Loading Resources Like Images While Running Project Distributed as Jar Archive

Loading resources like images while running project distributed as JAR archive

First of all, change this line :

image = ImageIO.read(getClass().getClassLoader().getResource("resources/icon.gif"));

to this :

image = ImageIO.read(getClass().getResource("/resources/icon.gif"));

More info, on as to where lies the difference between the two approaches, can be found on this thread - Different ways of loading a Resource

For Eclipse:

• How to add Images to your Resource Folder in the Project

For NetBeans:

• Handling Images in a Java GUI Application
• How to add Images to the Project

For IntelliJ IDEA:

• Right-Click the src Folder of the Project. Select New -> Package
• Under New Package Dialog, type name of the package, say resources. Click OK
• Right Click resources package. Select New -> Package
• Under New Package Dialog, type name of the package, say images. Click OK
• Now select the image that you want to add to the project, copy it. Right click resources.images package, inside the IDE, and select Paste

• Use the last link to check how to access this file now in Java code. Though for this example, one would be using

  getClass().getResource("/resources/images/myImage.imageExtension");

• Press Shift + F10, to make and run the project. The resources and images folders, will be created automatically inside the out folder.

If you are doing it manually :

• How to add Images to your Project
• How to Use Icons
• A Little extra clarification, as given in this answer's first
  code example.

QUICK REFERENCE CODE EXAMPLE(though for more detail consider, A little extra clarification link):

package swingtest;

import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.*;

/**
 * Created with IntelliJ IDEA.
 * User: Gagandeep Bali
 * Date: 7/1/14
 * Time: 9:44 AM
 * To change this template use File | Settings | File Templates.
 */
public class ImageExample {

    private MyPanel contentPane;

    private void displayGUI() {
        JFrame frame = new JFrame("Image Example");
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);

        contentPane = new MyPanel();

        frame.setContentPane(contentPane);
        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    private class MyPanel extends JPanel {

        private BufferedImage image;

        public MyPanel() {
            try {
                image = ImageIO.read(MyPanel.class.getResource("/resources/images/planetbackground.jpg"));
            } catch (IOException ioe) {
                ioe.printStackTrace();
            }
        }

        @Override
        public Dimension getPreferredSize() {
            return image == null ? new Dimension(400, 300): new Dimension(image.getWidth(), image.getHeight());
        }

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

    public static void main(String[] args) {
        Runnable runnable = new Runnable() {
            @Override
            public void run() {
                new ImageExample().displayGUI();
            }
        };
        EventQueue.invokeLater(runnable);
    }
}

Swing - Include images in JAR file

You are accessing your file through its path on disk before it gets put into a JAR. You need to use a resource loader as explained in:
How to read a file from jar in Java?

Java Images not drawn when running java -jar

Before all be sure your resource is correctly loaded (for example with a System.out())!

Instead to use ImageIcon(String location) use ImageIcon(URL location) constructor because your image is not on hdd, but live compressed as URL in your classpath (something like MyJar.jar!/path/to/image.png"); you have to modify your image loading as

this.getClass().getClassLoader().getResource("MyImage.png");

Image won't show up when using JAR file

Change it:

image = ImageIO.read(getClass().getResource("/images/Chess_Pieces.png"));

See :

• Different ways of loading a file as an InputStream

• Loading image resource

Cannot Load Images from Jar

Check classpath of your project in your IDE. For example in eclipse there is configuration for each folder (Properties->JAva Build Path->Source Tab). It may be set to exclude png files.

How to includes all images in jar file using eclipse

You need to get it from the classpath instead of from the local disk file system.

Assuming that images is actually a package and that this package is inside the same JAR as the current class, then do so:

final public ImageIcon iReport = 
    new ImageIcon(getClass().getResource("/images/Report.png"));

NullPointerException when loading images in .jar-file

URL url = ClassLoader.getSystemResource(image);

This URL translates to absolute path in the file system which will be an invalid path for a file within jar. For example, if you have a file called foo.png under bar.jar the URL will be /path_to_current_dir/bar.jar/!foo.png which is invalid. Instead you can read the file as a stream:

InputStream is = getClass().getClassLoader().getResourceAsStream(image);
ImageIO.read(is);

Write an image from project resources to the byte array

I suggest do the following:

Use commons IO, then:

InputStream is = getClass().getResourceAsStream("/icons/default_image.png")
byte[] bytes = IOUtils.toByteArray(is);

(try and catch the exceptions.)

Edit As of Java 9 no Library needed:

InputStream is = getClass().getResourceAsStream("/icons/default_image.png")
byte[] bytes = is.readAllBytes();

(Again try and catch the exceptions.)

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