diff --git a/build.gradle b/build.gradle
index ed05510f..74edad2f 100644
--- a/build.gradle
+++ b/build.gradle
@@ -203,7 +203,7 @@ subprojects { subproject ->
 
 	checkstyle {
 		configDirectory.set(rootProject.file("src/checkstyle"))
-		toolVersion = '8.38'
+		toolVersion = '9.0'
 	}
 
 	jacocoTestReport {
diff --git a/spring-kafka/src/main/java/org/springframework/kafka/config/StreamsBuilderFactoryBean.java b/spring-kafka/src/main/java/org/springframework/kafka/config/StreamsBuilderFactoryBean.java
index be3903cc..6db3fed4 100644
--- a/spring-kafka/src/main/java/org/springframework/kafka/config/StreamsBuilderFactoryBean.java
+++ b/spring-kafka/src/main/java/org/springframework/kafka/config/StreamsBuilderFactoryBean.java
@@ -193,9 +193,9 @@ public class StreamsBuilderFactoryBean extends AbstractFactoryBean<StreamsBuilde
 
 	/**
 	 * Obsolete.
+	 * @param exceptionHandler the handler.
 	 * @deprecated in favor of
 	 * {@link #setStreamsUncaughtExceptionHandler(StreamsUncaughtExceptionHandler)}.
-	 * @param exceptionHandler the handler.
 	 */
 	@Deprecated
 	public void setUncaughtExceptionHandler(Thread.UncaughtExceptionHandler exceptionHandler) {
diff --git a/spring-kafka/src/main/java/org/springframework/kafka/config/StreamsBuilderFactoryBeanCustomizer.java b/spring-kafka/src/main/java/org/springframework/kafka/config/StreamsBuilderFactoryBeanCustomizer.java
index 1ad24065..e93804af 100644
--- a/spring-kafka/src/main/java/org/springframework/kafka/config/StreamsBuilderFactoryBeanCustomizer.java
+++ b/spring-kafka/src/main/java/org/springframework/kafka/config/StreamsBuilderFactoryBeanCustomizer.java
@@ -22,12 +22,11 @@ package org.springframework.kafka.config;
  * implementation of this interface is found in the application context (or one is marked
  * as {@link org.springframework.context.annotation.Primary}, it will be invoked after the
  * factory bean has been created and before it is started.
- * @deprecated in favor of {@code StreamsBuilderFactoryBeanConfigurer} due to a name
- * clash with a similar class in Spring Boot.
  *
  * @author Gary Russell
  * @since 2.3
- *
+ * @deprecated in favor of {@code StreamsBuilderFactoryBeanConfigurer} due to a name
+ * clash with a similar class in Spring Boot.
  */
 @Deprecated
 @FunctionalInterface
diff --git a/spring-kafka/src/main/java/org/springframework/kafka/event/KafkaEvent.java b/spring-kafka/src/main/java/org/springframework/kafka/event/KafkaEvent.java
index 03dc4171..62b09d3d 100644
--- a/spring-kafka/src/main/java/org/springframework/kafka/event/KafkaEvent.java
+++ b/spring-kafka/src/main/java/org/springframework/kafka/event/KafkaEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015-2020 the original author or authors.
+ * Copyright 2015-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -45,8 +45,8 @@ public abstract class KafkaEvent extends ApplicationEvent {
 	 * @param type the container type (e.g. {@code MessageListenerContainer.class}).
 	 * @param <T> the type.
 	 * @return the container.
-	 * @see #getSource(Class)
 	 * @since 2.2.1
+	 * @see #getSource(Class)
 	 */
 	@SuppressWarnings("unchecked")
 	public <T> T getContainer(Class<T> type) {
@@ -62,9 +62,9 @@ public abstract class KafkaEvent extends ApplicationEvent {
 	 * @param type the container type (e.g. {@code MessageListenerContainer.class}).
 	 * @param <T> the type.
 	 * @return the container.
+	 * @since 2.2.1
 	 * @see #getContainer(Class)
 	 * @see #getSource()
-	 * @since 2.2.1
 	 */
 	@SuppressWarnings("unchecked")
 	public <T> T getSource(Class<T> type) {
diff --git a/spring-kafka/src/main/java/org/springframework/kafka/listener/BatchLoggingErrorHandler.java b/spring-kafka/src/main/java/org/springframework/kafka/listener/BatchLoggingErrorHandler.java
index 432bfcb3..edd8349a 100644
--- a/spring-kafka/src/main/java/org/springframework/kafka/listener/BatchLoggingErrorHandler.java
+++ b/spring-kafka/src/main/java/org/springframework/kafka/listener/BatchLoggingErrorHandler.java
@@ -27,10 +27,9 @@ import org.springframework.lang.Nullable;
 /**
  * Simple handler that logs each record.
