获取任意年的二月有多少天

import java.util.Calendar;
import java.util.Scanner;

public class CalendarTest {

    public static void main(String[] args) {
        
        Calendar c = Calendar.getInstance();
        Scanner in = new Scanner(System.in);
        int year = in.nextInt();
        c.set(year,2, 1);
        c.add(Calendar.DAY_OF_MONTH, -1);
        printCalendar(c);
    }
    public static void printCalendar(Calendar c)
    {
        sop(c.get(Calendar.DAY_OF_MONTH)+"天");
    }
    public static void sop(Object obj)
    {
        System.out.println(obj);
    }

}