# Flowable-engine in OSGi - Tutorials/examples?

**URL:** https://forum.flowable.org/t/flowable-engine-in-osgi-tutorials-examples/3086
**Category:** Flowable Engine
**Created:** [December 18, 2018, 3:22pm UTC](https://forum.flowable.org/t/flowable-engine-in-osgi-tutorials-examples/3086 "2018-12-18T15:22:38Z")
**Posts on this page:** 13
**Page:** 1

<div class="post-metadata">

### Author: ![Ceddaerrix](https://avatars.discourse-cdn.com/v4/letter/c/c77e96/32.png) [@Ceddaerrix](https://forum.flowable.org/u/Ceddaerrix)
#### Post date: [December 18, 2018, 3:22pm UTC](https://forum.flowable.org/t/flowable-engine-in-osgi-tutorials-examples/3086/1 "2018-12-18T15:22:38Z")

</div>

I am trying to use Flowable-engine v6.4.0 on Felix Framework. Unfortunately, I do not appear to successfully instantiate a ProcessEngineConfiguration.

Is there a functional example/tutorial available for using Flowable-engine in OSGi?

Thanks in advance

---

<div class="post-metadata">

### Author: ![Robinyo](https://avatars.discourse-cdn.com/v4/letter/r/dec6dc/32.png) [@Robinyo](https://forum.flowable.org/u/Robinyo)
#### Post date: [December 20, 2018, 9:43pm UTC](https://forum.flowable.org/t/flowable-engine-in-osgi-tutorials-examples/3086/2 "2018-12-20T21:43:18Z")

</div>

> [@Ceddaerrix](#):
>
> Is there a functional example/tutorial available for using Flowable-engine in OSGi?

There is an example re OSGi and Activiti in the [Activiti in Action](https://www.manning.com/books/activiti-in-action) book.

I also found this post: [Using the Activiti-Engine as bundle in JBoss AS 7.2 ~ Wrong tracks of a developer](http://wrongtracks.blogspot.com/2013/06/using-activiti-engine-as-bundle-in.html)

---

<div class="post-metadata">

### Author: ![Ceddaerrix](https://avatars.discourse-cdn.com/v4/letter/c/c77e96/32.png) [@Ceddaerrix](https://forum.flowable.org/u/Ceddaerrix)
#### Post date: [December 27, 2018, 11:36pm UTC](https://forum.flowable.org/t/flowable-engine-in-osgi-tutorials-examples/3086/3 "2018-12-27T23:36:16Z")

</div>

Thanks for the input.  
The last link you provided helped me solving some problems instantiating a Process Engine due to modules I was missing.

---

<div class="post-metadata">

### Author: ![Ceddaerrix](https://avatars.discourse-cdn.com/v4/letter/c/c77e96/32.png) [@Ceddaerrix](https://forum.flowable.org/u/Ceddaerrix)
#### Post date: [January 7, 2019, 1:46pm UTC](https://forum.flowable.org/t/flowable-engine-in-osgi-tutorials-examples/3086/4 "2019-01-07T13:46:50Z")

