Keywords: final

final means "cannot be changed after assignment": a final variable cannot be reassigned, a final method cannot be overridden, and a final class cannot be extended.

Yes. You can always read a final variable's value and assign it to another variable. final prevents reassignment of the variable, not reading its value.

It compiles as a declaration, but you must assign it exactly once before reading it. For a local, the definite assignment rule applies. For a field, every constructor must assign it.

final prevents change (variable/method/class). finally is a cleanup block that always runs. finalize() is a deprecated GC callback – never use it.