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     key = key.trim();
  56     final ProducerRecord<String, Object> record = new ProducerRecord<>(
  57         topic,  // Topic
  58         key,    // Key
  59         new ClientMessage(key, value) // Value
  60     );
  61
  62     return send(record);
  63   }
  64
  65   @PostMapping(path = "/")
  66   public DeferredResult<ProduceResult> greeting(
  67       @RequestBody String name)
  68   {
  69     name = name.trim();
  70     final ProducerRecord<String, Object> record = new ProducerRecord<>(
  71         topic,  // Topic
  72         name,    // Key
  73         new Greeting(name) // Value
  74     );
  75
  76     return send(record);
  77   }
  78
  79   private DeferredResult<ProduceResult> send(ProducerRecord<String, Object> record)
  80   {
  81     DeferredResult<ProduceResult> result = new DeferredResult<>();
  82
  83     final long time = System.currentTimeMillis();
  84
  85     producer.send(record, (metadata, e) ->
  86     {
  87       long now = System.currentTimeMillis();
  88       if (e == null)
  89       {
  90         // HANDLE SUCCESS
  91         produced++;
  92         result.setResult(new ProduceSuccess(metadata.partition(), metadata.offset()));
  93         log.debug(
  94             "{} - Sent key={} message={} partition={}/{} timestamp={} latency={}ms",
  95             id,
  96             record.key(),
  97             record.value(),
  98             metadata.partition(),
  99             metadata.offset(),
 100             metadata.timestamp(),
 101             now - time
 102         );
 103       }
 104       else
 105       {
 106         // HANDLE ERROR
 107         result.setErrorResult(new ProduceFailure(e));
 108         log.error(
 109             "{} - ERROR key={} timestamp={} latency={}ms: {}",
 110             id,
 111             record.key(),
 112             metadata == null ? -1 : metadata.timestamp(),
 113             now - time,
 114             e.toString()
 115         );
 116       }
 117     });
 118
 119     long now = System.currentTimeMillis();
 120     log.trace(
 121         "{} - Queued key={} latency={}ms",
 122         id,
 123         record.key(),
 124         now - time
 125     );
 126
 127     return result;
 128   }
 129
 130   @ExceptionHandler
 131   @ResponseStatus(HttpStatus.BAD_REQUEST)
 132   public ErrorResponse illegalStateException(IllegalStateException e)
 133   {
 134     return new ErrorResponse(e.getMessage(), HttpStatus.BAD_REQUEST.value());
 135   }
 136
 137   @PreDestroy
 138   public void destroy() throws ExecutionException, InterruptedException
 139   {
 140     log.info("{} - Destroy!", id);
 141     log.info("{} - Closing the KafkaProducer", id);
 142     producer.close();
 143     log.info("{}: Produced {} messages in total, exiting!", id, produced);
 144   }
 145 }