Kafka Streams

Kafka Streams is a powerful Java library provided by Apache Kafka for building stream processing applications. It allows you to process and analyze data in real-time as it flows through Kafka topics. With Kafka Streams, you can easily perform various tasks such as filtering, aggregating, transforming, and joining data streams.

Getting Started with Kafka Streams

To get started with Kafka Streams, you need to set up a Kafka Streams application. Here's an example of how to create a basic Kafka Streams application using the Kafka Streams API in Java:

1<<code>>

Let's go through the code:

1. First, we import the required classes from the Kafka Streams API.
2. Next, we set up the configuration for our Kafka Streams application, including the application ID and the bootstrap servers.
3. Then, we create a StreamsBuilder object, which will be used to define the stream processing topology.
4. We define the stream processing logic by specifying the input topic, applying transformations on the stream, and specifying the output topic.
5. Finally, we build the Kafka Streams application using the StreamsBuilder and the configuration, and start it.

With this basic Kafka Streams application, you can process and transform data in real-time as it flows through Kafka topics. You can further explore the Kafka Streams API to learn more about its advanced features and capabilities.

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class Main {

  public static void main(String[] args) {

    // Create a Kafka Streams application

    Properties config = new Properties();

    config.put(StreamsConfig.APPLICATION_ID_CONFIG, "my-streams-app");

    config.put(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");

​

    StreamsBuilder builder = new StreamsBuilder();

​

    // Define the stream processing logic

    KStream<String, String> input = builder.stream("inputTopic");

    KStream<String, String> transformed = input

        .filter((key, value) -> value.contains("important"))

        .mapValues(value -> value.toUpperCase());

    transformed.to("outputTopic");

​

    // Build and start the Kafka Streams application

    KafkaStreams streams = new KafkaStreams(builder.build(), config);

    streams.start();

  }

}