topic Re: Activiti + osgi in Alfresco Archive

Activiti + osgi

bhj2 — Mon, 29 Aug 2011 14:52:18 GMT

Does anybody already use activiti with OSGI? Was it a good experience? Best regards!

Re: Activiti + osgi

schikkal — Tue, 30 Aug 2011 21:48:18 GMT

We are using activiti engine (not the web tooling) in servicemix/fuse osgi container along with activiti eclipse plugins (for authoring bpmn processes). There may be some corner issues, but for most of our needs for now, it works well. We had to add some glue code around it for spring and deployment configurations, but that is simple. We also added apache karaf (part of servicemix/fuse) shell commands to manage the deployed bpmn defintions and instances (if there is enough interest, we can contribute the karaf commands code to community).

Regards,
-Srinivasan

Re: Activiti + osgi

bhj2 — Thu, 01 Sep 2011 06:52:09 GMT

It tried to do it, the JavaDelegate classes I need are found by the classloader but I have the following exception when trying to start a process:

1 sept. 2011 08:46:00 org.activiti.engine.impl.interceptor.CommandContext close
GRAVE: Error while closing command context
org.activiti.engine.ActivitiException: test.activiti.FormEnginePrepareTaskBean doesn't implement org.activiti.engine.delegate.JavaDelegate nor org.activiti.engine.impl.pvm.delegate.ActivityBehavior
 at org.activiti.engine.impl.bpmn.helper.ClassDelegate.getActivityBehaviorInstance(ClassDelegate.java:136)
 at org.activiti.engine.impl.bpmn.helper.ClassDelegate.execute(ClassDelegate.java:110)
 at org.activiti.engine.impl.pvm.runtime.AtomicOperationActivityExecute.execute(AtomicOperationActivityExecute.java:40)
 at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:76)
 at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:481)
 at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerStart.eventNotificationsCompleted(AtomicOperationTransitionNotifyListenerStart.java:48)
 at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:52)
 at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:76)
 at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:481)
 at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:45)
 at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:76)
 at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:481)
 at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionCreateScope.execute(AtomicOperationTransitionCreateScope.java:44)
 at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:76)
 at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:481)
 at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerTake.execute(AtomicOperationTransitionNotifyListenerTake.java:61)
 at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:76)
 at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:481)
 at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionDestroyScope.execute(AtomicOperationTransitionDestroyScope.java:111)
 at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:76)
 at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:481)
 at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerEnd.eventNotificationsCompleted(AtomicOperationTransitionNotifyListenerEnd.java:36)
 at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:52)
 at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:76)
 at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:481)
 at org.activiti.engine.impl.persistence.entity.ExecutionEntity.take(ExecutionEntity.java:326)
 at org.activiti.engine.impl.bpmn.behavior.BpmnActivityBehavior.performOutgoingBehavior(BpmnActivityBehavior.java:92)
 at org.activiti.engine.impl.bpmn.behavior.BpmnActivityBehavior.performDefaultOutgoingBehavior(BpmnActivityBehavior.java:49)
 at org.activiti.engine.impl.bpmn.behavior.FlowNodeActivityBehavior.leave(FlowNodeActivityBehavior.java:44)
 at org.activiti.engine.impl.bpmn.behavior.FlowNodeActivityBehavior.execute(FlowNodeActivityBehavior.java:36)
 at org.activiti.engine.impl.pvm.runtime.AtomicOperationActivityExecute.execute(AtomicOperationActivityExecute.java:40)
 at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:76)
 at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:481)
 at org.activiti.engine.impl.pvm.runtime.AtomicOperationProcessStartInitial.eventNotificationsCompleted(AtomicOperationProcessStartInitial.java:44)
 at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:52)
 at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:76)
 at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:481)
 at org.activiti.engine.impl.pvm.runtime.AtomicOperationProcessStart.eventNotificationsCompleted(AtomicOperationProcessStart.java:44)
 at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:52)
 at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:76)
 at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:481)
 at org.activiti.engine.impl.persistence.entity.ExecutionEntity.start(ExecutionEntity.java:280)
 at org.activiti.engine.impl.cmd.SubmitStartFormCmd.execute(SubmitStartFormCmd.java:80)
 at org.activiti.engine.impl.cmd.SubmitStartFormCmd.execute(SubmitStartFormCmd.java:35)
 at org.activiti.engine.impl.interceptor.CommandExecutorImpl.execute(CommandExecutorImpl.java:24)
 at org.activiti.engine.impl.interceptor.CommandContextInterceptor.execute(CommandContextInterceptor.java:42)
 at org.activiti.engine.impl.interceptor.LogInterceptor.execute(LogInterceptor.java:33)
 at org.activiti.engine.impl.FormServiceImpl.submitStartFormData(FormServiceImpl.java:64)
 at egovrunnerserver.Activator.start(Activator.java:51)
 at org.eclipse.osgi.framework.internal.core.BundleContextImpl$1.run(BundleContextImpl.java:783)
 at java.security.AccessController.doPrivileged(Native Method)
 at org.eclipse.osgi.framework.internal.core.BundleContextImpl.startActivator(BundleContextImpl.java:774)
 at org.eclipse.osgi.framework.internal.core.BundleContextImpl.start(BundleContextImpl.java:755)
 at org.eclipse.osgi.framework.internal.core.BundleHost.startWorker(BundleHost.java:370)
 at org.eclipse.osgi.framework.internal.core.AbstractBundle.resume(AbstractBundle.java:374)
 at org.eclipse.osgi.framework.internal.core.Framework.resumeBundle(Framework.java:1067)
 at org.eclipse.osgi.framework.internal.core.StartLevelManager.resumeBundles(StartLevelManager.java:561)
 at org.eclipse.osgi.framework.internal.core.StartLevelManager.resumeBundles(StartLevelManager.java:546)
 at org.eclipse.osgi.framework.internal.core.StartLevelManager.incFWSL(StartLevelManager.java:459)
 at org.eclipse.osgi.framework.internal.core.StartLevelManager.doSetStartLevel(StartLevelManager.java:243)
 at org.eclipse.osgi.framework.internal.core.StartLevelManager.dispatchEvent(StartLevelManager.java:440)
 at org.eclipse.osgi.framework.eventmgr.EventManager.dispatchEvent(EventManager.java:227)
 at org.eclipse.osgi.framework.eventmgr.EventManager$EventThread.run(EventManager.java:337)

