Java – repaint swing JComponent after interval

I was assigned a project and I had to use the Gregorian calendar object in Java to make an analog clock First, we are told to let the clock work so that the correct time is displayed each time it runs Then we were told to redraw the clock every second I created a timer object and thought I could add an actionlistener and redraw it every time actionperformed was called, but obviously redrawing cannot be used in this way This is my code:

import javax.swing.*;
    import java.awt.event.*;
    import java.awt.geom.*;
    import java.awt.*;
    import java.util.Calendar;
    import java.util.GregorianCalendar;
    import java.util.Date;
    import javax.swing.Timer;
    import java.lang.Math;    

    public class SwingClock {

    public static void main(String[] args)
    {
        EventQueue.invokelater(new Runnable()
        {
            public void run()
            {
                MyFrame frame = new MyFrame();
                frame.setDefaultCloSEOperation(JFrame.EXIT_ON_CLOSE);
                ActionListener listener = new TimePrinter();
                Timer t = new Timer(1000,listener);
                GregorianCalendar calendar = new GregorianCalendar();
                t.start();
                frame.setVisible(true);
            }
        });
    }
}

    class TimePrinter implements ActionListener
    {
        public void actionPerformed(ActionEvent event)
        {
            //I'd like to repaint here every second,but I can't
        }
    }

    class MyFrame extends JFrame
    {
        public MyFrame()
        {
            setTitle("Swing Clock");
            setSize(DEFAULT_WIDTH,DEFAULT_HEIGHT);

            MyComponent component = new MyComponent();
            add(component);
        }

        public static final int DEFAULT_WIDTH = 500;
        public static final int DEFAULT_HEIGHT = 500;
    }

    class MyComponent extends JComponent
    {
        public void paint(Graphics g)
        {
            Graphics2D g2 = (Graphics2D)g;
            int leftX = 50,topY = 50,width = 300,height = 300;
            Rectangle2D rect = new Rectangle2D.Double(leftX,topY,width,height);

            Ellipse2D clockFace = new Ellipse2D.Double();
            clockFace.setFrame(rect);
            g2.draw(clockFace);

            double centerX = clockFace.getCenterX();
            double centerY = clockFace.getCenterY();
            GregorianCalendar calendar = new GregorianCalendar();
            int hour = calendar.get(Calendar.HOUR_OF_DAY);

            int minute = calendar.get(Calendar.MINUTE);
            int second = calendar.get(Calendar.SECOND);

            double minusMinute = (90 - (minute*6))*(Math.PI/180);           
            double minuteCosine = Math.cos(minusMinute);
            double minuteSine = Math.sin(minusMinute);

            double minusSecond = (90 - (second*6))*(Math.PI/180);
            double secondcosine = Math.cos(minusSecond);
            double secondSine = Math.sin(minusSecond);

            double hourTheta = (90-(hour+(minute/60)*30))*(Math.PI/180);
            g2.draw(new Line2D.Double(centerX,centerY,centerX+50*(Math.cos(hourTheta)),centerY - 50*(Math.sin(hourTheta))));   
            g2.draw(new Line2D.Double(centerX,centerX+150*(minuteCosine),centerY-150*(minuteSine)));
        g2.draw(new Line2D.Double(centerX,centerX+100*secondcosine,centerY-100*(secondSine)));
        }
    }

Any ideas on how to solve this problem? Maybe I'm wrong?

Solution

"Swing program should override paintcomponent () instead of paint ()," although you will see that this is not necessary at all Second, you use javax swing. Timer is correct Third, why not make yourself comfortable and use jlabel instances to display time?