--- /dev/null
+package de.juplo.kafka;
+
+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 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;
+
+
+@Slf4j
+public class SimpleConsumer
+{
+ private long consumed = 0;
+ private KafkaConsumer<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;
+ }
+
+
+ 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++;
+ log.info(
+ "{} - {}: {}/{} - {}={}",
+ id,
+ record.offset(),
+ record.topic(),
+ record.partition(),
+ record.key(),
+ record.value()
+ );
+ }
+ // 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);
+ }
+ }
+ }
+
+
+ public static void main(String[] args) throws Exception
+ {
+ 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();
+ }
+}
+++ /dev/null
-package de.juplo.kafka;
-
-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 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;
-
-
-@Slf4j
-public class SimpleConsumer
-{
- private long consumed = 0;
- private KafkaConsumer<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;
- }
-
-
- 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++;
- log.info(
- "{} - {}: {}/{} - {}={}",
- id,
- record.offset(),
- record.topic(),
- record.partition(),
- record.key(),
- record.value()
- );
- }
- // 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);
- }
- }
- }
-
-
- public static void main(String[] args) throws Exception
- {
- 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();
- }
-}