Kafka + Spring Boot

What this is

A hands-on Kafka setup in plain Java: a producer, a consumer, and a real-world data source (Twitter's streaming API) feeding the producer instead of a hardcoded message.

Design

• Producer — configures KafkaProducer with bootstrap servers + string (de)serializers, sends a ProducerRecord to first_topics, and flushes/closes cleanly.
• Consumer — configures KafkaConsumer with a consumer group (my-app) and earliest offset reset, subscribes to first_topics, and polls in a loop.
• TwitterProducer — the interesting piece: opens a filtered Twitter stream via the Hosebird Client (hbc), buffers incoming tweets on a BlockingQueue, and republishes each one onto the twitter_tweets Kafka topic through a KafkaProducer, with an async callback for send errors.

Tech

Java, Apache Kafka client, Twitter Hosebird Client (hbc), Maven

How to Run

1. Start a local Kafka broker on 127.0.0.1:9092
2. Run Consumer to subscribe to the topic you care about (first_topics or twitter_tweets)
3. Run Producer for a simple hello-world message, or TwitterProducer (with Twitter API credentials) to stream live tweets into Kafka