Web Development with Clojure, 2nd Edition

Calling Methods

Once we have an instance of a class, we can call methods on it. The notation is similar to making a regular function call. When we call a method, we pass the object its first parameter, followed by any other parameters that the method accepts.

(let [f (File. ".")]
 (println (.getAbsolutePath f)))

Here we’ve created a new file object f and we’ve called .getAbsolutePath on it. Notice that methods have a period (.) in front of them to differentiate them from regular Clojure functions. If we wanted to call a static function or a variable in a class, we would use the / notation, as follows:

(str File/separator "foo" File/separator "bar")

(Math/sqrt 256)

We can also chain multiple method calls together using the double ...