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, String> 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 String value)
  32   {
  33     DeferredResult<ProduceResult> result = new DeferredResult<>();
  34
  35     final long time = System.currentTimeMillis();
  36
  37     final ProducerRecord<String, String> record = new ProducerRecord<>(
  38         topic,  // Topic
  39         partition, // Partition
  40         key,    // Key
  41         value   // Value
  42     );
  43
  44     record.headers().add("source", id.getBytes());
  45     if (correlationId != null)
  46     {
  47       record.headers().add("id", BigInteger.valueOf(correlationId).toByteArray());
  48     }
  49
  50     producer.send(record, (metadata, e) ->
  51     {
  52       long now = System.currentTimeMillis();
  53       if (e == null)
  54       {
  55         // HANDLE SUCCESS
  56         produced++;
  57         result.setResult(new ProduceSuccess(metadata.partition(), metadata.offset()));
  58         log.debug(
  59             "{} - Sent key={} message={} partition={}/{} timestamp={} latency={}ms",
  60             id,
  61             record.key(),
  62             record.value(),
  63             metadata.partition(),
  64             metadata.offset(),
  65             metadata.timestamp(),
  66             now - time
  67         );
  68       }
  69       else
  70       {
  71         // HANDLE ERROR
  72         result.setErrorResult(new ProduceFailure(e));
  73         log.error(
  74             "{} - ERROR key={} timestamp={} latency={}ms: {}",
  75             id,
  76             record.key(),
  77             metadata == null ? -1 : metadata.timestamp(),
  78             now - time,
  79             e.toString()
  80         );
  81       }
  82     });
  83
  84     long now = System.currentTimeMillis();
  85     log.trace(
  86         "{} - Queued message with key={} latency={}ms",
  87         id,
  88         record.key(),
  89         now - time
  90     );
  91
  92     return result;
  93   }
  94
  95   @ExceptionHandler
  96   @ResponseStatus(HttpStatus.BAD_REQUEST)
  97   public ErrorResponse illegalStateException(IllegalStateException e)
  98   {
  99     return new ErrorResponse(e.getMessage(), HttpStatus.BAD_REQUEST.value());
 100   }
 101 }