Object-Oriented Concepts - SCJP Sun Certified Programmer for Java Platform SE6 - page 400

The MyLogger class is also declared final , meaning that it cannot be subclassed. For
example, the following InvalidLogger class does not compile because it attempts to extend
MyLogger :
public class InvalidLogger extends MyLogger {
public InvalidLogger(java.io.File dest) {
super(dest);
}
}
The compiler generates the following error:
InvalidLogger.java:1: cannot inherit from final MyLogger
public class InvalidLogger extends MyLogger {
^
1 error
Naming Convention for Final Variables
The naming conventions of Java specify that variable names of constants be in all
uppercase letters. For example:
final long TIME = new java.util.Date().getTime();
If the variable name is a compound word, use the underscore character to separate
the words. For example:
final String COMPANY_NAME = “Sybex”;
For more information on Java naming conventions, visit http://java.sun.com/docs/
codeconv.
The final modifi er on a fi eld does not affect how the fi eld is inherited. A subclass still
inherits the fi eld in the same manner as a non-fi nal fi eld; final methods are also inherited in
the same manner as non- final methods. The only difference is that a final method cannot
be overridden in the child class.
Static methods can also be declared final , meaning they cannot be overridden. For
example, the following MyStaticLogger class declares a final static method named
logMessage :
import java.io.File;
public class MyStaticLogger {