Usage of Inner class

[Ravi Kiran Savirigana]

Hi
I always wonder what is the actual use of Inner classes in Java.

I thought about it and came up with one use...dont know whether this is correct or not

If there is a logic that could be actually separated from another class, and if it is not worth of creating a new object...may be due to memory management...then Inner class is the solution...

Is this actually correct??

Appreciate your time on this qn.

[Campbell Ritchie]

That doesn't sound a good design. Inner classes have nothing to do with memory management. The inner class represents something which is closely related to the outer class. So a LinkedList class would have a (probably nested) LinkedNode class.

[Ravi Kiran Savirigana]

hey Campbell,
Thankyou very much for the reply. The comment i made earlier is just a guess...

But I still dont understand why, even if a class is very close to another class, why cant it be in a new class, rather than in the same class. Is there any specific reason...My doubt is ...why a new concept...if we can go with the older one...which is already a good OO approach..

[Campbell Ritchie]

There may be no need for the inner class to be available to other classes. A LinkedList does not need to expose its inner ListNode class.

[Ravi Kiran Savirigana]

Hi Campbell,
Thanks for the reply...now I got it...May be...if you dont want to expose your class to others...and you want to keep it seperately ifrom your class...then Inner Class is the solution...
May be a type of security???