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

   1 package de.juplo.kafka;
   2
   3 import lombok.RequiredArgsConstructor;
   4 import lombok.extern.slf4j.Slf4j;
   5 import org.apache.kafka.clients.producer.KafkaProducer;
   6 import org.apache.kafka.clients.producer.ProducerRecord;
   7 import org.springframework.http.HttpStatus;
   8 import org.springframework.web.bind.annotation.*;
   9 import org.springframework.web.context.request.async.DeferredResult;
  10
  11 import java.math.BigInteger;
  12
  13
  14 @Slf4j
  15 @RequestMapping
  16 @ResponseBody
  17 @RequiredArgsConstructor
  18 public class RestProducer
  19 {
  20   private final String id;
  21   private final String topic;
  22   private final Integer partition;
  23   private final KafkaProducer<String, Object> producer;
  24
  25   private long produced = 0;
  26
  27   @PostMapping(path = "{key}")
  28   public DeferredResult<ProduceResult> send(
  29       @PathVariable String key,
  30       @RequestHeader(name = "X-id", required = false) Long correlationId,
  31       @RequestBody Integer number)
  32   {
  33     ResultRecorder result = new ResultRecorder(1);
  34
  35     send(key, number, correlationId, result);
  36
  37     return result.getDeferredResult();
  38   }
  39
  40   private void send(
  41       String key,
  42       Object value,
  43       Long correlationId,
  44       ResultRecorder result)
  45   {
  46     final long time = System.currentTimeMillis();
  47
  48     final ProducerRecord<String, Object> record = new ProducerRecord<>(
  49         topic,  // Topic
  50         partition, // Partition
  51         key,    // Key
  52         value   // Value
  53     );
  54
  55     record.headers().add("source", id.getBytes());
  56     if (correlationId != null)
  57     {
  58       record.headers().add("id", BigInteger.valueOf(correlationId).toByteArray());
  59     }
  60
  61     producer.send(record, (metadata, e) ->
  62     {
  63       long now = System.currentTimeMillis();
  64       if (e == null)
  65       {
  66         // HANDLE SUCCESS
  67         result.addSuccess(metadata);
  68         produced++;
  69         log.debug(
  70             "{} - Sent key={} message={} partition={}/{} timestamp={} latency={}ms",
  71             id,
  72             record.key(),
  73             record.value(),
  74             metadata.partition(),
  75             metadata.offset(),
  76             metadata.timestamp(),
  77             now - time
  78         );
  79       }
  80       else
  81       {
  82         // HANDLE ERROR
  83         result.addFailure(e);
  84         log.error(
  85             "{} - ERROR key={} timestamp={} latency={}ms: {}",
  86             id,
  87             record.key(),
  88             metadata == null ? -1 : metadata.timestamp(),
  89             now - time,
  90             e.toString()
  91         );
  92       }
  93     });
  94
  95     long now = System.currentTimeMillis();
  96     log.trace(
  97         "{} - Queued message with key={} latency={}ms",
  98         id,
  99         record.key(),
 100         now - time
 101     );
 102   }
 103
 104   @ExceptionHandler
 105   @ResponseStatus(HttpStatus.BAD_REQUEST)
 106   public ErrorResponse illegalStateException(IllegalStateException e)
 107   {
 108     return new ErrorResponse(e.getMessage(), HttpStatus.BAD_REQUEST.value());
 109   }
 110 }