Gregory's Server@nikitonsky @mkvlr unix domain sockets where not supported OOTB in Java until recently. and http client still does not support them yet https://bugs.java.com/bugdatabase/view_bug.do?bug_id=JDK-8275838 (submitted by me ~2years ago. so you had to use native libs.
@ieugen @mkvlr there are two LTS Java releases already that support them, I think it’s pretty stable? Why would you need http client?