Sonar Fixes

Author: garyrussell

spring-kafka/src/main/java/org/springframework/kafka/listener/CommonDelegatingErrorHandler.java

@@ -216,13 +216,14 @@ private Throwable shallowTraverseCauseChain(Throwable thrownException) {
 
 	@Nullable
 	private Throwable traverseCauseChain(Throwable thrownException) {
-		while (thrownException != null && thrownException.getCause() != null) {
-			if (this.classifier.classify(thrownException)) { // NOSONAR using Boolean here is not dangerous
-				return thrownException;
+		Throwable cause = thrownException;
+		while (cause != null && cause.getCause() != null) {
+			if (this.classifier.classify(cause)) { // NOSONAR using Boolean here is not dangerous
+				return cause;
 			}
-			thrownException = thrownException.getCause();
+			cause = cause.getCause();
 		}
-		return thrownException;
+		return cause;
 	}
 
 }

spring-kafka/src/main/java/org/springframework/kafka/retrytopic/ListenerContainerFactoryConfigurer.java

@@ -22,9 +22,6 @@
 import java.util.function.Consumer;
 import java.util.regex.Pattern;
 
-import org.apache.commons.logging.LogFactory;
-
-import org.springframework.core.log.LogAccessor;
 import org.springframework.kafka.KafkaException;
 import org.springframework.kafka.config.ConcurrentKafkaListenerContainerFactory;
 import org.springframework.kafka.config.KafkaListenerContainerFactory;
@@ -61,9 +58,6 @@
  */
 public class ListenerContainerFactoryConfigurer {
 
-	private static final LogAccessor LOGGER = new LogAccessor(
-			LogFactory.getLog(ListenerContainerFactoryConfigurer.class));
-
 	private BackOff providedBlockingBackOff = null;
 
 	private Class<? extends Exception>[] blockingExceptionTypes = null;

spring-kafka/src/main/java/org/springframework/kafka/retrytopic/RetryTopicConfigurationSupport.java

@@ -68,8 +68,6 @@
 */
 public class RetryTopicConfigurationSupport {
 
-	private static final String BACK_OFF_MANAGER_THREAD_EXECUTOR_BEAN_NAME = "backOffManagerThreadExecutor";
-
 	private static final AtomicBoolean ONLY_ONE_ALLOWED = new AtomicBoolean(true);
 
 	private final RetryTopicComponentFactory componentFactory = createComponentFactory();