1 package de.juplo.kafka;
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;
11 import java.math.BigInteger;
17 @RequiredArgsConstructor
18 public class RestProducer
20 private final String id;
21 private final String topic;
22 private final Integer partition;
23 private final KafkaProducer<String, Object> producer;
25 private long produced = 0;
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)
33 // Der Service verschickt für eine Zahl n immer n+1 Nachrichten.
35 // ADD: { "number": 3, "next": 1 }
36 // ADD: { "number": 3, "next": 2 }
37 // ADD: { "number": 3, "next": 3 }
38 // CALC: { "number": 3 }
40 ResultRecorder result = new ResultRecorder(number+1);
42 for (int i = 1; i <= number; i++)
44 send(key, new AddNumberMessage(number, i), correlationId, result);
46 send(key, new CalculateSumMessage(number), correlationId, result);
48 return result.getDeferredResult();
55 ResultRecorder result)
57 final long time = System.currentTimeMillis();
59 final ProducerRecord<String, Object> record = new ProducerRecord<>(
61 partition, // Partition
66 record.headers().add("source", id.getBytes());
67 if (correlationId != null)
69 record.headers().add("id", BigInteger.valueOf(correlationId).toByteArray());
72 producer.send(record, (metadata, e) ->
74 long now = System.currentTimeMillis();
78 result.addSuccess(metadata);
81 "{} - Sent key={} message={} partition={}/{} timestamp={} latency={}ms",
96 "{} - ERROR key={} timestamp={} latency={}ms: {}",
99 metadata == null ? -1 : metadata.timestamp(),
106 long now = System.currentTimeMillis();
108 "{} - Queued message with key={} latency={}ms",
116 @ResponseStatus(HttpStatus.BAD_REQUEST)
117 public ErrorResponse illegalStateException(IllegalStateException e)
119 return new ErrorResponse(e.getMessage(), HttpStatus.BAD_REQUEST.value());