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