Hi All, I'm trying to find the best way to consume messages produced from a bean that produce messages sending them to a 'delegate' field.
I've not found the ideal solution for my scenario as feasible, I've found quite good alternative but with a big limit. I would like you to confirm me my ideal solution is not feasible and to suggest me a strategy to handle this limit. The beans I use implements the delegation concept when producing events (I've not found some equivalent EIP, the concept implemented is like this one: http://developer.apple.com/library/ios/#documentation/general/conceptual/CocoaEncyclopedia/DelegatesandDataSources/DelegatesandDataSources.html ) That is, my bean has a setter for the delegate that when != null it is used for sending "events". Quick and simplified example: public class SmileController implements Runnable { // The delegate interface public interface FaceDelegate { void smile(); } // The delegate property private FaceDelegate delegate = null; // The delegate setter public void setDelegate(FaceDelegate delegate) { this.delegate = delegate; } @Override public void run() { if (delegate != null) { delegate.smile(); } else { // log error or queue the message or something else } } } I use this bean in Spring and I pass a class FaceImpl implements FaceDelegate {...} as delegate for SmileController in this way: <bean id="face" class="org.example.FaceImpl" /> <bean id="smileController" class="org.example.SmileController"> <property name="delegate" ref="face"/> </bean> I desire to decouple FaceImpl and SmileController with Camel, and ideally my solution would be to write a route this way: <bean id="smileController" class="org.example.SmileController" /> <camelContext id="camelContext" xmlns="http://camel.apache.org/schema/spring "> <route> <from uri="bean:smileController"/> <to uri="direct:face"/> </route> </camelContext> but I can't as the bean component can't be used for consumer endpooints. I could annotate with @Produce the field FaceDelegate delegate, but this create for me a dependency with org.apache.camel APIs and sometime I can't change the code. So I've found I can use a camel proxy created in a Spring Bean configuration file: <camel:proxy id="faceProxy" serviceUrl="direct:face" serviceInterface="org.example.FaceDelegate" /> <bean id="smileController" class="org.example.SmileController"> <property name="delegate" ref="faceProxy" /> </bean> This solve most of my problems and in this way I don't have to modify the java code. I'm not yet fully satisfied as I still have a coupling I want to get rid off. I want to deploy my FaceController bean as an OSGi service and consume its events in another bundle. I would define the service with spring and spring-osgi in this way: --- beans_bundle_1.xml --- <!-- At the beginning, my SmileController will have a null delegate. Note: I've added a "startSmiling" method to the service which start timer that call run every 10 seconds. --> <bean id="smileController" class="org.example.SmileController" init-method="startSmiling"/> <!-- I publish it to OSGi. Note: I've made the service implements a super interface for resolving it in OSGi --> <osgi:service id="smileControllerService" ref="smileController" interface="org.example.SmileControllerInterface"/> And in another OSGi bundle I want to use camel to add a proxy to this service and start receiving his 'smiles': --- beans_bundle_2.xml --- <osgi:reference id="smileControllerService" interface="org.example.SmileControllerInterface" bean-name="smileController"/> <!-- what can I do here???? --> What do you think it is best to do to handle this deployment configuration? Am I missing some other camel feature that could allow me to better implement this scenario? I hope I've explained clearly my context, sorry if I've been long, if I had more time I would have been shorter message. Thank you, Cristiano
