Kafka producer how to catch ConnectException?

[Eric Koston]

I want to figure out, how can I catch the exception, if the kafka server is not online.  

I tried as following: 

    import org.apache.kafka.clients.producer.*;

    import org.apache.kafka.common.serialization.LongSerializer;

    import org.apache.kafka.common.serialization.StringSerializer;

    

    import java.util.Properties;

    import java.util.concurrent.ExecutionException;

    

    public class KafkaProducerClient {

    

      private final static String TOPIC = "test";

      private final static String BOOTSTRAP_SERVERS = "localhost:9092";

    

      private static Producer<String, String> createProducer() {

        Properties props = new Properties();

        props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG,

            BOOTSTRAP_SERVERS);

        props.put(ProducerConfig.CLIENT_ID_CONFIG, "KafkaExampleProducer");

        props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG,

            LongSerializer.class.getName());

        props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG,

            StringSerializer.class.getName());

        return new KafkaProducer<>(props);

      }

    

      public static void main(String[] args) {

    

    

        final Producer<String, String> producer = createProducer();

        try {

    

          final ProducerRecord<String, String> record = new ProducerRecord<>(TOPIC, "key", "Hello value ");

          RecordMetadata metadata = producer.send(record).get();

    

        } catch (InterruptedException e) {

          e.printStackTrace();

        } catch (ExecutionException e) {

          e.printStackTrace();

        } catch (Exception e) {

          e.printStackTrace();

        } finally {

          producer.flush();

          producer.close();

        }

      }

    }

I've got following error:

    09:50:59.271 [kafka-producer-network-thread | KafkaExampleProducer] DEBUG org.apache.kafka.clients.NetworkClient - [Producer clientId=KafkaExampleProducer] Node -1 disconnected.

    09:50:59.271 [kafka-producer-network-thread | KafkaExampleProducer] WARN org.apache.kafka.clients.NetworkClient - [Producer clientId=KafkaExampleProducer] Connection to node -1 could not be established. Broker may not be available.

    09:50:59.271 [kafka-producer-network-thread | KafkaExampleProducer] DEBUG org.apache.kafka.clients.NetworkClient - [Producer clientId=KafkaExampleProducer] Give up sending metadata request since no node is available

    09:50:59.322 [kafka-producer-network-thread | KafkaExampleProducer] DEBUG org.apache.kafka.clients.NetworkClient - [Producer clientId=KafkaExampleProducer] Give up sending metadata request since no node is available

    09:50:59.373 [kafka-producer-network-thread | KafkaExampleProducer] DEBUG org.apache.kafka.clients.NetworkClient - [Producer clientId=KafkaExampleProducer] Give up sending metadata request since no node is available

    09:50:59.423 [kafka-producer-network-thread | KafkaExampleProducer] DEBUG org.apache.kafka.clients.NetworkClient - [Producer clientId=KafkaExampleProducer] Give up sending metadata request since no node is available

    09:50:59.474 [kafka-producer-network-thread | KafkaExampleProducer] DEBUG org.apache.kafka.clients.NetworkClient - [Producer clientId=KafkaExampleProducer] Give up sending metadata request since no node is available

    09:50:59.525 [kafka-producer-network-thread | KafkaExampleProducer] DEBUG org.apache.kafka.clients.NetworkClient - [Producer clientId=KafkaExampleProducer] Give up sending metadata request since no node is available

    09:50:59.576 [kafka-producer-network-thread | KafkaExampleProducer] DEBUG org.apache.kafka.clients.NetworkClient - [Producer clientId=KafkaExampleProducer] Give up sending metadata request since no node is available

    09:50:59.626 [kafka-producer-network-thread | KafkaExampleProducer] DEBUG org.apache.kafka.clients.NetworkClient - [Producer clientId=KafkaExampleProducer] Give up sending metadata request since no node is available

    09:50:59.677 [kafka-producer-network-thread | KafkaExampleProducer] DEBUG org.apache.kafka.clients.NetworkClient - [Producer clientId=KafkaExampleProducer] Give up sending metadata request since no node is available

    09:50:59.727 [kafka-producer-network-thread | KafkaExampleProducer] DEBUG org.apache.kafka.clients.NetworkClient - [Producer clientId=KafkaExampleProducer] Give up sending metadata request since no node is available

    09:50:59.778 [kafka-producer-network-thread | KafkaExampleProducer] DEBUG org.apache.kafka.clients.NetworkClient - [Producer clientId=KafkaExampleProducer] Give up sending metadata request since no node is available

    09:50:59.829 [kafka-producer-network-thread | KafkaExampleProducer] DEBUG org.apache.kafka.clients.NetworkClient - [Producer clientId=KafkaExampleProducer] Give up sending metadata request since no node is available

    09:50:59.880 [kafka-producer-network-thread | KafkaExampleProducer] DEBUG org.apache.kafka.clients.NetworkClient - [Producer clientId=KafkaExampleProducer] Give up sending metadata request since no node is available

    09:50:59.931 [kafka-producer-network-thread | KafkaExampleProducer] DEBUG org.apache.kafka.clients.NetworkClient - [Producer clientId=KafkaExampleProducer] Give up sending metadata request since no node is available

    09:50:59.982 [kafka-producer-network-thread | KafkaExampleProducer] DEBUG org.apache.kafka.clients.NetworkClient - [Producer clientId=KafkaExampleProducer] Give up sending metadata request since no node is available

    09:51:00.033 [kafka-producer-network-thread | KafkaExampleProducer] DEBUG org.apache.kafka.clients.NetworkClient - [Producer clientId=KafkaExampleProducer] Give up sending metadata request since no node is available

    09:51:00.084 [kafka-producer-network-thread | KafkaExampleProducer] DEBUG org.apache.kafka.clients.NetworkClient - [Producer clientId=KafkaExampleProducer] Initialize connection to node localhost:9092 (id: -1 rack: null) for sending metadata request

    09:51:00.084 [kafka-producer-network-thread | KafkaExampleProducer] DEBUG org.apache.kafka.clients.NetworkClient - [Producer clientId=KafkaExampleProducer] Initiating connection to node localhost:9092 (id: -1 rack: null)

    09:51:00.085 [kafka-producer-network-thread | KafkaExampleProducer] DEBUG org.apache.kafka.common.network.Selector - [Producer clientId=KafkaExampleProducer] Connection with localhost/127.0.0.1 disconnected

    java.net.ConnectException: Connection refused

    at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)

    at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717)

    at org.apache.kafka.common.network.PlaintextTransportLayer.finishConnect(PlaintextTransportLayer.java:50)

    at org.apache.kafka.common.network.KafkaChannel.finishConnect(KafkaChannel.java:106)

    at org.apache.kafka.common.network.Selector.pollSelectionKeys(Selector.java:444)

    at org.apache.kafka.common.network.Selector.poll(Selector.java:398)

    at org.apache.kafka.clients.NetworkClient.poll(NetworkClient.java:460)

    at org.apache.kafka.clients.producer.internals.Sender.run(Sender.java:239)

    at org.apache.kafka.clients.producer.internals.Sender.run(Sender.java:163)

    at java.lang.Thread.run(Thread.java:748) 

as you can see, the error never got caught. 

What am I doing wrong?