JBoss Community

Hello there,

I have a problem with mapping the Human Task output to process variables. My code is inspired by the https://community.jboss.org/people/bpmn2user/blog/2011/09/21/jbpm5-web-example blog post.

I run it in Tomcat 6, using the Mina HT service.

Here is my process definition:

<?xml version="1.0" encoding="UTF-8"?> 
<definitions id="Definition"
             targetNamespace="http://www.jboss.org/drools"
             typeLanguage="http://www.java.com/javaTypes"
             expressionLanguage="http://www.mvel.org/2.0"
             xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://www.omg.org/spec/BPMN/20100524/MODEL BPMN20.xsd"
             xmlns:g="http://www.jboss.org/drools/flow/gpd"
             xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI"
             xmlns:dc="http://www.omg.org/spec/DD/20100524/DC"
             xmlns:di="http://www.omg.org/spec/DD/20100524/DI"
             xmlns:tns="http://www.jboss.org/drools">

  <itemDefinition id="_mgnlDataItem" structureRef="java.util.Map" />

  <itemDefinition id="_9-mgnlDataItem" structureRef="java.util.Map" />

  <process processType="Private" isExecutable="true" id="jch.workflow.test" name="Flow Test" tns:packageName="defaultPackage" >

    <extensionElements>
     <tns:import name="java.util.Map" />
    </extensionElements>
    <!-- process variables -->
    <property id="mgnlData" itemSubjectRef="_mgnlDataItem"/>

    <!-- nodes -->
    <startEvent id="_1" name="StartProcess" />
    <endEvent id="_6" name="End" >
        <terminateEventDefinition/>
    </endEvent>
    <scriptTask id="_7" name="Entry Script" scriptFormat="http://www.java.com/java" >
      <script>String processId = "" + kcontext.getProcessInstance().getId();
System.out.println("ENTRY SCRIPT: " + processId);
Map data = (Map) kcontext.getVariable("mgnlData");
if (data==null) {
  System.out.println("Empty DATA");
} else {
  System.out.println("DATA: " + data.toString());
}
</script>
    </scriptTask>
    <scriptTask id="_8" name="Exit Script" scriptFormat="http://www.java.com/java" >
      <script>String processId = "" + kcontext.getProcessInstance().getId();
System.out.println("EXIT SCRIPT: " + processId);
Map data = (Map) kcontext.getVariable("mgnlData");
if (data==null) {
  System.out.println("Empty DATA");
} else {
  System.out.println("DATA: " + data.toString());
}
</script>
    </scriptTask>
    <userTask id="_9" name="User Task" >
      <extensionElements>
        <tns:onEntry-script scriptFormat="http://www.java.com/java">
          <script>System.out.println("Human Task - Entry action");</script>
        </tns:onEntry-script>
        <tns:onExit-script scriptFormat="http://www.java.com/java">
          <script>System.out.println("Human Task - Exit action");</script>
        </tns:onExit-script>
      </extensionElements>
      <ioSpecification>
        <dataInput id="_9_ContentInput" name="Content" />
        <dataOutput id="_9_mgnlDataOutput" name="mgnlData" />
        <inputSet>
          <dataInputRefs>_9_ContentInput</dataInputRefs>
        </inputSet>
        <outputSet>
          <dataOutputRefs>_9_mgnlDataOutput</dataOutputRefs>
        </outputSet>
      </ioSpecification>
      <dataInputAssociation>
        <sourceRef>mgnlData</sourceRef>
        <targetRef>_9_ContentInput</targetRef>
      </dataInputAssociation>
      <dataOutputAssociation>
        <sourceRef>_9_mgnlDataOutput</sourceRef>
        <targetRef>mgnlData</targetRef>
      </dataOutputAssociation>
      <potentialOwner>
        <resourceAssignmentExpression>
          <formalExpression>peter</formalExpression>
        </resourceAssignmentExpression>
      </potentialOwner>
    </userTask>

    <!-- connections -->
    <sequenceFlow id="_8-_6" sourceRef="_8" targetRef="_6" />
    <sequenceFlow id="_1-_7" sourceRef="_1" targetRef="_7" />
    <sequenceFlow id="_9-_8" sourceRef="_9" targetRef="_8" />
    <sequenceFlow id="_7-_9" sourceRef="_7" targetRef="_9" />

  </process>

  <bpmndi:BPMNDiagram>
    ...
  </bpmndi:BPMNDiagram>

</definitions>

This is how I start the process:

    public RunningProcess launch(Workflow workflow, Map<String, Object> parameters) throws WorkflowException {
        Map<String,Object> processParams = new HashMap<String,Object>();
        processParams.put(RunningProcess.DATA, parameters);
        try {
            // start user transaction
            UserTransaction ut = (UserTransaction) new InitialContext().lookup("java:comp/UserTransaction");
            ut.begin();
            // start process
            ProcessInstance pi = this.ksession.startProcess(workflow.getId(), processParams);
            this.ksession.fireAllRules();
            // commit
            ut.commit();
            return new ProcessImpl(pi);
        } catch (Exception e) {
            log.debug("Error starting workflow [" + workflow.getId() + "].", e);
            throw new WorkflowException("Error starting workflow.", e);
        }
    }

RunningProcess.DATA containg the "mgnlData" string, Workflow is my bean holding the process definition data, RunningProcess / ProcessImpl are my wrappers for the ProcessInstace. Then I call this method from:

Map<String, Object> data = new HashMap<String, Object>();
data.put("string", "string value");
data.put("int", 42);
process = manager.launch("test", data);

And how I handle the Human Task:

// prepare data
Map<String, Object> data = new HashMap<String, Object>();
Map<String, Object> mgnlData = new HashMap<String, Object>();
mgnlData.put("int", 1111);
mgnlData.put("string", "new value");
data.put(RunningProcess.DATA, mgnlData);
// start user transaction
UserTransaction ut = (UserTransaction) new InitialContext().lookup("java:comp/UserTransaction");
ut.begin();
// start processing the task
BlockingTaskOperationResponseHandler responseHandler = new BlockingTaskOperationResponseHandler();
this.taskClient.start(summary.getId(), user, responseHandler);
responseHandler.waitTillDone(1000);
// and complete the task
responseHandler = new BlockingTaskOperationResponseHandler();
this.taskClient.complete(summary.getId(), user, map2contentData(data), responseHandler);
responseHandler.waitTillDone(2000);
// commit transaction
ut.commit();

The map2contentData method is based on the code from jBPM5 web example blog post:

    protected ContentData map2contentData(Map data) {
        ContentData contentData = null;
        if (data != null) {
            ByteArrayOutputStream bos = new ByteArrayOutputStream();
            ObjectOutputStream out;
            try {
                out = new ObjectOutputStream(bos);
                out.writeObject(data);
                out.close();
                contentData = new ContentData();
                contentData.setContent(bos.toByteArray());
                contentData.setAccessType(AccessType.Inline);
            } catch (IOException e) {
                log.error("Problem saving output data.", e);
            }
        }
        return contentData;
    }

But it results in the empty process variable in the end (console output):

ENTRY SCRIPT: 425984
DATA: {int=42, string=string value}
Human Task - Entry action

...

Human Task - Exit action
EXIT SCRIPT: 425984
Empty DATA

I expect sort-of PEBKAC error, but I couldn't find what did I forget...