Why is almost everything in the API final

[Pedro Duque Vieira]

Hi,

Why is almost everything in the API final? OK, I understand there is a
security problem and not making things final could potential open security
holes.
What I'm puzzled about is that the rest of the JDK doesn't use this pattern
and so I wonder if it is still effective this way?
I'm asking this because the penalties are significant, since you can not
easily extend the API because you can't subclass most framework classes.

Thanks, best regards,

-- 
Pedro Duque Vieira