Please share any links to configure activiti with camel. All examples I could get were showing SERVICETASK->CAMELROUTE->FILE and then FILE->RECIEVETASK(Activiti)

This involves some BUSINESS\_KEY, which I couldn't figure out what exactly is

I need an example showing SERVICE TASK -> CAMEL ROUTE-> RECEIEVTASK(Signal the Activiti). I dont know why but this example gives me error 

file: activiti-flow.bpmn20.xml:

```
<process id="camelprocess" name="My process" isExecutable="true">
<startEvent id="startevent1" name="Start"></startEvent>
<serviceTask id="servicetask1" name="Service Task" activiti:async="true" activiti:delegateExpression="${camel}"></serviceTask>
<receiveTask id="receivetask1" name="Receive Task"></receiveTask>
<endEvent id="endevent1" name="End"></endEvent>
<sequenceFlow id="flow1" sourceRef="startevent1" targetRef="servicetask1"></sequenceFlow>
<sequenceFlow id="flow2" sourceRef="servicetask1" targetRef="receivetask1"></sequenceFlow>
<sequenceFlow id="flow3" sourceRef="receivetask1" targetRef="endevent1"></sequenceFlow>

```

activiti-camel-spring.xml

```
<bean id="camel" class="org.activiti.camel.CamelBehaviour">
    <constructor-arg index="0">
        <list>
            <bean class="org.activiti.camel.SimpleContextProvider">
                <constructor-arg index="0" value="camelprocess" />
                <constructor-arg index="1" ref="camelContext" />
            </bean>
        </list>
    </constructor-arg>
</bean>

<camel:camelContext id="camelContext">

    <camel:route>
        <camel:from uri="activiti:camelprocess:servicetask1"/>
        <camel:to uri="bean:serviceActivator?method=doSomething(${body})"/>
        <camel:to uri="activiti:camelprocess:receivetask1"/>
    </camel:route> 

</camel:camelContext>

```

Error is:

```
 1|ERROR|org.slf4j.helpers.MarkerIgnoringBase:161||||>> Failed delivery for (MessageId:    ID-viscx73-PC-49557-1376961951564-0-1 on ExchangeId: ID-viscx73-PC-49557-1376961951564-0-2). Exhausted after delivery attempt: 1 caught:       org.activiti.engine.ActivitiIllegalArgumentException: Business key is null 

at   org.activiti.engine.impl.ProcessInstanceQueryImpl.processInstanceBusinessKey(ProcessInstanceQueryImpl.java:87)
at org.activiti.camel.ActivitiProducer.findProcessInstanceId(ActivitiProducer.java:78)
at org.activiti.camel.ActivitiProducer.signal(ActivitiProducer.java:58)
at org.activiti.camel.ActivitiProducer.process(ActivitiProducer.java:49)
at         org.apache.camel.util.AsyncProcessorConverterHelper$ProcessorToAsyncProcessorBridge.process     (AsyncProcessorConverterHelper.java:61)
at org.apache.camel.util.AsyncProcessorHelper.process(AsyncProcessorHelper.java:73)

```

All forums/links that has ACTIVITI->CAMELROUTE(FILE) then
 in other route CAMEL\_FILE->RECIEVETASK

And they suggest to add some key like PROCESS\_KEY\_PROPERTY or PROCESS\_ID\_PROPERTY
I don't get where these properties fit into

I am trying to work it from example at link 
<http://bpmn20inaction.blogspot.in/2013/03/using-camel-routes-in-activiti-made.html>

I am not sure whether process after giving service task to camel, is not moving at all to receive task and waiting up there or CAMEL is unable to find receive task

Please share some suggestion on this

Thanks