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.Consumer;
import org.apache.kafka.clients.consumer.KafkaConsumer;
import org.apache.kafka.common.errors.WakeupException;
import org.apache.kafka.common.serialization.StringDeserializer;
public class SimpleConsumer
{
private long consumed = 0;
- private KafkaConsumer<String, String> consumer;
+ private Consumer<String, String> consumer;
private Lock lock = new ReentrantLock();
private Condition stopped = lock.newCondition();
public SimpleConsumer()
{
- // 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;
+ this.consumer = null; // TODO: Eine Instanz von KafkaConsumer erzeugen
}
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++;
- log.info(
- "{} - {}: {}/{} - {}={}",
- id,
- record.offset(),
- record.topic(),
- record.partition(),
- record.key(),
- record.value()
- );
- }
- // tag::loop[]
+ // TODO:
+ // Über consumer.poll() Nachrichten abrufen und diese
+ // über log.info() ausgeben.
}
- // end::loop[]
}
catch(WakeupException e)
{
- log.info("{} - RIIING!", id);
+ log.info("{} - Closing the KafkaConsumer", id);
+ consumer.close();
}
catch(Exception e)
{
}
finally
{
+ log.info("{} - Shutting down...");
this.lock.lock();
try
{
- log.info("{} - Closing the KafkaConsumer", id);
- consumer.close();
- log.info("C - DONE!");
+ log.info("{} - DONE!");
stopped.signal();
}
finally