  *
- * @deprecated - use the {@link CommonLoggingErrorHandler} instead.
- *
  * @author Gary Russell
  * @since 1.1
+ * @deprecated - use the {@link CommonLoggingErrorHandler} instead.
  */
 @Deprecated
 public class BatchLoggingErrorHandler implements BatchErrorHandler {
diff --git a/spring-kafka/src/main/java/org/springframework/kafka/listener/ConditionalDelegatingBatchErrorHandler.java b/spring-kafka/src/main/java/org/springframework/kafka/listener/ConditionalDelegatingBatchErrorHandler.java
index 029d357f..76a78a32 100644
--- a/spring-kafka/src/main/java/org/springframework/kafka/listener/ConditionalDelegatingBatchErrorHandler.java
+++ b/spring-kafka/src/main/java/org/springframework/kafka/listener/ConditionalDelegatingBatchErrorHandler.java
@@ -30,11 +30,9 @@ import org.springframework.util.Assert;
  * An error handler that delegates to different error handlers, depending on the exception
  * type.
  *
- * @deprecated in favor of {@link CommonDelegatingErrorHandler}.
- *
  * @author Gary Russell
  * @since 2.7.4
- *
+ * @deprecated in favor of {@link CommonDelegatingErrorHandler}.
  */
 @Deprecated
 public class ConditionalDelegatingBatchErrorHandler implements ListenerInvokingBatchErrorHandler {
diff --git a/spring-kafka/src/main/java/org/springframework/kafka/listener/ConditionalDelegatingErrorHandler.java b/spring-kafka/src/main/java/org/springframework/kafka/listener/ConditionalDelegatingErrorHandler.java
index 1d696a7e..51a72475 100644
--- a/spring-kafka/src/main/java/org/springframework/kafka/listener/ConditionalDelegatingErrorHandler.java
+++ b/spring-kafka/src/main/java/org/springframework/kafka/listener/ConditionalDelegatingErrorHandler.java
@@ -31,11 +31,9 @@ import org.springframework.util.Assert;
  * An error handler that delegates to different error handlers, depending on the exception
  * type.
  *
- * @deprecated in favor of {@link CommonDelegatingErrorHandler}.
- *
  * @author Gary Russell
  * @since 2.7.4
- *
+ * @deprecated in favor of {@link CommonDelegatingErrorHandler}.
  */
 @Deprecated
 public class ConditionalDelegatingErrorHandler implements ContainerAwareErrorHandler {
diff --git a/spring-kafka/src/main/java/org/springframework/kafka/listener/ContainerProperties.java b/spring-kafka/src/main/java/org/springframework/kafka/listener/ContainerProperties.java
index 505eaee3..5551cb26 100644
--- a/spring-kafka/src/main/java/org/springframework/kafka/listener/ContainerProperties.java
+++ b/spring-kafka/src/main/java/org/springframework/kafka/listener/ContainerProperties.java
@@ -179,7 +179,7 @@ public class ContainerProperties extends ConsumerProperties {
 
 		/**
 		 * Create an alias.
-		 * @param v22 the mode for which this is an alias.
+		 * @param v12 the mode for which this is an alias.
 		 */
 		EOSMode(EOSMode v12) {
 			this.mode = v12;
diff --git a/spring-kafka/src/main/java/org/springframework/kafka/listener/ContainerStoppingBatchErrorHandler.java b/spring-kafka/src/main/java/org/springframework/kafka/listener/ContainerStoppingBatchErrorHandler.java
index 915c831d..1f8218e5 100644
--- a/spring-kafka/src/main/java/org/springframework/kafka/listener/ContainerStoppingBatchErrorHandler.java
+++ b/spring-kafka/src/main/java/org/springframework/kafka/listener/ContainerStoppingBatchErrorHandler.java
@@ -30,10 +30,9 @@ import org.springframework.util.Assert;
  * A container error handler that stops the container after an exception
  * is thrown by the listener.
  *
- * @deprecated in favor of {@link CommonContainerStoppingErrorHandler}.
- *
  * @author Gary Russell
  * @since 2.1
+ * @deprecated in favor of {@link CommonContainerStoppingErrorHandler}.
