Question

Possible Duplicate:
Why is a serializable inner class not serializable?

I have a class that does not implement Serializable. Inside of that class I have a data class which holds data for the whole program which implements Serializable and has a version ID.

My problem is that when I try to serialze a data object with in my main class I get a object write error from the main class and not the data class. The main class does not implement Serializable.

Can you serialize a class within a non-serializable class?

Example:

class main
{
   class data implements Serializable
   {  // data and functions }

   public void main(args)
   { data d = new data();
     // ofcourse I have the proper inits and checks for the output stream and such
     writeObject(data);  // Throws Class not Serializable error.}
} 

Answer 1

As data is not static it implicitly has a reference to its outer class main which is not Serializable.

Try making the class static.