A long while ago I wrote a Java book [1] (my usual cookbook style) and decided to also support Scala and Clojure. It was so very much easier writing Clojure wrappers than Scala wrappers.

Java and Clojure mix very well in projects: set up a separate Java source path and let lein build everything.

[1] you can grab a free copy at http://markwatson.com/opencontent_data/book_java.pdf - it is my Java Semantic Web book.