JAVA編程實現：計算妳的生日還有多少天，妳的生日是星期幾。

import java.util.Calendar;

import java.util.Date;

import java.util.InputMismatchException;

import java.util.Locale;

import java.util.Scanner;

public class Du {

public static void main(String[] args) {

String birthday = null;

while(true){

System.out.println("Please input your birthday in format: (yyyy-MM-dd):");

try{

Scanner scanner = new Scanner(System.in);

birthday = scanner.next("\\d{4}-[01]\\d-[0-3]\\d\\s*");

break;

}catch(InputMismatchException mismatchExp){

System.out.println("Invalid birthday date in format! Date should be in format(yyyy-MM-dd')");

}

}

String[] ary = birthday.trim().split("-");

int year = Integer.parseInt(ary[0]);

int month = Integer.parseInt(ary[1]);

int date = Integer.parseInt(ary[2]);

Calendar calendar = Calendar.getInstance(Locale.US);

calendar.set(Calendar.YEAR, year);

calendar.set(Calendar.MONTH, month-1);

calendar.set(Calendar.DATE, date);

String weekDay = new SimpleDateFormat("E").format(calendar.getTime());

calendar.setTime(new Date());

long now = calendar.getTimeInMillis();

if(calendar.get(Calendar.MONTH)+1 > month){

calendar.add(Calendar.YEAR, 1);

}

calendar.set(Calendar.MONTH, month-1);

calendar.set(Calendar.DATE, date);

long nextBirthMillionSeconds = calendar.getTimeInMillis();

long julianDay = (nextBirthMillionSeconds - now)/(1000*60*60*24);

System.out.println(weekDay);

System.out.println("Only " + julianDay + " left for your birthday");

}

}

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Please input your birthday in format: (yyyy-MM-dd):

1977-09-08

Thu

Only 167 left for your birthday