Why Can\'t I Load Images in My Exported JAR from Eclipse?

Images onLoadable in Exported JAR from Eclipse

Encounters with images failing to render when loading a JAR file exported from Eclipse can be frustrating. Despite the images being present within the exported JAR, they might not be visible due to incorrect loading techniques.

Resource Path Variables and Code Variations

One vital aspect is the correct use of the resource path. The referenced images should be packaged within Eclipse's designated resource folder or placed alongside the source code within the project structure.

Various methods can be utilized to load the images:

label.setIcon(new ImageIcon(MainFrame.class.getResource("/resources/header.jpg")));

URL url = getClass().getResource("/resources/header.jpg");
Image image = Toolkit.getDefaultToolkit().getImage(url);
label.setIcon(new ImageIcon(image));

try
{
    label.setIcon(new  ImageIcon(ImageIO.read(getClass().getResource("/resources/header.jpg"))));
}
catch (IOException e1)
{
    e1.printStackTrace();
}

Resolving Resource Loading Issues

To gain insight into the reason behind the failure to render images, a comparison with working examples can prove helpful. The following section presents scenarios with illustrations and step-by-step guides to assist in troubleshooting:

Example 1

With resources located within src, follow these steps:

• Modify the project file structure, with resources as a package within src.

• In your code, use the following resource path alongside the MainFrame class:

  URL url = MainFrame.class.getResource("/resources/stackoverflow.png");

• Export as a runnable JAR and run it.

Example 2

For resources that are not within src but are included in the project:

• Ensure the resources folder is on the project build path.

• Access the images in the code, but omit the resources prefix from the path:

  URL url = Main.class.getResource("/stackoverflow.png");

• Export the JAR as mentioned above.

Launch Configuration

Once the images can be loaded from within Eclipse, setting up a launch configuration is crucial for exporting the JAR. Go through this simple process to create a configuration:

• Right-click on the project and select Run->Run Configurations.
• Create a new launch configuration for your project.
• Ensure this configuration is selected when exporting as a Runnable JAR.

Verification

• When examining the exported JAR's manifest, the following lines should be present:

  Rsrc-Main-Class: com.stackoverflow.test.Main

• The expanded JAR should include the following file structure:

  stackoverflow.png (resource file)

• Running this JAR should render the image successfully.

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