Java custom processor

Now, in the src/main/java/kioto/custom directory, create a file called CustomProcessor.java with the content of Listing 4.16.

The following is the content of Listing 4.16, CustomProcessor.java (part 1):

package kioto.custom;
import ...

public final class CustomProcessor {

  private Consumer<String, HealthCheck> consumer;
  private Producer<String, String> producer;

  public CustomProcessor(String brokers) {
    Properties consumerProps = new Properties();
    consumerProps.put("bootstrap.servers", brokers);
    consumerProps.put("group.id", "healthcheck-processor");
    consumerProps.put("key.deserializer", StringDeserializer.class);
    consumerProps.put("value.deserializer",                        HealthCheckDeserializer.class);
    consumer = new KafkaConsumer<>(consumerProps);
    Properties producerProps...