juplo.de Git - demos/kafka/training/blob - src/main/java/de/juplo/kafka/SimpleProducer.java

   1 package de.juplo.kafka;
   2
   3 import lombok.extern.slf4j.Slf4j;
   4 import org.apache.kafka.clients.producer.Producer;
   5 import org.apache.kafka.clients.producer.KafkaProducer;
   6 import org.apache.kafka.clients.producer.ProducerRecord;
   7 import org.apache.kafka.common.serialization.StringSerializer;
   8
   9 import java.util.Properties;
  10 import java.util.concurrent.CompletableFuture;
  11
  12
  13 @Slf4j
  14 public class SimpleProducer
  15 {
  16   private final String id;
  17   private final String topic;
  18   private final Producer<String, String> producer;
  19
  20   private long produced = 0;
  21   private volatile boolean running = true;
  22   private volatile boolean done = false;
  23
  24   public SimpleProducer(String broker, String topic, String clientId)
  25   {
  26     this(broker, topic, clientId, null);
  27   }
  28
  29   public SimpleProducer(String broker, String topic, String clientId, String transactionalId)
  30   {
  31     Properties props = new Properties();
  32     props.put("bootstrap.servers", broker);
  33     props.put("client.id", clientId); // Nur zur Wiedererkennung
  34     if (transactionalId != null)
  35       props.put("transactional.id", transactionalId); // Aktiviert außerdem enable.idempotence=true
  36     props.put("key.serializer", StringSerializer.class.getName());
  37     props.put("value.serializer", StringSerializer.class.getName());
  38
  39     this.id = clientId;
  40     this.topic = topic;
  41     producer = new KafkaProducer<>(props);
  42     producer.initTransactions();
  43   }
  44
  45   public void run()
  46   {
  47     long i = 0;
  48
  49     try
  50     {
  51       for (; running ; i++)
  52       {
  53         send(Long.toString(i%10), Long.toString(i));
  54         Thread.sleep(500);
  55       }
  56     }
  57     catch (InterruptedException e) {}
  58     finally
  59     {
  60       log.info("{}: Closing the KafkaProducer", id);
  61       producer.close();
  62       log.info("{}: Produced {} messages in total, exiting!", id, produced);
  63       done = true;
  64     }
  65   }
  66
  67   void begin()
  68   {
  69     producer.beginTransaction();
  70   }
  71
  72   void commit()
  73   {
  74     producer.commitTransaction();
  75   }
  76
  77   CompletableFuture<Long> send(String key, String value)
  78   {
  79     final CompletableFuture<Long> result = new CompletableFuture<>();
  80     final long time = System.currentTimeMillis();
  81
  82     final ProducerRecord<String, String> record = new ProducerRecord<>(
  83         topic,  // Topic
  84         key,    // Key
  85         value   // Value
  86     );
  87
  88     producer.send(record, (metadata, e) ->
  89     {
  90       long now = System.currentTimeMillis();
  91       if (e == null)
  92       {
  93         // HANDLE SUCCESS
  94         produced++;
  95         log.debug(
  96             "{} - Sent key={} message={} partition={}/{} timestamp={} latency={}ms",
  97             id,
  98             record.key(),
  99             record.value(),
 100             metadata.partition(),
 101             metadata.offset(),
 102             metadata.timestamp(),
 103             now - time
 104         );
 105         result.complete(metadata.offset());
 106       }
 107       else
 108       {
 109         // HANDLE ERROR
 110         log.error(
 111             "{} - ERROR key={} timestamp={} latency={}ms: {}",
 112             id,
 113             record.key(),
 114             metadata == null ? -1 : metadata.timestamp(),
 115             now - time,
 116             e.toString()
 117         );
 118         result.completeExceptionally(e);
 119       }
 120     });
 121
 122     long now = System.currentTimeMillis();
 123     log.trace(
 124         "{} - Queued #{} key={} latency={}ms",
 125         id,
 126         value,
 127         record.key(),
 128         now - time
 129     );
 130
 131     return result;
 132   }
 133
 134
 135   public static void main(String[] args) throws Exception
 136   {
 137     String broker = ":9092";
 138     String topic = "test";
 139     String clientId = "DEV";
 140
 141     switch (args.length)
 142     {
 143       case 3:
 144         clientId = args[2];
 145       case 2:
 146         topic = args[1];
 147       case 1:
 148         broker = args[0];
 149     }
 150
 151     SimpleProducer instance = new SimpleProducer(broker, topic, clientId);
 152
 153     Runtime.getRuntime().addShutdownHook(new Thread(() ->
 154     {
 155       instance.running = false;
 156       while (!instance.done)
 157       {
 158         log.info("Waiting for main-thread...");
 159         try
 160         {
 161           Thread.sleep(1000);
 162         }
 163         catch (InterruptedException e) {}
 164       }
 165       log.info("Shutdown completed.");
 166     }));
 167
 168     log.info(
 169         "Running SimpleProducer: broker={}, topic={}, client-id={}",
 170         broker,
 171         topic,
 172         clientId);
 173     instance.run();
 174   }
 175 }