I have a multimodule maven project organized such that one module is the JAX-RS application and another module is the KumuluzEE app itself. The latter depends on the former. I have pushed a very small repo to demonstrate the issue at https://github.com/andref/kumuluzee-uberjar-bug.
The app runs fine from any IDE or from the command line:
java -cp $(ls application/target/classes/lib/*.jar | paste -s -d":" -) \
com.kumuluz.ee.EeApplication
During the start-up process, it notes:
INFO -- KumuluzEE running in an exploded class and dependency runtime.
The app responds as expected:
$ curl -X HEAD -I http://localhost:8080/v1/hello
HTTP/1.1 200 OK
Date: Sat, 01 Sep 2018 17:21:08 GMT
X-Powered-By: KumuluzEE/2.5.3
Content-Type: application/json
Content-Length: 11
Server: Jetty(9.4.8.v20171121)
Now, if I run the uberjar generated by the kumuluzee-maven-plugin, things go wrong. The app notes:
INFO -- KumuluzEE running inside a JAR runtime.
And although it appears to be running, it does not respond:
$ curl -X HEAD -I http://localhost:8080/v1/hello
HTTP/1.1 404 Not Found
Date: Sat, 01 Sep 2018 17:21:56 GMT
X-Powered-By: KumuluzEE/2.5.3
Cache-Control: must-revalidate,no-cache,no-store
Content-Type: text/html;charset=iso-8859-1
Content-Length: 324
Server: Jetty(9.4.8.v20171121)
As there's nothing really weird about packaging the JAX-RS resources and application in a jar (since the equivalent war webapp would run just fine), I believe this must be a bug in either the maven plugin or the class loading mechanism used by the uberjar.