Feat. JetStream Support for Source

[somratdutta]

We have added support for NATS JetStream for Source. Also added is a test-case for the Source class. We are open to feedback and actively working on to improve the current state of this project.

[somratdutta]

Hi @scottf, I have made some changes as per the latest discussion. You can see the commit here. I also agree on your PR for supporting Serializable Consumer Configuration, I would refactor the Jetstream connector code once its merged.

Upcoming improvements:

• add support for both Flink and Nats deserializers.
• implement checkpointing in JetstreamReader as per discussion.
• support for multiple subjects.

[somratdutta]

Updates in this commit :

• Removed NatsConsumeOptions and updated configurations in NatsJetStreamSource and related classes:

  • Replaced NatsConsumeOptions with SerializableConsumerConfiguration for more efficient JSON serialization.
  • Updated NatsJetStreamSource, NatsJetStreamSourceBuilder, and related classes to use SerializableConsumerConfiguration.
  • Ensured proper handling of ConsumerConfiguration instances through SerializableConsumerConfiguration.

• Fixed Method Visibility in ExampleErrorListener to Match Interface Requirements:

  • Adjusted method visibility in ExampleErrorListener to comply with the interface requirements.
  • Ensured all interface methods are properly implemented with the correct access modifiers.

• Refactored NatsJetStreamSourceTest:

  • Modified test cases to use SerializableConsumerConfiguration instead of NatsConsumeOptions.
  • Ensured proper thread interruption handling and Flink environment cleanup.
  • Added explicit null checks and descriptive comments for better code readability.

Note : This refactoring is done based on this PR which adds Serialisable wrappers. It hasn't been released yet, so the jnats version is bumped for next release.

@scottf

[tkeller-moxe]

Hey our team is interested in this! Do we know the status of this PR?