java从键盘输入年份和月份， 输出该月份的日历表：

以下是一个简单的 Java 代码，可以从键盘输入年份和月份，输出该月份的日历表。

import java.util.Scanner;

public class Calendar {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("请输入年份：");
        int year = scanner.nextInt();
        System.out.print("请输入月份：");
        int month = scanner.nextInt();
        printCalendar(year, month);
    }

    public static void printCalendar(int year, int month) {
        int days = getDaysOfMonth(year, month);
        int firstDayOfWeek = getFirstDayOfWeek(year, month);
        System.out.println("日 一 二 三 四 五 六");
        for (int i = 1; i <= days; i++) {
            if (i == 1) {
                for (int j = 0; j < firstDayOfWeek; j++) {
                    System.out.print("   ");
                }
            }
            System.out.printf("%2d ", i);
            if ((i + firstDayOfWeek) % 7 == 0) {
                System.out.println();
            }
        }
    }

    public static int getDaysOfMonth(int year, int month) {
        int[] daysOfMonth = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
        if (month == 2 && isLeapYear(year)) {
            return 29;
        }
        return daysOfMonth[month - 1];
    }

    public static int getFirstDayOfWeek(int year, int month) {
        int dayOfWeek = 0;
        for (int i = 1900; i < year; i++) {
            dayOfWeek = (dayOfWeek + 365 + (isLeapYear(i) ? 1 : 0)) % 7;
        }
        for (int i = 1; i < month; i++) {
            dayOfWeek = (dayOfWeek + getDaysOfMonth(year, i)) % 7;
        }
        return dayOfWeek;
    }

    public static boolean isLeapYear(int year) {
        return year % 4 == 0 && year % 100 != 0 || year % 400 == 0;
    }
}

运行上述代码后，会提示输入年份和月份，输入后即可输出该月份的日历表。