</div>

After solving instantiating the Process Engine based on the information using Flowable-engine v5.23.0 on Felix Framework, while calling `RuntimeService.startProcessInstanceByKey()` I get some class loading issues for classes used in the activity delegate that are imported from another bundle:

```
java.lang.NoClassDefFoundError: <My Class URL>
	at java.lang.Class.getDeclaredMethods0(Native Method)
	at java.lang.Class.privateGetDeclaredMethods(Unknown Source)
	at java.lang.Class.getDeclaredMethod(Unknown Source)
	at java.io.ObjectStreamClass.getPrivateMethod(Unknown Source)
	at java.io.ObjectStreamClass.access$1700(Unknown Source)
	at java.io.ObjectStreamClass$3.run(Unknown Source)
	at java.io.ObjectStreamClass$3.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.io.ObjectStreamClass.<init>(Unknown Source)
	at java.io.ObjectStreamClass.lookup(Unknown Source)
	at java.io.ObjectOutputStream.writeObject0(Unknown Source)
	at java.io.ObjectOutputStream.writeObject(Unknown Source)
	at org.activiti.engine.impl.variable.SerializableType.serialize(SerializableType.java:93)
	at org.activiti.engine.impl.variable.SerializableType.setValue(SerializableType.java:69)
	at org.activiti.engine.impl.persistence.entity.VariableInstanceEntity.setValue(VariableInstanceEntity.java:178)
	at org.activiti.engine.impl.persistence.entity.VariableInstanceEntity.create(VariableInstanceEntity.java:74)
	at org.activiti.engine.impl.persistence.entity.VariableInstanceEntity.createAndInsert(VariableInstanceEntity.java:60)
	at org.activiti.engine.impl.persistence.entity.VariableScopeImpl.createVariableInstance(VariableScopeImpl.java:895)
	at org.activiti.engine.impl.persistence.entity.ExecutionEntity.createVariableInstance(ExecutionEntity.java:1194)
	at org.activiti.engine.impl.persistence.entity.VariableScopeImpl.createVariableLocal(VariableScopeImpl.java:808)
	at org.activiti.engine.impl.persistence.entity.VariableScopeImpl.createVariableLocal(VariableScopeImpl.java:795)
	at org.activiti.engine.impl.persistence.entity.VariableScopeImpl.setVariable(VariableScopeImpl.java:689)
	at org.activiti.engine.impl.persistence.entity.VariableScopeImpl.setVariable(VariableScopeImpl.java:646)
	at org.activiti.engine.impl.persistence.entity.VariableScopeImpl.setVariables(VariableScopeImpl.java:590)
	at org.activiti.engine.impl.cmd.StartProcessInstanceCmd.initializeVariables(StartProcessInstanceCmd.java:122)
	at org.activiti.engine.impl.cmd.StartProcessInstanceCmd.execute(StartProcessInstanceCmd.java:107)
	at org.activiti.engine.impl.cmd.StartProcessInstanceCmd.execute(StartProcessInstanceCmd.java:37)
	at org.activiti.engine.impl.interceptor.CommandInvoker.execute(CommandInvoker.java:24)
	at org.activiti.engine.impl.interceptor.CommandContextInterceptor.execute(CommandContextInterceptor.java:57)
	at org.activiti.engine.impl.interceptor.LogInterceptor.execute(LogInterceptor.java:31)
	at org.activiti.engine.impl.cfg.CommandExecutorImpl.execute(CommandExecutorImpl.java:40)
	at org.activiti.engine.impl.cfg.CommandExecutorImpl.execute(CommandExecutorImpl.java:35)
	at org.activiti.engine.impl.RuntimeServiceImpl.startProcessInstanceByKey(RuntimeServiceImpl.java:82)
	at 
...
	at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ClassNotFoundException: <My Class Name>
	at java.net.URLClassLoader.findClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	at org.apache.felix.framework.BundleWiringImpl.doImplicitBootDelegation(BundleWiringImpl.java:1817)
	at org.apache.felix.framework.BundleWiringImpl.tryImplicitBootDelegation(BundleWiringImpl.java:1746)
	at org.apache.felix.framework.BundleWiringImpl.searchDynamicImports(BundleWiringImpl.java:1699)
	at org.apache.felix.framework.BundleWiringImpl.findClassOrResourceByDelegation(BundleWiringImpl.java:1575)
	at org.apache.felix.framework.BundleWiringImpl.access$300(BundleWiringImpl.java:79)
	at org.apache.felix.framework.BundleWiringImpl$BundleClassLoader.loadClass(BundleWiringImpl.java:1982)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	... 63 more

```

Even though I have the packages properly set in \<Import-Package\>, I keep my process failed to start for this reason.  
Has anyone met that issue?

---

<div class="post-metadata">

### Author: ![donkon](https://avatars.discourse-cdn.com/v4/letter/d/f475e1/32.png) [@donkon](https://forum.flowable.org/u/donkon)
#### Post date: [January 7, 2019, 2:06pm UTC](https://forum.flowable.org/t/flowable-engine-in-osgi-tutorials-examples/3086/5 "2019-01-07T14:06:38Z")

</div>

We had no classloading issues with flowable 5.23.0 and Karaf. Since the bundle containing the process engine can not know all Java Delegate classes, we added

```
<DynamicImport-Package>*</DynamicImport-Package>

```

to the bundle.

