ImageIcon Not Displaying in java

fullscreen, imageicon, java, macos, swing

Solution

When using images, you want to load them through URL with `Class.getResource()`, which returns a URL. Passing a String the the `ImageIcon` will cause the image to be looked up through the file system. Though this may work during development in your IDE, you'll come to find out it won't work at time of deployment. Better make the changes now. To use this method, you want do this

ImageIcon icon = new ImageIcon(Images.class.getResource("/Users/georgebastow/Picture/background.jpg"));

For this to work though, you file structure needs to look like this

ProjectRoot
          src
             Users
                  georgebastow
                            Picture
                                  background.jpg

A more common approach is just to put the image a reousrces folder in the src

ProjectRoot
          src
             resources
                     background.jpg

And use this path

ImageIcon icon = new ImageIcon(Images.class.getResource("/resources/background.jpg"));                     

When you build, your IDE will transfer the images to the class path.

Side Note

- Don't paint on top level containers like `JFrame`. Instead use `JPanel` or `JComponent` and override the `paintComponent` method. if using `JPanel`, you should also call `super.paintComponent` in the `paintComponent` method.

Run you Swing Apps from the Event Dispatch Thread like this

public static void main(String[] args) {
    SwingUtiliities.invokeLater(new Runnable(){
        public void run() {
            new Images();
        }
    });
}

See Initial Thread

Don't call `Thread.sleep()`. When running from the EDT (like you should), you will block it. Instead use a `java.swing.Timer` if it's animation you're looking for. Even if it's not animation, still use it! See this example for `Timer` program.

- Also as @mKorbel mentioned, you never add anything to the frame.

UPDATE

Run this example. I also forgot to mention, when you paint on `JPanel` you also want to override the `getPreferredSize()`. This will give your panel a size.

`src/resources/stackoverflow5.png`

import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class TestImage {

    public TestImage() {
        JFrame frame = new JFrame("Test Image");
        frame.add(new NewImagePanel());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);
    }

    public class NewImagePanel extends JPanel {

        private BufferedImage img;

        public NewImagePanel() {
            try {
                img = ImageIO.read(TestImage.class.getResource("/resources/stackoverflow5.png"));
            } catch (IOException ex) {
                System.out.println("Could not load image");
            }
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(600, 600);
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            g.drawImage(img, 0, 0, getWidth(), getHeight(), this);
        }
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new TestImage();
            }
        });
    }
}

Problem

Original source