Analoge Uhr in GUI | gebe 73e*g

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Calendar;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.WindowConstants;

public class SimpleDigitalClock {

    public static void main(String[] args) {

        JFrame f = new JFrame();
        f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        DigitalClock myClock = new DigitalClock();
        f.add(myClock);
        f.pack();
        f.setVisible(true);
    }

    static class DigitalClock extends JPanel {

        String stringTime;
        int hour, minute, second;

        String correctionHour = "";
        String correctionMinute = "";
        String correctionSecond = "";

        public void setStringTime(String xyz) {
            this.stringTime = xyz;
        }

        public int findMinimumBetweenTwoNumbers(int a, int b) {
            return (a <= b) ? a : b;
        }

        DigitalClock() {

            Timer t1 = new Timer(1000, new ActionListener() {
                public void actionPerformed(ActionEvent e) {

                    repaint();
                }
            });
            t1.start();
        }

        @Override
        public void paintComponent(Graphics g) {
            super.paintComponent(g);

            Calendar now = Calendar.getInstance();
            hour = now.get(Calendar.HOUR_OF_DAY);
            minute = now.get(Calendar.MINUTE);
            second = now.get(Calendar.SECOND);

            if (hour < 10) {
                this.correctionHour = "0";
            }
            if (hour >= 10) {
                this.correctionHour = "";
            }

            if (minute < 10) {
                this.correctionMinute = "0";
            }
            if (minute >= 10) {
                this.correctionMinute = "";
            }

            if (second < 10) {
                this.correctionSecond = "0";
            }
            if (second >= 10) {
                this.correctionSecond = "";
            }
            setStringTime(correctionHour + hour + ":" + correctionMinute+ minute + ":" + correctionSecond + second);
            g.setColor(Color.BLACK);
            int length = findMinimumBetweenTwoNumbers(this.getWidth(),this.getHeight());
            Font myFont = new Font("SansSerif", Font.PLAIN, length / 5);
            g.setFont(myFont);
            g.drawString(stringTime, (int) length/6, length/2);

        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(200, 200);
        }

    }

}