }
    public static void printMonth(int year, int month){
        printMonthTitle(year,month);
        printMonthBody(year,month);
    }
    public static void printMonthTitle(int year,int month){
        String monthName = getMonthName( month);
        System.out.println("        "+monthName+" "+year+"        ");
        System.out.println("----------------------------");
        System.out.println(" Sun Mon Tue Wed Thu Fri Sat");
    }
    public static void printMonthBody(int year, int month){
        int startDay = getStartDay(year, month);
        int numberInMonth = getNumberOfDaysInMonth(year,month);
        System.out.println("startDays: "+startDay);
        for(int i=0;i<startDay;i++)
            System.out.print("    ");
        for(int i=1;i<=numberInMonth;i++){
            System.out.printf("%4d",i);
            if((i+startDay)%7==0)
                System.out.println();
        }
        System.out.println();
    }
    public static String getMonthName(int month){
        String monthName = "";
        switch (month){
            case 1: monthName+="January";break;
            case 2: monthName+="February";break;
            case 3: monthName+="March";break;
            case 4: monthName+="April";break;
            case 5: monthName+="May";break;
            case 6: monthName+="June";break;
            case 7: monthName+="July";break;
            case 8: monthName+="August";break;
            case 9: monthName+="September";break;
            case 10: monthName+="October";break;
            case 11: monthName+="November";break;
            case 12: monthName+="December";break;            
        }
        return monthName;
    }
    public static int getStartDay(int year, int month){
        final int START_DAY_FOR_JAN_1_1800 = 3;
        int toatlNumber = getTotalNumberOfDays(year,month);
        System.out.println("totalNumber: "+toatlNumber);
        return (toatlNumber + START_DAY_FOR_JAN_1_1800)%7;   
    }
    public static int getTotalNumberOfDays(int year,int month){
        int totalNumber = 0;
        for (int i=1800;i<year;i++){
            if (isLeapYear(year))
                totalNumber += 366;
            else
                totalNumber += 365;
        }
        for (int j=1;j<month;j++)
            totalNumber += getNumberOfDaysInMonth(year,j);        
        return totalNumber;
    }
    public static int getNumberOfDaysInMonth(int year,int month){
        int numberOfMonth=0;
        if(month==1||month==3||month==5||month==7||month==8||month==10||month==12)
            numberOfMonth = 31;
        if(month==2)
            numberOfMonth = isLeapYear(year)?29:28;
        if(month==4||month==6||month==9||month==11)
            numberOfMonth = 30;
        return numberOfMonth;
    }
    public static boolean isLeapYear(int year){
        boolean isLeap = (year%4==0&&year%100!=0)||(year%400==0);
        return isLeap;
    }
}