Load a class with a given name.
It will try to load the class in the following order:
From Thread.currentThread().getContextClassLoader()
Using the basic Class.forName()
From ClassLoaderUtil.class.getClassLoader()
From the callingClass.getClassLoader()
Parameters: className - The name of the class to load Parameters: callingClass - The Class object of the calling object throws: ClassNotFoundException - If the class cannot be found anywhere.