jlink fails on ring-json 0.5.1 - clojure

Question

I have a small Clojure project with /project.clj:
(defproject testjackson "0.1.0-SNAPSHOT"
:main testjackson.core
:dependencies [[org.clojure/clojure "1.10.3"]
[ring/ring-json "0.5.0"]])
and /src/testjackson/core.clj:
(ns testjackson.core
(:gen-class)
(:require [ring.middleware.json :refer [wrap-json-body]]))
(defn -main [& _] (println :testing wrap-json-body))
When I run it, it just prints:
$ java -jar target/testjackson-0.1.0-SNAPSHOT-standalone.jar
:testing #object[ring.middleware.json$wrap_json_body 0x37cd92d6 ring.middleware.json$wrap_json_body#37cd92d6]
It runs as expected. I can also execute jdeps on the uberjar to get the list of used modules:
$ jdeps --print-module-deps --ignore-missing-deps target/testjackson-0.1.0-SNAPSHOT-standalone.jar
java.base,java.desktop,java.sql,jdk.unsupported
However, when I bump ring-json version to 0.5.1, the jdeps call fails:
$ jdeps --print-module-deps --ignore-missing-deps target/testjackson-0.1.0-SNAPSHOT-standalone.jar
Exception in thread "main" java.lang.module.FindException: Module com.fasterxml.jackson.core not found, required by com.fasterxml.jackson.dataformat.smile
at java.base/java.lang.module.Resolver.findFail(Resolver.java:877)
at java.base/java.lang.module.Resolver.resolve(Resolver.java:191)
at java.base/java.lang.module.Resolver.resolve(Resolver.java:140)
at java.base/java.lang.module.Configuration.resolve(Configuration.java:422)
at java.base/java.lang.module.Configuration.resolve(Configuration.java:256)
at jdk.jdeps/com.sun.tools.jdeps.JdepsConfiguration$Builder.build(JdepsConfiguration.java:564)
at jdk.jdeps/com.sun.tools.jdeps.JdepsTask.buildConfig(JdepsTask.java:603)
at jdk.jdeps/com.sun.tools.jdeps.JdepsTask.run(JdepsTask.java:557)
at jdk.jdeps/com.sun.tools.jdeps.JdepsTask.run(JdepsTask.java:533)
at jdk.jdeps/com.sun.tools.jdeps.Main.main(Main.java:49)
How can this be fixed in the context of this small example program?

