On Java 11, HttpClient was added to Java (no more need to use Apache’s HttpClient). and this presents some changes to the usual way of consuming Documentum REST services. The main “issue” is that there is no MultiPart class provided to easily handle multipart content (create a document), so we need to do it manually. I’ve upload a project to GitHub with basic examples of using Documentum REST services with Java 11: DctmRest11