Java控制台日历小程序

朱雀 2022-12-03 02:22 176阅读 0赞

package calendar;
    
    import java.text.SimpleDateFormat;
    import java.util.Date;
    import java.util.Scanner;
    
    public class CalendarPojo {
    
        public static void main(String[] args) {
    
            Date date = new Date();
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
            String dateStr = sdf.format(date);
            Integer subYear = Integer.parseInt(dateStr.substring(0, 4)); // 截取年份
            Integer subMonth = Integer.parseInt(dateStr.substring(5, 7)); // 截取月份
            Integer subDay = Integer.parseInt(dateStr.substring(8, 10)); // 截取日号
            System.out.println("当前系统日期：" + subYear + "年" + subMonth + "月" + subDay + "日");
    
            Scanner sc = new Scanner(System.in);
            System.out.print("\n请输入年份：");
            int year = sc.nextInt();
            if (year < 1900 || year > subYear) {
                while (true) {
                    System.out.println("提示：请规范输入年份，年份只能在1900~" + subYear + "之间！");
                    System.out.print("请输入年份：");
                    year = sc.nextInt();
                    if (year >= 1900 && year <= subYear) {
                        break;
                    }
                }
            }
            System.out.print("\n请输入月份：");
            int month = sc.nextInt();
            if (month < 0 || month > 12) {
                while (true) {
                    System.out.println("提示：请规范输入月份，年份只能在1~12之间！");
                    System.out.print("请输入月份：");
                    month = sc.nextInt();
                    if (month > 0 && month <= 12) {
                        break;
                    }
                }
            }
            int sumDay = 0; // 天数累加
    
            // 闰年平年判断
            for (int i = 1900; i < year; i++) {
                if (i % 4 == 0 && i % 100 != 0 || i % 400 == 0) {
                    sumDay += 366;
                } else {
                    sumDay += 365;
                }
            }
    
            // 月份天数
            for (int i = 1; i < month; i++) {
                if (i == 2) {
                    if (i % 4 == 0 && i % 100 != 0 || i % 400 == 0) {
                        sumDay += 29;
                    } else {
                        sumDay += 28;
                    }
                } else if (i == 4 || i == 6 || i == 9 || i == 11) {
                    sumDay += 30;
                } else {
                    sumDay += 31;
                }
            }
    
            // 天数打印判断
            sumDay += 1; // 总天数加1(当月1号)
            int week = sumDay % 7; // 计算1号是星期几
            int monthDay = 0;
            for (int i = 1; i <= 12; i++) {
                if (month == 2) {
                    if (i % 4 == 0 && i % 100 != 0 || i % 400 == 0) {
                        monthDay = 29;
                    } else {
                        monthDay = 28;
                    }
                } else if (month == 4 || month == 6 || month == 9 || month == 11) {
                    monthDay = 30;
                } else {
                    monthDay = 31;
                }
            }
    
            // 打印排版
            System.out.println("\n----------" + year + "年" + month + "月----------");
            System.out.println("日\t一\t二\t三\t四\t五\t六");
            for (int i = 0; i < week; i++) {
                System.out.print("\t");
            }
            for (int i = 1; i <= monthDay; i++) {
                if (sumDay % 7 == 0) {
                    System.out.println();
                }
                if (i < 10) {
                    System.out.print("0" + i + "\t");
                } else {
                    System.out.print(i + "\t");
                }
                sumDay += 1;
            }
    
        }
    
    }