日期

[java]代码库

import java.util.*;
 
/**
 * 判断某日期是这一年的第几天
 * 
 */
public class Demo {
    public static void main(String[] args) {
        int day = 0;
        int month = 0;
        int year = 0;
        int sum = 0;
        int leap;
        System.out.print("请输入年 月 日 （使用空格分开）\n");
        Scanner input = new Scanner(System.in);
        year = input.nextInt();
        month = input.nextInt();
        day = input.nextInt();
        switch (month) /* 先计算某月以前月份的总天数 */
        {
        case 1:
            sum = 0;
            break;
        case 2:
            sum = 31;
            break;
        case 3:
            sum = 59;
            break;
        case 4:
            sum = 90;
            break;
        case 5:
            sum = 120;
            break;
        case 6:
            sum = 151;
            break;
        case 7:
            sum = 181;
            break;
        case 8:
            sum = 212;
            break;
        case 9:
            sum = 243;
            break;
        case 10:
            sum = 273;
            break;
        case 11:
            sum = 304;
            break;
        case 12:
            sum = 334;
            break;
        default:
            System.out.println("data error");
            break;
        }
        sum = sum + day; /* 再加上某天的天数 */
        if (year % 400 == 0 || (year % 4 == 0 && year % 100 != 0))/* 判断是不是闰年 */
            leap = 1;
        else
            leap = 0;
        if (leap == 1 && month > 2)/* 如果是闰年且月份大于2,总天数应该加一天 */
            sum++;
        System.out.println("It is the the day:" + sum);
    }
}