  *
  */
 @Deprecated
diff --git a/spring-kafka/src/main/java/org/springframework/kafka/listener/ContainerStoppingErrorHandler.java b/spring-kafka/src/main/java/org/springframework/kafka/listener/ContainerStoppingErrorHandler.java
index 76297f78..b0e70d6c 100644
--- a/spring-kafka/src/main/java/org/springframework/kafka/listener/ContainerStoppingErrorHandler.java
+++ b/spring-kafka/src/main/java/org/springframework/kafka/listener/ContainerStoppingErrorHandler.java
@@ -30,10 +30,9 @@ import org.springframework.util.Assert;
  * A container error handler that stops the container after an exception
  * is thrown by the listener.
  *
- * @deprecated in favor of {@link CommonContainerStoppingErrorHandler}.
- *
  * @author Gary Russell
  * @since 2.1
+ * @deprecated in favor of {@link CommonContainerStoppingErrorHandler}.
  *
  */
 @Deprecated
diff --git a/spring-kafka/src/main/java/org/springframework/kafka/listener/LoggingErrorHandler.java b/spring-kafka/src/main/java/org/springframework/kafka/listener/LoggingErrorHandler.java
index a213ad8c..e3f97f8f 100644
--- a/spring-kafka/src/main/java/org/springframework/kafka/listener/LoggingErrorHandler.java
+++ b/spring-kafka/src/main/java/org/springframework/kafka/listener/LoggingErrorHandler.java
@@ -25,10 +25,9 @@ import org.springframework.lang.Nullable;
 /**
  * The {@link ErrorHandler} implementation for logging purpose.
  *
- * @deprecated - use the {@link CommonLoggingErrorHandler} instead.
- *
  * @author Marius Bogoevici
  * @author Gary Russell
+ * @deprecated - use the {@link CommonLoggingErrorHandler} instead.
  */
 @Deprecated
 public class LoggingErrorHandler implements ErrorHandler {
diff --git a/spring-kafka/src/main/java/org/springframework/kafka/listener/RecoveringBatchErrorHandler.java b/spring-kafka/src/main/java/org/springframework/kafka/listener/RecoveringBatchErrorHandler.java
index ba330385..eb4ab587 100644
--- a/spring-kafka/src/main/java/org/springframework/kafka/listener/RecoveringBatchErrorHandler.java
+++ b/spring-kafka/src/main/java/org/springframework/kafka/listener/RecoveringBatchErrorHandler.java
@@ -35,12 +35,10 @@ import org.springframework.util.backoff.BackOff;
  * exception, error handling is delegated to a {@link SeekToCurrentBatchErrorHandler} with
  * this handler's {@link BackOff}. If the record is recovered, its offset is committed.
  *
- * @deprecated in favor of {@link DefaultErrorHandler}.
- *
  * @author Gary Russell
  * @author Myeonghyeon Lee
  * @since 2.5
- *
+ * @deprecated in favor of {@link DefaultErrorHandler}.
  */
 @Deprecated
 public class RecoveringBatchErrorHandler extends FailedBatchProcessor
diff --git a/spring-kafka/src/main/java/org/springframework/kafka/listener/SeekToCurrentBatchErrorHandler.java b/spring-kafka/src/main/java/org/springframework/kafka/listener/SeekToCurrentBatchErrorHandler.java
index 9194307d..3197c749 100644
--- a/spring-kafka/src/main/java/org/springframework/kafka/listener/SeekToCurrentBatchErrorHandler.java
+++ b/spring-kafka/src/main/java/org/springframework/kafka/listener/SeekToCurrentBatchErrorHandler.java
@@ -31,12 +31,10 @@ import org.springframework.util.backoff.BackOffExecution;
  * An error handler that seeks to the current offset for each topic in a batch of records.
  * Used to rewind partitions after a message failure so that the batch can be replayed.
  *
- * @deprecated with no replacement - use {@link DefaultErrorHandler} with an infinite
- * {@link BackOff}.
- *
  * @author Gary Russell
  * @since 2.1
- *
+ * @deprecated with no replacement - use {@link DefaultErrorHandler} with an infinite
+ * {@link BackOff}.
