Hi Rajith & Rafi, I should be able to shed some light on the migration implications of this change.
To check that I've understood what you're proposing - so the existing BindingURL implementation would be used for the 0-8/0-9 codepaths and you're only writing an impl for the 0-10 path ? Regards, Marnie On Wed, Nov 25, 2009 at 11:06 PM, Rafael Schloming <rafa...@redhat.com>wrote: > Rajith Attapattu wrote: > >> Hi All >> >> I have been thinking about adding support in the JMS client for the >> new address format currently implemented in python and c++ by Rafi and >> Gordon. >> I am exploring the viability of the following approach. Comments and >> suggestions are most welcomed. >> Please feel free to suggest class names etc. It's not easy coming up >> with names :). >> >> Given that AMQDestination is used all over the code base, I am >> thinking about using an incremental approach to minimize disruptions. >> I have tried a prototype of this idea and it seems to work reasonably >> well. >> >> 1. Extract an interface from the current AMQDestination class and name >> the interface as AMQDestination (which extends the >> javax.jms.Destination). >> > > Is it possible for you to post the interface you extracted? > > > 2. The current AMQDestination class will be renamed to >> AMQBindingURLDestination which implements AMQDestination >> >> Step 1 & 2 will ensure that the current code compiles and that >> majority of the code remains unchanged. >> Since the current AMQDestination abstract class is based on the >> binding URL concept I suggest to rename it to AMQBindingURLDestination >> >> 3. Add an abstract class AMQAddressDestination that implements >> AMQDestination. >> 4. Add AMQAddressDestination_0_10 >> 5. Add support in AMQSession_0_10, BMProducer/Consumer_0_10 to check >> if the destination type and support appropriate behaviour. >> >> Step 3 will add generic support for the new addressing format and step >> 4 a mapping to the 0_10 syntax. >> Step 5 will provide the required functionality to support the address >> format while retaining backwards compatibility. >> >> 5. Later on we can look at making AMQDestination a proper interface >> rather than a stop gap measure. >> In order to do this a fair bit of tinkering would be needed in the >> AMQSession, BMProducer/Consumer etc.. >> >> We would obviously need a parser for the new addressing format. >> I believe Rafi has volunteered to whip that as he was working on one >> for python :) >> > > I'm happy to provide one for Java as well. As a first step I'll document > and post the syntax. Writing a Java parser should be quick, I just want to > get as much feedback as I can first, so that the syntax is as final as > possible before doing it. > > One question I have is about how we'll provide access to alternate syntaxes > via jndi configuration and the JMS API (i.e. > createQueue(...)/createTopic(...)). I can think of a few options, e.g. > switching between syntaxes using a system/connection property. Or maybe > having some sort of meta-syntax that that would permit usage of the two > syntaxes side by side, e.g. "OLD: ...", "NEW: ...", or possibly some > combination of the two approaches. > > One of the things I'm unsure of here is what we need to provide in terms of > backwards-compatibility/migration support for our users, e.g. do we need to > provide the ability to use both syntaxes side-by-side on the same > connection, or can we expect people to be using only one syntax or the > other? Are there other migration options/issues we should be considering? > > --Rafael > > > --------------------------------------------------------------------- > Apache Qpid - AMQP Messaging Implementation > Project: http://qpid.apache.org > Use/Interact: mailto:dev-subscr...@qpid.apache.org > >
