Hello, unfortunately, I'm not able to reply to ticket #57 (there is no reply button). I just wanted to add this information:
For Android 8 and later, you can use ConnectivityManager to get the DNS server addresses of the current connection. For a code sample, see https://gitlab.com/bitfireAT/davdroid/commit/076962e5ed0db80ab9efb4b7b94b0bacd0d7a0a1 (prepareLookup)
If you still think this is an issue/use case, please create a pull request on dnsjava's new home at Github: https://github.com/dnsjava/dnsjava