There's nothing called "method level synchonization" that contrasts with anything that could be called "class level sychronizations". One thing you might possibly be referring to is the difference between synchronization of class (static) methods and instance (non-static) methods. Instance methods are synchronized at the instance level -- i.e., threads compete for individual objects, but the same method can be called simultaneously on two separate objects. Static methods are synchronized on the Class object for the class, and all Threads must compete for that to call any static synchronized methods in a class.
I'm going to move this to our Threads and Synchronization forum; it surely isn't Advanced Java.