See discussion in this email:

http://mail.openjdk.java.net/pipermail/security-dev/2013-August/008346.html

Briefly, the example binds to a loopback address (whether IPv4 or IPv6 is unspecified, but it will be one or the other). The example suggests using localhost, which might resolve to the wrong loopback address.

The example should be changed to recommend using the appropriate IPv4 or IPv6 loopback address instead of "localhost".