显示2012年之前的月份日历代码

import java.util.Scanner;
public class BookDemo6_12 {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
// 提示输入一个年份
System.out.println(“请输入一个完整的年份（e.g., 2012):”);
int year = input.nextInt();
// 提示输入一个月份
System.out.println(“请输入一个1~12的月份”);
int month = input.nextInt();
// 打印这年这个月的日历的方法
printMonth(year, month);
}
public static void printMonth(int year, int month) {
// 打印日历的标题
printMonthTitle(year, month);
// 打印日历的内容
printMonthBody(year, month);
}
// 显示日历标题的方法
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”);
}
// 获取月份的英文名
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”;
}
return monthName;
}
// 显示日历内容
public static void printMonthBody(int year, int month) {
// 获取这个月最开始的一天是星期几
int startDay = getStartDay(year, month);
// 获取这个月有几天
int numberOfDaysInMonth = getNumberOfDaysInMonth(year, month);
// 打印月份表
int i = 0;
for (i = 0; i < startDay; i++) {
System.out.print(” “);
}
for (i = 1; i <= numberOfDaysInMonth; i++) {
System.out.printf(“%4d”, i);
if ((i + startDay) % 7 == 0) {
System.out.println();
}
}
System.out.println();
}
// 获取这个月的最开始一天是星期几
public static int getStartDay(int year, int month) {
// 1800年一月一日是星期三
final int START_DAY_FOR_JAN_1_1800 = 3;
// 获取1800年1月1日和输入月份相差的总天数
int totalNumberOfDays = getTotalNumberOfDays(year, month);
// 返回这年这个月的第一天是星期几
return (totalNumberOfDays + START_DAY_FOR_JAN_1_1800) % 7;
}
// 获取相差总天数的方法
public static int getTotalNumberOfDays(int year, int month) {
int total = 0;
// 获取相差天数
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;
}
// 获取这个月有几天的方法 31 30 29 28
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 == 9 || month == 9 || month == 11) {
return 30;
}
if (month == 2) {
return isLeapYear(year) ? 29 : 28;
}
return 0;
}
// 判断是否为闰年的方法
public static boolean isLeapYear(int year) {
return year % 400 == 0 || (year % 4 == 0 && year % 100 != 0);
}
}