A problem with the first solution is that InetAddress has a cache, so, when you lose the connection for the next few invocation the name is resolved via the java cache.
With the URL connection aproach you have the problem that you use getContent that should fetch html so there you have data consumption. If the invocations are done very often that could be a problem (more so if you dont have an unlimited data plan on the device running the software).
I think the best solution would be to do a TCP connection to the 80 port an close it inmediatly after a successfull connection. That would behave as the final code but would have much less traffic.
