+++ /dev/null
-*.iml
-.idea
-target
if [ "$1" = "cleanup" ]
then
docker-compose down -v
- mvn clean
exit
fi
-mvn package || exit 1
-if [ "$1" = "build" ]; then exit; fi
-
trap 'kill $(jobs -p) 2>/dev/null' EXIT
docker-compose up -d
echo "Waiting for the Kafka-Cluster to become ready..."
docker-compose exec cli cub kafka-ready -b kafka:9092 1 60 > /dev/null 2>&1 || exit 1
-
-echo "Producing messages"
-mvn exec:java@producer
-
-echo "Reading messages"
-mvn exec:java@consumer &
-sleep 7
-kill $(jobs -p)
-sleep 2
-
-echo "Re-Reading messages"
-mvn exec:java@consumer &
-sleep 7
-kill $(jobs -p)
-sleep 2
+++ /dev/null
-<?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
- xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-
- <modelVersion>4.0.0</modelVersion>
-
- <parent>
- <groupId>org.springframework.boot</groupId>
- <artifactId>spring-boot-starter-parent</artifactId>
- <version>2.6.5</version>
- <relativePath/> <!-- lookup parent from repository -->
- </parent>
-
- <groupId>de.juplo.kafka</groupId>
- <artifactId>first-contact</artifactId>
- <name>First Contact: a Simple Producer and a simple Consumer-Group</name>
- <version>1.0-SNAPSHOT</version>
-
- <dependencies>
- <dependency>
- <groupId>org.apache.kafka</groupId>
- <artifactId>kafka-clients</artifactId>
- </dependency>
- <dependency>
- <groupId>org.projectlombok</groupId>
- <artifactId>lombok</artifactId>
- </dependency>
- <dependency>
- <groupId>ch.qos.logback</groupId>
- <artifactId>logback-classic</artifactId>
- </dependency>
- </dependencies>
-
- <build>
- <plugins>
- <plugin>
- <groupId>org.codehaus.mojo</groupId>
- <artifactId>exec-maven-plugin</artifactId>
- <version>3.0.0</version>
- <executions>
- <execution>
- <id>producer</id>
- <configuration>
- <mainClass>de.juplo.kafka.SimpleProducer</mainClass>
- </configuration>
- </execution>
- <execution>
- <id>consumer</id>
- <configuration>
- <mainClass>de.juplo.kafka.SimpleConsumer</mainClass>
- </configuration>
- </execution>
- </executions>
- </plugin>
- </plugins>
- </build>
-
-</project>
+++ /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.producer.KafkaProducer;
-import org.apache.kafka.clients.producer.ProducerRecord;
-import org.apache.kafka.common.serialization.StringSerializer;
-
-import java.util.Properties;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Future;
-
-
-@Slf4j
-public class SimpleProducer
-{
- private final String id;
- private final String topic;
- private final KafkaProducer<String, String> producer;
-
- private long produced = 0;
-
- public SimpleProducer(String clientId, String topic)
- {
- // tag::create[]
- Properties props = new Properties();
- props.put("bootstrap.servers", "localhost:9092");
- props.put("key.serializer", StringSerializer.class.getName());
- props.put("value.serializer", StringSerializer.class.getName());
-
- KafkaProducer<String, String> producer = new KafkaProducer<>(props);
- // end::create[]
-
- this.id = clientId;
- this.topic = topic;
- this.producer = producer;
- }
-
- public void run()
- {
- long i = 0;
-
- try
- {
- for (; i < 100 ; i++)
- {
- send(Long.toString(i%10), Long.toString(i));
- }
-
- log.info("{} - Done", id);
- }
- finally
- {
- log.info("{}: Closing the KafkaProducer", id);
- producer.close();
- log.info("{}: Produced {} messages in total, exiting!", id, produced);
- }
- }
-
- void send(String key, String value)
- {
- final long time = System.currentTimeMillis();
-
- final ProducerRecord<String, String> record = new ProducerRecord<>(
- topic, // Topic
- key, // Key
- value // Value
- );
-
- producer.send(record, (metadata, e) ->
- {
- long now = System.currentTimeMillis();
- if (e == null)
- {
- // HANDLE SUCCESS
- produced++;
- log.debug(
- "{} - Sent key={} message={} partition={}/{} timestamp={} latency={}ms",
- id,
- record.key(),
- record.value(),
- metadata.partition(),
- metadata.offset(),
- metadata.timestamp(),
- now - time
- );
- }
- else
- {
- // HANDLE ERROR
- log.error(
- "{} - ERROR key={} timestamp={} latency={}ms: {}",
- id,
- record.key(),
- metadata == null ? -1 : metadata.timestamp(),
- now - time,
- e.toString()
- );
- }
- });
-
- long now = System.currentTimeMillis();
- log.trace(
- "{} - Queued #{} key={} latency={}ms",
- id,
- value,
- record.key(),
- now - time
- );
- }
-
-
- public static void main(String[] args) throws Exception
- {
- SimpleProducer producer = new SimpleProducer("P", "test");
- producer.run();
- }
-}
+++ /dev/null
-<?xml version="1.0" encoding="UTF-8"?>
-<configuration>
-
- <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
- <encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
- <Pattern>%highlight(%-5level) %m%n</Pattern>
- </encoder>
- </appender>
-
- <logger name="de.juplo" level="TRACE"/>
- <!-- logger name="org.apache.kafka.clients" level="DEBUG" / -->
-
- <root level="INFO">
- <appender-ref ref="STDOUT" />
- </root>
-
-</configuration>
projects / demos / kafka / training / commitdiff