Hi,
I'm evaluating possible solutions for a new web service api we need to make. Initially it will have to be a somewhat rpc-ish api (we're targetting existing j2me/gprs clients), but I hope to make it so that we can evolve it into something more restish as we go along.
My main concern right now is how to handle the mapping between the domain and the representations, with the added complexity of things like generated urls. Earlier this year, there was a thread on rest-discuss, which overall seemed to lean towards something like:
25. feb. 2010 kl. 20.37, Craig McClanahan [1]:
> When using JAX-RS, I'm finding myself more and more often building a
> set of JAXB annotated classes that directly represent my resources,
> separate from the classes that might represent my domain tier (with,
> perhaps, JPA or Hibernate annotations on them).
My own experience has been something of the same (or rather, trying the one model approach has proven difficult :) , but I am wondering if someone had more practical experiences/solutions to share for such a solution?
Let's take an example. Say you want some simple jaxb model where elements with generated urls will be reused in different representations:
<activity>
<person>
<orgUnit href="some url generated with jersey" />
</person>
</activity>
<orgUnits>
<orgUnit href="same url generated with jersey" />
</orgUnit>
So, I want some kind of service layer responsible for doing the mapping to/from a domain model to the jaxb resource model creating this xml. I would want this layer to be reasonably clean, without too much manual handling (or else changes quickly become difficult), but it has to solve a somewhat complex set of tasks:
- mapping between models where the dto/jaxb objects and the domain objects are not similar (not one-to-one).
- keeping track of objects that need things like urls generated and inserted at the appropriate place.
- modular, so the same object mapping can be reused in different representations
I could try to roll my own little framework helping with these tasks, but it would obviously be much better if there already are good solutions out there. What do others do, have you found good framework support for this?
And, while waiting for jersey-server-linking to be ready for primetime (can we expect it to be promoted from experimental soon?), I'm also contemplating how to elegantly handle the generation of urls. The last time I as working with jersey, I rolled my own annotations similar to jersey-server-linking, but would like to avoid it if possible. Any ideas?
[1]
http://tech.groups.yahoo.com/group/rest-discuss/message/14914
That will have to do for the weekend :)
Jo