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From "David W. Van Couvering" <David.Vancouver...@Sun.COM>
Subject Backward compatibility of DataSource implementations
Date Tue, 22 Nov 2005 22:43:31 GMT
In my ongoing investigation, it has become quickly obvious to me that 
the various DataSource implementations we have must be serializeable so 
they can be stored in a JNDI repository.

This means that they must maintain a strict level of compatibility so 
that there are not serialization errors if the version of the class 
stored in the JNDI repository is older than the version of the class in 
the classloader of the client.

 From the comments of ClientDataSource:

- No deleting of fields
- No changing of non-static to static or non-transient to transient, as 
this is equivalent to deleting fields
- No changing of field types within the class
- Cannot alter the position of the class in the class hierarchy
- Cannot change class name or package name

Also, it appears we are making every effort to keep the size of these 
objects reasonably small as they will in all likelihood be serialized 
over the network from the JNDI repository to the client.

Do I have that right?



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