[Objectbridge-jdo-dev] ojb suitable for jdo implementation

[Sebastian K. <seb...@mu...>]

Hi,

I'm strongly interested in (working on) open-source jdo implementations and 
noticed your project. I took a first look at ojb and wondered about the 
following problem:

If I understood the source code correctly, ojb uses reflection to read/write 
member variables of persistence capable classes. On the other hand, jdo uses 
an explicit interface (PersistenceCapable) implemented automatically by the 
enhancer. My question is: Do you want to keep the "reflection-based" approach 
for your jdo implementation? This would probably lead to problems when 
working with enhanced classes, as they expect a state-manager providing them 
their fields via the the methods defined in the PersistenceCapable (and 
StateManager) interfaces. However, the spec requires binary compatibility 
between jdo implementations, e.g. it has to work with classes enhanced by the 
reference enhancer.

Of course there are other tradeoffs between the reflection-based approach and 
an enhancer-based approach:

- Reflection should be somewhat slower than enhanced classes
- Enhancement is another step in the build process and can make debugging 
difficult
- Enhancement does not require Proxy-generated classes as stubs to load 
objects from the datastore on-demand.

So, to summarize my question: Do you want to keep the reflectio-based 
approach or is a solution possible, where data read from the data store is 
passed to a StateManager instead of directly into the PersistenceCapable 
instance?

ciao Sebastian

-- 
Sebastian Kanthak    |    seb...@mu...