Is custom enum Serializable too?

Question

I understand Enum is Serializable. Hence, it is safe to do so. (selectedCountry is enum Country)

Original enum without customer member var

Answer 1

The serialization of enum members is not working. The nonSerializable field is never serialized as @vmironov answered. Here is a test:

public enum Country {
Australia;

    public static class NonSerializableClass {
       public NonSerializableClass() {}
       public String dummy;
    }

    public NonSerializableClass nonSerializableClass;
}

The code writing the enum to the serialization stream:

public class SerializationTestWrite {
    public static void main(String[] args) throws Exception{
        FileOutputStream f = new FileOutputStream("tmp");
        ObjectOutput s = new ObjectOutputStream(f);

        Country.Australia.nonSerializableClass = new Country.NonSerializableClass();
        Country.Australia.nonSerializableClass.dummy = "abc";

        s.writeObject(Country.Australia);
        s.flush();

        System.out.println(Country.Australia.nonSerializableClass.dummy);
    }
}    

On writing the value of the dummy field is: abc

The code reading the enum from the serialization stream:

public class SerializationTestRead {
    public static void main(String[] args) throws Exception{
        FileInputStream in = new FileInputStream("tmp");
        ObjectInputStream so = new ObjectInputStream(in);
        Country readed = (Country) so.readObject();

        System.out.println(readed.nonSerializableClass);
    }
}

But on reading, the value of the field nonSerializableClass is: null