How to use

getResultVariableName

method

in

org.flowable.bpmn.model.ServiceTask

protected void verifyResultVariableName(Process process, ServiceTask serviceTask, List<ValidationError> errors) {
  if (StringUtils.isNotEmpty(serviceTask.getResultVariableName())
      && (ImplementationType.IMPLEMENTATION_TYPE_CLASS.equals(serviceTask.getImplementationType()) || 
              ImplementationType.IMPLEMENTATION_TYPE_DELEGATEEXPRESSION.equals(serviceTask.getImplementationType()))) {
    
    addError(errors, Problems.SERVICE_TASK_RESULT_VAR_NAME_WITH_DELEGATE, process, serviceTask, "'resultVariableName' not supported for service tasks using 'class' or 'delegateExpression");
  }
  if (serviceTask.isUseLocalScopeForResultVariable() && StringUtils.isEmpty(serviceTask.getResultVariableName())) {
    addWarning(errors, Problems.SERVICE_TASK_USE_LOCAL_SCOPE_FOR_RESULT_VAR_WITHOUT_RESULT_VARIABLE_NAME, process, serviceTask, "'useLocalScopeForResultVariable' is set, but no 'resultVariableName' is set. The property would not be used");
  }
}

public ServiceTaskExpressionActivityBehavior(ServiceTask serviceTask, Expression expression, Expression skipExpression) {
  this.serviceTaskId = serviceTask.getId();
  this.expression = expression;
  this.skipExpression = skipExpression;
  this.resultVariable = serviceTask.getResultVariableName();
  this.mapExceptions = serviceTask.getMapExceptions();
  this.useLocalScopeForResultVariable = serviceTask.isUseLocalScopeForResultVariable();
}

  protected void mapProperties(Object element) {
    ServiceTask serviceTask = (ServiceTask) element;
    if (ImplementationType.IMPLEMENTATION_TYPE_CLASS.equals(serviceTask.getImplementationType())) {
      createPropertyNode("Class", serviceTask.getImplementation());
    } else if (ImplementationType.IMPLEMENTATION_TYPE_EXPRESSION.equals(serviceTask.getImplementationType())) {
      createPropertyNode("Expression", serviceTask.getImplementation());
    } else if (ImplementationType.IMPLEMENTATION_TYPE_DELEGATEEXPRESSION.equals(serviceTask.getImplementationType())) {
      createPropertyNode("Delegate expression", serviceTask.getImplementation());
    }
    createPropertyNode("Result variable name", serviceTask.getResultVariableName());
    createPropertyNode("Use local scope for result variable", serviceTask.isUseLocalScopeForResultVariable());
  }
}

@Override
public ServiceTaskExpressionActivityBehavior createServiceTaskExpressionActivityBehavior(ServiceTask serviceTask) {
  Expression expression = expressionManager.createExpression(serviceTask.getImplementation());
  Expression skipExpression;
  if (StringUtils.isNotEmpty(serviceTask.getSkipExpression())) {
    skipExpression = expressionManager.createExpression(serviceTask.getSkipExpression());
  } else {
    skipExpression = null;
  }
  return new ServiceTaskExpressionActivityBehavior(serviceTask.getId(), expression, skipExpression,
      serviceTask.getResultVariableName(), serviceTask.getMapExceptions());
}

