Java で java.util.Date を文字列に変換するにはどうすればよいですか?

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

public class DateToStringExample {

    public static void main(String[] args) {
        String pattern = "MM/dd/yyyy HH:mm:ss";

        // Create an instance of SimpleDateFormat used for formatting 
        // the string representation of date according to the chosen pattern
        DateFormat df = new SimpleDateFormat(pattern);

        // Get the today date using Calendar object.
        Date today = Calendar.getInstance().getTime();        
        // Using DateFormat format method we can create a string 
        // representation of a date with the defined format.
        String todayAsString = df.format(today);

        // Print the result!
        System.out.println("Today is: " + todayAsString);
    }
}