How do you call a static method in my own Java class from Clojure?

Question

I would like to call a static method in a Java class I have created from Clojure. How would I go about doing so?

What I have tried so far is simply creating a Java class in the same folder as my Clojure source, but either I am given a ClassNotFoundException or I am told that there is no such namespace. I have also attempted importing the class in various different ways, ending up redifining the Java package declaration several times with no further result.

I am using Leiningen for handling my Clojure project.

Possible duplicate of [Java and Clojure with Leiningen](http://stackoverflow.com/questions/5432163/java-and-clojure-with-leiningen) — kongeor, Jun 17 '16 at 15:12

score 2 · Accepted Answer · answered Jun 17 '16 at 15:44

You must also give information about the location of your Java class in the project.clj file of your project.

Here's an example.

The Java class:

public class BestClass {
    public static String testThis() {
        return "Hello";
    }
}

This class is located in use-java\src\java where use-java is the project directory.

project.clj:

(defproject use-java "0.1.0-SNAPSHOT"
  :description "FIXME: write description"
  :url "http://example.com/FIXME"
  :license {:name "Eclipse Public License"
            :url "http://www.eclipse.org/legal/epl-v10.html"}
  :dependencies [[org.clojure/clojure "1.8.0"]]
  :java-source-paths ["src/java/"]
  :main ^:skip-aot use-java.core
  :target-path "target/%s"
  :profiles {:uberjar {:aot :all}})

The important part in the file above is :java-source-paths ["src/java/"].

Note that you can change the location of the class but :java-source-paths must be changed accordingly.

core.clj:

(ns use-java.core
  (:import BestClass))

(defn try-out-java-method []
  (BestClass/testThis))

Calling try-out-java-method gives:

use-java.core> (try-out-java-method)
"Hello"

can you give more details about the project structure, where is `core.clj` located, to what package `BestClass` belongs, etc ? I tried what you said and it didn't work — niceman, Apr 22 '17 at 14:29

How do you call a static method in my own Java class from Clojure?

1 Answers1