Method local inner class and accessing local variables

[Larry Olson]

Hi,

I understand that method local inner classes (i.e. inner classes defined from within a method) can't access the method's local variables, since the local variables live on the stack and are bust after the method is done, but the instance of the method local inner class could live much longer (since a reference could be returned and used).

But I also read that while the method local inner classes can't access a local variable, there is an exception to the rule - that the method local inner class could access a "final" local variable. How come? Don't all local variables including "final" local variables live on the stack? So how can a method inner classe's instance access a "final" local variable, even though it can't access non-final local variables.

Could someone please throw some light on this?

Thanks

[Ankit Garg]

The method local inner class gets a copy of the final variables of the enclosing method. Since it is known that the value of the final variable won't change, so when an instance of the method local inner class is created, it gets a copy of the final variables of the class which the method local inner class stores as instance fields. This is all hidden from us and is done automatically by the compiler...

[Larry Olson]

I see. One of those mysteries of java that happens under the covers. Thanks.

[Abimaran Kugathasan]

Ankit Garg wrote:The method local inner class gets a copy of the final variables of the enclosing method. Since it is known that the value of the final variable won't change, so when an instance of the method local inner class is created, it gets a copy of the final variables of the class which the method local inner class stores as instance fields. This is all hidden from us and is done automatically by the compiler...

So, it is an attribute of that method local inner class?

[Ankit Garg]

Abimaran Kugathasan wrote:So, it is an attribute of that method local inner class?

Yes they (i.e. final local variables of a method) becomes an instance field of the method local inner class...

[Abimaran Kugathasan]

Thanks Ankit......