Is it possible for AbstractKafkaListenerContainerFactory's setContainerCustomizer to receive null parameter during runtime?

[zephyrdark]

Hi everyone, my service's KafkaListenerContainer 'crashes' due to 'Fatal consumer exception' caused by auth exceptions when broker changes its SSL configs.

I found out that I can set authExceptionRetryInterval property of the KafkaListenerContainer to not throw 'Fatal consumer exception' upon broker's changes SSL configs. Also, my KafkaListenerContainers would continuously reconnect to broker - this is my preferred expected behaviour.

• Specifically, I made a @Component that accepts a AbstractKafkaListenerContainerFactory. Then, i use the factory's setContainerCustomizer function to set future containers' ContainerProperties's authexceptionretryinterval property. I have tested the behaviour locally and it seems to work as expected.

However, I am concerned of the "future containers" possibly being null - is this a possibility? If so, I would need to handle NPE.

[artembilan]

"future containers" possibly being null

Would you mind to elaborate?
The ContainerCustomizer is called from the AbstractKafkaListenerContainerFactory at the moment when target container is created.
If that factory is out of use, then no customizer calls.
Therefore no way that it somehow may lead to null.

[zephyrdark]

"future containers" possibly being null

Would you mind to elaborate?

I am introducing ContainerCustomizer as a new piece of code to my service (it would be my first PR at work 😊!), so I wanted to check if I needed to handle NPE within it (my team has a practice of doing so).

The ContainerCustomizer is called from the AbstractKafkaListenerContainerFactory at the moment when target container is created. If that factory is out of use, then no customizer calls. Therefore no way that it somehow may lead to null.

Thank you, this behaviour is what I wanted to confirm - I have read through the library code but I just wanted to be sure.