Error when used "Execution listeners" at Http-task

Hi all,
I am having a problem with my project. I don’t know what the problem is. It is an error about the working between action “user-task” and “http-task”. Here are the details

1. My process
image

2. Config “http-task”

3. Process flowable

> <?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:flowable="http://flowable.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.flowable.org/processdef"> <process id="ta" name="ta" isExecutable="true"> <startEvent id="s1" name="s1" flowable:formFieldValidation="true"></startEvent> <serviceTask id="t1" name="t1" flowable:parallelInSameTransaction="true" flowable:type="http"> <extensionElements> <flowable:field name="requestMethod"> <flowable:string><![CDATA[GET]]></flowable:string> </flowable:field> <flowable:field name="requestUrl"> <flowable:string><![CDATA[${getUrl}]]></flowable:string> </flowable:field> <flowable:executionListener event="start" class="com.workflowengine.delegate.HttpListener"></flowable:executionListener> <flowable:executionListener event="end" class="com.workflowengine.delegate.EndListener"></flowable:executionListener> </extensionElements> </serviceTask> <endEvent id="e1" name="e1"></endEvent> <userTask id="u1" name="u1" flowable:formFieldValidation="true"></userTask> <sequenceFlow id="f1" name="f1" sourceRef="s1" targetRef="t1"></sequenceFlow> <sequenceFlow id="f4" name="f4" sourceRef="u1" targetRef="e1"></sequenceFlow> <boundaryEvent id="t2" name="t2" attachedToRef="u1" cancelActivity="true"> <timerEventDefinition> <timeDate>2022-09-19</timeDate> </timerEventDefinition> </boundaryEvent> <sequenceFlow id="f2" name="f2" sourceRef="t1" targetRef="u1"></sequenceFlow> <sequenceFlow id="f3" name="f3" sourceRef="t2" targetRef="t1"></sequenceFlow> </process> <bpmndi:BPMNDiagram id="BPMNDiagram_ta"> <bpmndi:BPMNPlane bpmnElement="ta" id="BPMNPlane_ta"> <bpmndi:BPMNShape bpmnElement="s1" id="BPMNShape_s1"> <omgdc:Bounds height="30.0" width="30.0" x="90.00000000000001" y="150.00000000000003"></omgdc:Bounds> </bpmndi:BPMNShape> <bpmndi:BPMNShape bpmnElement="t1" id="BPMNShape_t1"> <omgdc:Bounds height="80.0" width="99.99999999999997" x="255.00000000000003" y="135.00000000000003"></omgdc:Bounds> </bpmndi:BPMNShape> <bpmndi:BPMNShape bpmnElement="e1" id="BPMNShape_e1"> <omgdc:Bounds height="28.0" width="28.0" x="585.0000000000002" y="165.00000000000006"></omgdc:Bounds> </bpmndi:BPMNShape> <bpmndi:BPMNShape bpmnElement="u1" id="BPMNShape_u1"> <omgdc:Bounds height="80.0" width="100.0" x="360.00000000000006" y="360.00000000000006"></omgdc:Bounds> </bpmndi:BPMNShape> <bpmndi:BPMNShape bpmnElement="t2" id="BPMNShape_t2"> <omgdc:Bounds height="31.0" width="31.0" x="379.50000000000006" y="344.50000000000006"></omgdc:Bounds> </bpmndi:BPMNShape> <bpmndi:BPMNEdge bpmnElement="f1" id="BPMNEdge_f1"> <omgdi:waypoint x="119.93150837893873" y="165.7465842736863"></omgdi:waypoint> <omgdi:waypoint x="255.00000000000003" y="172.50000000000006"></omgdi:waypoint> </bpmndi:BPMNEdge> <bpmndi:BPMNEdge bpmnElement="f2" id="BPMNEdge_f2"> <omgdi:waypoint x="305.0" y="214.95000000000005"></omgdi:waypoint> <omgdi:waypoint x="305.0" y="400.0"></omgdi:waypoint> <omgdi:waypoint x="360.00000000000006" y="400.00000000000006"></omgdi:waypoint> </bpmndi:BPMNEdge> <bpmndi:BPMNEdge bpmnElement="f3" id="BPMNEdge_f3"> <omgdi:waypoint x="388.21774143141386" y="346.05793092578097"></omgdi:waypoint> <omgdi:waypoint x="324.43513513513517" y="214.95000000000005"></omgdi:waypoint> </bpmndi:BPMNEdge> <bpmndi:BPMNEdge bpmnElement="f4" id="BPMNEdge_f4"> <omgdi:waypoint x="423.5069047619048" y="360.00000000000006"></omgdi:waypoint> <omgdi:waypoint x="481.0" y="190.0"></omgdi:waypoint> <omgdi:waypoint x="485.0" y="183.0"></omgdi:waypoint> <omgdi:waypoint x="585.0084447149624" y="179.48917856474918"></omgdi:waypoint> </bpmndi:BPMNEdge> </bpmndi:BPMNPlane> </bpmndi:BPMNDiagram> </definitions>

4. Error when start process

Please help me. Thank you so much!

I got it. I wrong implement JavaDelegate.
Thank all.