题目：输入某年某月某日，判断这一天是这一年的第几天？ Java 源代码 东海陈光剑

/**
 * @author 东海 陈光剑  chenguangjian 2013-4-1下午09:24:06
 * Email: [e-mail]
 * Blog:  http://blog.sina.com.cn/universsky11
 *        http://blog.csdn.net/universsky
 */
package iSword;

/**
 * @author 东海 陈光剑  chenguangjian 2013-4-1下午09:24:06
 * Email: [e-mail]
 * Blog:  http://blog.sina.com.cn/universsky11
 *        http://blog.csdn.net/universsky
 */
import java.util.*;
public class count_days {

	/**
	 * @author 东海 陈光剑  chenguangjian 2013-4-1下午09:24:06
	 * Email: [e-mail]
	 * Blog:  http://blog.sina.com.cn/universsky11
	 *        http://blog.csdn.net/universsky
	 */
	
	public static void main(String[] args) {
	     int year, month, day;
	     int days = 0;
	     int d = 0;
	     int e;
	     input ymd = new input();
	     do {
	     e = 0;
	     System.out.print("输入年：");
	     year =ymd.input();
	     System.out.print("输入月：");
	     month = ymd.input();
	     System.out.print("输入天：");
	     day = ymd.input();
	     if (year < 0 || month < 0 || month > 12 || day < 0 || day > 31) {
	     System.out.println("输入错误，请重新输入！");
	     e=1 ; 
	     }
	     }while( e==1);
	      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;
	      }
	      d += days;
	      }
	     System.out.println(year + "-" + month + "-" + day + "是这年的第" + (d+day) + "天。");
	}
	}



	class input{
		
	public int input() {
	     int value = 0;
	     Scanner s = new Scanner(System.in);
	     value = s.nextInt();
	     return value;
	}
	
}