实现Clonable接口，但不必重写clone（）方法

Question

I'm learning Java and there is something that I couldn't understand. If I understand correctly, by implementing an interface I am forced to implement all the methods that the interface has.

But, what in the case of the Clonable ? If I implement it, I'm not forced to implement the clone method. Why is this happening?

Answer 1

Clonable is a marker interface, which let you know that object can be cloned. You are not forced to implement clone method, because this method already exists in your class with protected access modifier (inherit from Object::clone).

Answer 2

因为Cloneable接口没有这种方法。