java实现1.编写一个程序，程序提供两种功能:1)根据用户输入的年份输出该年日历。2) 根据用户输入的日期，输出该天星期。 程序应具有良好的人机交互性能，即:程序应向用户提示功能说明，并可根据用户的功能选择，执行对应的功能，并给出带详细描述信息的最终执行结果。

ChatGPT: 您好！这是一个很有趣的问题。以下是我提供的 Java 代码，可以实现您所需的两种功能：

import java.util.Scanner;

public class CalendarProgram {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("欢迎使用日历程序！");
        System.out.println("请选择您需要的功能：");
        System.out.println("1. 根据年份输出日历");
        System.out.println("2. 根据日期输出星期");
        int choice = scanner.nextInt();
        if (choice == 1) {
            System.out.println("请输入年份：");
            int year = scanner.nextInt();
            printCalendar(year);
        } else if (choice == 2) {
            System.out.println("请输入日期（格式为yyyy-MM-dd）：");
            String date = scanner.next();
            printWeekday(date);
        } else {
            System.out.println("输入错误，请重新运行程序！");
        }
    }

    public static void printCalendar(int year) {
        System.out.println(year + "年的日历如下：");
        for (int month = 1; month <= 12; month++) {
            System.out.println("--------" + year + "年" + month + "月" + "--------");
            System.out.println("日\t一\t二\t三\t四\t五\t六");
            int days = getDaysOfMonth(year, month);
            int firstDayOfWeek = getFirstDayOfWeek(year, month);
            for (int i = 1; i <= days; i++) {
                if (i == 1) {
                    for (int j = 0; j < firstDayOfWeek; j++) {
                        System.out.print("\t");
                    }
                }
                System.out.print(i + "\t");
                if ((i + firstDayOfWeek) % 7 == 0) {
                    System.out.println();
                }
            }
            System.out.println();
        }
    }

    public static void printWeekday(String date) {
        String[] dateArray = date.split("-");
        int year = Integer.parseInt(dateArray[0]);
        int month = Integer.parseInt(dateArray[1]);
        int day = Integer.parseInt(dateArray[2]);
        int weekday = getWeekday(year, month, day);
        String[] weekdays = {"周日", "周一", "周二", "周三", "周四", "周五", "周六"};
        System.out.println(date + "是" + weekdays[weekday] + "。");
    }

    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;
        } else {
            return daysOfMonth[month - 1];
        }
    }

    public static int getFirstDayOfWeek(int year, int month) {
        int day = 1;
        for (int i = 1900; i < year; i++) {
            if (isLeapYear(i)) {
                day += 366;
            } else {
                day += 365;
            }
        }
        for (int i = 1; i < month; i++) {
            day += getDaysOfMonth(year, i);
        }
        return (day - 1) % 7;
    }

    public static int getWeekday(int year, int month, int day) {
        int firstDayOfWeek = getFirstDayOfWeek(year, month);
        int days = 0;
        for (int i = 1; i < day; i++) {
            days++;
            if ((firstDayOfWeek + days) % 7 == 0) {
                days = 0;
            }
        }
        return (firstDayOfWeek + days) % 7;
    }

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

这个程序可以根据用户输入的年份输出该年的日历，或者根据用户输入的日期输出该天是星期几。程序会提示用户选择功能，并根据用户的选择执行对应的功能。如果您有任何问题，请随时问我！