Do you use org.activiti.osgi.blueprint.ProcessEngineFactoryWithELResolver as processEngineFactory?

---

<div class="post-metadata">

### Author: ![Ceddaerrix](https://avatars.discourse-cdn.com/v4/letter/c/c77e96/32.png) [@Ceddaerrix](https://forum.flowable.org/u/Ceddaerrix)
#### Post date: [January 8, 2019, 6:47am UTC](https://forum.flowable.org/t/flowable-engine-in-osgi-tutorials-examples/3086/6 "2019-01-08T06:47:43Z")

</div>

> [@donkon](#):
>
> we added
> 
> ```auto
> <DynamicImport-Package>*</DynamicImport-Package>
> 
> ```
> 
> to the bundle.
> 
> Do you use org.activiti.osgi.blueprint.ProcessEngineFactoryWithELResolver as processEngineFactory?

I have already `<DynamicImport-Package>*</DynamicImport-Package>` set on that bundle.

As per org.activiti.osgi.blueprint.ProcessEngineFactoryWithELResolver as processEngineFactory, I do not have any blueprint in my bundle (not too familiar with). I am programatically instantiating the Process Engine using a `StandaloneInMemProcessEngineConfiguration`.

---

<div class="post-metadata">

### Author: ![Ceddaerrix](https://avatars.discourse-cdn.com/v4/letter/c/c77e96/32.png) [@Ceddaerrix](https://forum.flowable.org/u/Ceddaerrix)
#### Post date: [January 8, 2019, 9:10am UTC](https://forum.flowable.org/t/flowable-engine-in-osgi-tutorials-examples/3086/7 "2019-01-08T09:10:14Z")

</div>

The error mentioned above was caused by the OSGi service/interface instance I was sending as a variable (while being serialized).  
Still, after commenting all references to that interface in the code in my Flowable-based bundle, class loading issues appeared in regard to the custom delegate used in the first task of the process.

**From** :

> \<serviceTask id=“XYZ” name=“ABC” activiti:class=“my.delegates.CustomDelegate” \>

**The error is:**

> “org.activiti.engine.ActivitiClassLoadingException: Class not found: my.delegates.CustomDelegate  
> at org.activiti.engine.impl.util.ReflectUtil.loadClass(ReflectUtil.java:87)  
> at org.activiti.engine.impl.util.ReflectUtil.instantiate(ReflectUtil.java:134)  
> at org.activiti.engine.impl.bpmn.helper.ClassDelegate.defaultInstantiateDelegate(ClassDelegate.java:238)  
> at org.activiti.engine.impl.bpmn.helper.ClassDelegate.instantiateDelegate(ClassDelegate.java:228)  
> at org.activiti.engine.impl.bpmn.helper.ClassDelegate.getActivityBehaviorInstance(ClassDelegate.java:207)  
> at org.activiti.engine.impl.bpmn.helper.ClassDelegate.execute(ClassDelegate.java:151)  
> at org.activiti.engine.impl.pvm.runtime.AtomicOperationActivityExecute.execute(AtomicOperationActivityExecute.java:60)  
> at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:650)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:643)  
> at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerStart.eventNotificationsCompleted(AtomicOperationTransitionNotifyListenerStart.java:52)  
> at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:56)  
> at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:650)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:643)  
> at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:49)  
> at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:650)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:643)  
> at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionCreateScope.execute(AtomicOperationTransitionCreateScope.java:49)  
> at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:650)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:643)  
> at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerTake.execute(AtomicOperationTransitionNotifyListenerTake.java:80)  
> at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:650)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:643)  
> at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionDestroyScope.execute(AtomicOperationTransitionDestroyScope.java:116)  
> at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:650)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:643)  
> at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerEnd.eventNotificationsCompleted(AtomicOperationTransitionNotifyListenerEnd.java:35)  
> at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:56)  
> at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:650)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:643)  
> at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:49)  
> at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:650)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:643)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.take(ExecutionEntity.java:460)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.take(ExecutionEntity.java:438)  
> at org.activiti.engine.impl.bpmn.behavior.BpmnActivityBehavior.performOutgoingBehavior(BpmnActivityBehavior.java:140)  
> at org.activiti.engine.impl.bpmn.behavior.BpmnActivityBehavior.performDefaultOutgoingBehavior(BpmnActivityBehavior.java:66)  
> 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:60)  
> at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:650)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:643)  
> at org.activiti.engine.impl.pvm.runtime.AtomicOperationProcessStartInitial.eventNotificationsCompleted(AtomicOperationProcessStartInitial.java:45)  
> at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:56)  
> at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:650)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:643)  
> at org.activiti.engine.impl.pvm.runtime.AtomicOperationProcessStart.eventNotificationsCompleted(AtomicOperationProcessStart.java:64)  
> at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:56)  
> at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:650)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:643)  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.start(ExecutionEntity.java:388)  
> at org.activiti.engine.impl.cmd.StartProcessInstanceCmd.execute(StartProcessInstanceCmd.java:115)  
> at org.activiti.engine.impl.cmd.StartProcessInstanceCmd.execute(StartProcessInstanceCmd.java:37)  
> at org.activiti.engine.impl.interceptor.CommandInvoker.execute(CommandInvoker.java:24)  
> at org.activiti.engine.impl.interceptor.CommandContextInterceptor.execute(CommandContextInterceptor.java:57)  
> at org.activiti.engine.impl.interceptor.LogInterceptor.execute(LogInterceptor.java:31)  
> at org.activiti.engine.impl.cfg.CommandExecutorImpl.execute(CommandExecutorImpl.java:40)  
> at org.activiti.engine.impl.cfg.CommandExecutorImpl.execute(CommandExecutorImpl.java:35)  
> at org.activiti.engine.impl.RuntimeServiceImpl.startProcessInstanceByKey(RuntimeServiceImpl.java:82)”

