输入某年某月某日，判断这一天是这一年的第几天？

public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
		System.out.println("输入年份：");
		int year = scan.nextInt();
		System.out.println("输入月份：");
		int month = scan.nextInt();
		System.out.println("输入日期：");
		int day = scan.nextInt();
		//判断是否是闰年
		//GregorianCalendar:判断年份是否是闰年的方法
		GregorianCalendar gre = new GregorianCalendar();
		boolean isLeapYear=gre.isLeapYear(year);//返回true:是闰年，false：不是闰年
		
		int ap=isLeapYear?29:28;//判断2月份的天数
		int days=0;
		switch (month) {
		case 1:
			days=day;
			break;
		case 2:
			days=31+day;
			break;
		case 3:
			days=31+ap+day;
			break;
		case 4:
			days=31+ap+31+day;
			break;
		case 5:
			days=31+ap+31+30+day;
			break;
		case 6:
			days=31+ap+31+30+31+day;
			break;
		case 7:
			days=31+ap+31+30+31+30+day;
			break;
		case 8:
			days=31+ap+31+30+31+30+31+day;
			break;
		case 9:
			days=31+ap+31+30+31+30+31+31+day;
			break;
		case 10:
			days=31+ap+31+30+31+30+31+31+30+day;
			break;
		case 11:
			days=31+ap+31+30+31+30+31+31+30+31+day;
			break;
		case 12:
			days=31+ap+31+30+31+30+31+31+30+31+30+day;
			break;
 
		default:
			System.out.println("月份输入错误");
			break;
		}
		System.out.println("这一天是这一年的第"+days+"天");
}
 
}

public class asgasaf {
    /**
     * 输入某年某月某日，判断这一天是这一年的第几天？
     * 
     */
    public static void main(String[] args) {
        int year;
        int mouth;
        int day=0;
        int days;
        //累计天数
        int d=0;
        int e = 0;
        Scanner scanner = new Scanner(System.in);
        do {
            System.out.println("输入年:");
            year = scanner.nextInt();
            System.out.println("输入月:");
            mouth = scanner.nextInt();
            System.out.println("输入日:");
            days = scanner.nextInt();
            if (mouth < 0 || mouth > 12 || days < 0 || days > 31) {
                System.out.println("input error!");
                e = 1;
            }
        } while (e == 1);
        for (int i = 1; i