Bael 6414 (#15835)

* BAEL-7490 read write file in separate thread

* Change the to try resources

* Update the code to sync with article

* First draft

* Fix Main error

* update the main code to send message

spring-kafka-3/src/main/java/com/baeldung/spring/kafka/viewheaders/KafkaMessageConsumer.java

@@ -0,0 +1,33 @@
+package com.baeldung.spring.kafka.viewheaders;
+
+import java.util.Map;
+
+import org.springframework.kafka.annotation.KafkaListener;
+import org.springframework.kafka.support.KafkaHeaders;
+import org.springframework.messaging.handler.annotation.Header;
+import org.springframework.messaging.handler.annotation.Headers;
+import org.springframework.messaging.handler.annotation.Payload;
+import org.springframework.stereotype.Service;
+
+@Service
+public class KafkaMessageConsumer {
+
+    @KafkaListener(topics = { "my-topic" }, groupId = "my-consumer-group")
+    public void listen(@Payload String message, @Headers Map<String, Object> headers) {
+        System.out.println("Received message: " + message);
+        System.out.println("Headers:");
+        headers.forEach((key, value) -> System.out.println(key + ": " + value));
+
+        String topicName = (String) headers.get(KafkaHeaders.TOPIC);
+        System.out.println("Topic: " + topicName);
+        int partitionID = (int) headers.get(KafkaHeaders.RECEIVED_PARTITION_ID);
+        System.out.println("Partition ID: " + partitionID);
+    }
+
+    @KafkaListener(topics = { "my-topic" }, groupId = "my-consumer-group")
+    public void listen(@Payload String message, @Header(KafkaHeaders.RECEIVED_TOPIC) String topicName,
+        @Header(KafkaHeaders.RECEIVED_PARTITION_ID) int partition) {
+        System.out.println("Topic: " + topicName);
+        System.out.println("Partition ID: " + partition);
+    }
+}

spring-kafka-3/src/main/java/com/baeldung/spring/kafka/viewheaders/Main.java

@@ -0,0 +1,63 @@
+package com.baeldung.spring.kafka.viewheaders;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.apache.kafka.clients.consumer.ConsumerConfig;
+import org.apache.kafka.clients.consumer.KafkaConsumer;
+import org.apache.kafka.clients.producer.ProducerConfig;
+import org.apache.kafka.common.serialization.StringDeserializer;
+import org.apache.kafka.common.serialization.StringSerializer;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.kafka.core.DefaultKafkaProducerFactory;
+import org.springframework.kafka.core.KafkaTemplate;
+import org.springframework.kafka.core.ProducerFactory;
+
+@SpringBootApplication
+public class Main {
+
+    @Autowired
+    static KafkaMessageConsumer kafkaMessageConsumer;
+
+    @Bean
+    public KafkaTemplate<String, String> kafkaTemplate() {
+        return new KafkaTemplate<>(producerFactory());
+    }
+
+    @Bean
+    public ProducerFactory<String, String> producerFactory() {
+        Map<String, Object> configProps = new HashMap<>();
+        configProps.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");
+        configProps.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
+        configProps.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
+        return new DefaultKafkaProducerFactory<>(configProps);
+    }
+
+    @Bean
+    public KafkaConsumer<String, String> kafkaConsumer() {
+        Map<String, Object> configProps = new HashMap<>();
+        configProps.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");
+        configProps.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
+        configProps.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
+        configProps.put(ConsumerConfig.GROUP_ID_CONFIG, "my-consumer-group");
+        return new KafkaConsumer<>(configProps);
+    }
+
+    public static void main(String[] args) {
+        ConfigurableApplicationContext context = SpringApplication.run(Main.class, args);
+
+        // Get the KafkaTemplate bean from the application context
+        KafkaTemplate<String, String> kafkaTemplate = context.getBean(KafkaTemplate.class);
+
+        // Send a message to the "my-topic" Kafka topic
+        String message = "Hello Baeldung!";
+        kafkaTemplate.send("my-topic", message);
+
+        // Close the application context
+        context.close();
+    }
+}