The current java.net.URI conforms to RFC 2396, which requires that the hostname part of the URI is ASCII. Thus it doesn't support internationalized domain names. There is attempt to amend RFC 2396 to allow escaped encoded non-ascii domain names. See http://www.ietf.org/proceedings/03mar/I-D/draft-ietf-idn-uri-03.txt for nternationalized Domain Names in URIs. We should revisit this in the next release to see whether it's approporiate to support it.