slf4j Logger, LoggerFactory not working at runtime from a child jar - runtime

Question

I am a facing an issue while using slf4j Logger and LoggerFactory in a child jar (suppose CHILD.jar).
I am deploying one EAR in WebSphere. The EAR structure is like below-
Parent ear>
META-INF
Project Specific dependency jars
Project Sub Modules bundled as jars
commons-logging-1.0.4.jar
common-logging-api-1.1.jar
CHILD.jar
In CHILD.jar's MANIFEST.MF we are not giving any CLASSPTH entry as this CHILD.jar is used by several other applications and those other applications may not use any same slf4j implementor.
Below is the MANIFEST file structure-
Manifest-Version: 1.0
Build-Jdk: 1.7.0
Built-By: C12560
Archiver-Version: Plexus Archiver
Created-By: Apache Maven 3.0.4
In our application, we are keeping all the jar at the same hierarchy where the CHILD.jar is present.
Now while deploying, no exception is thrown. At runtime, it is throwing InvocationTargetException (and NoClassDefFoundError) in all those classes where we have used org.slf4j.Logger and org.slf4j.LoggerFactory.
If we comment out all these logger entries, the application is working fine and no exception is thrown at runtime.
Even if we use org.apache.log4j.Logger instead of org.slf4j.Logger, the code is working at runtime(Note- log4j-1.2.13.jar is present in the same hierarchy as CHILD.jar).
Queries-
Is slf4j not getting its implementor?
Any jar I have to include in the hierachy same as CHILD.jar?
Please note- I have tried including jcl-over-slf4j jar and log4j-over-slf4j.jar(and removed common-logging.jar) in the same hierarchy as CHILD.jar but it didn't work.
Any help is highly appreciated.

Answer 1

if you want to use jcl or log4j as implementor of slf4j, what you need is slf4j-jcl.jar or slf4j-log4j.jar.
Besides, when getting a NoClassDefFoundError, you should go through the full stacktrace. Usually it is caused by some other exception.