Why slideshow not working in Java using Swing and Awt?

I am doing slideshow of images program in java using timer. In timer event listner i have added code to chnage image but image is not changing. Below is the code i have written

class ImagePanel extends JPanel {

    private Image backgroundImage;

    public ImagePanel(Image backgroundImage) {
        super();
        this.backgroundImage = backgroundImage;
    }

    public void paintComponent(Graphics g) {
        super.paintComponent(g);        
        g.drawImage(this.backgroundImage, 0, 0, null);
    }
}

public class A extends JFrame{
    static int counter;
    List<String> imagePaths;
    int nimgpaths=0;
    static A frame = new A();
    public static void main(String[] args) {
        frame.setSize(1024, 768);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getPath();
        /* Getting required image */
        Image backgroundImage = null;
        String pathToTheImage = "C:\\Documents and Settings\\Administrator\\My Documents\\My Pictures\\civ1.JPG";
        try {
            backgroundImage = ImageIO.read(new File(pathToTheImage));
        } catch (IOException e) {
            e.printStackTrace();
        }

        /* Initializing panel with the our image */
        ImagePanel panel = new ImagePanel(backgroundImage);
        frame.getContentPane().add(panel);
        frame.setVisible(true);
        frame.timerEvent();
        //frame.show();
    }

    public void timerEvent(){
    Timer timer = new Timer(5000, new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
            System.out.println("Time event occured");
            if(counter > nimgpaths)
                counter=0;
            String imgPath=imagePaths.get(counter);
            Image background开发者_Go百科Image = null;
            try {
            backgroundImage = ImageIO.read(new File(imgPath));
        }catch (Exception e1) {
            e1.printStackTrace();
        }

        /* Initializing panel with the our image */
            frame.removeAll();
        ImagePanel panel = new ImagePanel(backgroundImage);
        panel.repaint();
        //panel.setBackground(backgroundImage);
        frame.getContentPane().add(panel);

        }
    });
    timer.start();
    }

   // To get path of images
    public void getPath(){
        DbOps db=new DbOps();
        imagePaths=db.getPath();
        nimgpaths=imagePaths.size();
        for(Iterator i=imagePaths.iterator();i.hasNext();){
            System.out.println((String)i.next());
        }

    }

}

Why are you using a custom panel and painting?

Your code is simply painting the image at its preferred size. This functionality is available when you use a JLabel. Then when you use the label all you need to do is use:

label.setIcon(....);

when you want to change the image. Read the section from the Swing tutorial on How to Use Icons for more information.

The only reason to create a custom component is if you plan to scale the image or do something fancy like that. If this is the case then you can use something like the Background Panel which supports scaled images as well as a setImage() method so you can change the image dynamically.

A much better design for ImagePanel would let you just replace the image, rather than removing the component. If you do have to replace a visible component, though, you have to call validate() on its container, or the new one isn't going to show up (most of the time, anyway.) I think that's your problem here.

frame.removeAll() is not doing what you would expect - it is removing the components from the frame itself rather than removing the components from the content pane of the frame. Change the code at the end of the timer's action listener to something like this to fix it:

    ImagePanel panel = new ImagePanel(backgroundImage);
    frame.getContentPane().removeAll();
    frame.getContentPane().add(panel);
    frame.getContentPane().invalidate();
    frame.getContentPane().validate();

Your concept itself is wrong.

You can refresh the panel like so:

public void refreshPanel(JPanel panel){
   panel.removeAll();
   panel.invalidate();
   panel.validate();
}

Problem:

I see in your code that you are trying to create more than one object of the same panel, which you need to refresh.

It would be better to create one panel object and refresh that object.

ImagePanel panel = new ImagePanel(backgroundImage);

Hope you can understand what I wanted to explain to you.

If you are still confused then let me know.