spring-boot-rest/spring-kafka/src/test/java/com/baeldung/spring/kafka/KafkaRetryableIntegrationTest.java

package com.baeldung.spring.kafka;

import static org.assertj.core.api.AssertionsForClassTypes.assertThat;

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;

import org.junit.Before;
import org.junit.ClassRule;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.kafka.config.KafkaListenerEndpointRegistry;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.kafka.listener.AcknowledgingConsumerAwareMessageListener;
import org.springframework.kafka.listener.ConcurrentMessageListenerContainer;
import org.springframework.kafka.test.EmbeddedKafkaBroker;
import org.springframework.kafka.test.context.EmbeddedKafka;

import com.fasterxml.jackson.databind.ObjectMapper;

@SpringBootTest(classes = RetryableApplicationKafkaApp.class)
@EmbeddedKafka(partitions = 1, brokerProperties = { "listeners=PLAINTEXT://localhost:9092", "port=9092" })
public class KafkaRetryableIntegrationTest {
    @ClassRule
    public static EmbeddedKafkaBroker embeddedKafka = new EmbeddedKafkaBroker(1, true, "multitype");

    @Autowired
    private KafkaListenerEndpointRegistry registry;

    @Autowired
    private KafkaTemplate<String, String> template;

    private ObjectMapper objectMapper = new ObjectMapper();

    private static final String CONTAINER_GROUP = "multiGroup";

    private static final String TOPIC = "topic";

    @Before
    public void setup() {
        System.setProperty("spring.kafka.bootstrap-servers", embeddedKafka.getBrokersAsString());
    }

    @Test
    public void givenEmbeddedKafkaBroker_whenSendingAWellFormedMessage_thenMessageIsConsumed() throws Exception {
        ConcurrentMessageListenerContainer<?, ?> container = (ConcurrentMessageListenerContainer<?, ?>) registry.getListenerContainer(CONTAINER_GROUP);
        container.stop();
        @SuppressWarnings("unchecked") AcknowledgingConsumerAwareMessageListener<String, String> messageListener = (AcknowledgingConsumerAwareMessageListener<String, String>) container.getContainerProperties()
          .getMessageListener();
        CountDownLatch latch = new CountDownLatch(1);
        container.getContainerProperties()
          .setMessageListener((AcknowledgingConsumerAwareMessageListener<String, String>) (data, acknowledgment, consumer) -> {
              messageListener.onMessage(data, acknowledgment, consumer);
              latch.countDown();
          });
        Greeting greeting = new Greeting("test1", "test2");
        container.start();
        template.send(TOPIC, objectMapper.writeValueAsString(greeting));
        assertThat(latch.await(10, TimeUnit.SECONDS)).isTrue();
    }

    @Test
    public void givenEmbeddedKafkaBroker_whenSendingAMalFormedMessage_thenMessageIsConsumedAfterRetry() throws Exception {
        ConcurrentMessageListenerContainer<?, ?> container = (ConcurrentMessageListenerContainer<?, ?>) registry.getListenerContainer(CONTAINER_GROUP);
        container.stop();
        @SuppressWarnings("unchecked") AcknowledgingConsumerAwareMessageListener<String, String> messageListener = (AcknowledgingConsumerAwareMessageListener<String, String>) container.getContainerProperties()
          .getMessageListener();
        CountDownLatch latch = new CountDownLatch(1);
        container.getContainerProperties()
          .setMessageListener((AcknowledgingConsumerAwareMessageListener<String, String>) (data, acknowledgment, consumer) -> {
              messageListener.onMessage(data, acknowledgment, consumer);
              latch.countDown();
          });
        container.start();
        Greeting greeting = new Greeting("test", "test");
        template.send(TOPIC, objectMapper.writeValueAsString(greeting));
        //this message will go on error
        Greeting greeting2 = new Greeting("test2", "test2");
        template.send(TOPIC, objectMapper.writeValueAsString(greeting2));
        assertThat(latch.await(10, TimeUnit.SECONDS)).isTrue();
    }

}