Hey Petr, I have the same issue. But I just cope with it; I wire up default dependencies directly in the connector and task constructors, expose them through properties, and modify them to refer to mocks in my unit tests.
It's not a great approach, but it is simple. Why KConnect does take control from me how tasks are created? ... Or > instead of getTaskClass() to have createTask() on Connector which returns > task instance. The problem is that in distributed mode, Kafka Connect will be creating connectors on "arbitrary" nodes, and then very likely creating tasks on nodes where the connector is not instantiated. This is my understanding of why Kafka Connect takes the control away from you. I'm not saying it can't be done better, but it's definitely not without reason. :-) Mathieu On Mon, Mar 13, 2017 at 4:42 AM, Petr Novak <oss.mli...@gmail.com> wrote: > Hello, > > Nobody has experience with Kafka Connect tasks with external dependencies? > > > > Thanks, > > Petr > > > > From: Petr Novak [mailto:oss.mli...@gmail.com] > Sent: 23. února 2017 14:48 > To: users@kafka.apache.org > Subject: Pattern to create Task with dependencies (DI) > > > > Hello, > > it seems that KConnect take control over creating task instance and > requires > no-arg constructor. What is the recommended pattern when I need to create a > task which has dependency e.g. on some db client and I want to be able to > pass in mock in tests, preferable through constructor? > > In Java I probably have to divide actual task implementation into separate > class and use method forwarding from task factory class. I assume that this > factory, whose class would be passed to KConnect, requires to extend > abstract class whose “this” I have to pass to implementing class as another > dependency. I can’t figure out anything less ugly. > > > > In Scala it can be done elegantly through mixin composition which is > invisible to KConnect. > > > > Why KConnect does take control from me how tasks are created? Why KConnect > doesn’t accept factory class on which it would call no-arg create method > which would return instance of my task so that I can control how it is > created and which dependencies are created. Or instead of getTaskClass() to > have createTask() on Connector which returns task instance. > > > > Many thanks for advice, > > Petr > >
