juplo.de Git - demos/kafka/training/blob - src/main/java/de/juplo/kafka/ApplicationRecordHandler.java

   1 package de.juplo.kafka;
   2
   3 import lombok.RequiredArgsConstructor;
   4 import lombok.extern.slf4j.Slf4j;
   5 import org.springframework.kafka.annotation.KafkaHandler;
   6 import org.springframework.kafka.annotation.KafkaListener;
   7 import org.springframework.kafka.support.KafkaHeaders;
   8 import org.springframework.messaging.handler.annotation.Header;
   9 import org.springframework.messaging.handler.annotation.Payload;
  10
  11 import java.time.Duration;
  12 import java.util.HashMap;
  13 import java.util.Map;
  14 import java.util.Optional;
  15
  16
  17 @RequiredArgsConstructor
  18 @Slf4j
  19 @KafkaListener(
  20     id = "${spring.kafka.consumer.group-id}",
  21     topics = "${sumup.adder.topic}")
  22 public class ApplicationRecordHandler
  23 {
  24   private final AdderResults results;
  25   private final Optional<Duration> throttle;
  26   private final String id;
  27
  28   private final Map<Integer, AdderBusinessLogic> state = new HashMap<>();
  29
  30
  31   @KafkaHandler
  32   public void addNumber(
  33       @Header(KafkaHeaders.RECEIVED_PARTITION_ID)
  34       Integer partition,
  35       @Header(KafkaHeaders.RECEIVED_MESSAGE_KEY)
  36       String user,
  37       @Payload
  38       MessageAddNumber message)
  39   {
  40     log.debug("{} - Received {} for {} on {}", id, message, user, partition);
  41     state.get(partition).addToSum(user, message.getNext());
  42     throttle();
  43   }
  44
  45   @KafkaHandler
  46   public void calculateSum(
  47       @Header(KafkaHeaders.RECEIVED_PARTITION_ID)
  48       Integer partition,
  49       @Header(KafkaHeaders.RECEIVED_MESSAGE_KEY)
  50       String user,
  51       @Payload
  52       MessageCalculateSum message)
  53   {
  54     AdderResult result = state.get(partition).calculate(user);
  55     log.info("{} - New result for {}: {}", id, user, result);
  56     results.addResults(partition, user, result);
  57     throttle();
  58   }
  59
  60   private void throttle()
  61   {
  62     if (throttle.isPresent())
  63     {
  64       try
  65       {
  66         Thread.sleep(throttle.get().toMillis());
  67       }
  68       catch (InterruptedException e)
  69       {
  70         log.warn("{} - Intrerrupted while throttling: {}", id, e);
  71       }
  72     }
  73   }
  74
  75   protected void addPartition(Integer partition, Map<String, AdderResult> state)
  76   {
  77     this.state.put(partition, new AdderBusinessLogic(state));
  78   }
  79
  80   protected Map<String, AdderResult> removePartition(Integer partition)
  81   {
  82     return this.state.remove(partition).getState();
  83   }
  84 }