import org.apache.kafka.clients.producer.*;
import java.util.Properties;
public class KafkaProducerExample {
public static void main(String[] args) {
Properties properties = new Properties();
properties.put("bootstrap.servers", "localhost:9092");
properties.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
properties.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");
Producer<String, String> producer = new KafkaProducer<>(properties);
ProducerRecord<String, String> record = new ProducerRecord<>("my-topic", "key", "Hello Kafka!");
producer.send(record, new Callback() {
@Override
public void onCompletion(RecordMetadata metadata, Exception exception) {
if (exception != null) {
exception.printStackTrace();
} else {
System.out.println("Message sent successfully: " +
"topic=" + metadata.topic() +
", partition=" + metadata.partition() +
", offset=" + metadata.offset());
}
}
});
producer.close();
}
}
import org.apache.kafka.clients.consumer.*;
import java.util.Collections;
import java.util.Properties;
public class KafkaConsumerExample {
public static void main(String[] args) {
Properties properties = new Properties();
properties.put("bootstrap.servers", "localhost:9092");
properties.put("group.id", "my-consumer-group");
properties.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
properties.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
Consumer<String, String> consumer = new KafkaConsumer<>(properties);
consumer.subscribe(Collections.singletonList("my-topic"));
while (true) {
ConsumerRecords<String, String> records = consumer.poll(1000);
for (ConsumerRecord<String, String> record : records) {
System.out.println("Received message: " +
"topic=" + record.topic() +
", partition=" + record.partition() +
", offset=" + record.offset() +
", key=" + record.key() +
", value=" + record.value());
}
}
}
}
properties
broker.id=0
listeners=PLAINTEXT://localhost:9092
log.dirs=/tmp/kafka-logs
zookeeper.connect=localhost:2181
properties
bootstrap.servers=localhost:9092
group.id=my-consumer-group
key.deserializer=org.apache.kafka.common.serialization.StringDeserializer
value.deserializer=org.apache.kafka.common.serialization.StringDeserializer
