Thanks Demian,

I'm still doing something wrong but I don't see it.

I followed the example carefully but I am still  getting a null ServiceTask parameter. Before I get to the ServiceTask I have a HumanTask with the same POJO as input and output in my BPMN file. I'm using the example TestWorkItemHandler and not doing anything with the POJO. Do I need to?

In the ServiceTask I'm using ServiceTaskHandler.

In jUnit...

  @Test

          public void evaluateScore() throws Exception {

  // given

                    final StatefulKnowledgeSession kSession = createKnowledgeSession(fr.getKbase());

                    TestWorkItemHandler testWorkItemHandler = new TestWorkItemHandler();

                    kSession.getWorkItemManager().registerWorkItemHandler("Human Task", testWorkItemHandler);

                    WorkItemManager wim = kSession.getWorkItemManager();

                    kSession.getWorkItemManager().registerWorkItemHandler("Service Task", new ServiceTaskHandler());

...

                    Map<String, Object> params = new HashMap<String, Object>();

                    params.put("vars", vars);

...

                    new Thread(new Runnable() {

                              public void run() {

                                        kSession.fireUntilHalt(); // fireAllRules hangs

                              }

                    }).start();

                    ProcessInstance pi = kSession.startProcess("x.x.x.workflow.xxx", params);

                    Thread.sleep(250);

  // then

        assertTrue(pi.getState() == ProcessInstance.STATE_ACTIVE);

        restoreSession(kSession, true);

        WorkItem workItem = testWorkItemHandler.getWorkItem();

        assertNotNull(workItem);

        assertEquals(workItem.PENDING, workItem.getState());

...

wim.completeWorkItem(workItem.getId(), null);

After completing the HumanTask workItem it executes the ServiceTask

          public XX execute(XX vars) {

  if(vars == null) { //@FIXME shouldn't be null

                              vars = new XX();

                              vars.setValidScore(true);

                    }

  if(vars.isCanScore()) { //@TODO real implementation

                              vars.setValidScore(true);

                    }

                    return vars;

          }

In BPMN

...

  <itemDefinition id="_varsItem" structureRef="x.x.x.workflow.xxx" />

...

  <itemDefinition id="_11_InMessageType" structureRef=""x.x.x.workflow.xxx" />

  <message id="_11_InMessage" itemRef="_11_InMessageType" />

  <interface id="_11_ServiceInterface" name=""x.x.x.workflow.xxx.EvaluateScore">

    <operation id="_11_ServiceOperation" name="execute">

      <inMessageRef>_11_InMessage</inMessageRef>

    </operation>

  </interface>

...

    <!-- process variables -->

    <property id="vars" itemSubjectRef="_varsItem"/>

...

    <serviceTask id="_11" name="Evaluate Score" operationRef="_11_ServiceOperation" implementation="Other" >

      <ioSpecification>

        <dataInput id="_11_varsInput" name="vars" />

        <dataOutput id="_11_varsOutput" name="vars" />

        <inputSet>

          <dataInputRefs>_11_varsInput</dataInputRefs>

        </inputSet>

        <outputSet>

          <dataOutputRefs>_11_varsOutput</dataOutputRefs>

        </outputSet>

      </ioSpecification>

      <dataInputAssociation>

        <sourceRef>vars</sourceRef>

        <targetRef>_11_varsInput</targetRef>

      </dataInputAssociation>

      <dataOutputAssociation>

        <sourceRef>_11_varsOutput</sourceRef>

        <targetRef>vars</targetRef>

      </dataOutputAssociation>

    </serviceTask>

Thanks again for your help, this is very frustrating. 

I made this change

    <serviceTask id="_11" name="Evaluate Score" operationRef="_11_ServiceOperation" implementation="Other" >

      <ioSpecification>

        <dataInput id="_11_varsInput" name="Parameter" />

        <dataOutput id="_11_varsOutput" name="Result" />

But the parameter is still null in my service task method. BPMN2-ServiceProcess and its jUnit test testServiceTask() show no other references to "Parameter" so I didn't change anything else.

Also ServiceTaskHandler doesn't provide a getter for workItem so I don't see how to debug or call

public class ServiceTaskHandler implements WorkItemHandler {

    public void executeWorkItem(WorkItem workItem, WorkItemManager manager)

Demian,

I was doing the same as your example except my itemDefinition had a structureRef, some examples define it and some don't.

Then I copied my project and started removing tasks to make it simple. After I deleted the Human Task preceding  my Service Task the parameter was correctly passed to the service method.

It looks like I have to propagate the POJO past the Human Task. What am I supposed to do? I'm using a copy of Kris TestWorkItemHandler ( it's still in jUnit).

The reason the service task parameter worked after removing the Human Task is that the TestWorkItemHandler(s) I copied from examples completed the task with null results. Once I passed the pojo to workItemManager.completeWorkItem(...) my service task method then got the pojo. This means you have to customize your testWorkItemHandlers to complete with the result you expect.

class MyAutomaticHumanSimulatorWorkItemHandler implements WorkItemHandler {

          private List<WorkItem> workItems = new ArrayList<WorkItem>();

          public void executeWorkItem(WorkItem workItem, WorkItemManager workItemManager) {

                    workItems.add(workItem);

                    System.out.println("Map of Parameters = " + workItem.getParameters());

  PIvars vars = (PIvars) workItem.getParameter("vars");

                    vars.setCanScore(true);

                    vars.setScore(new BigDecimal(4));

                    Map<String,Object>results = new HashMap();

                    results.put("vars", vars);

                    workItemManager.completeWorkItem(workItem.getId(), results);

                    System.out.println("Workitem completed  " + workItem.getName());

  }