WebEngine is not loading files linked in HTML (javafx)

问题

Here is the <head> tag of content.html:

<head>
    <title>TODO supply a title</title>
    <meta charset="UTF-8">
    <script type="text/javascript" src="codemirror.js"></script>
    <link rel="stylesheet" href="codemirror.css">
    <script type="text/javascript" src="matchbrackets.js"></script>
    <script type="text/javascript" src="closebrackets.js"></script>
    <script type="text/javascript" src="expression.js"></script>
    <style>
        .right {
            text-align: right;
        }
    </style>
</head>

File is loaded via:

view.getEngine().load(getClass().getResource("content.html").toExternalForm());

HTML file loads just fine, but none of the files referenced with src or href (css/js). All linked files are in the same package as HTML file. So is the class that loads it.