The following tests don't work with eng. nightly build.
http://www.w3.org/International/tests/sec-iri-3
http://www.w3.org/2001/08/iri-test/ (most tests on this page don't work)

According to Edward,
> Regarding name resolving against i18n uri/url, it's quite complicated. The URI class, which implements both RFC 3986 & 3987, is scheme agnostic. So scheme-specific behavior like name resolving for http scheme is out of scope of URI class. And the DNS infrastructure is still ASCII-only. That's what IDN class for. So one must do like this:
> URI uri = ...;
> InetAddress.getByName(IDN.toASCII(uri.getHost()));
>
> But URL.openConnection() makes it even more complex. I think the example below is absolutely reasonable:
> URI uri = ...;
> HttpURLConnection conn = (HttpURLConnection)
> uri.toURL().openConnection();
> conn.getResponseCode();
> It donesn't work for non-ASCII URI now. Just file a bug for that to me.