Name: dbT83986 Date: 03/01/99


Currently, debugging a problem in serialization code is difficult.
The stack trace information that one gets is often just a long
sequence of recursive writeObject()/readObject() calls. This tells
one very little about where in the graph of objects that the
serialization actually failed.

What I'd like to see is a second trace that shows what objects
were being serialized at the time. It should list the object
(using toString()) and which field it was stored in. For example...

java.io.NotSerializableException: Mustard
   field "toppings": Mustard["Grey Pupon"]
   field "lunch": Sandwich["Smoked Meat"]
   field "container": PinicBasket[Sandwich,Pop,PotatoChips]
   ...
   field "star": Star[Yellow,K7,"The Sun"]
   field "galaxy": SpiralArmedGalaxy["Milky Way"]
   root: Universe@12345678

The above trace would very quickly show that either the class
"Mustard" needs to be made serializable (which admittedly could
be determined from the exception message) or that the "toppings"
field in the "Sandwich" class needs to be made transient. This
last insight would take a lot of luck if one had to manually
trace all the references starting from the root Universe.

I suggest that you make the necessary changes in the ObjectStreamException
class. That way any exception specific to serialization will
carry the "serialization trace". I'm not sure what format would
make the most sense (the listing above is only an example). Also,
I anticipate that you'll need to give special consideration to
representing elements in an array.
(Review ID: 53980)
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