AnsweredAssumed Answered

Execution of JavaServiceTask via variable

Question asked by anandvivek on Mar 23, 2017
Latest reply on Mar 24, 2017 by gdharley

Hi, I am trying to execute the service task via variable.

When I am using literal in the service task it works. But when I assign the variable with the same literal it doesnt work.

 

CASE 1: Using literal in delegateExpression

 

Below is an example

 

Process XML

 

<?xml version="1.0" encoding="UTF-8"?>
<definitions xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:activiti="http://activiti.org/bpmn" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:omgdc="http://www.omg.org/spec/DD/20100524/DC" xmlns:omgdi="http://www.omg.org/spec/DD/20100524/DI" typeLanguage="http://www.w3.org/2001/XMLSchema" expressionLanguage="http://www.w3.org/1999/XPath" targetNamespace="http://www.activiti.org/test">
<process id="test1" name="test1" isExecutable="true">
<startEvent id="startevent1" name="Start"></startEvent>
<endEvent id="endevent1" name="End"></endEvent>
<serviceTask id="servicetask1" name="Service Task" activiti:delegateExpression="${LineManagerCompletionService}"></serviceTask>
<sequenceFlow id="flow1" sourceRef="startevent1" targetRef="servicetask1"></sequenceFlow>
<sequenceFlow id="flow2" sourceRef="servicetask1" targetRef="endevent1"></sequenceFlow>
<dataObject id="assignee" name="assignee" itemSubjectRef="xsd:string">
<extensionElements>
<activiti:value></activiti:value>
</extensionElements>
</dataObject>
</process>
<bpmndi:BPMNDiagram id="BPMNDiagram_test1">
<bpmndi:BPMNPlane bpmnElement="test1" id="BPMNPlane_test1">
<bpmndi:BPMNShape bpmnElement="startevent1" id="BPMNShape_startevent1">
<omgdc:Bounds height="35.0" width="35.0" x="280.0" y="210.0"></omgdc:Bounds>
</bpmndi:BPMNShape>
<bpmndi:BPMNShape bpmnElement="endevent1" id="BPMNShape_endevent1">
<omgdc:Bounds height="35.0" width="35.0" x="910.0" y="210.0"></omgdc:Bounds>
</bpmndi:BPMNShape>
<bpmndi:BPMNShape bpmnElement="servicetask1" id="BPMNShape_servicetask1">
<omgdc:Bounds height="55.0" width="105.0" x="520.0" y="210.0"></omgdc:Bounds>
</bpmndi:BPMNShape>
<bpmndi:BPMNEdge bpmnElement="flow1" id="BPMNEdge_flow1">
<omgdi:waypoint x="315.0" y="227.0"></omgdi:waypoint>
<omgdi:waypoint x="520.0" y="237.0"></omgdi:waypoint>
</bpmndi:BPMNEdge>
<bpmndi:BPMNEdge bpmnElement="flow2" id="BPMNEdge_flow2">
<omgdi:waypoint x="625.0" y="237.0"></omgdi:waypoint>
<omgdi:waypoint x="910.0" y="227.0"></omgdi:waypoint>
</bpmndi:BPMNEdge>
</bpmndi:BPMNPlane>
</bpmndi:BPMNDiagram>
</definitions>

 

@Named("LineManagerCompletionService")
public class LineManagerCompletionService implements JavaDelegate {

@Override
public void execute(DelegateExecution execution) throws Exception {
System.out.println("******Saving LM Decision******");
}

}

 

Case 2 : Using Delegate Expression as Variable

 

XML

 

<?xml version="1.0" encoding="UTF-8"?>
<definitions xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:activiti="http://activiti.org/bpmn" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:omgdc="http://www.omg.org/spec/DD/20100524/DC" xmlns:omgdi="http://www.omg.org/spec/DD/20100524/DI" typeLanguage="http://www.w3.org/2001/XMLSchema" expressionLanguage="http://www.w3.org/1999/XPath" targetNamespace="http://www.activiti.org/test">
<process id="test1" name="test1" isExecutable="true">
<startEvent id="startevent1" name="Start"></startEvent>
<endEvent id="endevent1" name="End"></endEvent>
<serviceTask id="servicetask1" name="Service Task" activiti:delegateExpression="${assignee}"></serviceTask>
<sequenceFlow id="flow1" sourceRef="startevent1" targetRef="servicetask1"></sequenceFlow>
<sequenceFlow id="flow2" sourceRef="servicetask1" targetRef="endevent1"></sequenceFlow>
<dataObject id="assignee" name="assignee" itemSubjectRef="xsd:string">
<extensionElements>
<activiti:value>LineManagerCompletionService</activiti:value>
</extensionElements>
</dataObject>
</process>
<bpmndi:BPMNDiagram id="BPMNDiagram_test1">
<bpmndi:BPMNPlane bpmnElement="test1" id="BPMNPlane_test1">
<bpmndi:BPMNShape bpmnElement="startevent1" id="BPMNShape_startevent1">
<omgdc:Bounds height="35.0" width="35.0" x="280.0" y="210.0"></omgdc:Bounds>
</bpmndi:BPMNShape>
<bpmndi:BPMNShape bpmnElement="endevent1" id="BPMNShape_endevent1">
<omgdc:Bounds height="35.0" width="35.0" x="910.0" y="210.0"></omgdc:Bounds>
</bpmndi:BPMNShape>
<bpmndi:BPMNShape bpmnElement="servicetask1" id="BPMNShape_servicetask1">
<omgdc:Bounds height="55.0" width="105.0" x="520.0" y="210.0"></omgdc:Bounds>
</bpmndi:BPMNShape>
<bpmndi:BPMNEdge bpmnElement="flow1" id="BPMNEdge_flow1">
<omgdi:waypoint x="315.0" y="227.0"></omgdi:waypoint>
<omgdi:waypoint x="520.0" y="237.0"></omgdi:waypoint>
</bpmndi:BPMNEdge>
<bpmndi:BPMNEdge bpmnElement="flow2" id="BPMNEdge_flow2">
<omgdi:waypoint x="625.0" y="237.0"></omgdi:waypoint>
<omgdi:waypoint x="910.0" y="227.0"></omgdi:waypoint>
</bpmndi:BPMNEdge>
</bpmndi:BPMNPlane>
</bpmndi:BPMNDiagram>
</definitions>

 

Failure Trace

 

org.activiti.engine.ActivitiIllegalArgumentException: Delegate expression ${assignee} did neither resolve to an implementation of interface org.activiti.engine.impl.pvm.delegate.ActivityBehavior nor interface org.activiti.engine.delegate.JavaDelegate
at org.activiti.engine.impl.bpmn.behavior.ServiceTaskDelegateExpressionActivityBehavior.execute(ServiceTaskDelegateExpressionActivityBehavior.java:100)

Outcomes