Consider the following from Effective Java Item 11 (Override clone judiciously) where Josh Bloch is explaining what is wrong with the clone() contract .
There are a number of problems with this contract. The provision that “no constructors are called” is too strong. A well-behaved clone method can call constructors to create objects internal to the clone under construction. If the class is final, clone can even return an object created by a constructor.
Can someone explain what Josh Bloch is saying in the first paragraph by "If the class is final, clone can even return an object created by a constructor." What does final have to do with clone() here?
If a class is not final, clone has to return the most derived class for which it was called. That can't work with a constructor, because clone doesn't know which one to call. If a class is final, it can't have any subclasses, so there's no danger in calling its constructor when cloning.