Java实现简单的万年历

????????????Java??:

import java.util.Scanner;
public class Calendar {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.print("?????:");
int year = scanner.nextInt();
System.out.print("?????:");
int month = scanner.nextInt();
printCalendar(year, month);
}
public static void printCalendar(int year, int month) {
// ??????????????
int firstDayOfWeek = getFirstDayOfWeek(year, month);
// ????
System.out.println(" ?  ?  ?  ?  ?  ?  ?");
// ????
for (int i = 0; i < firstDayOfWeek; i++) {
System.out.print("    ");
}
// ????
int daysInMonth = getDaysInMonth(year, month);
for (int i = 1; i <= daysInMonth; i++) {
System.out.printf("= ", i);
if ((i + firstDayOfWeek) % 7 == 0) {
System.out.println();
}
}
}
public static int getFirstDayOfWeek(int year, int month) {
int totalDays = 0;
// ???1900?1?1??????????
for (int i = 1900; i < year; i++) {
totalDays += isLeapYear(i) ? 366 : 365;
}
for (int i = 1; i < month; i++) {
totalDays += getDaysInMonth(year, i);
}
// ??????????????
return (totalDays + 1) % 7;
}
public static boolean isLeapYear(int year) {
return (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0);
}
public static int getDaysInMonth(int year, int month) {
if (month == 2) {
return isLeapYear(year) ? 29 : 28;
} else if (month == 4 || month == 6 || month == 9 || month == 11) {
return 30;
} else {
return 31;
}
}
}

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