It's return a bean than was instatinated with constructor (new MyServiceImpl()) - so it's not "anonymous object" but named bean in spring.

That bean stored in spring context for later user by same name or class.

anonymous object - it's a different entity. I think here you refer something like mymethod(new InterfaceName { ...implementation ... })

In other word you compare apples and oranges.

To make it annonymus your notation should looks like:

@Bean public MyService myService() { return new MyServiceInterface() { .... do something ... }; }