Expression Resolving
The camunda-engine-cdi
library exposes CDI beans via Expression Language, using a custom resolver. This makes it possible to reference beans from the process:
<userTask id="authorizeBusinessTrip" name="Authorize Business Trip"
camunda:assignee="#{authorizingManager.account.username}" />
Where “authorizingManager” could be a bean provided by a producer method:
@Inject
@ProcessVariable
private Object businessTripRequesterUsername;
@Produces
@Named
public Employee authorizingManager() {
TypedQuery<Employee> query = entityManager.createQuery("SELECT e FROM Employee e WHERE e.account.username='"
+ businessTripRequesterUsername + "'", Employee.class);
Employee employee = query.getSingleResult();
return employee.getManager();
}
We can use the same feature to call a business method of an EJB in a service task, using the camunda:expression="${myEjb.method()}"
-extension.
Note that this requires a @Named
-annotation on the MyEjb-class.