  */
 @Deprecated
 public class SeekToCurrentBatchErrorHandler extends KafkaExceptionLogLevelAware
diff --git a/spring-kafka/src/main/java/org/springframework/kafka/listener/SeekToCurrentErrorHandler.java b/spring-kafka/src/main/java/org/springframework/kafka/listener/SeekToCurrentErrorHandler.java
index fdaff75b..2c2289f6 100644
--- a/spring-kafka/src/main/java/org/springframework/kafka/listener/SeekToCurrentErrorHandler.java
+++ b/spring-kafka/src/main/java/org/springframework/kafka/listener/SeekToCurrentErrorHandler.java
@@ -30,13 +30,11 @@ import org.springframework.util.backoff.BackOff;
  * records. Used to rewind partitions after a message failure so that it can be
  * replayed.
  *
- * @deprecated in favor of {@link DefaultErrorHandler}.
- *
  * @author Gary Russell
  * @author Artem Bilan
  *
  * @since 2.0.1
- *
+ * @deprecated in favor of {@link DefaultErrorHandler}.
  */
 @Deprecated
 public class SeekToCurrentErrorHandler extends FailedRecordProcessor implements ContainerAwareErrorHandler {
diff --git a/spring-kafka/src/main/java/org/springframework/kafka/listener/adapter/DelegatingInvocableHandler.java b/spring-kafka/src/main/java/org/springframework/kafka/listener/adapter/DelegatingInvocableHandler.java
index abec5b9f..fe1ef33c 100644
--- a/spring-kafka/src/main/java/org/springframework/kafka/listener/adapter/DelegatingInvocableHandler.java
+++ b/spring-kafka/src/main/java/org/springframework/kafka/listener/adapter/DelegatingInvocableHandler.java
@@ -108,9 +108,9 @@ public class DelegatingInvocableHandler {
 	 * @param bean the bean.
 	 * @param beanExpressionResolver the resolver.
 	 * @param beanExpressionContext the context.
+	 * @since 2.1.3
 	 * @deprecated in favor of
 	 * {@link #DelegatingInvocableHandler(List, InvocableHandlerMethod, Object, BeanExpressionResolver, BeanExpressionContext, BeanFactory, Validator)}
-	 * @since 2.1.3
 	 */
 	@Deprecated
 	public DelegatingInvocableHandler(List<InvocableHandlerMethod> handlers,
diff --git a/spring-kafka/src/main/java/org/springframework/kafka/listener/adapter/RetryingMessageListenerAdapter.java b/spring-kafka/src/main/java/org/springframework/kafka/listener/adapter/RetryingMessageListenerAdapter.java
index 9a8a47cd..f5b20592 100644
--- a/spring-kafka/src/main/java/org/springframework/kafka/listener/adapter/RetryingMessageListenerAdapter.java
+++ b/spring-kafka/src/main/java/org/springframework/kafka/listener/adapter/RetryingMessageListenerAdapter.java
@@ -35,9 +35,8 @@ import org.springframework.util.Assert;
  * @param <K> the key type.
  * @param <V> the value type.
  *
- * @deprecated since 2.8 - use a suitably configured error handler instead.
- *
  * @author Gary Russell
+ * @deprecated since 2.8 - use a suitably configured error handler instead.
  *
  */
 @Deprecated
diff --git a/spring-kafka/src/main/java/org/springframework/kafka/support/mapping/Jackson2JavaTypeMapper.java b/spring-kafka/src/main/java/org/springframework/kafka/support/mapping/Jackson2JavaTypeMapper.java
index a048245e..3f45504a 100644
--- a/spring-kafka/src/main/java/org/springframework/kafka/support/mapping/Jackson2JavaTypeMapper.java
+++ b/spring-kafka/src/main/java/org/springframework/kafka/support/mapping/Jackson2JavaTypeMapper.java
@@ -39,7 +39,16 @@ public interface Jackson2JavaTypeMapper extends ClassMapper {
 	 * headers. Only applies if both exist.
 	 */
 	enum TypePrecedence {
-		INFERRED, TYPE_ID
+
+		/**
+		 * The type is inferred from the destination method.
+		 */
+		INFERRED,
+
+		/**
+		 * The type is obtained from headers.
+		 */
+		TYPE_ID
 	}
 
 	void fromJavaType(JavaType javaType, Headers headers);
diff --git a/src/checkstyle/checkstyle.xml b/src/checkstyle/checkstyle.xml
index a5f43811..313da7c2 100644
--- a/src/checkstyle/checkstyle.xml
+++ b/src/checkstyle/checkstyle.xml
@@ -110,7 +110,6 @@
 			<property name="authorFormat" value=".+\s.+"/>
 		</module>
 		<module name="JavadocMethod">
-			<property name="scope" value="public"/>
 		</module>
 		<module name="JavadocVariable">
 			<property name="scope" value="public"/>