I would like to know what are drawbacks of a stateless class (if any)? Has anyone seen a real-world application where some use case mandated the creation of a stateless class (No hello world please )? I think a stateless class means a class without any fields.
I never heard "stateless class", but I think you mean immutable objects (very useful notion!). Or maybe a class which doesn't have any fields, so usually it looks like just bunch of pure functions.