Does Grails + Maven + JCL work in conjunction?

Question

I'm working with IntelliJ IDEA 10.0.1 and Grails 1.3.7. I have a mavenized Grails project which depends on many logging libraries.

Here's the problem:
I have to use JCL as logging framework, but grails per default is working with SLF4J and has some default dependencies like jcl-over-slf4j, which are inherited by every grails project. First of all I have excluded every jcl-over-slf4j transitive dependency in my project pom file and verified with mvn dependency:tree that my pom is clean of any SLF4J bridging libraries.

But nevertheless jcl-over-slf4j is still beeing downloaded to my local maven repo when I try to start my grails app. This leads obviously to a StackOverflowError at runtime, since both jcl-over-slf4j and slf4j-jcl are in the classpath.

So because of which declaration the jcl-over-slf4j dependency is still beeing downloaded?

Since my pom is clean the obvious conclusion would be that Grails itself depends on those libraries. As mentioned before Grails has some default dependencies, on which every Grails project depends.

I know that I can exclude inherited depencencies in the BuildConfig.groovy file and if I run grails dependency-report I can also see that these dependencies are not listed anymore.

grails.project.dependency.resolution = { 
    inherits("global") {
      excludes "jcl-over-slf4j", "jul-to-slf4j", "slf4j-log4j12"
    }
}

But even then the jcl-over-slf4j dependency is still beeing downloaded to my repo when I start my grails app! Am I missing something? Is there a different way to exclude inherited grails dependencies when you're using a mavenized grails project?

Any help would be appreciated

Thanks! Slash

Mr. Slash Mr. Slash · Accepted Answer · 2011-06-07T07:14:15

Ok I think I got the answer now..

The problem is that the defined maven-grails-plugin (which is mandatory when you use maven + grails) within my pom file depends on jcl-over-slf4j and therefore gets downloaded when I start my application through maven. With my current maven version (2.2.1) it's not possible to exclude a dependency from a plugin. There is also a jjira issue regarding this problem. Can not exclude a dependency from a plugin

As soon as I remove the maven-grails-plugin the dependency is not downloaded anymore, but as drawback I'm not able to start the application through maven anymore..

Lessons learned: Don't use Maven + Grails + JCL in conjunction.

Note that with mvn dependency:tree just project dependencies are listed, but plugin dependencies are NOT listed.

Hope this is of any help! Regards Slash

Does Grails + Maven + JCL work in conjunction?

1 Answers