Hi,
Looks like there has no opponent for jervis' proposal, I will
create a
jira task for this proposal and sign it me.
Cheers
Unreal
"Liu, Jervis" <[EMAIL PROTECTED]> wrote:
________________________________
From: Dan Diephouse [mailto:[EMAIL PROTECTED]
Sent: Tue 1/23/2007 1:02 AM
To: [email protected]
Subject: Re: Proposal for chaning CXF Interceptor APIs. WAS: RE: When
should we close the handlers in CXF?
On 1/22/07, Liu, Jervis wrote:
>
> Hi, I would like to summarize what we have been discussed in this
thread
> (including Eoghan's proposal posted last Oct [1]) regarding
Interceptor
API
> changes. Any comments would be appreciated.
>
> Currently our Interceptor APIs look like below:
>
> public interface Interceptor {
> void handleMessage(T message) throws Fault;
> void handleFault(T message);
> }
>
> Also in the interceptor chain, we have a notion of sub-chain or
> interceptor chain reentrance by calling message.getInterceptorChain
().doIntercept(message)
> or message.getInterceptorChain().doInterceptInSubChain(message).
>
> The main issues we have with the current implementation are:
>
> 1. Fault handling. See Eoghag's email [1]
>
> 2. Sub-chain reentrance. See previous discussion in this thread.
>
> We propose to change Interceptor API as below:
>
> public interface Interceptor {
> void handleMessage(T message) throws Fault;
> void handleFault(T message);
> void close(T message);
> }
>
> handleFault(T message) method is used to process fault message
(which is
> done by handleMessage() in fault-chain currently).
> I'm not sure I understand how you want to use this. I guess I could
see
two
> ways
> 1. Remove In/OutFault interceptors and call handleFault on the In/Out
> interceptors. I don't know that mapping works especially well though.
> 2. Don't call handleFault on in/out interceptors, but only on the
> in/outFault interceptors - this would mean, for example, that the
logic
from
> Soap11OutFaultInterceptor would be moved from the handleMessage to
> handleFault.
> Can you be more specific about what you mean?
Sorry, after rethinking about this, I've changed my mind slightly, so
here
is the idea:
CXF Interceptor API will be similiar to JAX-WS API, section 9.3.2.1.
Throw ProtocolException or a subclass This indicates that normal message
processing should cease.
Subsequent actions depend on whether the MEP in use requires a
response to
the message currently
being processed or not:
Response: Normal message processing stops, fault message processing
starts. The message direction
is reversed, if the message is not already a fault message then it is
replaced with a fault message4,
and the runtime invokes handleFault on the next handler or dispatches
the
message (see
section 9.1.2.2) if there are no further handlers.
No response: Normal message processing stops, close is called on each
previously invoked handler
in the chain, the exception is dispatched (see section 9.1.2.3).
Throw any other runtime exception This indicates that normal message
processing should cease. Subse-
quent actions depend on whether the MEP in use includes a response to
the
message currently being
processed or not:
Response: Normal message processing stops, close is called on each
previously invoked handler in
the chain, the message direction is reversed, and the exception is
dispatched (see section 9.1.2.3).
No response: Normal message processing stops, close is called on each
previously invoked handler
in the chain, the exception is dispatched (see section 9.1.2.3).
However, the difference is CXF interceptors are not designed to hook in
user logic as these JAX-WS handlers do, thus handleFault is not needed
in CXF interceptors (correct me if I am wrong, but I believe this is
the purpose that JAX-WS handlers's handleFault method designed for.
I.e, when
a known exception - ProtocolException occurs, handleFault() gives
handler
developer a hook to clean up sth, for example, roll back a transaction,
this is different from what close() is supposed to do. The latter is
designed to clean things up under a succeeded situation). For any
Runtime
exceptions thrown by interceptors, we just wrap it as soap exception
then
dispatch it back calling handleMessage.
So here is the change we need to make:
1. Add a postHandleMessage() into Interceptor interface
2. Remove handleFault() method from Interceptor interface. Or we can
still keep it for a while until we are absolutely sure we wont need
this method, but I presume there is nothing we need to do in this
method.
3. We will NOT add a close() method into Interceptor interface, as
CXF interceptors are stateless, there is no resources need to be
closed.
public interface Interceptor {
void handleMessage(T message) throws Fault;
void postHandleMessage(T message);
}
When an interceptor chain ends normally, we need to call
postHandleMessage() on each previously traversed interceptor in a
reversed
direction.
When a fault occurs on the in-bound chain, an exception will be thrown
from the interceptor, after catching the exception in
PhaseInterceptorChain, we unwind the current chain by calling
postHandleMessage() on each previously traversed interceptor and
then jump
to the out-fault-chain, calling handleMessage() on each interceptor
with
the fault message.
Any thoughs?
> close(T message) method is called on a reverse direction at the end of
> interceptor chain or when a fault or exception occurs. Take the fault
> handling case as an example, below is how handleFault and close work
> together
> +1 to close() - Although I think Eoghan has a good point about the
ordering
> not necessarily being the same. I think we need to do a little bit
more
> digging before we can know whether or not sub chains can be removed.
> when a fault occurs on the in-chain, we unwind the current chain by
calling
> close() on each previously traversed interceptor and then jump to the
> out-fault-chain, calling handleFault() on each interceptor with the
fault
> message.
>
> Close method is also used to remove the sub-chain reentrance. See the
> SOAPHandlerInterceptor example I posted previously.
>
> Cheers,
> Jervis
>
> [1]
>
http://mail-archives.apache.org/mod_mbox/incubator-cxf-dev/200611.mbox/[EMAIL PROTECTED]
>
>
--
Dan Diephouse
Envoi Solutions
http://envoisolutions.com | http://netzooid.com/blog
---------------------------------
Access over 1 million songs - Yahoo! Music Unlimited.
