Process Variable Problem

[se040]

Hi,

I am using the activity engine in a small web application configured like this:

         ProcessEngines.init();
         ProcessEngineConfiguration engConf = ProcessEngineConfiguration
               .createStandaloneProcessEngineConfiguration();
         engConf.setDataSourceJndiName(dataSourceJndiName);
         engConf.setHistory(history);
         engConf.setClassLoader(Thread.currentThread().getContextClassLoader()); //added after problem ocurred!
         engine = engConf.buildProcessEngine();

So basically it all works fine. The only problem is that when using custom data types (all of which of course implement Serializable + have UID generated) as process Variables I get Exceptions like the following:

org.activiti.engine.ActivitiException: coudn't deserialize object in variable 'acessedBy'
   at org.activiti.engine.impl.variable.SerializableType.getValue(SerializableType.java:60)
   at org.activiti.engine.impl.persistence.entity.VariableInstanceEntity.getValue(VariableInstanceEntity.java:158)
   at org.activiti.engine.impl.persistence.entity.VariableScopeImpl.getVariable(VariableScopeImpl.java:93)
   at org.testmyapp.tasks.processone.ProcessOneEndListener.notify(ProcessOneEndListener.java:35)
   at org.activiti.engine.impl.delegate.ExecutionListenerInvocation.invoke(ExecutionListenerInvocation.java:34)
   at org.activiti.engine.impl.delegate.DelegateInvocation.proceed(DelegateInvocation.java:37)
   at org.activiti.engine.impl.delegate.DefaultDelegateInterceptor.handleInvocation(DefaultDelegateInterceptor.java:25)
   at org.activiti.engine.impl.bpmn.helper.ClassDelegate.notify(ClassDelegate.java:70)
   at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:42)
   at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:80)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:546)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:541)
   at org.activiti.engine.impl.pvm.runtime.AtomicOperationActivityEnd.eventNotificationsCompleted(AtomicOperationActivityEnd.java:54)
   at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:56)
   at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:80)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:546)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:541)
   at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:49)
   at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:80)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:546)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:541)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.end(ExecutionEntity.java:354)
   at org.activiti.engine.impl.bpmn.behavior.NoneEndEventActivityBehavior.execute(NoneEndEventActivityBehavior.java:24)
   at org.activiti.engine.impl.pvm.runtime.AtomicOperationActivityExecute.execute(AtomicOperationActivityExecute.java:44)
   at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:80)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:546)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:541)
   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:80)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:546)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:541)
   at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:49)
   at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:80)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:546)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:541)
   at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionCreateScope.execute(AtomicOperationTransitionCreateScope.java:49)
   at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:80)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:546)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:541)
   at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerTake.execute(AtomicOperationTransitionNotifyListenerTake.java:65)
   at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:80)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:546)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:541)
   at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionDestroyScope.execute(AtomicOperationTransitionDestroyScope.java:115)
   at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:80)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:546)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:541)
   at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerEnd.eventNotificationsCompleted(AtomicOperationTransitionNotifyListenerEnd.java:36)
   at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:56)
   at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:80)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:546)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:541)
   at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:49)
   at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:80)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:546)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:541)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.take(ExecutionEntity.java:381)
   at org.activiti.engine.impl.bpmn.behavior.BpmnActivityBehavior.performOutgoingBehavior(BpmnActivityBehavior.java:102)
   at org.activiti.engine.impl.bpmn.behavior.BpmnActivityBehavior.performDefaultOutgoingBehavior(BpmnActivityBehavior.java:51)
   at org.activiti.engine.impl.bpmn.behavior.FlowNodeActivityBehavior.leave(FlowNodeActivityBehavior.java:44)
   at org.activiti.engine.impl.bpmn.behavior.AbstractBpmnActivityBehavior.leave(AbstractBpmnActivityBehavior.java:47)
   at org.activiti.engine.impl.bpmn.behavior.UserTaskActivityBehavior.signal(UserTaskActivityBehavior.java:92)
   at org.activiti.engine.impl.persistence.entity.ExecutionEntity.signal(ExecutionEntity.java:364)
   at org.activiti.engine.impl.persistence.entity.TaskEntity.complete(TaskEntity.java:156)
   at org.activiti.engine.impl.cmd.CompleteTaskCmd.completeTask(CompleteTaskCmd.java:63)
   at org.activiti.engine.impl.cmd.CompleteTaskCmd.execute(CompleteTaskCmd.java:57)
   at org.activiti.engine.impl.cmd.CompleteTaskCmd.execute(CompleteTaskCmd.java:28)
   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.TaskServiceImpl.complete(TaskServiceImpl.java:144)
   at org.testmyapp.engine.ActivitiEngineServices.completeTask(ActivitiEngineServices.java:132)
   at org.testmyapp.engine.ActivitiEngineServices$Proxy$_$$_WeldClientProxy.completeTask(ActivitiEngineServices$Proxy$_$$_WeldClientProxy.java)
   at org.testmyapp.tasks.ProcessOne.doPost(ProcessOne.java:136)
   at javax.servlet.http.HttpServlet.service(HttpServlet.java:688)
   at javax.servlet.http.HttpServlet.service(HttpServlet.java:770)
   at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1550)
   at org.apache.catalina.core.ApplicationDispatcher.doInvoke(ApplicationDispatcher.java:809)
   at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:671)
   at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:505)
   at org.apache.catalina.core.ApplicationDispatcher.doDispatch(ApplicationDispatcher.java:476)
   at org.apache.catalina.core.ApplicationDispatcher.dispatch(ApplicationDispatcher.java:355)
   at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:305)
   at org.testmyapp.tasks.ProcessOne.doPost(ProcessOne.java:132)
   at javax.servlet.http.HttpServlet.service(HttpServlet.java:688)
   at javax.servlet.http.HttpServlet.service(HttpServlet.java:770)
   at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1550)
   at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281)
   at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
   at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
   at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595)
   at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:161)
   at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:331)
   at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:231)
   at com.sun.enterprise.v3.services.impl.ContainerMapper$AdapterCallable.call(ContainerMapper.java:317)
   at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:195)
   at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:860)
   at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:757)
   at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1056)
   at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:229)
   at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137)
   at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104)
   at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90)
   at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79)
   at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54)
   at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59)
   at com.sun.grizzly.ContextTask.run(ContextTask.java:71)
   at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532)
   at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513)
   at java.lang.Thread.run(Thread.java:722)
Caused by: java.lang.ClassNotFoundException: org.testmyapp.entities.Access
   at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
   at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
   at java.security.AccessController.doPrivileged(Native Method)
   at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
   at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
   at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
   at java.lang.Class.forName0(Native Method)
   at java.lang.Class.forName(Class.java:264)
   at java.io.ObjectInputStream.resolveClass(ObjectInputStream.java:622)
   at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1593)
   at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1514)
   at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1750)
   at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1347)
   at java.io.ObjectInputStream.readObject(ObjectInputStream.java:369)
   at org.activiti.engine.impl.variable.SerializableType.getValue(SerializableType.java:49)
   … 110 more