Re: Activiti + osgi

trademak — Thu, 01 Sep 2011 06:59:56 GMT

Hi,

The exception says it all doesn't it. The FormEnginePrepareTaskBean needs to implement JavaDelegate or ActivityBehavior.

Best regards,

Re: Activiti + osgi

bhj2 — Thu, 01 Sep 2011 07:32:37 GMT

Hi,

The exception says it all doesn't it. The FormEnginePrepareTaskBean needs to implement JavaDelegate or ActivityBehavior.

Best regards,

Yes but what is strange is that my class FormEnginePrepareTaskBean implements JavaDelegate.

public class FormEnginePrepareTaskBean implements JavaDelegate {

 private Expression formEngine;

 @Override
 public void execute(DelegateExecution execution) {
   execution.setVariable("formEngine",
     formEngine.getValue(execution));
 }
}

Re: Activiti + osgi

trademak — Thu, 01 Sep 2011 07:56:17 GMT

Ok good to know. I think this may have something to do with the OSGi wrapper.
Can you explain a bit more about your setup. Are you using Apache Karaf for example?
Can you post your example project?

Thanks,

Re: Activiti + osgi

bhj2 — Thu, 01 Sep 2011 09:00:55 GMT

I'm using eclipse equinox as osgi container and not Apache Karaf.

I'll post my exemple project this afternoon.
Thank you for your help!

Re: Activiti + osgi

bhj2 — Thu, 01 Sep 2011 12:30:35 GMT

Here are my two bundles and my test process. In the bundles you will have to add the necessary libraries(mybatis-3.0.4, activiti-engine-5.7 & h2-1.2.132). Sorry for my test i did'nt do a maven project

Is the project in the form you needed it?

<?xml version="1.0" encoding="UTF-8"?>
<definitions xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
 xmlns:activiti="http://activiti.org/bpmn" targetNamespace="EGovRunnerProcesses">

 <process id="MyTestProcess" name="MyTest Process">
  <startEvent id="theStart" activiti:initiator="initiator">
   <extensionElements>
    <activiti:formProperty id="person" type="string" />
    <activiti:formProperty id="reason" type="string" />
   </extensionElements>
  </startEvent>

  <sequenceFlow id='flow1' sourceRef='theStart'
   targetRef='task1' />

  <serviceTask id="task1" name="first task"
   activiti:class="test.FormEnginePrepareTaskBean">
  </serviceTask>

  <sequenceFlow id='flow2' sourceRef='task1'
   targetRef='theEnd' />

  <endEvent id="theEnd" />
 </process>

</definitions>

Re: Activiti + osgi

trademak — Fri, 02 Sep 2011 09:49:04 GMT

Hi,

I made some first steps in testing this. So the projects you uploaded are fine for me to test.
However I need some more time to investigate this. I'll come back to this in a couple of days.

Best regards,

Re: Activiti + osgi

thay — Sun, 04 Sep 2011 08:21:40 GMT

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"A lot of little holes tied together with strings." replied the little girl.

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Re: Activiti + osgi

jupi — Mon, 05 Sep 2011 16:14:55 GMT

I use Felix and activiti version 5.7.
I couldn't use groovy scripts in osgi environment.

Caused by: org.activiti.engine.ActivitiException: Can't find scripting engine for 'groovy'
        at org.activiti.engine.impl.scripting.ScriptingEngines.evaluate(ScriptingEngines.java:66)
        at org.activiti.engine.impl.bpmn.behavior.ScriptTaskActivityBehavior.execute(ScriptTaskActivityBehavior.java:43)
        at org.activiti.engine.impl.pvm.runtime.AtomicOperationActivityExecute.execute(AtomicOperationActivityExecute.java:40)

So i had to fall back to use javascript for scripting of ScriptTasks, although the groovy bundle was started. This was only a minor issue.

