import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Calendar;import java.util.Date;import java.util.Scanner;//输入某年某月某日，判断这一天是这一年的第几天？public class Test {	public static void main(String[] args) throws ParseException {		Scanner sc = new Scanner(System.in);		System.out.println("请输入你的日期,格式为yyy-MM-dd:");		SimpleDateFormat sdf = new SimpleDateFormat("yyy-MM-dd");		Date d;		String s ; 		while (true) {			s = sc.nextLine();				try {				d = sdf.parse(s);				break;			} catch (Exception e) {				System.out.println("请输入正确日期yyy-MM-dd格式:");			}		}		Calendar c = Calendar.getInstance();		c.setTime(d);		System.out.println(s+"是这一年的第"+c.get(Calendar.DAY_OF_YEAR)+"天");	}}