The classloading system is quite flexible, getting a class to load is generally just matter of configuration (e.g. system paths in jboss-deployment-structure.xml). Perhaps that comment is for an older AS version.
First of all thanks for your response!
The problem is that I actualy get the warning log and the class not found exception within jboss as 7.1.1. I agree that classloading is flexible however I'd like to know why this class cannot be found since I'm using oracle jdk and the class is actually there?
Java vendor specific classes (sun.* classes for example) aren't made visible to the applications by default. Take a look at the classloading chapter on how it all works https://docs.jboss.org/author/display/AS71/Class+Loading+in+AS7