resteasy providers missing after mvn package

Question

I have written some code that uses some resteasy libraries.

The code works fine in Eclipse but produces exceptions when excecuted as fat-jar build with the maven sha

Answer 1

The accepted answer is correct, but is for Maven's Shade plugin. If you're using Gradle's Shadow plugin, you must merge service descriptor files.

Using Gradle's Kotlin DSL:

tasks {
    withType<ShadowJar> { mergeServiceFiles() }
}

Using Gradle's Groovy DSL:

shadowJar { mergeServiceFiles() }

Answer 2

Ok, i found the solution.

Maven shade plugin allows you to force append files that are identically named...

So what the maven-shade-plugin in the pom.xml lags is:

<transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
  <resource>META-INF/services/javax.ws.rs.ext.Providers</resource>
</transformer>

https://maven.apache.org/plugins/maven-shade-plugin/examples/resource-transformers.html#AppendingTransformer