no compile time error when autowired annotation is not used and reference of that class is used to call method of that class

steps to reproduce:-
1.create an interface (ex inf)
2.create a class(ex con) that implements interface.
3.create a class(ex con2).
4.Declare a reference(ex ref)of con in con2 without using autowire annotation.
5.use ref to call method of con

Expected result:-Complile time error should show when calling con class method using ref.

Actual result:- No Complile time error is showing when calling con class method using ref.