Re: Display jpg in JPanel problem

Knute Johnson <>
Sun, 27 Jun 2010 09:20:07 -0700
On 6/27/2010 2:08 AM, jimmy wrote:

Thanks all for your help again. I didn't include the complete code for
my GUI as it was built using NetBeans and contains lots of other
buttons and panels, which were not relevant to the problem. I was
unaware of the SSCCE method of describing a problem, and I find it a
very good method. I did write an SSCCE example showing my problem, but
I fear that, as pointed out by Knute Johnson, the problems with my
code run deeper than the problem I described. I haven't fully grasped
how to work with images, therefore I am going to buy a book on Java
today (Head First Java seems to receive high praise) and spend some
time getting to grips with the basics.

Thanks Daniel Pitts for the JLabel suggestion, however I need to be
able to manipulate the images, which I believe is beyond the scope of

In the meantime I need to create a GUI for image analysis, so I have
started one in MATLAB (which I am much more familiar with than Java).
My intention is to create the final version in Java however.



import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import javax.imageio.*;
import javax.swing.*;

public class test extends JPanel {
     private BufferedImage image;

     public void setImage(BufferedImage bi) {
         image = bi;
         if (image != null) {
             setPreferredSize(new Dimension(

     public void paintComponent(Graphics g) {
         if (image != null)

     public static void main(String[] args) {
         EventQueue.invokeLater(new Runnable() {
             public void run() {
                 final JFrame f = new JFrame();
                 final test t = new test();
                 JScrollPane sp = new JScrollPane(t);
                 JButton b = new JButton("Load Image");
                 b.addActionListener(new ActionListener() {
                     public void actionPerformed(ActionEvent ae) {
                         JFileChooser chooser = new JFileChooser();
                         if (chooser.showOpenDialog(f) ==
                          JFileChooser.APPROVE_OPTION) {
                             try {
                                 File file = chooser.getSelectedFile();
                                 if (file.exists())
                             } catch (IOException ioe) {


Knute Johnson
email s/nospam/knute2010/

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