In one section of the book, it explains that we can easily use function show in clojure.contrib.repl.utils to display document of Java library but that was for Clojure.
According to Where Did Clojure.Contrib Go, show moved to clojure.reflect/reflect. Let play with it a little bit.
Pretty handy.
Note: you also can open Javadoc in browser with this snippet
(javadoc java.lang.Math)