How to create a JavaFX WebBrowser javascript listener without a Member name

I have been using this snippet for creating js listener in my javafx browser:

       engine.getLoadWorker().stateProperty().addListener(
                (observable, oldValue, newValue) -> {
                    if (newValue == Worker.State.SUCCEEDED) {
                        System.out.println("changed event detected");
                        JSObject win = (JSObject) engine.executeScript("window");
                        win.setMember("java", new JavascriptListener());
                    }
                }
        );

But I would like to be able to call my functions without prefixing them with "java".

Is that possible?