Hi Andrew,
On 7/14/06, Andrew McCulloch <[EMAIL PROTECTED]> wrote:
I have been reading up a bit on the EJB 3 spec and I would like to look into
updating / cloning the current EJBControl to support the EJB 3.0 client
contracts. I am looking for a few pointers on what features of the new spec
the community might be most interested in (it may be too new for this
feedback). I would also be receptive to any other thoughts on this topic
that you may have.
My current plan:
1. Determine if the current controls works against EJB 3 beans that use the
back-compat annotations in the spec to produce the remote interfaces and
other EJB 2.1 artifacts.
+1
2. Determine what would have to be modified on the Session Bean Control to
use only the Business interface through direct lookups.
3. Determine what would have to be modified on the Entity Bean Control to
use only EJB 3.0 artifacts through direct lookups.
4. Determine what would have to be modified on the 2 controls to make use of
EJB Dependency Injection instead of direct lookups.
Can you describe a few use-cases for these items? I'm not very
knowledgeable about EJB 3, but it seems to me that the EJB 3 client
model has essentially standardized much of the value-add that the EJB
control offered in terms of simplifying the EJB 2.1 client model, to
the point where I don't really understand how what you're proposing
would make life easier for the developer.
Take a classic session bean use-case:
---
EJB 2.1:
Trader trader = null;
try {
InitialContext ic = new InitialContext();
TraderHome home = (TraderHome)ic.lookup("MyTraderBean");
trader = home.create();
TradeResult tradeResult = trader.buy(stock, shares);
return tradeResult;
}
catch (NamingException e) {
...
}
catch (CreateException e) {
...
}
catch (RemoteException e) {
...
}
finally {
if (trader != null)
trader.remove();
}
EJB Control:
@Control
TraderControlBean traderControl;
try {
TradeResult tradeResult = traderControl.buy(stock, shares);
return tradeResult;
}
catch (RemoteException re) {
...
}
finally {
if (traderControl != null)
traderControl.remove();
}
EJB 3:
@EJB
Trader trader
TradeResult tradeResult = trader.buy(stock, shares);
return tradeResult;
---
Between what the spec has done in switching to an injection model,
removing the need for a home interface (and corresponding
indirection), and removing the need to support RemoteExceptions on the
business interface, I'm at a bit of a loss to see where there's real
value to be added in evolving the current EJB control to make it
easier to work with EJB 3 beans.
My sense is that the value of the EJB control today is in providing
EJB3-style ease-of-use on top of EJB 2.1 beans -- and actually, this
is an area where EJB3 didn't really make huge inroads. Even though
the EJB 3 client model supports accessing 2.1 beans, there is still
value in what the EJB control does wrt collapsing the remote/local &
home interfaces and managing some of the exceptions.
An ideal result would be the ability to treat an EJB 2.1 remote/local
interface just like an EJB 3 business interface. Collapsing the
remote/local & home interfaces is the easy part, but there's a tension
between simplifying exception handling and ease of authoring.. since
the remote interface will always throw RemoteException, it seems the
only way to eliminate it would be to author a separate interface
(which is a drag)...
