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.ProducerRecord;
   5 import org.apache.kafka.clients.producer.RecordMetadata;
   6 import org.springframework.http.HttpStatus;
   7 import org.springframework.kafka.core.KafkaTemplate;
   8 import org.springframework.web.bind.annotation.*;
   9 import org.springframework.web.context.request.async.DeferredResult;
  10
  11 import javax.annotation.PreDestroy;
  12 import java.util.concurrent.ExecutionException;
  13
  14
  15 @Slf4j
  16 @RestController
  17 public class RestProducer
  18 {
  19   private final String id;
  20   private final String topic;
  21   private final KafkaTemplate<String, Object> kafkaTemplate;
  22
  23   private long produced = 0;
  24
  25   public RestProducer(
  26       ApplicationProperties properties,
  27       KafkaTemplate<String, Object> kafkaTemplate)
  28   {
  29     this.id = properties.getClientId();
  30     this.topic = properties.getTopic();
  31     this.kafkaTemplate = kafkaTemplate;
  32   }
  33
  34   @PostMapping(path = "{key}")
  35   public DeferredResult<ProduceResult> message(
  36       @PathVariable String key,
  37       @RequestBody String value)
  38   {
  39     key = key.trim();
  40     final ProducerRecord<String, Object> record = new ProducerRecord<>(
  41         topic,  // Topic
  42         key,    // Key
  43         new ClientMessage(key, value) // Value
  44     );
  45
  46     return send(record);
  47   }
  48
  49   @PutMapping(path = "{key}")
  50   public DeferredResult<ProduceResult> message(@PathVariable String key)
  51   {
  52     key = key.trim();
  53     final ProducerRecord<String, Object> record = new ProducerRecord<>(
  54         topic,  // Topic
  55         key,    // Key
  56         new FooMessage(key, System.currentTimeMillis()) // Value
  57     );
  58
  59     return send(record);
  60   }
  61
  62   @PostMapping(path = "/")
  63   public DeferredResult<ProduceResult> greeting(
  64       @RequestBody String name)
  65   {
  66     name = name.trim();
  67     final ProducerRecord<String, Object> record = new ProducerRecord<>(
  68         topic,  // Topic
  69         name,    // Key
  70         new Greeting(name) // Value
  71     );
  72
  73     return send(record);
  74   }
  75
  76   private DeferredResult<ProduceResult> send(ProducerRecord<String, Object> record)
  77   {
  78     DeferredResult<ProduceResult> result = new DeferredResult<>();
  79
  80     final long time = System.currentTimeMillis();
  81
  82     kafkaTemplate.send(record).addCallback(
  83       (sendResult) ->
  84       {
  85         long now = System.currentTimeMillis();
  86
  87         // HANDLE SUCCESS
  88         RecordMetadata metadata = sendResult.getRecordMetadata();
  89         produced++;
  90         result.setResult(new ProduceSuccess(metadata.partition(), metadata.offset()));
  91         log.debug(
  92             "{} - Sent key={} message={} partition={}/{} timestamp={} latency={}ms",
  93             id,
  94             record.key(),
  95             record.value(),
  96             metadata.partition(),
  97             metadata.offset(),
  98             metadata.timestamp(),
  99             now - time
 100         );
 101       },
 102       (e) ->
 103       {
 104         long now = System.currentTimeMillis();
 105
 106         // HANDLE ERROR
 107         result.setErrorResult(new ProduceFailure(e));
 108         log.error(
 109             "{} - ERROR key={} timestamp=-1 latency={}ms: {}",
 110             id,
 111             record.key(),
 112             now - time,
 113             e.toString()
 114         );
 115       });
 116
 117     long now = System.currentTimeMillis();
 118     log.trace(
 119         "{} - Queued key={} latency={}ms",
 120         id,
 121         record.key(),
 122         now - time
 123     );
 124
 125     return result;
 126   }
 127
 128   @ExceptionHandler
 129   @ResponseStatus(HttpStatus.BAD_REQUEST)
 130   public ErrorResponse illegalStateException(IllegalStateException e)
 131   {
 132     return new ErrorResponse(e.getMessage(), HttpStatus.BAD_REQUEST.value());
 133   }
 134
 135   @PreDestroy
 136   public void destroy() throws ExecutionException, InterruptedException
 137   {
 138     log.info("{} - Destroy!", id);
 139     log.info("{}: Produced {} messages in total, exiting!", id, produced);
 140   }
 141 }