Method local Inner class

Question

Why method local class can access only the final varaible of the method?
I found somewhere that this is because the non-final local variables go out of scope after method completion, but i wonder final local variables also reside on the stack.
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()
}

Answer 1

pxNet wrote:
and so you are now saying it accesses the original variable, not a copy of it?No, I'm not saying that at all; see reply #1. The situation is quite the opposite, the inner class accesses a copy of the variable. Direct access to the local variable is most definitely not allowed. But that doesn't have anything to do with parameter-passing semantics.
I'll try to clarify with another demonstration of the problem. Assume that direct access to non-final local variables was actually allowed, and that the following example would compile (it won't, of course): class Outer {
    Inner method() {
        Object o = "foo";
        return new Inner() {
            public void modifyLocalVariable() {
                o = "bar";
    interface Inner {
        void modifyLocalVariable();
    public static void main(String[] args) {
        Inner inner = new Outer().method();
        inner.modifyLocalVariable(); // what local variable is this modifying?
                                     // the local variable in method() has gone
                                     // out of scope!
}Because of the way anonymous inner and local classes are implemented, they get a copy of the local variables (per the JLS). Mind you, there isn't any parameter passing going on at all in this example.
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