Run this in a browser and the console spits out 'Resource "/fxtest/test.css" not found' even though fxtest/test.css is in the jar.

    @Override public void start(Stage stage) {

        final Button button = new Button("Button");

        Scene scene = new Scene(new StackPane(button), 200, 200);
        scene.getStylesheets().add("/fxtest/test.css");
        stage.setScene(scene);
        stage.show();

    }

It appears that the calls to StyleManager method getURL need to be wrapped in a doPriv