I must be missing something either in the OSGi configuration of the bundle, or in the bundles itself, but I cannot figure this out.

---

<div class="post-metadata">

### Author: ![donkon](https://avatars.discourse-cdn.com/v4/letter/d/f475e1/32.png) [@donkon](https://forum.flowable.org/u/donkon)
#### Post date: [January 8, 2019, 11:38am UTC](https://forum.flowable.org/t/flowable-engine-in-osgi-tutorials-examples/3086/8 "2019-01-08T11:38:52Z")

</div>

You should give the ProcessEngineFactoryWithELResolver a try, I guess, it influences the classloading behaviour. You can configure the bean without having blueprint, the bean property ‘blueprintContextELResolver’ can be null:

```
    <bean id="blueprintELResolver" class="org.activiti.osgi.blueprint.BlueprintELResolver" />

    <bean id="processEngineFactory" class="org.activiti.osgi.blueprint.ProcessEngineFactoryWithELResolver" init-method="init" destroy-method="destroy">
    		<property name="processEngineConfiguration" ref="processEngineConfiguration" />
    		<property name="bundle" ref="blueprintBundle" />
    		<property name="blueprintELResolver" ref="blueprintELResolver" />
    </bean>
```

---

<div class="post-metadata">

### Author: ![Ceddaerrix](https://avatars.discourse-cdn.com/v4/letter/c/c77e96/32.png) [@Ceddaerrix](https://forum.flowable.org/u/Ceddaerrix)
#### Post date: [January 9, 2019, 8:03pm UTC](https://forum.flowable.org/t/flowable-engine-in-osgi-tutorials-examples/3086/9 "2019-01-09T20:03:33Z")

</div>

Using the blueprint as:

> ```
> <bean id="processEngineConfiguration" class="org.activiti.engine.impl.cfg.StandaloneInMemProcessEngineConfiguration" ext:field-injection="true">
> <property name="dataSource" ref="dataSource" />
> <property name="databaseSchemaUpdate" value="true" />
> <property name="asyncExecutorActivate" value="true" />
> <property name="disableIdmEngine" value="true" />
> <property name="resolverFactories">
> <list>
> <bean class="org.activiti.engine.impl.scripting.VariableScopeResolverFactory" />
> </list>
> </property>
> </bean>
> 
> <bean id="blueprintELResolver" class="org.activiti.osgi.blueprint.BlueprintELResolver" />
> 
> <bean id="processEngineFactory" class="org.activiti.osgi.blueprint.ProcessEngineFactoryWithELResolver" init-method="init" destroy-method="destroy">
> <property name="processEngineConfiguration" ref="processEngineConfiguration" />
> <property name="bundle" ref="blueprintBundle" />
> <property name="blueprintELResolver" ref="blueprintELResolver" />
> </bean>
> <reference id="dataSource" interface="javax.sql.DataSource" />
> 
> ```

