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.apache.kafka.clients.consumer.ConsumerRecord;
   6 import org.springframework.kafka.annotation.KafkaHandler;
   7 import org.springframework.kafka.annotation.KafkaListener;
   8 import org.springframework.kafka.listener.adapter.ConsumerRecordMetadata;
   9 import org.springframework.kafka.support.KafkaHeaders;
  10 import org.springframework.messaging.handler.annotation.Header;
  11 import org.springframework.messaging.handler.annotation.Headers;
  12 import org.springframework.messaging.handler.annotation.Payload;
  13
  14 import java.time.Duration;
  15 import java.util.HashMap;
  16 import java.util.Map;
  17 import java.util.Optional;
  18
  19
  20 @RequiredArgsConstructor
  21 @Slf4j
  22 @KafkaListener(
  23   id = "${spring.kafka.client-id}",
  24   idIsGroup = false,
  25   topics = "${sumup.adder.topic}",
  26   autoStartup = "false")
  27 public class ApplicationRecordHandler implements RecordHandler<String, Message>
  28 {
  29   private final AdderResults results;
  30   private final Optional<Duration> throttle;
  31   private final String id;
  32
  33   private final Map<Integer, AdderBusinessLogic> state = new HashMap<>();
  34
  35
  36   @KafkaHandler
  37   @Override
  38   public void addNumber(
  39     @Header(KafkaHeaders.RECEIVED_MESSAGE_KEY) String user,
  40     @Header(KafkaHeaders.RECEIVED_TOPIC) String topic,
  41     @Header(KafkaHeaders.RECEIVED_PARTITION_ID) Integer partition,
  42     @Header(KafkaHeaders.OFFSET) Long offset,
  43     @Payload MessageAddNumber message)
  44   {
  45     state.get(partition).addToSum(user, message.getNext());
  46     throttle();
  47   }
  48
  49   @KafkaHandler
  50   @Override
  51   public void calcSum(
  52     @Header(KafkaHeaders.RECEIVED_MESSAGE_KEY) String user,
  53     @Header(KafkaHeaders.RECEIVED_TOPIC) String topic,
  54     @Header(KafkaHeaders.RECEIVED_PARTITION_ID) Integer partition,
  55     @Header(KafkaHeaders.OFFSET) Long offset,
  56     @Payload MessageCalculateSum message)
  57   {
  58     AdderResult result = state.get(partition).calculate(user);
  59     log.info("{} - New result for {}: {}", id, user, result);
  60     results.addResults(partition, user, result);
  61     throttle();
  62   }
  63
  64   private void throttle()
  65   {
  66     if (throttle.isPresent())
  67     {
  68       try
  69       {
  70         Thread.sleep(throttle.get().toMillis());
  71       }
  72       catch (InterruptedException e)
  73       {
  74         log.warn("{} - Intrerrupted while throttling: {}", id, e);
  75       }
  76     }
  77   }
  78
  79   protected void addPartition(Integer partition, Map<String, AdderResult> state)
  80   {
  81     this.state.put(partition, new AdderBusinessLogic(state));
  82   }
  83
  84   protected Map<String, AdderResult> removePartition(Integer partition)
  85   {
  86     return this.state.remove(partition).getState();
  87   }
  88
  89
  90   public Map<Integer, AdderBusinessLogic> getState()
  91   {
  92     return state;
  93   }
  94
  95   public AdderBusinessLogic getState(Integer partition)
  96   {
  97     return state.get(partition);
  98   }
  99 }