Why does CheckStyle suggest that I use a final method?-Collection of common programming errors

When you declare a method to be final, you’re saying that the method may not be overridden.

Quote from the Java Language Specification:

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.

The common slogan (due to Joshua Bloch I believe) is

           “Design and Document for Inheritance or Else Prohibit it“

So, unless you’re intention is to let subclasses override the method (and potentially change the behavior of the super-class (all methods are virtual in Java)) then make the method final.