javafx 2 webview自定义url处理程序,不工作相对url

我有简单的应用程序代码:

webView.getEngine().load("classpath:data/index.html");

自定义URLStreamHandler:

public class Handler extends URLStreamHandler {
    private final ClassLoader classLoader;

    public Handler() {
        this.classLoader = getClass().getClassLoader();
    }

    public Handler(ClassLoader classLoader) {
        this.classLoader = classLoader;
    }

    @Override
    protected URLConnection openConnection(URL u) throws IOException {
        URL resourceUrl = classLoader.getResource(u.getPath());
        if(resourceUrl == null)
            throw new IOException("Resource not found: " + u);

        return resourceUrl.openConnection();
    }
}

安装人:

URL.setURLStreamHandlerFactory(protocol -> {
    if(protocol.equals("classpath")) {
        return new Handler();
    } else {
        return null;
    }
});

它加载data/index.html:

    


Hello, World!!!

但结果图像没有出现.

如何让WebView解析像"download.jpg"这样的相关链接？