Unclear whether Maven/Java based deps are supported

[GavinEsbergerOVO]

It is unclear from the README whether there is support for Maven/Java based dependencies or not.
I've create a test project that suggests it is not, however, I'd like it clarified whether this is to be expected or if I'm running into an issue.

I've create a new lein app via lein new git-down-test. Then I modified to project.clj to be as follows:

(defproject git-down-test "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 "1.10.0"]
                 ;;
                 ;[org.apache.commons/commons-lang3 "6b9964f"]
                 [org.apache.commons/commons-lang3 "3.12.0"]
                 ;;
                 ]
  :main ^:skip-aot git-down-test.core
  :repositories [["public-github" {:url "git://github.com"}]]
  :plugins [[reifyhealth/lein-git-down "0.4.0"]]
  :middleware [lein-git-down.plugin/inject-properties]
  :git-down {org.apache.commons/commons-lang3 {:coordinates apache/commons-lang}}
  :target-path "target/%s"
  :profiles {:uberjar {:aot :all}})

I can then proves this works via the following

~/I/p/git-down-test $ lein repl
nREPL server started on port 50263 on host 127.0.0.1 - nrepl://127.0.0.1:50263
REPL-y 0.3.7, nREPL 0.2.12
Clojure 1.10.0
OpenJDK 64-Bit Server VM 11.0.2+9
    Docs: (doc function-name-here)
          (find-doc "part-of-name-here")
  Source: (source function-name-here)
 Javadoc: (javadoc java-object-or-class-here)
    Exit: Control+D or (exit) or (quit)
 Results: Stored in vars *1, *2, *3, an exception in *e

git-down-test.core=> (import org.apache.commons.lang3.RandomUtils)
org.apache.commons.lang3.RandomUtils
git-down-test.core=> (RandomUtils/nextBoolean)
false

However, when I modify the project.clj to use [org.apache.commons/commons-lang3 "6b9964f"] instead then the following happens.

~/I/p/git-down-test $ lein deps
Retrieving apache/commons-lang/6b9964f/commons-lang-6b9964f.pom from public-github
Retrieving apache/commons-lang/6b9964f/commons-lang-6b9964f.jar from public-github
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by clojure.lang.Reflector (file:/usr/local/Cellar/leiningen/2.8.1/libexec/leiningen-2.8.1-standalone.jar) to method com.sun.org.apache.xerces.internal.dom.CoreDocumentImpl.getDocumentElement()
WARNING: Please consider reporting this to the maintainers of clojure.lang.Reflector
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
Created /Users/me/.gitlibs/libs/apache/commons-lang/6b9964ff4b89205d63eac3db005757edf19e9dda/target/commons-lang3-3.12.1-SNAPSHOT.jar
~/I/p/git-down-test $ lein repl
nREPL server started on port 49638 on host 127.0.0.1 - nrepl://127.0.0.1:49638
REPL-y 0.3.7, nREPL 0.2.12
Clojure 1.10.0
OpenJDK 64-Bit Server VM 11.0.2+9
    Docs: (doc function-name-here)
          (find-doc "part-of-name-here")
  Source: (source function-name-here)
 Javadoc: (javadoc java-object-or-class-here)
    Exit: Control+D or (exit) or (quit)
 Results: Stored in vars *1, *2, *3, an exception in *e

git-down-test.core=> (import org.apache.commons.lang3.RandomUtils)

Execution error (ClassNotFoundException) at java.net.URLClassLoader/findClass (URLClassLoader.java:471).
org.apache.commons.lang3.RandomUtils

If this is not expected to work then I'm not requesting it, merely that it more clearly stated this is not the intention.

[manderson202]

Thanks for raising the issue. The intent of lein-git-down is primarily for Clojure projects. There is nothing necessarily stopping someone from using it to bring in Java/mvn projects, but that project would have to have a very simple pom (eg: just dependencies, src path, resource path) since the tool doesn't know how to build a full Maven project. Looks like commons/lang3 references a parent pom and uses some Maven build plugins. The resulting jar isn't built correctly and so the class can't be found on the classpath. Will make a note to add a comment in the README for a future release.

[aiba]

I would be thrilled if it were possible in a future release to use lein-git-down to depend on Java/mvn projects.