Java实现给定一个日期 求出这个日期是这一年中的第几天

import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.*;public class Date {public static void main(String[] args){Scanner sc=new Scanner(System.in);while(sc.hasNext()){String dateStr=sc.nextLine(); SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd"); java.util.Date startDate = null; try {startDate = sdf.parse(dateStr);} catch (ParseException e) {// TODO Auto-generated catch blocke.printStackTrace();} Calendar startCalendar = Calendar.getInstance(); startCalendar.setTime(startDate); int index = startCalendar.get(Calendar.DAY_OF_YEAR); System.out.println(index); } }}