如何从外部捆绑资源导入CSS文件

Question

I'm trying to import an OSGi bundle resource (a CSS file called style.css) from another bundle called cssBundle :

public void addCSS() {
    Bundle bundle = FrameworkUtil.getBundle(this.getClass());
    Bundle[] bArray = bundle.getBundleContext().getBundles();
    Bundle cssBundle = null;
    for (Bundle b : bArray) {
        if (b.getSymbolicName().equals("cssBundle")) {
            cssBundle = b;
            break;
        }
    }
    Enumeration<URL> resources = null;
    try {
        resources = cssBundle.getResources("/resources/css/mainscreen.css");
    } catch (IOException e) {
        e.printStackTrace();
    }
    if (resources != null) {
        URL myCSSURL = resources.nextElement();
        try {
            URI uri = myCSSURL.toURI();
            File f = new File(uri);
            scene.getStylesheets().add("file:///" + f.getAbsolutePath().replace("\\", "/"));
        } catch (URISyntaxException e) {
            e.printStackTrace();
        }
    }
}

However, this way, I get:

Exception in thread "JavaFX Application Thread" java.lang.IllegalArgumentException: URI scheme is not "file"
at java.io.File.<init>(Unknown Source)

What would be the right, or better way to go about it?

System.out.println(myCSSURL);

OUTPUTS

bundle://13.1:1/resources/css/style.css  

Is there a way I could add this onto my Scene without using URLs?

Answer 1

The URI represeting the resource from the bundle can not be represented as a file. So the approach to create a file from the URI is not possible.

What you can do with the bundle resource is to get an InputStream for it. So you can use this to copy the stream contents to a file in the temp folder and give that file to scene.getStylesheets().add.

Another approach might be to define an Import-Package in your bundle for resources.css. This will make the file available on the classpath of your bundle. So maybe the scene.getStylesheets().add("/resources/css") will then work.

Answer 2

That exception means it cannot find your file. You should investigate creating a URI to the CSS file.

URI uri = new URI("file:///C:/other/mydir/myfile.txt");