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.KafkaProducer;
   5 import org.apache.kafka.clients.producer.ProducerRecord;
   6 import org.apache.kafka.common.serialization.StringSerializer;
   7 import org.springframework.http.HttpStatus;
   8 import org.springframework.kafka.support.serializer.JsonSerializer;
   9 import org.springframework.web.bind.annotation.*;
  10 import org.springframework.web.context.request.async.DeferredResult;
  11
  12 import javax.annotation.PreDestroy;
  13 import java.util.Properties;
  14 import java.util.concurrent.ExecutionException;
  15
  16
  17 @Slf4j
  18 @RestController
  19 public class RestProducer
  20 {
  21   private final String id;
  22   private final String topic;
  23   private final KafkaProducer<String, Object> producer;
  24
  25   private long produced = 0;
  26
  27   public RestProducer(ApplicationProperties properties)
  28   {
  29     this.id = properties.getClientId();
  30     this.topic = properties.getTopic();
  31
  32     Properties props = new Properties();
  33     props.put("bootstrap.servers", properties.getBootstrapServer());
  34     props.put("client.id", properties.getClientId());
  35     props.put("acks", properties.getAcks());
  36     props.put("batch.size", properties.getBatchSize());
  37     props.put("delivery.timeout.ms", 20000); // 20 Sekunden
  38     props.put("request.timeout.ms",  10000); // 10 Sekunden
  39     props.put("linger.ms", properties.getLingerMs());
  40     props.put("compression.type", properties.getCompressionType());
  41     props.put("key.serializer", StringSerializer.class.getName());
  42     props.put("value.serializer", JsonSerializer.class.getName());
  43     props.put(JsonSerializer.TYPE_MAPPINGS,
  44         "message:" + ClientMessage.class.getName() + "," +
  45         "greeting:" + Greeting.class.getName());
  46
  47     this.producer = new KafkaProducer<>(props);
  48   }
  49
  50   @PostMapping(path = "{key}")
  51   public DeferredResult<ProduceResult> message(
  52       @PathVariable String key,
  53       @RequestBody String value)
  54   {
  55     final ProducerRecord<String, Object> record = new ProducerRecord<>(
  56         topic,  // Topic
  57         key,    // Key
  58         new ClientMessage(key, value) // Value
  59     );
  60
  61     return send(record);
  62   }
  63
  64   @PostMapping(path = "/")
  65   public DeferredResult<ProduceResult> greeting(
  66       @RequestBody String name)
  67   {
  68     final ProducerRecord<String, Object> record = new ProducerRecord<>(
  69         topic,  // Topic
  70         name,    // Key
  71         new Greeting(name) // Value
  72     );
  73
  74     return send(record);
  75   }
  76
  77   private DeferredResult<ProduceResult> send(ProducerRecord<String, Object> record)
  78   {
  79     DeferredResult<ProduceResult> result = new DeferredResult<>();
  80
  81     final long time = System.currentTimeMillis();
  82
  83     producer.send(record, (metadata, e) ->
  84     {
  85       long now = System.currentTimeMillis();
  86       if (e == null)
  87       {
  88         // HANDLE SUCCESS
  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       else
 103       {
 104         // HANDLE ERROR
 105         result.setErrorResult(new ProduceFailure(e));
 106         log.error(
 107             "{} - ERROR key={} timestamp={} latency={}ms: {}",
 108             id,
 109             record.key(),
 110             metadata == null ? -1 : metadata.timestamp(),
 111             now - time,
 112             e.toString()
 113         );
 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("{} - Closing the KafkaProducer", id);
 140     producer.close();
 141     log.info("{}: Produced {} messages in total, exiting!", id, produced);
 142   }
 143 }