This test fails if proxy is set. It looks to be due to the behavior change since JDK-8161016.

"The behavior of HttpURLConnection when using a ProxySelector has been modified with this JDK release. Currently, HttpURLConnection.connect() call would fallback to a DIRECT connection attempt if the configured proxy/proxies failed to make a connection.

This release introduces a change whereby no DIRECT connection will be attempted in such a scenario. Instead, the HttpURLConnection.connect() method will fail and throw an IOException which occurred from the last proxy tested."

Since the test is not related with proxy, it looks necessary to explicitly turn off proxy

----------System.err:(35/2792)----------
Connecting to http://allowedAndFound.com:56586/foo
Exception in thread "main" java.lang.RuntimeException: (2) was not expecting
at LookupTest.test(LookupTest.java:51)
at LookupTest.main(LookupTest.java:85)
Caused by: java.net.UnknownHostException: www-proxy.us.oracle.com
at java.net.AbstractPlainSocketImpl.connect(java.base@9-ea/AbstractPlainSocketImpl.java:221)
at java.net.Socket.connect(java.base@9-ea/Socket.java:591)
at java.net.Socket.connect(java.base@9-ea/Socket.java:540)
at sun.net.NetworkClient.doConnect(java.base@9-ea/NetworkClient.java:182)
at sun.net.www.http.HttpClient.openServer(java.base@9-ea/HttpClient.java:432)
at sun.net.www.http.HttpClient$1.run(java.base@9-ea/HttpClient.java:484)
at sun.net.www.http.HttpClient$1.run(java.base@9-ea/HttpClient.java:482)
at java.security.AccessController.doPrivileged(java.base@9-ea/Native Method)
at sun.net.www.http.HttpClient.privilegedOpenServer(java.base@9-ea/HttpClient.java:481)
at sun.net.www.http.HttpClient.openServer(java.base@9-ea/HttpClient.java:522)
at sun.net.www.http.HttpClient.<init>(java.base@9-ea/HttpClient.java:211)
at sun.net.www.http.HttpClient.New(java.base@9-ea/HttpClient.java:308)
at sun.net.www.http.HttpClient.New(java.base@9-ea/HttpClient.java:326)
at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(java.base@9-ea/HttpURLConnection.java:1163)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect0(java.base@9-ea/HttpURLConnection.java:1102)
at sun.net.www.protocol.http.HttpURLConnection$6.run(java.base@9-ea/HttpURLConnection.java:986)
at sun.net.www.protocol.http.HttpURLConnection$6.run(java.base@9-ea/HttpURLConnection.java:984)
at java.security.AccessController.doPrivileged(java.base@9-ea/Native Method)
at java.security.AccessController.doPrivilegedWithCombiner(java.base@9-ea/AccessController.java:792)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(java.base@9-ea/HttpURLConnection.java:983)
at sun.net.www.protocol.http.HttpURLConnection.connect(java.base@9-ea/HttpURLConnection.java:930)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(java.base@9-ea/HttpURLConnection.java:1502)
at sun.net.www.protocol.http.HttpURLConnection.access$200(java.base@9-ea/HttpURLConnection.java:95)
at sun.net.www.protocol.http.HttpURLConnection$9.run(java.base@9-ea/HttpURLConnection.java:1422)
at sun.net.www.protocol.http.HttpURLConnection$9.run(java.base@9-ea/HttpURLConnection.java:1420)
at java.security.AccessController.doPrivileged(java.base@9-ea/Native Method)
at java.security.AccessController.doPrivilegedWithCombiner(java.base@9-ea/AccessController.java:792)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(java.base@9-ea/HttpURLConnection.java:1419)
at LookupTest.test(LookupTest.java:43)
... 1 more