java - HTTPS hostname wrong: should be <sub.domain.com>. What causes this?

Question

I am getting this 'HTTPS hostname wrong:' error when trying to connect to a server using https. My url looks something like this

https://sub.domain.com/tamnode/webapps/app/servlet.

I connect using the following code

    // Create a URLConnection object for a URL
    URL url = new URL(requestedURL);
    HttpURLConnection.setFollowRedirects(false);

    // connect
    connection = (HttpURLConnection) url.openConnection();
    connection.setDoOutput(true);
    connection.setRequestProperty("User-Agent", USER_AGENT); //$NON-NLS-1$

    OutputStreamWriter wr = new OutputStreamWriter(connection
            .getOutputStream());

but then get an error

IOException: HTTPS hostname wrong:  should be <sub.domain.com>. 
    at sun.net.www.protocol.https.HttpsClient.checkURLSpoofing
    ....

This is code which has worked in the past but no longer. There have been some changes to the system architecture but I need to get more data before approaching those responsible.

What can cause this error? Can I turn off the URLSpoofing check?

Answer 1

It looks like the SSL certificate for domain.com has been given to sub.domain.com. Or, more likely, what was domain.com has been renamed to sub.domain.com without updating the SSL certificate.