在java中輸入某年某月，判斷這一天是這一年的第多少天

對於這個問題，首先應該想到的閏年和非年年的之間的差別，基月和偶月的之間的差別，

具體看看程式設計怎麼實現把：

package excise;

import java.util.Scanner;

public class T011 {
	public static void main(String args[]) {
		boolean b = true;
		while (b) {
			System.out.println("請輸入年份：");
			Scanner s = new Scanner(System.in);
			long date = s.nextLong();
			String string_year = String.valueOf(date);
			int year = Integer.parseInt(string_year.substring(0, 4));
			int month = Integer.parseInt(string_year.substring(4, 6));
			int day = Integer.parseInt(string_year.substring(6));

			if ((month < 1 || month > 12) || (day < 1 || day > 31)) {
				System.out.println("輸入年份有錯誤，請重新輸入");
				b = true;

			} else {
				System.out.println("年份輸入正確");
				b = false;
				System.out.println("輸入的年份"+date+"是該年的第"+caculate(year,month,day)+"天");
			}
		}
		
	}
	
	public static int caculate(int year,int month,int day){
		int days = 0;
		for(int i=1;i<month;i++){
			switch(i){
			case 1:
			case 3:
			case 5:
			case 7:
			case 8:
			case 10:
			case 12:
			   days=31;
			   break;
			case 4:
			case 6:
			case 9:
			case 11:
			 days=30;
			break;
			case 2:
				if((year%400==0)||(year%4==0)||(year%100!=0)){
					days=29;
				}else{
					days=28;
				}
				break;
			default:
				break;
			}
			day+=days;
			
		}
		return day;
	}

}