Image not drawn in JPanel.paintComponent

Question

I am actually want to load image but only applet dialog open and no error occurred but the image is not loading.the code is below here

import java.awt.Graphics;
import java.awt.Image;
import java.awt.Toolkit;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Ball extends JPanel{
  Image image; 


  public Ball(){
    super();       
    image = Toolkit.getDefaultToolkit().getImage("/D:\\lolololo\\tuto\\bin\\sa.jpg");
  }

private Image getResource(String string) {
    return image;
    // TODO Auto-generated method stub

}

  public void paintComponent(Graphics g){


   // Draw our Image object.
   g.drawImage(image,50,10,574,960, this); // at location 50,10
     // 200 wide and high
  }

  public void main(String arg[]){
   JFrame frame = new JFrame("ShowImage");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   frame.setSize(800,500);

   Ball panel = new Ball();
   frame.setContentPane(panel);
   frame.setVisible(true);
  }
}

`"/D:\\lolololo\\tuto\\bin\\sa.jpg"` should not contain the leading `/`. It should be `"D:\\lolololo\\tuto\\bin\\sa.jpg"` presuming the rest of that path is correct. As an aside `public void main(String arg[]){` is **not** a valid method signature for the main method! — Andrew Thompson, Jun 28 '13 at 17:03
Given `Toolkit.getImage(String)` does not throw any errors when the image is not found, I prefer to use `ImageIO` to load them. It provides lots of helpful output when anything goes wrong. — Andrew Thompson, Jun 28 '13 at 17:08

score 1 · Answer 1 · answered Jun 28 '13 at 17:33

The way you are loading the image is wrong. This will never work when you extract as Runnable jar.

Create package ("res") inside inside your src

Now load the image this way

image = ImageIO.read(Ball.class.getResource("/res/sa.jpg"));

This will work.

As indicated by Andrew in his comment main class should be

public static void main(String arg[]) {}

David Kroukamp · Answer 2 · 2013-06-28T18:18:19.847

+1 to @AndrewThompsons comments.

1) Below is incorrect, you do not honer the paint chain by calling the supers implementation of super.paintComponent(...):

public void paintComponent(Graphics g) {
   // Draw our Image object.
   g.drawImage(image,50,10,574,960, this); // at location 50,10
   // 200 wide and high

}

As per docs for paintComponent:

Further, if you do not invoker super's implementation you must honor the opaque property, that is if this component is opaque, you must completely fill in the background in a non-opaque color. If you do not honor the opaque property you will likely see visual artifacts.

should be:

public class Ball extends JPanel {

    BufferedImage image;

    public Ball() {
       super();

       try {
           image=ImageIO.read(new File("c:/test.jpg"));//change to your path of file 
       }catch(Exception ex) {//file did not load properly
           ex.printStackTrace();
       }
    }

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

         // Draw our Image object.
         g.drawImage(image,0,0,image.getWidth(),image.getHeight(), this); // at location 50,10
        // 200 wide and high
    }

    @Override
    public Dimension getPreferredSize() {
        return new Dimension(image.getWidth(),image.getHeight());//replace with size of image
    }

}

Also notice:

I overrode getPreferredSize() of JPanel and returned Dimensions I wanted (i.e Image size) or the JPanel will only be as big as the components added to it and not the image (so if no components 0,0).
I also chose BufferedImage vs Image and surrounded the statement with a try catch to check if any errors are thrown.
I see you also had g.drawImage(image,50,10...) why 50 and 10 and not 0,0?

2) Also this (as @AndrewThompson has said):

image = Toolkit.getDefaultToolkit().getImage("/D:\\lolololo\\tuto\\bin\\sa.jpg");

No need for the / thats only if its located in your classes package etc not when its on your HDD at a set location.

3) also as said by @AndrewThompson a main method should be:

public static void main(String[] args){}

Notice the static modifer applied other wise its just another method.

4) Also dont use JFrame#setSize(..), rather use LayoutManager and/or override getPreferredSize and than simply call pack() on JFrame instance before setting it visible.

5) Also please have a read on Concurrency in Swing. especially the Event-Dispatch-Thread

Also see [this](http://stackoverflow.com/questions/14632998/null-exception-while-drawing-image-to-jframe/14633038#14633038) answer which shows many examples of drawing images — David Kroukamp, Jun 28 '13 at 18:22

Image not drawn in JPanel.paintComponent

2 Answers2