package de.juplo.kafka;
+import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.apache.kafka.clients.consumer.ConsumerRecord;
-import org.apache.kafka.clients.consumer.ConsumerRecords;
-import org.apache.kafka.clients.consumer.KafkaConsumer;
-import org.apache.kafka.common.errors.WakeupException;
-import org.apache.kafka.common.serialization.StringDeserializer;
+import org.springframework.kafka.annotation.KafkaHandler;
+import org.springframework.kafka.annotation.KafkaListener;
+import org.springframework.kafka.config.KafkaListenerEndpointRegistry;
+import org.springframework.kafka.support.KafkaHeaders;
+import org.springframework.messaging.handler.annotation.Header;
+import org.springframework.messaging.handler.annotation.Payload;
-import java.time.Duration;
-import java.util.Arrays;
-import java.util.Properties;
-import java.util.concurrent.locks.Condition;
-import java.util.concurrent.locks.Lock;
-import java.util.concurrent.locks.ReentrantLock;
+import java.util.List;
+import java.util.Optional;
+@RequiredArgsConstructor
@Slf4j
-public class SimpleConsumer
+@KafkaListener(
+ id = "${spring.kafka.client-id}",
+ idIsGroup = false,
+ topics = "${sumup.adder.topic}",
+ autoStartup = "false")
+public class EndlessConsumer
{
+ private final String id;
+ private final KafkaListenerEndpointRegistry registry;
+ private final ApplicationErrorHandler errorHandler;
+ private final RecordHandler recordHandler;
+
private long consumed = 0;
- private KafkaConsumer<String, String> consumer;
- private Lock lock = new ReentrantLock();
- private Condition stopped = lock.newCondition();
- public SimpleConsumer()
+ @KafkaHandler
+ public void addNumber(
+ @Header(KafkaHeaders.RECEIVED_MESSAGE_KEY) String key,
+ @Header(KafkaHeaders.RECEIVED_TOPIC) String topic,
+ @Header(KafkaHeaders.RECEIVED_PARTITION_ID) Integer partition,
+ @Header(KafkaHeaders.OFFSET) Long offset,
+ @Payload MessageAddNumber message)
{
- // tag::create[]
- Properties props = new Properties();
- props.put("bootstrap.servers", ":9092");
- props.put("group.id", "my-consumer"); // << Used for Offset-Commits
- // end::create[]
- props.put("auto.offset.reset", "earliest");
- // tag::create[]
- props.put("key.deserializer", StringDeserializer.class.getName());
- props.put("value.deserializer", StringDeserializer.class.getName());
-
- KafkaConsumer<String, String> consumer = new KafkaConsumer<>(props);
- // end::create[]
- this.consumer = consumer;
- }
+ log.info(
+ "{} - {}: {}/{} - {}={}",
+ id,
+ offset,
+ topic,
+ partition,
+ key,
+ message
+ );
+ recordHandler.addNumber(topic, partition, offset, key, message);
- public void run()
- {
- String id = "C";
-
- try
- {
- log.info("{} - Subscribing to topic test", id);
- consumer.subscribe(Arrays.asList("test"));
-
- // tag::loop[]
- while (true)
- {
- ConsumerRecords<String, String> records =
- consumer.poll(Duration.ofSeconds(1));
-
- // Do something with the data...
- // end::loop[]
- log.info("{} - Received {} messages", id, records.count());
- for (ConsumerRecord<String, String> record : records)
- {
consumed++;
+ }
+
+ @KafkaHandler
+ public void calculateSum(
+ @Header(KafkaHeaders.RECEIVED_MESSAGE_KEY) String key,
+ @Header(KafkaHeaders.RECEIVED_TOPIC) String topic,
+ @Header(KafkaHeaders.RECEIVED_PARTITION_ID) Integer partition,
+ @Header(KafkaHeaders.OFFSET) Long offset,
+ @Payload MessageCalculateSum message)
+ {
log.info(
"{} - {}: {}/{} - {}={}",
id,
- record.offset(),
- record.topic(),
- record.partition(),
- record.key(),
- record.value()
+ offset,
+ topic,
+ partition,
+ key,
+ message
);
- }
- // tag::loop[]
- }
- // end::loop[]
- }
- catch(WakeupException e)
- {
- log.info("{} - RIIING!", id);
- }
- catch(Exception e)
- {
- log.error("{} - Unexpected error: {}", id, e.toString());
- }
- finally
- {
- this.lock.lock();
- try
- {
- log.info("{} - Closing the KafkaConsumer", id);
- consumer.close();
- log.info("C - DONE!");
- stopped.signal();
- }
- finally
- {
- this.lock.unlock();
- log.info("{}: Consumed {} messages in total, exiting!", id, consumed);
- }
- }
+
+ recordHandler.calculateSum(topic, partition, offset, key, message);
+
+ consumed++;
+ }
+
+ public void start()
+ {
+ if (running())
+ throw new IllegalStateException("Consumer instance " + id + " is already running!");
+
+ log.info("{} - Starting - consumed {} messages before", id, consumed);
+ errorHandler.clearState();
+ registry.getListenerContainer(id).start();
+ }
+
+ public void stop()
+ {
+ if (!running())
+ throw new IllegalStateException("Consumer instance " + id + " is not running!");
+
+ log.info("{} - Stopping", id);
+ registry.getListenerContainer(id).stop();
+ log.info("{} - Stopped - consumed {} messages so far", id, consumed);
}
+ public boolean running()
+ {
+ return registry.getListenerContainer(id).isRunning();
+ }
- public static void main(String[] args) throws Exception
+ public Optional<Exception> exitStatus()
{
- SimpleConsumer instance = new SimpleConsumer();
-
- Runtime.getRuntime().addShutdownHook(new Thread(() ->
- {
- instance.lock.lock();
- try
- {
- instance.consumer.wakeup();
- instance.stopped.await();
- }
- catch (InterruptedException e)
- {
- log.warn("Interrrupted while waiting for the consumer to stop!", e);
- }
- finally
- {
- instance.lock.unlock();
- }
- }));
-
- instance.run();
+ if (running())
+ throw new IllegalStateException("No exit-status available: Consumer instance " + id + " is running!");
+
+ return errorHandler.getException();
}
}
projects / demos / kafka / training / blobdiff