输入某年某月某日，判断这一天是这一年的第几天 Java

以下是Java实现输入某年某月某日，判断这一天是这一年的第几天的代码：

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("请输入年份：");
        int year = scanner.nextInt();
        System.out.print("请输入月份：");
        int month = scanner.nextInt();
        System.out.print("请输入日期：");        int day = scanner.nextInt();
        int sum = 0;
        int[] days = {31,28,31,30,31,30,31,31,30,31,30,31};
        if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0) {
            days[1] = 29;
        }
        for (int i = 0; i < month - 1; i++) {
            sum += days[i];
        }
        sum += day;
        System.out.println(year + "年" + month + "月" + day + "日是这一年的第" + sum + "天。");
    }
}