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         "foo:" + FooMessage.class.getName() + "," +
  46         "greeting:" + Greeting.class.getName());
  47
  48     this.producer = new KafkaProducer<>(props);
  49   }
  50
  51   @PostMapping(path = "{key}")
  52   public DeferredResult<ProduceResult> message(
  53       @PathVariable String key,
  54       @RequestBody String value)
  55   {
  56     key = key.trim();
  57     final ProducerRecord<String, Object> record = new ProducerRecord<>(
  58         topic,  // Topic
  59         key,    // Key
  60         new ClientMessage(key, value) // Value
  61     );
  62
  63     return send(record);
  64   }
  65
  66   @PutMapping(path = "{key}")
  67   public DeferredResult<ProduceResult> message(@PathVariable String key)
  68   {
  69     key = key.trim();
  70     final ProducerRecord<String, Object> record = new ProducerRecord<>(
  71         topic,  // Topic
  72         key,    // Key
  73         new FooMessage(key, System.currentTimeMillis()) // Value
  74     );
  75
  76     return send(record);
  77   }
  78
  79   @PostMapping(path = "/")
  80   public DeferredResult<ProduceResult> greeting(
  81       @RequestBody String name)
  82   {
  83     name = name.trim();
  84     final ProducerRecord<String, Object> record = new ProducerRecord<>(
  85         topic,  // Topic
  86         name,    // Key
  87         new Greeting(name) // Value
  88     );
  89
  90     return send(record);
  91   }
  92
  93   private DeferredResult<ProduceResult> send(ProducerRecord<String, Object> record)
  94   {
  95     DeferredResult<ProduceResult> result = new DeferredResult<>();
  96
  97     final long time = System.currentTimeMillis();
  98
  99     producer.send(record, (metadata, e) ->
 100     {
 101       long now = System.currentTimeMillis();
 102       if (e == null)
 103       {
 104         // HANDLE SUCCESS
 105         produced++;
 106         result.setResult(new ProduceSuccess(metadata.partition(), metadata.offset()));
 107         log.debug(
 108             "{} - Sent key={} message={} partition={}/{} timestamp={} latency={}ms",
 109             id,
 110             record.key(),
 111             record.value(),
 112             metadata.partition(),
 113             metadata.offset(),
 114             metadata.timestamp(),
 115             now - time
 116         );
 117       }
 118       else
 119       {
 120         // HANDLE ERROR
 121         result.setErrorResult(new ProduceFailure(e));
 122         log.error(
 123             "{} - ERROR key={} timestamp={} latency={}ms: {}",
 124             id,
 125             record.key(),
 126             metadata == null ? -1 : metadata.timestamp(),
 127             now - time,
 128             e.toString()
 129         );
 130       }
 131     });
 132
 133     long now = System.currentTimeMillis();
 134     log.trace(
 135         "{} - Queued key={} latency={}ms",
 136         id,
 137         record.key(),
 138         now - time
 139     );
 140
 141     return result;
 142   }
 143
 144   @ExceptionHandler
 145   @ResponseStatus(HttpStatus.BAD_REQUEST)
 146   public ErrorResponse illegalStateException(IllegalStateException e)
 147   {
 148     return new ErrorResponse(e.getMessage(), HttpStatus.BAD_REQUEST.value());
 149   }
 150
 151   @PreDestroy
 152   public void destroy() throws ExecutionException, InterruptedException
 153   {
 154     log.info("{} - Destroy!", id);
 155     log.info("{} - Closing the KafkaProducer", id);
 156     producer.close();
 157     log.info("{}: Produced {} messages in total, exiting!", id, produced);
 158   }
 159 }