I still get a class loading related error:

> org.activiti.engine.impl.interceptor.CommandContext - Error while closing command context  
> org.activiti.engine.ActivitiException: couldn’t instantiate class my.delegates.CustomDelegate  
> at org.activiti.engine.impl.util.ReflectUtil.instantiate(ReflectUtil.java:137) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.bpmn.helper.ClassDelegate.defaultInstantiateDelegate(ClassDelegate.java:238) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.bpmn.helper.ClassDelegate.instantiateDelegate(ClassDelegate.java:228) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.bpmn.helper.ClassDelegate.getActivityBehaviorInstance(ClassDelegate.java:207) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.bpmn.helper.ClassDelegate.execute(ClassDelegate.java:151) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.pvm.runtime.AtomicOperationActivityExecute.execute(AtomicOperationActivityExecute.java:60) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:650) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:643) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerStart.eventNotificationsCompleted(AtomicOperationTransitionNotifyListenerStart.java:52) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:56) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:650) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:643) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:49) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:650) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:643) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionCreateScope.execute(AtomicOperationTransitionCreateScope.java:49) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:650) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:643) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerTake.execute(AtomicOperationTransitionNotifyListenerTake.java:80) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:650) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:643) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionDestroyScope.execute(AtomicOperationTransitionDestroyScope.java:116) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:650) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:643) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerEnd.eventNotificationsCompleted(AtomicOperationTransitionNotifyListenerEnd.java:35) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:56) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:650) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:643) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:49) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:650) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:643) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.take(ExecutionEntity.java:460) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.take(ExecutionEntity.java:438) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.bpmn.behavior.BpmnActivityBehavior.performOutgoingBehavior(BpmnActivityBehavior.java:140) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.bpmn.behavior.BpmnActivityBehavior.performDefaultOutgoingBehavior(BpmnActivityBehavior.java:66) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.bpmn.behavior.FlowNodeActivityBehavior.leave(FlowNodeActivityBehavior.java:44) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.bpmn.behavior.FlowNodeActivityBehavior.execute(FlowNodeActivityBehavior.java:36) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.pvm.runtime.AtomicOperationActivityExecute.execute(AtomicOperationActivityExecute.java:60) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:650) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:643) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.pvm.runtime.AtomicOperationProcessStartInitial.eventNotificationsCompleted(AtomicOperationProcessStartInitial.java:45) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:56) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:650) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:643) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.pvm.runtime.AtomicOperationProcessStart.eventNotificationsCompleted(AtomicOperationProcessStart.java:64) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:56) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97) [flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:650) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:643) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.persistence.entity.ExecutionEntity.start(ExecutionEntity.java:388) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.cmd.StartProcessInstanceCmd.execute(StartProcessInstanceCmd.java:115) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.cmd.StartProcessInstanceCmd.execute(StartProcessInstanceCmd.java:37) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.interceptor.CommandInvoker.execute(CommandInvoker.java:24) ~[flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.interceptor.CommandContextInterceptor.execute(CommandContextInterceptor.java:57) [flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.interceptor.LogInterceptor.execute(LogInterceptor.java:31) [flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.cfg.CommandExecutorImpl.execute(CommandExecutorImpl.java:40) [flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.cfg.CommandExecutorImpl.execute(CommandExecutorImpl.java:35) [flowable-engine-5.23.0.jar:5.23.0]  
> at org.activiti.engine.impl.RuntimeServiceImpl.startProcessInstanceByKey(RuntimeServiceImpl.java:82) [flowable-engine-5.23.0.jar:5.23.0]  
> at []  
> at java.lang.Thread.run(Thread.java:745) [?:1.8.0\_121]  
> Caused by: org.activiti.engine.ActivitiClassLoadingException: Class not found: com.ge.flowbase.server.orchestration.delegates.CalculationOutputFilesMappingDelegate  
> at org.activiti.engine.impl.util.ReflectUtil.loadClass(ReflectUtil.java:87) ~[?:?]  
> at org.activiti.engine.impl.util.ReflectUtil.instantiate(ReflectUtil.java:134) ~[?:?]  
> … 92 more  
> Caused by: java.lang.ClassNotFoundException: my.delegates.CustomDelegate  
> at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[?:1.8.0\_121]  
> at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[?:1.8.0\_121]  
> at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331) ~[?:1.8.0\_121]  
> at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[?:1.8.0\_121]  
> at java.lang.Class.forName0(Native Method) ~[?:1.8.0\_121]  
> at java.lang.Class.forName(Class.java:348) ~[?:1.8.0\_121]  
> at org.activiti.engine.impl.util.ReflectUtil.loadClass(ReflectUtil.java:291) ~[?:?]  
> at org.activiti.engine.impl.util.ReflectUtil.loadClass(ReflectUtil.java:68) ~[?:?]  
> at org.activiti.engine.impl.util.ReflectUtil.instantiate(ReflectUtil.java:134) ~[?:?]  
> … 92 more

