Wrote about Java integration, and private functions in Clojure Book
Some companies use Java, and they would like to explore Clojure. My new updates in Clojure book is aimed at them. I have added sections named Java Files in Clojure Project, which teaches one how current Java code can work along with Clojure projects. Another section named jar files in Clojure project, teaches one how to use jar files in Clojure. Some old Java libraries can be compiled into jar and thus code could be reused.
I am not a huge fan of private functions. I think still Python does not have a concept of private functions. Clojure does have private functions, till now my book avoided it, but not anymore. The section named Private Functions, teaches one how to code private functions, and it also tells how to test them.
My book is available online, as well as on Amazon as EPUB, paper back (in color) and hard cover (in color). I hope it’s of use to you.