See JBCL-117.

Isn't the real issue here that
org.jboss.virtual.protocol.vfsmemory.Handler
doesn't override

URLStreamHandler.hashCode(url)

It is using the "host" part of the url for something that is not a host.
This is leading to spurious DNS lookups that cannot be cached because they always fail.

The attached patch does this by overriding getHostAddress(URL) inside org.jboss.virtual.protocol.vfsmemory.Handler to always return null. This is also semantically correct, since vfsmemory "hosts" are not real hosts at all.

There's no reason to override hashCode() or equals(), as they both use getHostAddress().