@Override
protected void writeAdditionalAttributes(BaseElement element, BpmnModel model, XMLStreamWriter xtw) throws Exception {
  ServiceTask serviceTask = (ServiceTask) element;
  if (ImplementationType.IMPLEMENTATION_TYPE_CLASS.equals(serviceTask.getImplementationType())) {
    writeQualifiedAttribute(ATTRIBUTE_TASK_SERVICE_CLASS, serviceTask.getImplementation(), xtw);
  } else if (ImplementationType.IMPLEMENTATION_TYPE_EXPRESSION.equals(serviceTask.getImplementationType())) {
    writeQualifiedAttribute(ATTRIBUTE_TASK_SERVICE_EXPRESSION, serviceTask.getImplementation(), xtw);
  } else if (ImplementationType.IMPLEMENTATION_TYPE_DELEGATEEXPRESSION.equals(serviceTask.getImplementationType())) {
    writeQualifiedAttribute(ATTRIBUTE_TASK_SERVICE_DELEGATEEXPRESSION, serviceTask.getImplementation(), xtw);
  }
  if (StringUtils.isNotEmpty(serviceTask.getResultVariableName())) {
    writeQualifiedAttribute(ATTRIBUTE_TASK_SERVICE_RESULTVARIABLE, serviceTask.getResultVariableName(), xtw);
  }
  if (StringUtils.isNotEmpty(serviceTask.getType())) {
    writeQualifiedAttribute(ATTRIBUTE_TYPE, serviceTask.getType(), xtw);
  }
  if (StringUtils.isNotEmpty(serviceTask.getExtensionId())) {
    writeQualifiedAttribute(ATTRIBUTE_TASK_SERVICE_EXTENSIONID, serviceTask.getExtensionId(), xtw);
  }
  if (StringUtils.isNotEmpty(serviceTask.getSkipExpression())) {
    writeQualifiedAttribute(ATTRIBUTE_TASK_SERVICE_SKIP_EXPRESSION, serviceTask.getSkipExpression(), xtw);
  }
  if (serviceTask.isTriggerable()) {
    writeQualifiedAttribute(ATTRIBUTE_ACTIVITY_TRIGGERABLE, "true", xtw);
  }
  if (serviceTask.isUseLocalScopeForResultVariable()) {
    writeQualifiedAttribute(ATTRIBUTE_TASK_SERVICE_USE_LOCAL_SCOPE_FOR_RESULT_VARIABLE, "true", xtw);
  }
}

  public void setValues(ServiceTask otherElement) {
    super.setValues(otherElement);
    setImplementation(otherElement.getImplementation());
    setImplementationType(otherElement.getImplementationType());
    setResultVariableName(otherElement.getResultVariableName());
    setType(otherElement.getType());
    setOperationRef(otherElement.getOperationRef());
    setExtensionId(otherElement.getExtensionId());
    setSkipExpression(otherElement.getSkipExpression());

    fieldExtensions = new ArrayList<>();
    if (otherElement.getFieldExtensions() != null && !otherElement.getFieldExtensions().isEmpty()) {
      for (FieldExtension extension : otherElement.getFieldExtensions()) {
        fieldExtensions.add(extension.clone());
      }
    }

    customProperties = new ArrayList<>();
    if (otherElement.getCustomProperties() != null && !otherElement.getCustomProperties().isEmpty()) {
      for (CustomProperty property : otherElement.getCustomProperties()) {
        customProperties.add(property.clone());
      }
    }
  }
}

  public void setValues(ServiceTask otherElement) {
    super.setValues(otherElement);
    setImplementation(otherElement.getImplementation());
    setImplementationType(otherElement.getImplementationType());
    setResultVariableName(otherElement.getResultVariableName());
    setType(otherElement.getType());
    setOperationRef(otherElement.getOperationRef());
    setExtensionId(otherElement.getExtensionId());
    setSkipExpression(otherElement.getSkipExpression());
    setUseLocalScopeForResultVariable(otherElement.isUseLocalScopeForResultVariable());
    setTriggerable(otherElement.isTriggerable());

    fieldExtensions = new ArrayList<>();
    if (otherElement.getFieldExtensions() != null && !otherElement.getFieldExtensions().isEmpty()) {
      for (FieldExtension extension : otherElement.getFieldExtensions()) {
        fieldExtensions.add(extension.clone());
      }
    }

    customProperties = new ArrayList<>();
    if (otherElement.getCustomProperties() != null && !otherElement.getCustomProperties().isEmpty()) {
      for (CustomProperty property : otherElement.getCustomProperties()) {
        customProperties.add(property.clone());
      }
    }
  }
}

if (StringUtils.isEmpty(serviceTask.getResultVariableName())) {
  serviceTask.setResultVariableName(BpmnXMLUtil.getAttributeValue("resultVariable", xtr));

if (StringUtils.isNotEmpty(serviceTask.getResultVariableName())) {
  propertiesNode.put(PROPERTY_SERVICETASK_RESULT_VARIABLE, serviceTask.getResultVariableName());