Question

I’ve recently tried to set my default application icon with a .ico file I made myself. This is the code I used to create the icon:

initComponents();
java.net.URL url = ClassLoader.getSystemResource("/src/calculatormedii/resources/CMedii.ico");
Toolkit kit = Toolkit.getDefaultToolkit();
Image img = kit.createImage(url);
getFrame().setIconImage(img);

I have no idea why it’s so difficult to set the java desktop application icon in netbeans, it should just be a property field like the rest.
When I try to run the program, these errors show up:

    Uncaught error fetching image:
java.lang.NullPointerException
    at sun.awt.image.URLImageSource.getConnection(URLImageSource.java:99)
    at sun.awt.image.URLImageSource.getDecoder(URLImageSource.java:113)
    at sun.awt.image.InputStreamImageSource.doFetch(InputStreamImageSource.java:240)
    at sun.awt.image.ImageFetcher.fetchloop(ImageFetcher.java:172)
    at sun.awt.image.ImageFetcher.run(ImageFetcher.java:136)

No idea what to do now. If there is an alternate way to set the application icon please specify it (Like a property field in netbeans or something)

Answer 1

I strongly suspect it’s the URL you’re using. Using ClassLoader.getSystemResource, you shouldn’t need a leading slash – but I very much doubt that you want the src part either. You should make sure that your icon is copied to the same place that your class files is (e.g. a bin directory) and then just use:

URL url = ClassLoader.getSystemResource("calculatormedii/resources/CMedii.ico");