（Java）打印指定年月的日曆



日曆如下：

程序如下：

//打印指定年月的日曆
public class PrintCalendar {
	
	public static void main(String[] args) {
		int year=2013;
		int month=12;
		printMonth(year,month);
	}

	private static void printMonth(int year, int month) {//打印日曆
		printMonthTitle(year,month);
		printMonthBody(year,month);
	}

	private static void printMonthTitle(int year, int month) {//打印日曆標題
		System.out.println("      "+getMonthName(month)+" "+year);
		System.out.println("------------------------------");
		System.out.println(" Sun Mon Tue Wed Thu Fri Sat");
	}

	private static String getMonthName(int month) {
		String monthName=null;
		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";
		}
		return monthName;
	}
	
	public static boolean isLeapYear(int year){//判斷是否爲閏年
		return year%400==0||(year%4==0&&year%100!=0);
	}
	
	public static int getNumberOfDaysInMonth(int year,int month){//獲取對應月份天數
		if(month==1||month==3||month==5||month==7||month==8||month==10||month==12)
			return 31;
		if(month==4||month==6||month==9||month==11)
			return 30;
		if(month==2)
			return isLeapYear(year)?29:28;
		return 0;
	}
	
	public static int getTotalNumberOfDays(int year,int month){//獲取從1800年到當月的總天數
		int total=0;
		for(int i=1800;i<year;i++){
			if(isLeapYear(i))
				total=total+366;
			else
				total=total+365;
		}
		for(int i=1;i<month;i++)
			total=total+getNumberOfDaysInMonth(year,i);
		return total;
	}
	
	public static int getStartDay(int year,int month){//獲得當月第一天是星期幾
		int startDay1800=3;
		int totalNumberOfDays=getTotalNumberOfDays(year,month);
		return (totalNumberOfDays+startDay1800)%7;
	}
	
	public static void printMonthBody(int year,int month){//打印日曆體
		int startDay=getStartDay(year,month);
		int numberOfDaysInMonth=getNumberOfDaysInMonth(year,month);
		for(int i=0;i<startDay;i++){
			System.out.print("    ");
		}
		for(int i=1;i<=numberOfDaysInMonth;i++){
			if(i<10)
				System.out.print("   "+i);
			else
				System.out.print("  "+i);
			if((i+startDay)%7==0)
				System.out.println();
		}
		System.out.println();
	}
}