Write in Topic in Kafka through Java Code - apache-kafka

Question

i am trying to write in Kafka Topic through JAVA, as i have created the Topic, but want to insert some data in that topic.
Thanks in advance.

Answer 1

Here's an example of a synchronous producer. It should work with Kafka 0.11 (and a few prior releases too):
import org.apache.kafka.clients.producer.*;
import org.apache.kafka.common.serialization.LongSerializer;
import org.apache.kafka.common.serialization.StringSerializer;
import java.util.Properties;
public class MyKafkaProducer {
private final static String TOPIC = "my-example-topic";
private final static String BOOTSTRAP_SERVERS = "localhost:9092,localhost:9093,localhost:9094";
private static Producer<Long, String> createProducer() {
Properties props = new Properties();
props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, BOOTSTRAP_SERVERS);
props.put(ProducerConfig.CLIENT_ID_CONFIG, "MyKafkaProducer");
props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, LongSerializer.class.getName());
props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
return new KafkaProducer<>(props);
}
static void runProducer(final int sendMessageCount) throws Exception {
final Producer<Long, String> producer = createProducer();
try {
for (long index = 1; index <= sendMessageCount; index++) {
final ProducerRecord<Long, String> record = new ProducerRecord<>(TOPIC, index, "Message " + index);
RecordMetadata metadata = producer.send(record).get();
System.out.printf("sent record(key=%s value='%s')" + " metadata(partition=%d, offset=%d)\n",
record.key(), record.value(), metadata.partition(), metadata.offset());
}
} finally {
producer.flush();
producer.close();
}
}
public static void main(String[] args) throws Exception {
if (args.length == 0) {
runProducer(5);
} else {
runProducer(Integer.parseInt(args[0]));
}
}
}
You may need to modify some of the hard-coded settings.
Reference: http://cloudurable.com/blog/kafka-tutorial-kafka-producer/index.html