Vorlage für das Live-Coding zum `simple-producer`

diff --git a/src/main/java/de/juplo/kafka/ExampleProducer.java b/src/main/java/de/juplo/kafka/ExampleProducer.java
index a76458890f62b9c25ccc571a77a4f4821fb6fa9f..914a163b1536a6b471137a223b0a4d8273c8ae39 100644 (file)
--- a/src/main/java/de/juplo/kafka/ExampleProducer.java
+++ b/src/main/java/de/juplo/kafka/ExampleProducer.java
@@ -12,143 +12,46 @@ import java.util.Properties;
 @Slf4j
 public class ExampleProducer
 {
-  private final String id;
-  private final String topic;
-  private final Producer<String, String> producer;
-
   private volatile boolean running = true;
   private volatile boolean done = false;
   private long produced = 0;
 
-  public ExampleProducer(
-    String broker,
-    String topic,
-    String clientId)
+  public static void main(String[] args) throws Exception
   {
+    String broker = "localhost:9092";
+    String topic = "test";
+    String clientId = "DEV";
+
     Properties props = new Properties();
     props.put("bootstrap.servers", broker);
     props.put("client.id", clientId); // Nur zur Wiedererkennung
     props.put("key.serializer", StringSerializer.class.getName());
     props.put("value.serializer", StringSerializer.class.getName());
 
-    this.id = clientId;
-    this.topic = topic;
-    producer = new KafkaProducer<>(props);
-  }
+    Producer<String, String> producer = new KafkaProducer<>(props);
 
-  public void run()
-  {
-    long i = 0;
+    String id = clientId;
 
     try
     {
-      for (; running; i++)
-      {
-        send(Long.toString(i%10), Long.toString(i));
-        Thread.sleep(500);
-      }
-    }
-    catch (Exception e)
-    {
-      log.error("{} - Unexpected error!", id, e);
-    }
-    finally
-    {
-      log.info("{}: Closing the KafkaProducer", id);
-      producer.close();
-      log.info("{}: Produced {} messages in total, exiting!", id, produced);
-      done = true;
-    }
-  }
-
-  void send(String key, String value)
-  {
-    final long sendRequested = System.currentTimeMillis();
-
-    final ProducerRecord<String, String> record = new ProducerRecord<>(
-      topic,  // Topic
-      key,    // Key
-      value   // Value
-    );
-
-    producer.send(record, (metadata, e) ->
-    {
-      long sendRequestProcessed = System.currentTimeMillis();
-      if (e == null)
+      for (long i = 0; true; i++)
       {
-        // HANDLE SUCCESS
-        log.debug(
-          "{} - Sent message {}={}, partition={}, offset={}, timestamp={}, latency={}ms",
-          id,
-          key,
-          value,
-          metadata.partition(),
-          metadata.offset(),
-          metadata.timestamp(),
-          sendRequestProcessed - sendRequested
+        final ProducerRecord<String, String> record = new ProducerRecord<>(
+          topic,                 // Topic
+          Long.toString(i%10), // Key
+          Long.toString(i)       // Value
         );
-      }
-      else
-      {
-        // HANDLE ERROR
-        log.error(
-          "{} - ERROR for message {}={}, latency={}ms: {}",
-          id,
-          key,
-          value,
-          sendRequestProcessed - sendRequested,
-          e.toString()
-        );
-      }
-    });
 
-    long sendRequestQueued = System.currentTimeMillis();
-    produced++;
-    log.trace(
-      "{} - Queued message {}={}, latency={}ms",
-      id,
-      key,
-      value,
-      sendRequestQueued - sendRequested
-    );
-  }
+        producer.send(record);
 
+        log.debug("{} - Sent message {}={}", id, record.key(), record.value());
 
-  public static void main(String[] args) throws Exception
-  {
-    if (args.length != 3)
-    {
-      log.error("Three arguments required!");
-      log.error("arg[0]: Broker-Address");
-      log.error("arg[1]: Topic");
-      log.error("arg[2]: Unique Client-ID");
-      System.exit(1);
-      return;
+        Thread.sleep(500);
+      }
     }
-
-    log.info(
-      "Running ExampleProducer: broker={}, topic={}, client-id={}",
-      args[0],
-      args[1],
-      args[2]);
-
-    ExampleProducer instance = new ExampleProducer(args[0], args[1], args[2]);
-
-    Runtime.getRuntime().addShutdownHook(new Thread(() ->
+    finally
     {
-      instance.running = false;
-      while (!instance.done)
-      {
-        log.info("{} - Waiting for main-thread...", instance.id);
-        try
-        {
-          Thread.sleep(1000);
-        }
-        catch (InterruptedException e) {}
-      }
-      log.info("{} - Shutdown completed.", instance.id);
-    }));
-
-    instance.run();
+      log.info("{}: Exiting!", id);
+    }
   }
 }