Why constructor cannot be declared as final in java.

Answer 1

When you set a method as final, it means : “You don’t want any class override it”, but constructor by JLS (Java Language Specification) definition can’t be overridden, so it is clean.

Constructors aren't inherited so can't be overridden then what's the use to have final constructor! ;P

Answer 2

A constructor cannot be overriden.
So there'd be no point in doing that.