---

<div class="post-metadata">

### Author: ![Ceddaerrix](https://avatars.discourse-cdn.com/v4/letter/c/c77e96/32.png) [@Ceddaerrix](https://forum.flowable.org/u/Ceddaerrix)
#### Post date: [January 9, 2019, 10:53pm UTC](https://forum.flowable.org/t/flowable-engine-in-osgi-tutorials-examples/3086/10 "2019-01-09T22:53:56Z")

</div>

I have solved the issue above:  
_I can use the `activiti:class` attribute from without class loading issue. (Still needing to check the use of beans with the `activiti:delegateExpression` attribute)_

In a rush of finalizing my prototype, I made a few mistakes mostly due to the fact I had process-engine and workflow-processor in the same bundle and that I was not using ProcessEngine service exported from the blueprint.

Now, I am facing EL issues in conditional transitions, but they are due to the way my entity are structured.

---

<div class="post-metadata">

### Author: ![Ceddaerrix](https://avatars.discourse-cdn.com/v4/letter/c/c77e96/32.png) [@Ceddaerrix](https://forum.flowable.org/u/Ceddaerrix)
#### Post date: [January 10, 2019, 9:02am UTC](https://forum.flowable.org/t/flowable-engine-in-osgi-tutorials-examples/3086/11 "2019-01-10T09:02:52Z")

</div>

> [@Ceddaerrix](#):
>
> Still needing to check the use of beans with the `activiti:delegateExpression` attribute

I am having issues with the `activiti:delegateExpression` attribute as the bean is not found. Documented under [Flowable-engine in OSGi - Use of delegateExpression attribute resulting in bean not found issue](https://forum.flowable.org/t/flowable-engine-in-osgi-use-of-delegateexpression-attribute-resulting-in-bean-not-found-issue/3215)

---

<div class="post-metadata">

### Author: ![Robinyo](https://avatars.discourse-cdn.com/v4/letter/r/dec6dc/32.png) [@Robinyo](https://forum.flowable.org/u/Robinyo)
#### Post date: [January 11, 2019, 8:24pm UTC](https://forum.flowable.org/t/flowable-engine-in-osgi-tutorials-examples/3086/12 "2019-01-11T20:24:24Z")

</div>

Interesting post re Spring Boot and OSGi: [https://stackoverflow.com/questions/30881786/can-spring-boot-be-used-with-osgi-if-not-any-plans-to-have-an-osgi-spring-boot](https://stackoverflow.com/questions/30881786/can-spring-boot-be-used-with-osgi-if-not-any-plans-to-have-an-osgi-spring-boot)

---

<div class="post-metadata">

### Author: ![Ceddaerrix](https://avatars.discourse-cdn.com/v4/letter/c/c77e96/32.png) [@Ceddaerrix](https://forum.flowable.org/u/Ceddaerrix)
#### Post date: [January 14, 2019, 7:09am UTC](https://forum.flowable.org/t/flowable-engine-in-osgi-tutorials-examples/3086/13 "2019-01-14T07:09:26Z")

</div>

I have succeeded to finalize my implementation of Flowable (v5.23.0) in OSGi (Felix Framework v6.0.1)

Thanks to everyone’s inputs on the matter (or related topincs)