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

   1 package de.juplo.kafka;
   2
   3 import lombok.extern.slf4j.Slf4j;
   4 import org.apache.kafka.clients.producer.KafkaProducer;
   5 import org.apache.kafka.clients.producer.ProducerRecord;
   6 import org.apache.kafka.common.serialization.StringSerializer;
   7 import org.springframework.http.HttpStatus;
   8 import org.springframework.kafka.support.serializer.JsonSerializer;
   9 import org.springframework.web.bind.annotation.*;
  10 import org.springframework.web.context.request.async.DeferredResult;
  11
  12 import javax.annotation.PreDestroy;
  13 import java.util.Properties;
  14 import java.util.concurrent.ExecutionException;
  15
  16
  17 @Slf4j
  18 @RestController
  19 public class RestProducer
  20 {
  21   private final String id;
  22   private final String topic;
  23   private final KafkaProducer<String, ClientMessage> producer;
  24
  25   private long produced = 0;
  26
  27   public RestProducer(ApplicationProperties properties)
  28   {
  29     this.id = properties.getClientId();
  30     this.topic = properties.getTopic();
  31
  32     Properties props = new Properties();
  33     props.put("bootstrap.servers", properties.getBootstrapServer());
  34     props.put("client.id", properties.getClientId());
  35     props.put("acks", properties.getAcks());
  36     props.put("batch.size", properties.getBatchSize());
  37     props.put("delivery.timeout.ms", 20000); // 20 Sekunden
  38     props.put("request.timeout.ms",  10000); // 10 Sekunden
  39     props.put("linger.ms", properties.getLingerMs());
  40     props.put("compression.type", properties.getCompressionType());
  41     props.put("key.serializer", StringSerializer.class.getName());
  42     props.put("value.serializer", JsonSerializer.class.getName());
  43     props.put(JsonSerializer.TYPE_MAPPINGS, "message:" + ClientMessage.class.getName());
  44
  45     this.producer = new KafkaProducer<>(props);
  46   }
  47
  48   @PostMapping(path = "{key}")
  49   public DeferredResult<ProduceResult> send(
  50       @PathVariable String key,
  51       @RequestBody String value)
  52   {
  53     DeferredResult<ProduceResult> result = new DeferredResult<>();
  54
  55     final long time = System.currentTimeMillis();
  56
  57     final ProducerRecord<String, ClientMessage> record = new ProducerRecord<>(
  58         topic,  // Topic
  59         key,    // Key
  60         new ClientMessage(key, value) // Value
  61     );
  62
  63     producer.send(record, (metadata, e) ->
  64     {
  65       long now = System.currentTimeMillis();
  66       if (e == null)
  67       {
  68         // HANDLE SUCCESS
  69         produced++;
  70         result.setResult(new ProduceSuccess(metadata.partition(), metadata.offset()));
  71         log.debug(
  72             "{} - Sent key={} message={} partition={}/{} timestamp={} latency={}ms",
  73             id,
  74             record.key(),
  75             record.value(),
  76             metadata.partition(),
  77             metadata.offset(),
  78             metadata.timestamp(),
  79             now - time
  80         );
  81       }
  82       else
  83       {
  84         // HANDLE ERROR
  85         result.setErrorResult(new ProduceFailure(e));
  86         log.error(
  87             "{} - ERROR key={} timestamp={} latency={}ms: {}",
  88             id,
  89             record.key(),
  90             metadata == null ? -1 : metadata.timestamp(),
  91             now - time,
  92             e.toString()
  93         );
  94       }
  95     });
  96
  97     long now = System.currentTimeMillis();
  98     log.trace(
  99         "{} - Queued #{} key={} latency={}ms",
 100         id,
 101         value,
 102         record.key(),
 103         now - time
 104     );
 105
 106     return result;
 107   }
 108
 109   @ExceptionHandler
 110   @ResponseStatus(HttpStatus.BAD_REQUEST)
 111   public ErrorResponse illegalStateException(IllegalStateException e)
 112   {
 113     return new ErrorResponse(e.getMessage(), HttpStatus.BAD_REQUEST.value());
 114   }
 115
 116   @PreDestroy
 117   public void destroy() throws ExecutionException, InterruptedException
 118   {
 119     log.info("{} - Destroy!", id);
 120     log.info("{} - Closing the KafkaProducer", id);
 121     producer.close();
 122     log.info("{}: Produced {} messages in total, exiting!", id, produced);
 123   }
 124 }