Some tests, including test/jdk/java/net/HttpURLConnection/HttpURLConWithProxy.java , use the IP address "1.1.1.1" as a value. I think at the time the address was picked, the assumption was the address was not valid / not routable. Since April 2018 the address is part of CloudFlare's "Free" DNS product: <https://en.wikipedia.org/wiki/1.1.1.1>. (this test was originally written in 2016, before the service was launched)

I've verified using local packet captures that running the test does result in IP traffic being sent to 1.1.1.1.
 
An alternative value should be chosen (such as a reserved IP from RFC 6761) which will not result in runners of the test suit inadvertently sending IP packets to the CloudFlare service.