Java Swing: Displaying images from within a Jar

When running a Java app from eclipse my ImageIcon shows up just fine.

But after creating a jar the path to the image obviously gets screwed up.

Is there a way to extract an image from the jar at runtime so I can then open it up? Or, is there a better way to do this?

I'd like to distribute a single jar file if possible.

To create an ImageIcon from an image file within the same jars your code is loaded:

new javax.swing.ImageIcon(getClass().getResource("myimage.jpeg"))

Class.getResource returns a URL of a resource (or null!). ImageIcon has a constructors that load from a URL.

To construct a URL for a resource in a jar not on your "classpath", see the documentation for java.net.JarURLConnection.

You can try something like:

InputStream stream = this.getClass().getClassLoader().getResourceAsStream("/images/image.jpg");

In your JAR file, you might have a directory structure of:

MyJAR.jar
- com (class files in here)
- images
----image.jpg

This is working for me to load and set the content pane background image:

jar (or build path) contains:

 - com
 - img
 ---- bg.png

java contains:

JFrame f = new JFrame("Testing load resource from jar");
try {
    BufferedImage bg = ImageIO.read(getClass().getResource("/img/bg.png"));
    f.setContentPane(new ImagePanel(bg));
} catch (IOException e) {
    e.printStackTrace();
}

Tested and working in both jar and unjarred (is that the technical term) execution.

BTW getClass().getClassLoader().getResourceAsStream("/img/bg.png") - which I tried first - returned me a null InputStream.

In netbeans 8.1 what I've done is to include the folder of icons and other images called Resources inside the src folder in the project file. So whenever i build Jar file the folder is included there.The file tree should be like this:

• src (Java files in source packges are here)

• ** PACKAGE YOU NAMED IN PROJECT**

  • file.java

• Resources

  • image.jpg

The code should be like:

jToggleButton1.setIcon(new javax.swing.ImageIcon(this.getClass().getResource("/resources/image.jpg")));