From c364c07cd6b6f78273aa5af5b25fdeef0af04710 Mon Sep 17 00:00:00 2001
From: Kai Moritz <kai@juplo.de>
Date: Sat, 11 Feb 2023 06:45:40 +0100
Subject: [PATCH] NEU

---
 .../wordcount/counter/CounterApplication.java | 53 +++++++++++++++++++
 .../counter/CounterStreamProcessor.java       | 42 ++-------------
 2 files changed, 57 insertions(+), 38 deletions(-)

diff --git a/src/main/java/de/juplo/kafka/wordcount/counter/CounterApplication.java b/src/main/java/de/juplo/kafka/wordcount/counter/CounterApplication.java
index 1f73d32..1f2e4ad 100644
--- a/src/main/java/de/juplo/kafka/wordcount/counter/CounterApplication.java
+++ b/src/main/java/de/juplo/kafka/wordcount/counter/CounterApplication.java
@@ -1,14 +1,67 @@
 package de.juplo.kafka.wordcount.counter;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
+import lombok.extern.slf4j.Slf4j;
+import org.apache.kafka.clients.consumer.ConsumerConfig;
+import org.apache.kafka.common.serialization.Serdes;
+import org.apache.kafka.streams.StreamsConfig;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.kafka.support.serializer.JsonDeserializer;
+import org.springframework.kafka.support.serializer.JsonSerde;
+import org.springframework.kafka.support.serializer.JsonSerializer;
+
+import java.util.Properties;
+import java.util.concurrent.CompletableFuture;
+
+import static org.apache.kafka.streams.errors.StreamsUncaughtExceptionHandler.StreamThreadExceptionResponse.SHUTDOWN_CLIENT;
 
 
 @SpringBootApplication
 @EnableConfigurationProperties(CounterApplicationProperties.class)
+@Slf4j
 public class CounterApplication
 {
+	@Bean(initMethod = "start", destroyMethod = "stop")
+	public CounterStreamProcessor streamProcessor(
+			CounterApplicationProperties properties,
+			ObjectMapper objectMapper,
+			ConfigurableApplicationContext context)
+	{
+		Properties propertyMap = new Properties();
+
+		propertyMap.put(StreamsConfig.APPLICATION_ID_CONFIG, properties.getApplicationId());
+		propertyMap.put(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, properties.getBootstrapServer());
+		propertyMap.put(StreamsConfig.DEFAULT_KEY_SERDE_CLASS_CONFIG, Serdes.StringSerde.class.getName());
+		propertyMap.put(StreamsConfig.DEFAULT_VALUE_SERDE_CLASS_CONFIG, JsonSerde.class.getName());
+		propertyMap.put(JsonDeserializer.TRUSTED_PACKAGES, Word.class.getName()	);
+		propertyMap.put(JsonDeserializer.VALUE_DEFAULT_TYPE, Word.class.getName());
+		propertyMap.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
+
+		CounterStreamProcessor streamProcessor = new CounterStreamProcessor(
+				properties.getInputTopic(),
+				properties.getOutputTopic(),
+				propertyMap,
+				objectMapper);
+
+		streamProcessor.streams.setUncaughtExceptionHandler((Throwable e) ->
+		{
+			log.error("Unexpected error!", e);
+			CompletableFuture.runAsync(() ->
+			{
+				log.info("Stopping application...");
+				SpringApplication.exit(context, () -> 1);
+			});
+			return SHUTDOWN_CLIENT;
+		});
+
+
+		return streamProcessor;
+	}
+
 	public static void main(String[] args)
 	{
 		SpringApplication.run(CounterApplication.class, args);
diff --git a/src/main/java/de/juplo/kafka/wordcount/counter/CounterStreamProcessor.java b/src/main/java/de/juplo/kafka/wordcount/counter/CounterStreamProcessor.java
index 5248609..d529541 100644
--- a/src/main/java/de/juplo/kafka/wordcount/counter/CounterStreamProcessor.java
+++ b/src/main/java/de/juplo/kafka/wordcount/counter/CounterStreamProcessor.java
@@ -1,38 +1,25 @@
 package de.juplo.kafka.wordcount.counter;
 
-import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import lombok.extern.slf4j.Slf4j;
-import org.apache.kafka.clients.consumer.ConsumerConfig;
-import org.apache.kafka.common.serialization.Serdes;
 import org.apache.kafka.streams.KafkaStreams;
 import org.apache.kafka.streams.KeyValue;
 import org.apache.kafka.streams.StreamsBuilder;
-import org.apache.kafka.streams.StreamsConfig;
 import org.apache.kafka.streams.kstream.KStream;
-import org.springframework.boot.SpringApplication;
-import org.springframework.context.ConfigurableApplicationContext;
-import org.springframework.stereotype.Component;
 
-import jakarta.annotation.PostConstruct;
-import jakarta.annotation.PreDestroy;
 import java.util.Properties;
-import java.util.concurrent.CompletableFuture;
-
-import static org.apache.kafka.streams.errors.StreamsUncaughtExceptionHandler.StreamThreadExceptionResponse.SHUTDOWN_CLIENT;
 
 
 @Slf4j
-@Component
 public class CounterStreamProcessor
 {
 	public final KafkaStreams streams;
 
 
 	public CounterStreamProcessor(
-			CounterApplicationProperties properties,
-			ObjectMapper mapper,
-			ConfigurableApplicationContext context)
+			String inputTopic,
+			String outputTopic,
+			Properties properties)
 	{
 		StreamsBuilder builder = new StreamsBuilder();
 
@@ -54,36 +41,15 @@ public class CounterStreamProcessor
 				.count()
 				.mapValues(value->Long.toString(value))
 				.toStream()
-				.to(properties.getOutputTopic());
-
-		Properties props = new Properties();
-		props.put(StreamsConfig.APPLICATION_ID_CONFIG, properties.getApplicationId());
-		props.put(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, properties.getBootstrapServer());
-		props.put(StreamsConfig.DEFAULT_KEY_SERDE_CLASS_CONFIG, Serdes.String().getClass().getName());
-		props.put(StreamsConfig.DEFAULT_VALUE_SERDE_CLASS_CONFIG, Serdes.String().getClass().getName());
-		props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
-
-		streams = new KafkaStreams(builder.build(), props);
-		streams.setUncaughtExceptionHandler((Throwable e) ->
-		{
-			log.error("Unexpected error!", e);
-			CompletableFuture.runAsync(() ->
-			{
-				log.info("Stopping application...");
-				SpringApplication.exit(context, () -> 1);
-			});
-			return SHUTDOWN_CLIENT;
-		});
+		streams = new KafkaStreams(builder.build(), properties);
 	}
 
-	@PostConstruct
 	public void start()
 	{
 		log.info("Starting Stream-Processor");
 		streams.start();
 	}
 
-	@PreDestroy
 	public void stop()
 	{
 		log.info("Stopping Stream-Processor");
-- 
2.20.1