Objects returned by a java list not getting deserialized

Hi

I am calling a java function which return a list. This list include two types of object say Gallery and galleryGroup. These objects have implemented Externalizable interface. There are corresponding object in Flex say Gallery and GalleryGroup, which also implement IExternalizable interface.

A call has been made to java object to return the list which include object of Gallery and GalleryGroup. If object Gallery  is not instantiated before the result is received, It gives following error.

ArgumentError: Error #2173: Unable to read object in stream.  The class Gallery does not implement flash.utils.IExternalizable but is aliased to an externalizable class

If I create an object of Gallery i.e var galObj:Gallery = new Gallery();

before a call on remote object, result is retrieved successfully.

Is there a way to handle this error?

Thanks

Ajay