Java -交换日期格式的月和日

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

public class DateSwapExample {
    public static void main(String[] args) {
        String dateString = "2022-05-20";
        
        // Step 1: Parse date string into Date object
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        Date date = null;
        try {
            date = sdf.parse(dateString);
        } catch (Exception e) {
            e.printStackTrace();
        }
        
        // Step 2: Get month and day from date object
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        int month = calendar.get(Calendar.MONTH);
        int day = calendar.get(Calendar.DAY_OF_MONTH);
        
        // Step 3: Swap month and day
        int temp = month;
        month = day;
        day = temp;
        
        // Step 4: Convert swapped date back to string
        calendar.set(Calendar.MONTH, month);
        calendar.set(Calendar.DAY_OF_MONTH, day);
        date = calendar.getTime();
        String swappedDateString = sdf.format(date);
        
        System.out.println("Original date: " + dateString);
        System.out.println("Swapped date: " + swappedDateString);
    }
}

Original date: 2022-05-20
Swapped date: 2022-20-05