More important is that the classes of my bundle or classes from other bundles could not be reached by scripts of my processes.
I wonder if I could somehow specify the class loader of the scripting environment.

Is anybody there who could solve these issues?

Re: Activiti + osgi

trademak — Tue, 06 Sep 2011 06:17:18 GMT

Hi,

I'll be working with the OSGi implementation for the Activiti in Action book in the next days.
Note however that the Activiti OSGi module is mainly tested with Apache Karaf.
And that's what I'll be using for Activiti in Action.
But of course it should also be possible to get it running on Felix.

Best regards,

Re: Activiti + osgi

bhj2 — Tue, 06 Sep 2011 07:49:28 GMT

Hi,

I made some first steps in testing this. So the projects you uploaded are fine for me to test.
However I need some more time to investigate this. I'll come back to this in a couple of days.

Best regards,

And do you have the same exceptions?! Any progress?

Re: Activiti + osgi

jupi — Wed, 07 Sep 2011 12:35:46 GMT

More important is that the classes of my bundle or classes from other bundles could not be reached by scripts of my processes.
I wonder if I could somehow specify the class loader of the scripting environment.

I managed to get around this problem by passing an object (actually a service locator) as a variable to the process.

Re: Activiti + osgi

bhj2 — Thu, 08 Sep 2011 09:35:18 GMT

Hi,

I'll be working with the OSGi implementation for the Activiti in Action book in the next days.
Note however that the Activiti OSGi module is mainly tested with Apache Karaf.
And that's what I'll be using for Activiti in Action.
But of course it should also be possible to get it running on Felix.

Best regards,

Other question, what about the Activiti in Action book and this OSGI part? When is it going to be published? What will be the content? Will you write about the possibility to add the JavaDelegate classes in OSGI bundles at runtime?

Best regards

Re: Activiti + osgi

trademak — Fri, 09 Sep 2011 09:32:16 GMT

Hi,

I've not been able to work on this as much as I would have liked, but I've made some progress.
I still have to do some work on separating the JavaDelegate classes in separate bundles, so I didn't run into problems yet.

In the Activiti in Action book we'll discuss how to implement Activiti in Apache Karaf and that you can separate the process XML from the Java classes by using different bundles. This will also show hot deployment of a new version of the Java class bundle. The Activiti in Action book is already available in MEAP (which means that chapters will become available during writing). I've made quite some progress in the last weeks and we've 11/15 chapters written already. So I expect that the chapters should be ready in 1,5 month or so. Then the production process @ Manning will start, which also takes around 2 months.

Best regards,

Re: Activiti + osgi

trademak — Sun, 11 Sep 2011 12:38:18 GMT

Hi,

I've an OSGi example working on Apache Karaf. There are a number of pitfalls that I encountered while implementing the examples.
But you find the source code at the Activiti in Action google code repository: http://code.google.com/p/activitiinaction/ in the book-osgi-app project.

Best regards,

Re: Activiti + osgi

bhj2 — Mon, 12 Sep 2011 08:43:55 GMT

Hi,

I've an OSGi example working on Apache Karaf. There are a number of pitfalls that I encountered while implementing the examples.
But you find the source code at the Activiti in Action google code repository: http://code.google.com/p/activitiinaction/ in the book-osgi-app project.

Best regards,

Thank a lot. I didn't look at the code yet but it sounds very interesting!

About the Activiti in action book, we only found the 7 first chapters in MEAP. Arn't the chapters 8-11 available yet?

Best regards!

Re: Activiti + osgi

trademak — Mon, 12 Sep 2011 08:48:14 GMT

Hi,

There's a big update coming up for the Activiti in Action MEAP, which includes a rewrite of all chapters to Activiti 5.7 and the addition of chapter 11 + 12 (ESB and Rules).
We are working very hard on the remaining chapters, so you can expect new chapters arriving very soon.

Best regards,

Re: Activiti + osgi

kaech — Thu, 15 Sep 2011 09:31:30 GMT

More important is that the classes of my bundle or classes from other bundles could not be reached by scripts of my processes.
I wonder if I could somehow specify the class loader of the scripting environment.

I have the same problem using the OSGi-Activiti bundle from the Activiti in action book. Activiti is running a simple process including a ScriptTask. The ScriptTask does:

def customer = new org.mytypes.Customer();

At runtime GroovyScriptEngineImpl.eval it complains that the Customer class can not be found.

Using a ServiceLocator might be an option to solve the problem, although it would be nicer if Activiti could resolve and create the types without such an intermediary.

Another option would be a dynamic import on the Groovy-OSGI-bundle, but this doesn't seem to be a good idea cause it weakens the strict class loading mechanism in OSGi.

What would be the best way to provide the custom types to Activiti?
Suggestions would be welcome.