Kafka Consumer Using Java
Implementation of Kafka Consumer using Java
ppackage com.abc;
import java.time.Duration;
import java.util.Collections;
import java.util.Properties;
import java.util.concurrent.ExecutionException;
import org.apache.kafka.clients.consumer.ConsumerConfig;
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.serialization.StringDeserializer;
public class KafkaConsumerTest {
public static void main(String[] args) throws InterruptedException, ExecutionException{
//Create consumer property
String bootstrapServer = "localhost:9092";
String groupId = "my-first-consumer-group";
String topicName = "my-first-topic";
Properties properties = new Properties();
properties.setProperty(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServer);
properties.setProperty(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
properties.setProperty(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
properties.setProperty(ConsumerConfig.GROUP_ID_CONFIG, groupId);
properties.setProperty(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
properties.setProperty(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, "false");
//Create consumer
KafkaConsumer<String, String> consumer = new KafkaConsumer<>(properties);
//Subscribe consumer to topic(s)
consumer.subscribe(Collections.singleton(topicName));
//Poll for new data
while(true){
ConsumerRecords<String, String> records = consumer.poll(Duration.ofMillis(1000));
for(ConsumerRecord<String, String> record: records){
System.out.println(record.key() + record.value());
System.out.println(record.topic() + record.partition() + record.offset());
}
//Commit consumer offset manually (recommended)
consumer.commitAsync();
}
}
}