I think the engine tells me that it couldn't find the class of the datatype. I have tried all I could think of but since its my first time using activity plus my first time building a web application I think I might oversee things.

Further Details:
- Using GlassFish 3.1.2
- The engine is encapsuled in a bean and injected when needed (@Inject for that purpose).
- The error only occurs when I retrieve a variable not when I set a variable

If you need more details please ask. I welcome any help

Thanks in advance,
Stefan

[frederikherema1]

Seems like a classloading-issue, I guess it has something to do with this:


engConf.setClassLoader(Thread.currentThread().getContextClassLoader()); //added after problem ocurred!

Pleas note, activiti chains class-loading (first custom class loader set on engConf, second CurrentThread.CCL, and lastly class-local one. It seems that these class loaders aren't used when deserializing the variables, this will be resolved (also see https://github.com/Activiti/Activiti/pull/3/files).

A solution for now (until 5.11 is released) is to use a custom variable-type (extending serializableType) deserializing the object using the right class loader.

[se040]

Thanks for the answer, but I didn't really understand what you mean by using a custom variable type, sorry. All the variables / types I use implement Serializable.

[frederikherema1]

Yes, but there is a problem with the serializable variable-type in case a serializable class isn't loaded by the class-loader they loaded the activiti-engine jar itself, when DEserializing.

You have to wait for 5.11, beginning of next month, use 5.11-SNAPSHOT OR use a custom variable-type that fixes the deserialisation