where final variable reside ?

[Divya Gehlot]

Hi,
I have confusion that if declare a variable or object refernce as final then where they reside. As I was going through Inner classes topic and its like if declare variable as final Inner clas is able to access but not normal variable.

 class MyOuter2 {
private String x = "Outer2";
void doStuff() {
String z = "local variable";
class MyInner {
public void seeOuter() {
System.out.println("Outer x is " + x);
System.out.println("Local variable z is " + z); // Won't Compile!
} // close inner class method
} // close inner class definition
} // close outer class method doStuff()
} // close outer class   

Compiling the preceding code really upsets the compiler:
MyOuter2.java:8: local variable z is accessed from within inner class;
needs to be declared final
System.out.println("Local variable z is " + z);
^
Can any one exaplein why it is so?
Thanks in advance

[Manfred Klug]

Originally posted by Divya Gehlot:
Can any one exaplain why it is so?

Since it is specified this way in the JLS. Quote from 8.1.3 Inner Classes and Enclosing Instances.

Any local variable, formal method parameter or exception handler parameter used but not declared in an inner class must be declared final. Any local variable, used but not declared in an inner class must be definitely assigned (�16) before the body of the inner class.

[Deepinder Singh]

method local inner classes have access to member variables of the enclosing class.. if a local variable needs to be used it should be declared final....try writing a small program...if your into software ...you will find it used as part of IBatis ORM mapping tool usage...