java basics about final keyword

Question

Can final keyword be used for a method?

Answer 1

Absolutely! The final keyword can be applied to just about anything, in each case meaning "you don't get to change this anymore."

Here's what it means when applied to...

a variable: You simply cannot assign the variable a new value (rendering it a constant, of course)

a method: You cannot re-implement (i.e., override) this method in a subclass

a class: You cannot define a subclass

In each case we're simply indicating: once this thing is declared, this is the last value (or implementation) you'll ever see for it.

Answer 2

Yes, it is possible to declare a method as final. That will mean that a method cannot be overridden by its subclasses.

From The Java Language Specifications, Third Edition, Section 8.4.3.3:

A method can be declared final to prevent subclasses from overriding or hiding it. It is a compile-time error to attempt to override or hide a final method.

For more information, the Writing Final Classes and Methods page from The Java Tutorials has more information.