Compojure with Datomic won't compile - clojure

Question

I'm setting up a compojure app, and I want to have datomic as my database - but as soon as I add the client-pro dependency, my app won't run.
Here's what I did:
Registered for an account
Downloaded datomic-pro
Created a transactor.properties and updated it with the license-key I received on my email
Ran bin/transactor transactor.properties
Opened another tab, and created a database:
(require ‘[datomic.api :as d])
(def db-uri “datomic:dev://localhost:4334/hello”)
(d/create-database db-uri)
Started a peer server on another tab
bin/run -m datomic.peer-server -h localhost -p 8998 -a myaccesskey,mysecret -d hello,datomic:dev://localhost:4334/hello
Added [com.datomic/client-pro “0.8.28”] to my dependencies
When running lein ring server I am getting this error:
Caused by: java.lang.ClassNotFoundException: org.eclipse.jetty.util.thread.NonBlockingThread

Answer 1

A Quick Aside
Not a direct answer, but if you are just looking for a fast start with Datomic, you can clone the Tupelo Datomic repo here:
https://github.com/cloojure/tupelo-datomic
It includes a pre-configured version of Datomic Free. Just run lein test to see it in action. You can then add your own code.
Regarding Jetty
The answer from Erwin may be all you need. Another possibility is that you may need to add in transitive dependencies at specific versions, and use :exclude on others. Please also note that in project.clj important deps MUST be listed at the top of the file, as these deps versions (and their transitive deps versions) WILL OVERRIDE any deps versions specified later.
I have lein deps for one project that look like this in project.clj:
:exclusions [cheshire
com.cognitect/transit-clj
com.cognitect/transit-cljs
com.cognitect/transit-java
com.cognitect/transit-js
com.fasterxml.jackson.core/jackson-core
com.fasterxml.jackson.core/jackson-databind
com.fasterxml.jackson.dataformat/jackson-dataformat-cbor
com.fasterxml.jackson.dataformat/jackson-dataformat-smile
joda-time/joda-time
org.eclipse.jetty/jetty-server]
:dependencies [
; fundamental items must come first to override later transitive dependencies
[cheshire "5.8.1"]
[com.cognitect/transit-clj "0.8.313"]
[com.cognitect/transit-cljs "0.8.256"]
[com.cognitect/transit-java "0.8.337"]
[com.cognitect/transit-js "0.8.861"]
[com.fasterxml.jackson.core/jackson-core "2.9.9"]
[com.fasterxml.jackson.core/jackson-databind "2.9.9"]
[com.fasterxml.jackson.dataformat/jackson-dataformat-cbor "2.9.9"]
[com.fasterxml.jackson.dataformat/jackson-dataformat-smile "2.9.9"]
[joda-time/joda-time "2.10.3"]
[org.clojure/clojure "1.10.1"]
[org.eclipse.jetty/jetty-server "9.4.19.v20190610"]
then a list of 2nd-tier deps:
; high-priority libs, ensure these versions override any transitive dependency versions
[binaryage/devtools "0.9.10"]
[binaryage/oops "0.7.0"]
[com.andrewmcveigh/cljs-time "0.5.2"]
[com.cemerick/url "0.1.1"]
[org.clojure/core.async "0.4.500" :exclusions [org.clojure/tools.reader]]
[org.clojure/core.match "0.3.0"]
[org.clojure/test.check "0.9.0"]
[org.clojure/tools.cli "0.4.2"]
[org.clojure/tools.logging "0.5.0"]
[org.clojure/tools.nrepl "0.2.13"] ; #todo #awt upgrade => [nrepl "0.3.1"] from https://github.com/nrepl/nrepl
[prismatic/schema "1.1.11"]
[tupelo "0.9.144"]
[venantius/accountant "0.2.4"]
then 3nd-tier deps:
; "normal" dependency libs, whose transitive dependencies can be overridden by previous libs
[ch.qos.logback/logback-classic "1.2.3"]
[clj-http "3.10.0"]
[clj-time "0.15.1"] ; #todo switch to java.time & tupelo.java-time
[cljsjs/cytoscape "3.1.4-0"]
[com.amazonaws/aws-java-sdk "1.11.602" :exclusions [joda-time]]
[com.taoensso/carmine "2.19.1"]
[compojure "1.6.1"]
[cprop "0.1.14"]
[expound "0.7.2"]
[funcool/struct "1.4.0"]
[io.janusplatform/janus-environment-config "1.8.7-SNAPSHOT"]
[io.janusplatform/janus-logging-java "1.0.11-SNAPSHOT" :exclusions [com.google.guava/guava]]
[io.janusplatform/janus-resource-connector "4.3.0-SNAPSHOT"]
[jayq "2.5.5"]
[luminus-jetty "0.1.7" ]
[luminus-nrepl "0.1.6"]
[luminus/ring-ttl-session "0.3.3"]
[markdown-clj "1.10.0"]
[metosin/muuntaja "0.2.1"]
[metosin/ring-http-response "0.9.1"]
[metosin/spec-tools "0.10.0"]
[metosin/scjsv "0.5.0"]
[metrics-clojure-ring "2.10.0"]
[mount "0.1.16"]
[org.webjars/bootstrap "4.3.1"]
[org.webjars/font-awesome "5.9.0"]
[overtone/at-at "1.2.0"]
[ring-webjars "0.2.0"]
[ring/ring-codec "1.1.2"]
[ring/ring-core "1.7.1"]
[ring/ring-defaults "0.3.2"]
[ring/ring-json "0.4.0"]
[throttler "1.0.0"]
and some misc deps:
[amazonica "0.3.145" :exclusions [com.amazonaws/aws-java-sdk
com.fasterxml.jackson.core/jackson-core
com.fasterxml.jackson.dataformat/jackson-dataformat-cbor
org.apache.httpcomponents/httpclient]] ; #todo do we really need all these exclusions???
[cljs-ajax "0.8.0" :exclusions [cheshire
com.cognitect/transit-clj
com.cognitect/transit-java
org.apache.httpcomponents/httpasyncclient
org.apache.httpcomponents/httpcore
org.msgpack/msgpack]] ; #todo do we really need all these exclusions???
[org.springframework/spring-webmvc "5.1.8.RELEASE" :exclusions [org.springframework/spring-jcl
org.springframework/spring-aop]]
]
You can also see I had to exclude Jetty to prevent a transitive dependency from pulling in the wrong version, then specifically add in the version I wanted.