Clojure importing nested classes

Question

I am trying to write a couple of wrapper functions for the code here

it basically has the form (as given in the example page) of

String json = ...
VPackParser parser = new VPackParser.Builder().build();
VPackSlice slice = parser.fromJson(json);

I am aware that To import inner classes one uses $, but every combination of the following doesn't seem to work.

(ns the.pain.is.real
  (:require [clojure.reflect :as r])
  (:import
   com.arangodb.velocypack.VPackBuilder ;; fine
   com.arangodb.velocypack.VPackSlice ;; fine
   com.arangodb.velocypack.VPackParser ;; fine
   com.arangodb.velocypack.VPack ;; fine
   com.arangodb.velocypack.VPackParser$Builder ;; nope
))

I just get a Unhandled java.lang.ClassNotFoundException.

I had worked with some similar code that I had got working using:

(ns winning
  (:import com.arangodb.ArangoDB$Builder))
(.build (-> (new ArangoDB$Builder)
            (.host "127.0.0.1" 8529)
            (.user username)
            (.password password)))

Any ideas?

looking in the jar file does show

com/arangodb/velocypack/VPackParser$Builder.class

Is it just trial and error?

If you look inside the jar file you should be able to see the exact names of the class files. Perhaps you won't find a `VPackParser$Builder` there. — Chris Murphy, Sep 24 '17 at 13:35
@ChrisMurphy - ok. so it looks like there are 20 or so classes named ```com/arangodb/velocypack/VPackBuilder$8.class com/arangodb/velocypack/VPackBuilder$9.class ...``` — beoliver, Sep 24 '17 at 13:42
@ChrisMurphy - but I was looking at the wrong thing :( - yes there is one `com/arangodb/velocypack/VPackParser$Builder.class` — beoliver, Sep 24 '17 at 13:49
With Java I would always use a wildcard, so `com.arangodb.velocypack.*`, to make life simpler. Not sure if wildcards are possible for Clojure imports... — Chris Murphy, Sep 24 '17 at 13:56
Unfortunately a wildcard import is not possible: https://stackoverflow.com/questions/1990714/does-clojure-have-an-equivalent-of-javas-import-package — Chris Murphy, Sep 24 '17 at 22:57

score 3 · Accepted Answer · answered Sep 24 '17 at 13:54

Answering my own question.

It appears that two versions were downloaded when using lein deps. Even though only [com.arangodb/velocypack "1.0.0"] was in the project file, both 1.0.0 and 1.0.10 were in the .m2 dir. The class com/arangodb/velocypack/VPackParser$Builder.class is only found in version 1.0.10.

After changing the project file to [com.arangodb/velocypack "1.0.10"] the import works.

Clojure importing nested classes

1 Answers1