topic Re: Camel and Osgi in Alfresco Archive

Camel and Osgi

rvi — Wed, 11 Apr 2012 15:54:59 GMT

Hi,I want deploy a process with some camel servicetasks in a osgi container.I get this problem:the osgi engine bundle looks for JavaDelegate services,but CamelBehavior implements ActivityBehavior.It seems to work if we expose the CamelBehavior as a JavaDelegate with this implementationublic class

Re: Camel and Osgi

rvi — Fri, 13 Apr 2012 12:32:51 GMT

is it correct ? what is the difference between a JavaDelegate and and ActivityBehavior ?

would it be possible to better support camel with a osgi container in the activiti code:
- CamelBehavior implements directly JavaDelegate
- or BlueprintELResolver looks for ActivitiBehavior
?

actually this solution DOESN'T work. (it executes twice the outgoing relations..)

The only solution is to extend the BlueprintELResolver so it accepts ActivitiBehavior.
I've tested that with an extended ELresolver:


public class ExtendedELResolver extends BlueprintELResolver {

    private static final Logger LOGGER = Logger.getLogger(ExtendedELResolver.class.getName());
    private Map<String, ActivityBehavior> behaviorMap = new HashMap<String, ActivityBehavior>();

    public Object getValue(ELContext context, Object base, Object property) {
        if (base == null) {
            // according to javadoc, can only be a String
            String key = (String) property;
            for (String name : behaviorMap.keySet()) {
                if(name.equalsIgnoreCase(key)) {
                    context.setPropertyResolved(true);
                    return behaviorMap.get(name);
                }
            }
        }

        return super.getValue(context,base,property);
    }

    public void bindService(ActivityBehavior delegate, Map props) {
        String name = (String) props.get("osgi.service.blueprint.compname");
        behaviorMap.put(name, delegate);
        LOGGER.info("added Activiti service to behavior cache " + name);
    }

    public void unbindService(ActivityBehavior delegate, Map props) {
        String name = (String) props.get("osgi.service.blueprint.compname");
        if(behaviorMap.containsKey(name)) {
            behaviorMap.remove(name);
        }
        LOGGER.info("removed Activiti service from behavior cache " + name);
    }
}

and adding a reference-listener in the blueprint context of the osgi:


    <reference-list id="activityBehaviorProviders" availability="optional"
                    interface=[b]"org.activiti.engine.impl.pvm.delegate.ActivityBehavior"[/b]
                    activation="eager">
        <reference-listener ref="blueprintELResolver" bind-method="bindService" unbind-method="unbindService"/>
    </reference-list>
    <bean id="blueprintELResolver" [b]class="test.ExtendedBlueprintELResolver"[/b] />

of course it would be better to directly modify the BlueprintELResolver so it accepts the ActivitiBehavior. Should I open a JIRA ?

thanks,
Richard

Re: Camel and Osgi

nils1 — Thu, 10 May 2012 13:27:36 GMT

Hi Richard,

as a starting point, maybe you can have a look at the examples from Tijs Rademakers' book "Activiti in Action", available at http://activitiinaction.googlecode.com/svn/trunk/book-osgi-app

Hope that helps!

Cheers,
Nils

Re: Camel and Osgi

nils1 — Thu, 10 May 2012 14:48:37 GMT

Hi Richard,

you can also have a look at a showcase I created. It demonstrates how you can combine activiti and camel on an OSGi container (Karaf 2.2.5 in this case).

More specifically, it shows how to
1) start a process instance from a camel route
2) how to trigger a waiting process instance from a camel route

You'll find the code at https://svn.camunda.com/fox/demo/activiti/osgi-activiti-camel-showcase/

Please have a look at the README.txt for installation instructions.

Also, note that the demo uses Activiti 5.10-SNAPSHOT, so you'll need to check out and build the current trunk and install it to your local maven repository!

Hope that helps.

Cheers,
Nils