How does Kafka check if a topic has data?

Kafka provides some methods to check if a topic has data.

1. You can check the offsets of a topic using the Kafka command line tool. To view the offsets of a specific topic, you can use the following command:
2. Run the Kafka tool GetOffsetShell using the kafka-run-class.sh script, providing the broker list and topic name, with a time parameter of -1.
3. This will display the latest offset for each partition. If the offset for all partitions is 0, it indicates that the topic currently has no data.
4. Use the Kafka Consumer API to consume data from a topic. Create a Kafka Consumer instance, subscribe to the topic, and then poll for messages. If there are no messages to consume, it means that the topic currently has no data.
5. Get offset information for a topic using the Kafka AdminClient API. Create an AdminClient instance and use the describeTopics method to retrieve the offset information for the topic. By analyzing the returned offset information, you can determine if the topic has any data.

All of these methods can help you determine if a topic has data. Choose the method that is suitable for your scenario to check the data situation of the topic.