1. Overview

EzyKafka (Easy going to Kafka Interaction) is a framework support to interact to Apache Kafka, It supports:

Publish and consume message
Serialize and Deserialize to map message's data in byte array to POJO
Annotation driven

2. Structure of EzyKafka

EzyKafkaProxy: Manages producers, consumers and data serializers.
EzyKafkaProducer: Supports to send messages.
EzyKafkaProducer: Supports to receive and consume the messages.

3. Install EzyKafka

1. To create EzyKafka we need add dependency

<dependency>
    <groupId>com.tvd12</groupId>
    <artifactId>ezymq-kafka</artifactId>
    <version>1.2.6</version>
</dependency>

The latest version can be found in the Maven Central repository. You can configure EzyKafka like this:

    EzyKafkaProxy kafkaProxy = EzyKafkaProxy.builder()
        .scan("com.tvd12.ezymq.example.kafka")
        .build();

2. You can add to your configuration file like this:

    # for application.yaml
    kafka:
      producers:
        hello-world:
          topic: hello-world
      consumers:
        hello-world:
          topic: hello-world

    # for application.properties
    kafka.producers.hello-world.topic=hello-world
    kafka.consumers.hello-world.topic=hello-world

4. Example

Let’s say we need consume a message to sum 2 integer numbers, we can do it with EzyKafka follow by bellow steps.

4.1 Create message class

We need create a class has 2 fields: a and b:

    package com.tvd12.ezymq.kafka.test.request;
    import com.tvd12.ezyfox.message.annotation.EzyMessage;
    import lombok.AllArgsConstructor;
    import lombok.Data;
    import lombok.NoArgsConstructor;
    @Data
    @EzyMessage
    @AllArgsConstructor
    @NoArgsConstructor
    public class SumRequest {
        private int a;
        private int b;
    }

4.2 Create message handler class

Now we need create a handler class to handle the message:

    package com.tvd12.ezymq.kafka.test.handler;
    import com.tvd12.ezymq.kafka.annotation.EzyKafkaHandler;
    import com.tvd12.ezymq.kafka.handler.EzyKafkaMessageHandler;
    import com.tvd12.ezymq.kafka.test.request.SumRequest;
    @EzyKafkaHandler(
        topic = "test",
        command = "sum"
    )
    public class SumRequestHandler implements EzyKafkaMessageHandler {
        @Override
        public void process(SumRequest message) throws Exception {
            int result = message.getA() + message.getB();
            System.out.println("sum result: " + result);
        }
    }

4.3 Create a program for producer

We need create a class has main method to start a producer:

    package com.tvd12.ezymq.kafka.test;
    import com.tvd12.ezyfox.util.EzyThreads;
    import com.tvd12.ezymq.kafka.EzyKafkaProducer;
    import com.tvd12.ezymq.kafka.EzyKafkaProxy;
    import com.tvd12.ezymq.kafka.test.request.SumRequest;
    public final class SumProducerProgram {
        public static void main(String[] args) {
            final EzyKafkaProxy kafkaContext = EzyKafkaProxy
                .builder()
                .scan("com.tvd12.ezymq.kafka.test")
                .build();
            final EzyKafkaProducer producer = kafkaContext.getProducer("test");
            producer.send("sum", new SumRequest(1, 2));
            while (true) {
                EzyThreads.sleep(3);
            }
        }
    }

With configration like this:

    # for application.yaml
    kafka:
      producers:
        test:
          topic: test
          bootstrap.servers: localhost:9092
          client.id: KafkaProducerExample

4.4 Create a program for consumer

We need create a class has main method to start consumers:

    package com.tvd12.ezymq.kafka.test;
    import com.tvd12.ezymq.kafka.EzyKafkaProxy;
    public final class SumConsumerProgram {
        public static void main(String[] args) {
            EzyKafkaProxy
                .builder()
                .scan("com.tvd12.ezymq.kafka.test")
                .build();
        }
    }

With configration like this:

    # for application.yaml
    kafka:
      consumers:
        test:
          topic: test
          group.id: KafkaConsumerExample

4.5 Run the program

Now run the both SumConsumerProgram and SumProducerProgram programs separately, we will see the log in the SumConsumerProgram:

sum result: 3

You can see how to configure.

Introduce EzyKafka