计算某个日期是一年中的第几天

public static void main(String[] args) {
	
	System.out.println("接收用户输入一个月份和一个日期，计算出是一年当中的第几天");
	System.out.println("\t输入月份后，按下回车，在输入日期");
	System.out.println("\n请输入4位年数字");
	
	while (true) {
		int x;
		int day = 0;
		int cal = 0;
		Scanner scanner = new Scanner(System.in);
		int year = scanner.nextInt();
		boolean leapYear = isLeapYear(year);
		System.out.println("请输入月份：");
		int month = scanner.nextInt();
		
		// 闰年2月29天
		if (month == 2 && leapYear) {
			System.out.println("请输入日期：");
			day = scanner.nextInt();
			while (day > 29 || day < 1) {
				System.out.println("输入有误，重新输入日期：");
				x = scanner.nextInt();
				day = x;
			}
		}
		
		// 平年2月28天
		if (month == 2 && !leapYear) {
			System.out.println("请输入日期：");
			day = scanner.nextInt();
			while (day > 28 || day < 1) {
				System.out.println("输入有误，重新输入日期：");
				x = scanner.nextInt();
				day = x;
			}
		}
		
		if (month % 2 != 0) {
			System.out.println("请输入日期：");
			day = scanner.nextInt();
			while (day > 31 || day < 1) {
				System.out.println("输入有误，重新输入日期：");
				x = scanner.nextInt();
				day = x;
			}
		}
		
		if (month != 2 && month % 2 == 0) {
			System.out.println("请输入日期：");
			day = scanner.nextInt();
			while (day > 30 || day < 1) {
				System.out.println("输入有误，重新输入日期：");
				x = scanner.nextInt();
				day = x;
			}
		}
		System.out.println("你输入的是：" + year + "年" + month + "月" + day + "日");
		cal = getDays(year, month, day);
		System.out.println(year + "年" + month + "月" + day + "日, 是" + year + "中第" + cal + "天");
	}
}

/**
 * 判断是否是闰年
 * 能被4整除且不能被100整除，或者 能被400整除
 * @param year
 * @return
 */
public static boolean isLeapYear(int year) {
		
	boolean leapYear = false;
	if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0) {
		leapYear = true;
	}
	return leapYear;
}

/**
 * 根据年，月，日，计算总天数
 * @param year
 * @param month
 * @return
 */
public static int getDays(int year, int month, int day) {
	
	int arr[] = {31, 28, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30};
	boolean leapYear = isLeapYear(year);
	if (leapYear) {
		arr[1] = 29;
	}
	int sum = 0;
	for (int i = 0; i < month -1; i++) {
		sum += arr[i];
	}
	sum = sum + day;
	return sum;
}
public static void main(String[] args) {