refactor: `RestProducer` wird explizit erzeugt

[demos/kafka/training] / src / main / java / de / juplo / kafka / RestProducer.java

diff --git a/src/main/java/de/juplo/kafka/RestProducer.java b/src/main/java/de/juplo/kafka/RestProducer.java
index 7a5b324..debe366 100644 (file)
--- a/src/main/java/de/juplo/kafka/RestProducer.java
+++ b/src/main/java/de/juplo/kafka/RestProducer.java
@@ -1,100 +1,52 @@
 package de.juplo.kafka;
 
+import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.kafka.clients.producer.KafkaProducer;
 import org.apache.kafka.clients.producer.ProducerRecord;
-import org.apache.kafka.common.serialization.StringSerializer;
+import org.springframework.http.HttpStatus;
+import org.springframework.web.bind.annotation.*;
+import org.springframework.web.context.request.async.DeferredResult;
 
-import javax.annotation.PreDestroy;
-import java.util.Properties;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.ExecutorService;
+import java.math.BigInteger;
 
 
 @Slf4j
-public class EndlessProducer implements Runnable
+@RequestMapping
+@ResponseBody
+@RequiredArgsConstructor
+public class RestProducer
 {
-  private final ExecutorService executor;
   private final String id;
   private final String topic;
-  private final int throttleMs;
+  private final Integer partition;
   private final KafkaProducer<String, String> producer;
 
-  private boolean running = false;
-  private long i = 0;
   private long produced = 0;
 
-  public EndlessProducer(
-      ExecutorService executor,
-      String bootstrapServer,
-      String clientId,
-      String topic,
-      String acks,
-      int throttleMs)
+  @PostMapping(path = "{key}")
+  public DeferredResult<ProduceResult> send(
+      @PathVariable String key,
+      @RequestHeader(name = "X-id", required = false) Long correlationId,
+      @RequestBody String value)
   {
-    this.executor = executor;
-    this.id = clientId;
-    this.topic = topic;
-    this.throttleMs = throttleMs;
+    DeferredResult<ProduceResult> result = new DeferredResult<>();
 
-    Properties props = new Properties();
-    props.put("bootstrap.servers", bootstrapServer);
-    props.put("client.id", clientId);
-    props.put("acks", acks);
-    props.put("key.serializer", StringSerializer.class.getName());
-    props.put("value.serializer", StringSerializer.class.getName());
-
-    this.producer = new KafkaProducer<>(props);
-  }
-
-  @Override
-  public void run()
-  {
-    try
-    {
-      for (; running; i++)
-      {
-        send(Long.toString(i%10), Long.toString(i));
-
-        if (throttleMs > 0)
-        {
-          try
-          {
-            Thread.sleep(throttleMs);
-          }
-          catch (InterruptedException e)
-          {
-            log.warn("{} - Interrupted while throttling!", e);
-          }
-        }
-      }
-
-      log.info("{} - Done", id);
-    }
-    catch (Exception e)
-    {
-      log.error("{} - Unexpected Exception:", id, e);
-    }
-    finally
-    {
-      synchronized (this)
-      {
-        running = false;
-        log.info("{} - Stopped - produced {} messages so far", id, produced);
-      }
-    }
-  }
-
-  void send(String key, String value)
-  {
     final long time = System.currentTimeMillis();
 
     final ProducerRecord<String, String> record = new ProducerRecord<>(
         topic,  // Topic
+        partition, // Partition
         key,    // Key
         value   // Value
     );
 
+    record.headers().add("source", id.getBytes());
+    if (correlationId != null)
+    {
+      record.headers().add("id", BigInteger.valueOf(correlationId).toByteArray());
+    }
+
     producer.send(record, (metadata, e) ->
     {
       long now = System.currentTimeMillis();
@@ -102,6 +54,7 @@ public class EndlessProducer implements Runnable
       {
         // HANDLE SUCCESS
         produced++;
+        result.setResult(new ProduceSuccess(metadata.partition(), metadata.offset()));
         log.debug(
             "{} - Sent key={} message={} partition={}/{} timestamp={} latency={}ms",
             id,
@@ -116,6 +69,7 @@ public class EndlessProducer implements Runnable
       else
       {
         // HANDLE ERROR
+        result.setErrorResult(new ProduceFailure(e));
         log.error(
             "{} - ERROR key={} timestamp={} latency={}ms: {}",
             id,
@@ -129,50 +83,19 @@ public class EndlessProducer implements Runnable
 
     long now = System.currentTimeMillis();
     log.trace(
-        "{} - Queued #{} key={} latency={}ms",
+        "{} - Queued message with key={} latency={}ms",
         id,
-        value,
         record.key(),
         now - time
     );
-  }
 
-  public synchronized void start()
-  {
-    if (running)
-      throw new IllegalStateException("Producer instance " + id + " is already running!");
-
-    log.info("{} - Starting - produced {} messages before", id, produced);
-    running = true;
-    executor.submit(this);
+    return result;
   }
 
-  public synchronized void stop() throws ExecutionException, InterruptedException
+  @ExceptionHandler
+  @ResponseStatus(HttpStatus.BAD_REQUEST)
+  public ErrorResponse illegalStateException(IllegalStateException e)
   {
-    if (!running)
-      throw new IllegalStateException("Producer instance " + id + " is not running!");
-
-    log.info("{} - Stopping...", id);
-    running = false;
-  }
-
-  @PreDestroy
-  public void destroy() throws ExecutionException, InterruptedException
-  {
-    log.info("{} - Destroy!", id);
-    try
-    {
-      stop();
-    }
-    catch (IllegalStateException e)
-    {
-      log.info("{} - Was already stopped", id);
-    }
-    finally
-    {
-      log.info("{} - Closing the KafkaProducer", id);
-      producer.close();
-      log.info("{}: Produced {} messages in total, exiting!", id, produced);
-    }
+    return new ErrorResponse(e.getMessage(), HttpStatus.BAD_REQUEST.value());
   }
 }