From fd38f05b25d078a8c5daa870142f20092015f05f Mon Sep 17 00:00:00 2001
From: Kai Moritz <kai@juplo.de>
Date: Tue, 1 Apr 2025 19:51:54 +0200
Subject: [PATCH] =?utf8?q?Vorlage=20f=C3=BCr=20das=20Live-Coding=20zum=20`?=
 =?utf8?q?simple-producer`?=
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---
 .../java/de/juplo/kafka/ExampleProducer.java  | 132 +++---------------
 1 file changed, 20 insertions(+), 112 deletions(-)

diff --git a/src/main/java/de/juplo/kafka/ExampleProducer.java b/src/main/java/de/juplo/kafka/ExampleProducer.java
index 0bab4426..41eedb81 100644
--- a/src/main/java/de/juplo/kafka/ExampleProducer.java
+++ b/src/main/java/de/juplo/kafka/ExampleProducer.java
@@ -12,143 +12,51 @@ import java.util.Properties;
 @Slf4j
 public class ExampleProducer
 {
-  private final String id;
-  private final String topic;
-  private final Producer<String, String> producer;
+  private String id;
+  private String topic;
+  private 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 clientId = "DEV";
+    String topic = "test";
+
     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()
-  {
+    String id = clientId;
     long i = 0;
+    boolean running = true;
+    boolean done = false;
+    long produced = 0;
 
     try
     {
       for (; running; i++)
       {
-        send(Long.toString(i%10), Long.toString(i));
+        final ProducerRecord<String, String> record = new ProducerRecord<>(
+          topic,                 // Topic
+          Long.toString(i%10), // Key
+          Long.toString(i)       // Value
+        );
+
+        producer.send(record);
         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 time = System.currentTimeMillis();
-
-    final ProducerRecord<String, String> record = new ProducerRecord<>(
-      topic,  // Topic
-      key,    // Key
-      value   // Value
-    );
-
-    producer.send(record, (metadata, e) ->
-    {
-      long now = System.currentTimeMillis();
-      if (e == null)
-      {
-        // HANDLE SUCCESS
-        log.debug(
-          "{} - Sent message {}={}, partition={}, offset={}, timestamp={}, latency={}ms",
-          id,
-          key,
-          value,
-          metadata.partition(),
-          metadata.offset(),
-          metadata.timestamp(),
-          now - time
-        );
-      }
-      else
-      {
-        // HANDLE ERROR
-        log.error(
-          "{} - ERROR for message {}={}, latency={}ms: {}",
-          id,
-          key,
-          value,
-          now - time,
-          e.toString()
-        );
-      }
-    });
-
-    long now = System.currentTimeMillis();
-    produced++;
-    log.trace(
-      "{} - Queued message {}={}, latency={}ms",
-      id,
-      key,
-      value,
-      now - time
-    );
-  }
-
-
-  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;
-    }
-
-    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(() ->
-    {
-      instance.running = false;
-      while (!instance.done)
-      {
-        log.info("Waiting for main-thread...");
-        try
-        {
-          Thread.sleep(1000);
-        }
-        catch (InterruptedException e) {}
-      }
-      log.info("Shutdown completed.");
-    }));
-
-    instance.run();
-  }
 }
-- 
2.20.1