Answer 1

As near I as can find from searching, jdeps is from way back in Java 9. In fact, the version on my computer won't even accepts the 2 flags you used in the example, and it doesn't even have a --version option. Web searching shows no obvious uses for clojure.
What is the goal here? Your plain code works fine for me:
project.clj deps
:dependencies [
[org.clojure/clojure "1.11.1"]
[prismatic/schema "1.2.1"]
[ring/ring-json "0.5.1"]
[tupelo "22.05.24b"]
]
:plugins [[com.jakemccrary/lein-test-refresh "0.25.0"]
[lein-ancient "0.7.0"]
]
code
(ns demo.core
(:use tupelo.core)
(:require [ring.middleware.json :refer [wrap-json-body]])
(:gen-class))
(defn -main [& _]
(spyx (type wrap-json-body)))
and results
> lein clean ; lein run
(type wrap-json-body) => ring.middleware.json$wrap_json_body
Speculation
Although my jlink doesn't seem to work right, I can guess a little. Looking at project.clj, we can ask for a tree of depencencies:
> lein deps :tree
[nrepl "0.8.3" :exclusions [[org.clojure/clojure]]]
[org.clojure/clojure "1.11.1"]
[org.clojure/core.specs.alpha "0.2.62"]
[org.clojure/spec.alpha "0.3.218"]
[org.nrepl/incomplete "0.1.0" :exclusions [[org.clojure/clojure]]]
[prismatic/schema "1.2.1"]
[ring/ring-json "0.5.1"]
[cheshire "5.10.0"]
[com.fasterxml.jackson.core/jackson-core "2.10.2"]
[com.fasterxml.jackson.dataformat/jackson-dataformat-cbor "2.10.2"]
[com.fasterxml.jackson.dataformat/jackson-dataformat-smile "2.10.2"]
[tigris "0.1.2"]
[ring/ring-core "1.9.2"]
[commons-fileupload "1.4"]
[commons-io "2.6"]
[crypto-equality "1.0.0"]
[crypto-random "1.2.0"]
[ring/ring-codec "1.1.3"]
[commons-codec "1.15"]
So we see that ring-json needs cheshire, which needs jackson.
Going back to ring-json 0.5.0 we see different version of cheshire and jackson:
> lein deps :tree
[nrepl "0.8.3" :exclusions [[org.clojure/clojure]]]
[org.clojure/clojure "1.11.1"]
[org.clojure/core.specs.alpha "0.2.62"]
[org.clojure/spec.alpha "0.3.218"]
[org.nrepl/incomplete "0.1.0" :exclusions [[org.clojure/clojure]]]
[prismatic/schema "1.2.1"]
[ring/ring-json "0.5.0"]
[cheshire "5.9.0"]
[com.fasterxml.jackson.core/jackson-core "2.9.9"]
[com.fasterxml.jackson.dataformat/jackson-dataformat-cbor "2.9.9"]
[com.fasterxml.jackson.dataformat/jackson-dataformat-smile "2.9.9"]
[tigris "0.1.1"]
[ring/ring-core "1.7.1"]
[clj-time "0.14.3"]
[joda-time "2.9.9"]
[commons-fileupload "1.3.3"]
[commons-io "2.6"]
[crypto-equality "1.0.0"]
[crypto-random "1.2.0"]
[ring/ring-codec "1.1.1"]
[commons-codec "1.11"]
Note that you can force newer versions in project.clj if you want. Just manually require cheshire and jackson, and put them near the top!
:dependencies [
; priority 1 libs
[org.clojure/clojure "1.11.1"]
[cheshire "5.10.2"]
[com.fasterxml.jackson.core/jackson-core "2.13.3"]
[com.fasterxml.jackson.dataformat/jackson-dataformat-cbor "2.13.3"]
[com.fasterxml.jackson.dataformat/jackson-dataformat-smile "2.13.3"]
; priority 2 libs
[prismatic/schema "1.2.1"]
[ring/ring-json "0.5.0"]
; [tupelo "22.05.24b"]
]
with result
> lcr
time (lein do clean, run)
:type ring.middleware.json$wrap_json_body
8.11s user 0.59s system 218% cpu 3.989 total
~/expr/demo >
~/expr/demo >
~/expr/demo > lein deps :tree
[cheshire "5.10.2"]
[tigris "0.1.2"]
[com.fasterxml.jackson.core/jackson-core "2.13.3"]
[com.fasterxml.jackson.dataformat/jackson-dataformat-cbor "2.13.3"]
[com.fasterxml.jackson.core/jackson-databind "2.13.3"]
[com.fasterxml.jackson.core/jackson-annotations "2.13.3"]
[com.fasterxml.jackson.dataformat/jackson-dataformat-smile "2.13.3"]
[nrepl "0.8.3" :exclusions [[org.clojure/clojure]]]
[org.clojure/clojure "1.11.1"]
[org.clojure/core.specs.alpha "0.2.62"]
[org.clojure/spec.alpha "0.3.218"]
[org.nrepl/incomplete "0.1.0" :exclusions [[org.clojure/clojure]]]
[prismatic/schema "1.2.1"]
[ring/ring-json "0.5.0"]
[ring/ring-core "1.7.1"]
[clj-time "0.14.3"]
[joda-time "2.9.9"]
[commons-fileupload "1.3.3"]
[commons-io "2.6"]
[crypto-equality "1.0.0"]
[crypto-random "1.2.0"]
[ring/ring-codec "1.1.1"]
[commons-codec "1.11"]
Perhaps something similar will solve your problem. It has been crucial for me in the past.
Specifically, the jackson libs absolutely must
have all 3 sub-libraries on the same version. Because dependent libs
often don't update their own deps like jackson as often as they could, it is easy to get version conflicts when 2 or more libs each require different versions of jackson. The above technique of forcing a specific version of jackson (or any other lib) is a lifesaver. IMHO, it is also much better than trying to put in a bunch of lein :exclusions clauses.