Javadoc - Java API documentation
, h j will show the javadoc information for a Java method or class, opening the relevant page on the Oracle website for Java.
Navigate Java Source code
, g g to run the command
clj-find-var which shows
Selecting a specific Java package (namespace) will open the Java source code in a buffer
Include Java Sources
-M:java-11-source alias when starting Clojure to include the sources for Java 11 on the classpath, making them available for the Cider