Quoting from http://sites.google.com/site/gson/gson-design-document:
Why are most classes in Gson marked as final?
While Gson provides a fairly extensible architecture by providing pluggable serializers and deserializers, Gson classes were not specifically designed to be extensible. Providing non-final classes would have allowed a user to legitimately extend Gson classes, and then expect that behavior to work in all subsequent revisions. We chose to limit such use-cases by marking classes as final, and waiting until a good use-case emerges to allow extensibility. Marking a class final also has a minor benefit of providing additional optimization opportunities to Java compiler and virtual machine.
Why is this the case? [If I would guess: of JVM knows class is final it does not maintain method override tables? Are there any other reasons?]
What is the benefit in performance?
Does this applies to classes that are frequency instantiated (POJO?) or perhaps to class that are holders static methods (Utility classes) ?
Are methods defined as final also can theoretically improve performance?
Are there any implications?
Thank you, Maxim.