You cannot place http: // or https: // behind the IP address of the proxy server.
If your HTTP proxy supports https, then htmlunit will automatically use it. Below is an example of using a proxy server with htmlunit
For HTTP Proxy
ProxyConfig pc = new ProxyConfig();
pc.setSocksProxy(false); //Set to false if it is a http server
pc.setProxyHost("192.168.1.200"); //your proxy IP
pc.setProxyPort(proxyPort);
webClient.getOptions().setProxyConfig(pc);
, , - socks, setSocksProxy true.