calender.java

简单的日历程序

import javax.swing.*;

public class Calender{
	public static void main(String args[]){
		String strYear,strMonth;
		int year,month;
		strYear = JOptionPane.showInputDialog(null,"请输入年份：");
		strMonth = JOptionPane.showInputDialog(null,"请输入月份：");
		year = Integer.parseInt(strYear);
		month = Integer.parseInt(strMonth);
		
		printTitle(month,year);
		printBody(month,year);
	}
	public static void printTitle(int month,int year){
		System.out.println(getMonth(month)+" "+year);
		System.out.println("---------------------------");
		System.out.println("Sun"+" "+"Mon"+" "+"Tue"+" "+"Wen"+" "+"Tur"+" "+"Fri"+" "+"Sat");
	}
	public static String getMonth(int month){
		String monthName=" ";
		switch(month){
		case 1:monthName = "Januray";break;
		case 2:monthName = "Febuary";break;
		case 3:monthName = "March";break;
		case 4:monthName = "April";break;
		case 5:monthName = "May";break;
		case 6:monthName = "Jun";break;
		case 7:monthName = "July";break;
		case 8:monthName = "August";break;
		case 9:monthName = "September";break;
		case 10:monthName = "October";break;
		case 11:monthName = "Novomber";break;
		case 12:monthName = "December";break;
		}
		return monthName;
	}
	public static void printBody(int month,int year){
		//return 10;
		int ini = 3; //    1/1/1800
		int totalDay;
		int startDay;
		int monthHasDays=0;    //计算当前月有多少天 
		totalDay = getTotalDay(ini,month,year);
		startDay = (ini+totalDay)%7;
		monthHasDays = getMonthHasDays(month,year);
		JOptionPane.showMessageDialog(null,startDay);
		JOptionPane.showMessageDialog(null,totalDay);
		JOptionPane.showMessageDialog(null,monthHasDays);
		
		for(int i=1;i<=startDay;i++)       //第一天之前打印空格
			System.out.print("    ");
		for(int i=1;i<=monthHasDays;i++){
			if(i<10)
				System.out.print(i+"   ");
			else
				System.out.print(i+"  ");
			if((i+startDay)%7==0) System.out.println("");
		}
	}
	public static int getTotalDay(int ini,int month,int year){
		int totalDay = 0;
		for(int i=1800;i<year;i++){
			if(isLeap(i))
				totalDay += 366;
			else
				totalDay += 365;				
		}
		for(int j=1;j<month;j++){
			totalDay += getMonthHasDays(j,year);
		}
		return 	totalDay;
	}
	public static boolean isLeap(int year){
		if((year%400==0) ||((year%4==0)&&(year%100!=0)))
			return true;
		else 
			return false;
	}
	 public static int getMonthHasDays(int month,int year){
		int monthTotalDay;
		
		if(month==1 ||month==3 ||month==5 ||month==7 ||month==8 ||month==10 ||month==12)
			monthTotalDay = 31;
		else if(month==4 ||month==6 ||month==9 ||month==11)
			monthTotalDay = 30;
		else if(month==2)
			if(isLeap(year))
				monthTotalDay= 29;
			else
				monthTotalDay= 28;
		else 
			monthTotalDay= 0;
			//JOptionPane.showMessageDialog(null,"月份无效！请重新输入");
		return monthTotalDay;
	}
}