README.md

Event Streaming Utils library 1.0.0

Usage

Convention

All event IDs and channels need to be put into Java file into lib module, so it can be imported into other projects!

Configuration

Serializers and deserializers need to be specified in config.yaml:

streaming:
  kafka:
    consumer:
      bootstrap-servers: localhost:9092
      group-id: group1
      key-deserializer: org.apache.kafka.common.serialization.StringDeserializer
      value-deserializer: si.rso.event.streaming.serialization.EventStreamMessageDeserializer
    producer:
      bootstrap-servers: localhost:9092
      key-serializer: org.apache.kafka.common.serialization.StringSerializer
      value-serializer: si.rso.event.streaming.serialization.EventStreamMessageSerializer

Producing message

All messages sent to kafka need to be of type EventStreamMessage. You can create message like this:

import si.rso.event.streaming.EventStreamMessage;
import si.rso.event.streaming.EventStreamMessageBuilder;
import si.rso.event.streaming.JacksonMapper;

@Inject
@StreamProducer
private Producer<String, EventStreamMessage> producer;

public void sendToKafka() {
    Order order = service.getOrderToBeSent();
    String dataToBeSent = JacksonMapper.stringify(order);
    
    EventStreamMessage message = EventStreamMessageBuilder
        .getInstance()
        .ofType(ServiceStreamConfig.EVENT_ID)
        .withData(dataToBeSent)
        .build();

    ProducerRecord<String, EventStreamMessage> record = new ProducerRecord<>(ServiceStreamConfig.CHANNEL_ID, "key", message);
            
    producer.send(record, (meta, exc) -> {
        if (exc != null) {
            exc.printStackTrace();
        }
    });
}

Consuming message

@StreamListener(topics = {ServiceStreamConfig.CHANNEL_ID})
public void onMessage(ConsumerRecord<String, EventStreamMessage> record) {
    EventStreamMessage message = record.value();
    LOG.info("Consumed Kafka record of type " + message.getType());
    Order receivedOrder = JacksonMapper.toEntity(message.getData(), Order.class);
}

Reference implementations

Producer example

Producer class

config.yml

Consumer example

Consumer class

config.yml

Development

Deployment

To deploy snapshot version, simply execute:

mvn clean deploy -P rso