Hi, In the book, I see different bounded context requires a translation map or anti-corruption layer. So I guess that means two bounded context will not share same structure of domain model, otherwise why they need a translator? In qi4j, we also use the word context. But in the implementation, it is a composite extending several interfaces. Interface is a abstraction of role played in a context or collaboration. So, in qi4j, there are no translation between context, they all share same state with same structure. Therefore, I think the "context" are different, in Eric's book and in qi4j implementation.
2009/2/7 Niclas Hedhman <[email protected]> > On Sat, Feb 7, 2009 at 6:59 AM, tao wen <[email protected]> wrote: > > > Here the context might be more large scale than the context in qi4j. As > my > > understanding, qi4j assume a object can partipate as different roles in > > different "context" (or collaboration). So, a composite can have > different > > interface (mixin), glued in the runtime. I think in qi4j, context is the > > context within one application, but different scenario/collaboration > > (correct me if I am wrong, sorry in advance). The bounded context in > Eric's > > book or Greg's talk, is larger. > > In case of Evans, No. Contexts can not be very large, as the > Ubiquitous Language can not be maintained cross large organizational > structures. So, when teams are split for practical reasons, the > contexts are split along such organizational lines as well. We > actually re-enacted such scenario in the class (Domain Driven Theater > :-) ) where there was a split in words but not in effect. > > > They mean different system, or big portion > > of a system which forms its own physical boundary (some service gateway). > > No. This is from Evans' PoV totally irrelevant. If you take the > "Routing Service" example in the book, it is a separate context (arcs > and nodes) than the booking context (legs and stops) and from the Work > Order Context, although they very well might be within the same > physical application. That is not relevant. > > > Or we should not try to use one model to > > solve all the problem, like Eric pointed out: > > Correct. The GUM (Grand Unified Model) will fail. I have seen it > myself, and I am sure many people who likes DDD are also burned from > such experiences. Qi4j's mission in this space should be to find a way > to make multiple models in different contexts easier. Obviously Greg > think that we are doing something right, or he wouldn't mentioned it. > Evans have high hopes and wished he could spend cycles on it (he says > he is swamped)... > > Cheers > Niclas > -- > http://www.qi4j.org - New Energy for Java > > _______________________________________________ > qi4j-dev mailing list > [email protected] > http://lists.ops4j.org/mailman/listinfo/qi4j-dev >
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