Looks interesting. I would try to limit external dependencies by taking out Spring. I have a tiny abstraction layer for JMS written in Java (and another in JavaFX), where I feed in a Properties object with all the parameters (server location, authentication, etc.) and get quick access to various topic consumers and producers. I suspect that involving the properties object is not going to be very idiomatic clojure.
On Nov 24, 8:50 pm, Luc Prefontaine <[EMAIL PROTECTED]> wrote: > We use a synchronous layer to JMS queues implemented in Java to hook our > Clojure code to the messaging world. > > Two Java classes to implement a consumer and a producer with some common > inheritance are used. > We had already some Java implementation so we just beefed it up a bit to > make more robust. > > We use Spring to load beans so loading a consumer look like this: > > (defn create-producer-consumer [name] > (get-bean name) > ) > > The Spring bean being something similar to this: > > <bean id="connectionFactoryBean" > class="org.apache.activemq.pool.PooledConnectionFactory"> > <property name="connectionFactory" > ref="connectionSimpleFactoryBean" /> > </bean> > > <bean id="busMessageQConsumer" > class="com.softaddicts.products.higiebus.tools.jms.Consumer"> > <property name="subject" > > value="HIGIEBUS.QUEUES.BUS_DATA?consumer.exclusive=true" /> > <property name="connectionFactory" > ref="connectionFactoryBean" /> > <property name="transacted" value="true" /> > <property name="name" value="HIGIEBUSRouting" /> > <property name="ackMode" value="CLIENT_ACKNOWLEDGE" /> > </bean> > > Now we have small wrappers in Clojure like these: > > (defn read-message > "Consume messages" > [consumer] > (. consumer receive) > ) > > (deftrace send-message > ;; "Send messages" > [producer msg] > (. producer send msg) > ) > > (defn peek-text-message > "Peek at messages" > [consumer] > (let [message (. consumer browse)] > (if (not (nil? message)) (. message getText)) > ) > ) > > and so on for commits, rollbacks, ..... The Java classes handle > connection/release of resources, cleanup when the JVM exits, .... > We use the wrappers to protect ourselves from later changes in the > implementation. > > We use ActiveMq 5.1 with master slave redundancy. > > Eventually we want to create a wrapper to allow Clojure functions to be > called asynchronously but we are not there yet, > mainly because we have other priorities. > > Using the Spring framework is certainly is a viable option, we look at > to reuse existing code and getting Clojure code called directly > in an asynchronous fashion. > > We start the consumers in separate thread. polling for messages through > read-message and consort. This at least gives us some > asynchronous processing illusion for the moment. > > We expect to shrink the Java code down to a certain size in the next > months and shift more stuff to Clojure > but meanwhile we had to take the shortest path and that implied reusing > existing stuff from the first stage prototype. > We are scheduled to be in production in the next 8 weeks. > Clojure was targeted for the routing layer in our message bus, that's > were the immediate benefits are (dispatch logic, message cloning, ...) > > For now we have a resilient implementation ready for production so it's > satisfactory considering I heard about Clojure in September... > Since the beta book is in progress, i am also catching up rapidly about > the language and expect to spit out more elegant code in the > near future :))) > > Luc > > On Mon, 2008-11-24 at 16:36 -0800, falcon wrote: > > What is the best way of accessing Java Messaging Service though > > Clojure? > > > Sounds like Rich has already experimented, with good results: > > >>rhickey: I did some playing (in Clojure) with JMS and OpenMQ and it was > > >>awesome, easy, fun and vert fast, with pro level docs from Sun > > (http://clojure-log.n01se.net/date/2008-09-08.html) > > > Thanks --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~----------~----~----~----~------~----~------~--~---
