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.RecordMetadata;
   5 import org.springframework.http.HttpStatus;
   6 import org.springframework.kafka.core.KafkaTemplate;
   7 import org.springframework.web.bind.annotation.*;
   8 import org.springframework.web.context.request.async.DeferredResult;
   9
  10 import javax.annotation.PreDestroy;
  11 import java.util.concurrent.ExecutionException;
  12
  13
  14 @Slf4j
  15 @RestController
  16 public class RestProducer
  17 {
  18   private final String id;
  19   private final String topic;
  20   private final KafkaTemplate<String, Object> kafkaTemplate;
  21
  22   private long produced = 0;
  23
  24   public RestProducer(
  25       ApplicationProperties properties,
  26       KafkaTemplate<String, Object> kafkaTemplate)
  27   {
  28     this.id = properties.getClientId();
  29     this.topic = properties.getTopic();
  30     this.kafkaTemplate = kafkaTemplate;
  31   }
  32
  33   @PostMapping(path = "{key}")
  34   public DeferredResult<ProduceResult> message(
  35       @PathVariable String key,
  36       @RequestBody String value)
  37   {
  38     key = key.trim();
  39     return send(key, new ClientMessage(key, value));
  40   }
  41
  42   @PutMapping(path = "{key}")
  43   public DeferredResult<ProduceResult> message(@PathVariable String key)
  44   {
  45     key = key.trim();
  46     return send(key, new FooMessage(key, System.currentTimeMillis()));
  47   }
  48
  49   @PostMapping(path = "/")
  50   public DeferredResult<ProduceResult> greeting(
  51       @RequestBody String name)
  52   {
  53     name = name.trim();
  54     return send(name, new Greeting(name));
  55   }
  56
  57   private DeferredResult<ProduceResult> send(String key, Object value)
  58   {
  59     DeferredResult<ProduceResult> result = new DeferredResult<>();
  60
  61     final long time = System.currentTimeMillis();
  62
  63     kafkaTemplate.send(topic, key, value).addCallback(
  64       (sendResult) ->
  65       {
  66         long now = System.currentTimeMillis();
  67
  68         // HANDLE SUCCESS
  69         RecordMetadata metadata = sendResult.getRecordMetadata();
  70         produced++;
  71         result.setResult(new ProduceSuccess(metadata.partition(), metadata.offset()));
  72         log.debug(
  73             "{} - Sent key={} message={} partition={}/{} timestamp={} latency={}ms",
  74             id,
  75             key,
  76             value,
  77             metadata.partition(),
  78             metadata.offset(),
  79             metadata.timestamp(),
  80             now - time
  81         );
  82       },
  83       (e) ->
  84       {
  85         long now = System.currentTimeMillis();
  86
  87         // HANDLE ERROR
  88         result.setErrorResult(new ProduceFailure(e));
  89         log.error(
  90             "{} - ERROR key={} timestamp=-1 latency={}ms: {}",
  91             id,
  92             key,
  93             now - time,
  94             e.toString()
  95         );
  96       });
  97
  98     long now = System.currentTimeMillis();
  99     log.trace(
 100         "{} - Queued key={} latency={}ms",
 101         id,
 102         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("{}: Produced {} messages in total, exiting!", id, produced);
 121   }
 122 }