// Java program to convert
// GregorianCalendar to SimpleDateFormat
 
import java.text.SimpleDateFormat;
import java.util.GregorianCalendar;
 
public class GregorianCalendarToCalendar {
 
    public static void convert(
        GregorianCalendar gregorianCalendarDate)
    {
        // Creating an object of SimpleDateFormat
        SimpleDateFormat formattedDate
            = new SimpleDateFormat("dd-MMM-yyyy");
 
        // Use format() method to change the format
        // Using getTime() method,
        // this required date is passed
        // to format() method
        String dateFormatted
            = formattedDate.format(
                gregorianCalendarDate.getTime());
 
        // Displaying gregorian date in SimpleDateFormat
        System.out.print("SimpleDateFormat: "
                         + dateFormatted);
    }
 
    // Driver code
    public static void main(String[] args)
    {
 
        // Get the Gregorian Date to be converted.
        GregorianCalendar gcal = new GregorianCalendar();
        gcal.set(GregorianCalendar.YEAR, 2019);
 
        // In gregorian calendar month is started from 0
        // so for april month will be 03 not 04
        gcal.set(GregorianCalendar.MONTH, 03);
 
        gcal.set(GregorianCalendar.DATE, 03);
 
        // Displaying Current Date
        // using GregorianCalendar Class
        System.out.println("Gregorian date: "
                           + gcal.getTime());
 
        // Function to convert this to SimpleDateFormat
        convert(gcal);
    }
}

Gregorian date: Wed Apr 03 05:21:17 UTC 2019
SimpleDateFormat: 03-Apr-2019