Question

(ns lol.test
  (:gen-class
   :name lol.test
   :methods [[createHashMap [String] Java.util.HashMap]])
  (:import [java.util HashMap]))

(defn -createHashMap [this s]
  (HashMap. (assoc {} s "test")))

I’m trying to call clojure functions from java, for this purpose I’ve created this file which prefectly compiles with lein, I create a jar file by calling “lein uberjar”.

Now the problem is that when I call it from java like this:

lol.test l = new lol.test();
l.createhashMap("test");

it throws an ArityException

Wrong number of args (2) passed to

I’ve tried to remove ‘this’ argument from clojure code but it didn’t help. What’s the problem with this code?

Answer 1

You need to fix the :methods declaration. Right now you have

:methods [[createHashMap [String] java.util.HashMap]]

It has to become

:methods [[createHashMap [Test String] java.util.HashMap]]

otherwise you’re only getting a 1-arity method in your compiled class.