clojure/lein: How do I include a java file in my project?

Question

I have a java file with a single class and I want to include it in my lein project. Where do I put it and how do I import it? (I tried putting it in the src directory under the package path but it tells me ClassNotFound)

So the java file has this package declaration:

package com.thebuzzmedia.imgscalr;

and has this class:

public class Scalr {

I put it in ~/src/com/thebuzzmedia/imgscalr/Scalr.java and tried to import it from the repl thusly:

(import '(com.thebuzzmedia.imgscalr Scalr))

And I get this:

com.thebuzzmedia.imgscalr.Scalr
[Thrown class java.lang.ClassNotFoundException]

What am I missing?

possible duplicate of [Java and Clojure with Leiningen](http://stackoverflow.com/questions/5432163/java-and-clojure-with-leiningen) — Asfand Qazi, Jul 21 '14 at 10:49

score 25 · Accepted Answer · edited May 23 '17 at 12:09

25

Where to place Java sources really depends on which build system you're using. If you're using Leiningen, you have to configure the source paths:

(defproject my-project "0.0.1-SNAPSHOT"
  [...]
  :java-source-paths ["src/java" "test/java"])

Then you can import Java classes at those source locations in your code or at the REPL like you were already trying to do.

edited May 23 '17 at 12:09

Community

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answered Sep 22 '11 at 08:32

skuro

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Although I use [cake](http://clojure-cake.org/) and thus don't have to worry about this, my understanding is that newer versions of Lein have javac functionality baked in, without plugins. – amalloy Sep 22 '11 at 17:08
Indeed leiningen merged `javac-plugin` into its main codebase, it's not really a plugin anymore. I'll update the answer to reflect that. – skuro Sep 22 '11 at 20:51
This answer is out-of-date. Lein now uses :java-source paths as described by kiko and benkay. – Alan Thompson Feb 06 '14 at 02:56

score 12 · Answer 2 · edited Dec 04 '13 at 12:47

12

As of Leiningen 2.X, :java-source-path has been replaced with :java-source-paths, whose value is now specified as a vector rather than a string.

Example:

(defproject my-project "0.0.1-SNAPSHOT"
  [...]
  :java-source-paths ["src/main/java" "src/main/test"]
  ...)

edited Dec 04 '13 at 12:47

FUD

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answered May 18 '13 at 13:47

Kiko Fernandez

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score 8 · Answer 3 · answered Sep 16 '13 at 00:14

Since I do not have the reputation to comment on the above answers, I am left with no recourse but to leave my own, ever-so-slightly different answer.

The correct syntax (as of Leiningen 2.1.3) is:

(defproject
    ...
    :java-source-paths ["src/main/java/" "foo/bar/baz/"]
    ...
)

clojure/lein: How do I include a java file in my project?

3 Answers3