JavaFX webengine: Use http proxy for https websites

Question

I'm trying to connect to a website with javafx webengine/webview. I use a proxy that does not support the https protocol (so only http). When I try to connect to a http website, it works. However, when I try to load a https website, it ignores the proxy and uses my internet connection. When I use the same proxy in my browser I'm also able to connect to https websites and I wonder if it's possible to change my code so that the webengine will still use my http proxy instead of switching to my normal internet connection.

My code:

final String[] pArray = line.split(":");



            System.out.println("IP:" + pArray[0] + " Port:" + pArray[1]);
            System.setProperty("http.proxyHost",pArray[0]);
            System.setProperty("http.proxyPort",pArray[1]);
            System.setProperty("http.proxyUser",pArray[2]);
            System.setProperty("http.proxyPassword",pArray[3]);

            Authenticator.setDefault(
                      new Authenticator() {
                        @Override
                        public PasswordAuthentication getPasswordAuthentication() {
                          return new PasswordAuthentication(pArray[2], pArray[3].toCharArray());
                        }
                      }
                    );



            System.setProperty("java.net.useSystemProxies", "true");
            System.setProperty("jdk.http.auth.tunneling.disabledSchemes", "");

When I load my webengine:

engine.load("http://whatismyip.host");

The website (a http only website) displays the proxy IP.

But when I do:

engine.load("https://myip.is");

It shows the IP of my home connection, meaning it ignores the http proxy... How can I change that?

Regards