Java examples for testing Aiven for Apache Kafka

The sample scripts in this article demonstrate how to connect to your Aiven for Apache Kafka service and pass a few messages.

Note: The examples given here provide different options for the authentication method. For more information on the supported methods, see our article on Kafka authentication types.

Requirements:

• Keystore (client.keystore.p12) and truststore (client.truststore.jks) are properly created. For details, see our article on configuring Java SSL to access Kafka.

To test your Aiven for Apache Kafka service:

1. Log in to the Aiven web console and select your Kafka service.
   

2. If you want to use SASL authentication, turn on kafka_authentication_methods.sasl under Advanced configuration on the Overview page of your service.
   

3. Go to the Topics page for your service and add a new topic named demo-topic.
   

4. Create and run the producer script.

   • Using SSL authentication:

     package io.aiven.kafkaExample;
     import java.io.IOException;
     import java.util.Properties;
     import org.apache.kafka.clients.producer.KafkaProducer;
     import org.apache.kafka.clients.producer.ProducerRecord;
     
     public class Producer {
         public static void main(String[] args) throws IOException {
             Properties props = new Properties();
             props.put("bootstrap.servers", "getting-started-with-kafka.htn-aiven-demo.aivencloud.com:17705");
             props.put("security.protocol", "SSL");
             props.put("ssl.truststore.location", "client.truststore.jks");
             props.put("ssl.truststore.password", "secret");
             props.put("ssl.keystore.type", "PKCS12");
             props.put("ssl.keystore.location", "client.keystore.p12");
             props.put("ssl.keystore.password", "secret");
             props.put("ssl.key.password", "secret");
             props.put("key.serializer",
                 "org.apache.kafka.common.serialization.StringSerializer");
             props.put("value.serializer",
                 "org.apache.kafka.common.serialization.StringSerializer");
             KafkaProducer<String, String> producer = new KafkaProducer<>(props);
             producer.send(new ProducerRecord<String, String>("demo-topic", "test-message"));
             producer.close();
         }
     }

   • Using SASL-SSL authentication:

     package io.aiven.kafkaExample;
     import java.io.IOException;
     import java.util.Properties;
     import org.apache.kafka.clients.producer.KafkaProducer;
     import org.apache.kafka.clients.producer.ProducerRecord;
     
     public class Producer {
         public static void main(String[] args) throws IOException {
             Properties props = new Properties();
     
     String sasl_username = "avnadmin";
     String sasl_password = "<avnadmin-pw>";
     
     String jaasTemplate = "org.apache.kafka.common.security.scram.ScramLoginModule required username=\"%s\" password=\"%s\";";
     String jaasConfig = String.format(jaasTemplate, sasl_username, sasl_password);
     
             props.put("bootstrap.servers", "getting-started-with-kafka.htn-aiven-demo.aivencloud.com:<SASL_PORT>");
     props.put("security.protocol", "SASL_SSL");
     props.put("sasl.mechanism", "SCRAM-SHA-256");
     props.put("sasl.jaas.config", jaasConfig);
     props.put("ssl.endpoint.identification.algorithm", "");
     
     props.put("ssl.truststore.type", "jks");
             props.put("ssl.truststore.location", "client.truststore.jks");
             props.put("ssl.truststore.password", "secret");
     
             props.put("key.serializer",
               "org.apache.kafka.common.serialization.StringSerializer");
             props.put("value.serializer",
                 "org.apache.kafka.common.serialization.StringSerializer");
     
             KafkaProducer<String, String> producer = new KafkaProducer<>(props);
             producer.send(new ProducerRecord<String, String>("demo-topic", "test-message"));
             producer.close();
         }
     }

5. Create the consumer script.

   • Using SSL authentication:

     import java.io.IOException;
     import java.util.Arrays;
     import java.util.Properties;
     import org.apache.kafka.clients.consumer.ConsumerRecord;
     import org.apache.kafka.clients.consumer.ConsumerRecords;
     import org.apache.kafka.clients.consumer.KafkaConsumer;
     
     public class Consumer {
         public static void main(String[] args) throws IOException {
             Properties props = new Properties();
             props.put("bootstrap.servers", "getting-started-with-kafka.htn-aiven-demo.aivencloud.com:17705");
             props.put("security.protocol", "SSL");
             props.put("ssl.truststore.location", "client.truststore.jks");
             props.put("ssl.truststore.password", "secret");
             props.put("ssl.keystore.type", "PKCS12");
             props.put("ssl.keystore.location", "client.keystore.p12");
             props.put("ssl.keystore.password", "secret");
             props.put("ssl.key.password", "secret");
             props.put("group.id", "demo-group");
             props.put("key.deserializer",
               "org.apache.kafka.common.serialization.StringDeserializer");
             props.put("value.deserializer",
               "org.apache.kafka.common.serialization.StringDeserializer");
             KafkaConsumer<String, String> consumer = new KafkaConsumer<>(props);
             consumer.subscribe(Arrays.asList("demo-topic"));
             while (true) {
                 ConsumerRecords<String, String> records = consumer.poll(1000);
                 for (ConsumerRecord<String, String> record : records) {
                     System.out.printf("offset = %d, key = %s, value = %s",
                         record.offset(), record.key(), record.value());
                 }
             }
         }
     }

   • Using SASL-SSL authentication:

     import java.io.IOException;
     import java.util.Arrays;
     import java.util.Properties;
     import org.apache.kafka.clients.consumer.ConsumerRecord;
     import org.apache.kafka.clients.consumer.ConsumerRecords;
     import org.apache.kafka.clients.consumer.KafkaConsumer;
     
     public class Consumer {
         public static void main(String[] args) throws IOException {
             Properties props = new Properties();
     
     String sasl_username = "avnadmin";
     String sasl_password = "<avnadmin-pw>";
     
     String jaasTemplate = "org.apache.kafka.common.security.scram.ScramLoginModule required username=\"%s\" password=\"%s\";";
     String jaasConfig = String.format(jaasTemplate, sasl_username, sasl_password);
     
             props.put("bootstrap.servers", "getting-started-with-kafka.htn-aiven-demo.aivencloud.com:<SASL_PORT>");
     props.put("security.protocol", "SASL_SSL");
     props.put("sasl.mechanism", "SCRAM-SHA-256");
     props.put("sasl.jaas.config", jaasConfig);
     
     props.put("ssl.truststore.type", "jks");
             props.put("ssl.truststore.location", "client.truststore.jks");
             props.put("ssl.truststore.password", "secret");
     
             props.put("group.id", "demo-group");
             props.put("key.deserializer",
               "org.apache.kafka.common.serialization.StringDeserializer");
             props.put("value.deserializer",
               "org.apache.kafka.common.serialization.StringDeserializer");
             KafkaConsumer<String, String> consumer = new KafkaConsumer<>(props);
             consumer.subscribe(Arrays.asList("demo-topic"));
             while (true) {
                 ConsumerRecords<String, String> records = consumer.poll(1000);
                 for (ConsumerRecord<String, String> record : records) {
                     System.out.printf("offset = %d, key = %s, value = %s",
                         record.offset(), record.key(), record.value());
                 }
             }
         }
     }