refactor util class (#4197)

* refactor util class
* refactor remove unnecessary generic signatures

Signed-off-by: moonyoungCHAE <xpf_fl@naver.com>

Author: moonyoungCHAE

spring-kafka/src/main/java/org/springframework/kafka/config/KafkaListenerConfigUtils.java

@@ -23,7 +23,10 @@
  * @author Gary Russell
  * @author Tomaz Fernandes
  */
-public abstract class KafkaListenerConfigUtils {
+public final class KafkaListenerConfigUtils {
+
+	private KafkaListenerConfigUtils() {
+	}
 
 	/**
 	 * The bean name of the internally managed Kafka listener annotation processor.

spring-kafka/src/main/java/org/springframework/kafka/core/ProducerFactoryUtils.java

@@ -103,7 +103,7 @@ public static <K, V> KafkaResourceHolder<K, V> getTransactionalResourceHolder(
 				throw e;
 			}
 
-			resourceHolder = new KafkaResourceHolder<K, V>(producer, closeTimeout);
+			resourceHolder = new KafkaResourceHolder<>(producer, closeTimeout);
 			bindResourceToTransaction(resourceHolder, producerFactory);
 		}
 		return resourceHolder;
@@ -121,7 +121,7 @@ private static <K, V> void bindResourceToTransaction(KafkaResourceHolder<K, V> r
 		resourceHolder.setSynchronizedWithTransaction(true);
 		if (TransactionSynchronizationManager.isSynchronizationActive()) {
 			TransactionSynchronizationManager
-					.registerSynchronization(new KafkaResourceSynchronization<K, V>(resourceHolder, producerFactory));
+					.registerSynchronization(new KafkaResourceSynchronization<>(resourceHolder, producerFactory));
 		}
 	}