title: Unable to tunnel through proxy. Proxy returns HTTP/1.1 503 Service Unavailable
body: <p>I want to connect to an intranet server, the url that I need to connect is:</p>
  
  <pre><code>URLConnection conn = new URL("https://mywebsite").openConnection();
  </code></pre>
  
  <p>When I reach to the connect method call through:`</p>
  
  <pre><code>conn.connect();
  </code></pre>
  
  <p>I'm getting the following exception:</p>
  
  <pre><code>java.io.IOException: Unable to tunnel through proxy. Proxy rerurns HTTP/1.1 503 Service Unavailable"
  at sun.net.www.protocol.httpHttpURLConnection.doTunneling
  </code></pre>
  
  <p>How can I solve this exception, I have tried many solutions published on the net, but without any luck.</p>