Usage of @Autowired on constructor [closed]

Question

What is the benifit of using @Autowired on constructor as below,

@Autowired
public MyClass(A a){
} 

Answer 1

This way bean A will be injected into the constructor. It is cleaner because you kind of declare the dependencies of the bean, because it can't be instantiated without supplying A. This makes testing a lot easier.

Answer 2

You can have final fields in the class, and generally even immutable class - less moving parts, cleaner code, easier to understand.

And the class is easier to test, you always know what properties to set in it to have a working class (because constructor forces you to set those) - of course one might still pass nulls in the params.