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(e.g. 2001)");int year=input.nextInt();System.out.print("Enter month in 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){System.out.println("     "+getMonthName(month)+"     "+year);System.out.println("-------------------------");System.out.println(" Sun Mon Tue Wed Thu Fri Sat");}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="Octomber";break;case 11:monthName="Novemver";break;case 12:monthName="December";break;}return monthName;}public static void printMonthBody(int year,int month){int startDay=getStartDay(year,month);int numberOfDaysInMonth=getNumberOfDaysInMonth(year,month);int i=0;for(i=0;i<startDay;i++)System.out.print("    ");for(i=0;i<numberOfDaysInMonth;i++){System.out.printf("%4d",i+1);if((i+startDay+1)%7==0)System.out.println();}}public static int getStartDay(int year,int month){final int START_DAY_FOR_JAN_1_1800=3;int totalNumberOfDays=getTotalNumberOfDays(year,month);return ((totalNumberOfDays+START_DAY_FOR_JAN_1_1800)%7);}public static int getTotalNumberOfDays(int year,int month){int total=0;for(int i=1800;i<year;i++)if(isLeapYear(i))total+=366;elsetotal+=365;for(int i=1;i<month;i++){total+=getNumberOfDaysInMonth(year,i);}return total;}public static int getNumberOfDaysInMonth(int year,int month){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;//如果月份不正确则会返回0}public static boolean isLeapYear(int year){return (year%400==0||(year%4==0&&year%100!=0));}}