How do I see the methods associated with an object in Clojure?

Question

What function do I use, in Clojure, to see the methods of a Java object?

user=> (some-function some-java-object)
... lots of methods ...

Answer 1

Use java reflection.

(.getClass myObject)

gets you the class. To get methods,

(.getMethods (.getClass myObject))

Which gives you an array of methods. You can treat that like a sequence; I'd probably put it into a vector, so:

(vec (.getMethods (.getClass myObject)))

Answer 2

Since version 1.3, Clojure comes bundled with the clojure.reflect namespace. The function reflect in particular can be used to show all methods (and other information) for an object. It is not quite as convenient to use as show. On the other hand, it is much more general and it is quite easy to write your own version of show using reflect as a building block.

As an example, if you want to see all methods for String which returns a String:

user=> (use 'clojure.reflect)
user=> (use 'clojure.pprint)

user=> (->> (reflect "some object") 
            :members 
            (filter #(= (:return-type %) 'java.lang.String))
            (map #(select-keys % [:name :parameter-types])) 
            print-table)