Leonel Leonel - 6 months ago 6
Java Question

How to add an image to a JPanel?

I have a JPanel to which I'd like to add JPEG and PNG images that I generate on the fly.

All the examples I've seen so far in the Swing Tutorials, specially in the Swing examples use


I'm generating these images as byte arrays, and they are usually larger than the common icon they use in the examples, at 640x480.

  1. Is there any (performance or other) problem in using the ImageIcon class to display an image that size in a JPanel?

  2. What's the usual way of doing it?

  3. How to add an image to a JPanel without using the ImageIcon class?

Edit: A more careful examination of the tutorials and the API shows that you cannot add an ImageIcon directly to a JPanel. Instead, they achieve the same effect by setting the image as an icon of a JLabel. This just doesn't feel right...


Here's how I do it (with a little more info on how to load an image):

import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.JPanel;

public class ImagePanel extends JPanel{

    private BufferedImage image;

    public ImagePanel() {
       try {                
          image = ImageIO.read(new File("image name and path"));
       } catch (IOException ex) {
            // handle exception...

    protected void paintComponent(Graphics g) {
        g.drawImage(image, 0, 0, null); // see javadoc for more info on the parameters