Checkstyle changes

* Upgrade to Checkstyle 9.0
* apply some JavaDocs rules
* Fix JavaDocs rules violations
* Some other minor clean up in the affected classes

spring-integration-amqp/src/main/java/org/springframework/integration/amqp/channel/AbstractAmqpChannel.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -77,8 +77,8 @@ public abstract class AbstractAmqpChannel extends AbstractMessageChannel impleme
 	 * @param amqpTemplate the template.
 	 * @param outboundMapper the outbound mapper.
 	 * @param inboundMapper the inbound mapper.
-	 * @see #setExtractPayload(boolean)
 	 * @since 4.3
+	 * @see #setExtractPayload(boolean)
 	 */
 	AbstractAmqpChannel(AmqpTemplate amqpTemplate, AmqpHeaderMapper outboundMapper, AmqpHeaderMapper inboundMapper) {
 		Assert.notNull(amqpTemplate, "amqpTemplate must not be null");
@@ -132,8 +132,8 @@ public abstract class AbstractAmqpChannel extends AbstractMessageChannel impleme
 
 	/**
 	 * @return the extract payload.
-	 * @see #setExtractPayload(boolean)
 	 * @since 4.3
+	 * @see #setExtractPayload(boolean)
 	 */
 	protected boolean isExtractPayload() {
 		return this.extractPayload;

spring-integration-amqp/src/main/java/org/springframework/integration/amqp/channel/AbstractSubscribableAmqpChannel.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -87,8 +87,8 @@ abstract class AbstractSubscribableAmqpChannel extends AbstractAmqpChannel
 	 * @param amqpTemplate the template.
 	 * @param outboundMapper the outbound mapper.
 	 * @param inboundMapper the inbound mapper.
-	 * @see #setExtractPayload(boolean)
 	 * @since 4.3
+	 * @see #setExtractPayload(boolean)
 	 */
 	protected AbstractSubscribableAmqpChannel(String channelName, AbstractMessageListenerContainer container,
 			AmqpTemplate amqpTemplate, AmqpHeaderMapper outboundMapper, AmqpHeaderMapper inboundMapper) {
@@ -120,8 +120,8 @@ abstract class AbstractSubscribableAmqpChannel extends AbstractAmqpChannel
 	 * @param isPubSub true for a pub/sub channel.
 	 * @param outboundMapper the outbound mapper.
 	 * @param inboundMapper the inbound mapper.
-	 * @see #setExtractPayload(boolean)
 	 * @since 4.3
+	 * @see #setExtractPayload(boolean)
 	 */
 	protected AbstractSubscribableAmqpChannel(String channelName,
 			AbstractMessageListenerContainer container,

spring-integration-amqp/src/main/java/org/springframework/integration/amqp/channel/PointToPointSubscribableAmqpChannel.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -57,8 +57,8 @@ public class PointToPointSubscribableAmqpChannel extends AbstractSubscribableAmq
 	 * @param amqpTemplate the template.
 	 * @param outboundMapper the outbound mapper.
 	 * @param inboundMapper the inbound mapper.
-	 * @see #setExtractPayload(boolean)
 	 * @since 4.3
+	 * @see #setExtractPayload(boolean)
 	 */
 	public PointToPointSubscribableAmqpChannel(String channelName, AbstractMessageListenerContainer container,
 			AmqpTemplate amqpTemplate, AmqpHeaderMapper outboundMapper, AmqpHeaderMapper inboundMapper) {

spring-integration-amqp/src/main/java/org/springframework/integration/amqp/channel/PollableAmqpChannel.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -82,8 +82,8 @@ public class PollableAmqpChannel extends AbstractAmqpChannel
 	 * @param amqpTemplate the template.
 	 * @param outboundMapper the outbound mapper.
 	 * @param inboundMapper the inbound mapper.
-	 * @see #setExtractPayload(boolean)
 	 * @since 4.3
+	 * @see #setExtractPayload(boolean)
 	 */
 	public PollableAmqpChannel(String channelName, AmqpTemplate amqpTemplate, AmqpHeaderMapper outboundMapper,
 			AmqpHeaderMapper inboundMapper) {

spring-integration-amqp/src/main/java/org/springframework/integration/amqp/channel/PublishSubscribeAmqpChannel.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -68,8 +68,8 @@ public class PublishSubscribeAmqpChannel extends AbstractSubscribableAmqpChannel
 	 * @param amqpTemplate the template
 	 * @param outboundMapper the outbound mapper.
 	 * @param inboundMapper the inbound mapper.
-	 * @see #setExtractPayload(boolean)
 	 * @since 4.3
+	 * @see #setExtractPayload(boolean)
 	 */
 	public PublishSubscribeAmqpChannel(String channelName, AbstractMessageListenerContainer container,
 			AmqpTemplate amqpTemplate, AmqpHeaderMapper outboundMapper, AmqpHeaderMapper inboundMapper) {

spring-integration-amqp/src/main/java/org/springframework/integration/amqp/dsl/AbstractMessageListenerContainerSpec.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2019 the original author or authors.
+ * Copyright 2017-2021 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.
@@ -37,6 +37,9 @@ import org.springframework.util.backoff.BackOff;
 /**
  * Base class for container specs.
  *
+ * @param <S> the current spec extension type
+ * @param <C> the listener container type
+ *
  * @author Gary Russell
  * @author Artem Bilan
  *

spring-integration-amqp/src/main/java/org/springframework/integration/amqp/dsl/Amqp.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2020 the original author or authors.
+ * Copyright 2014-2021 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.
@@ -155,7 +155,7 @@ public final class Amqp {
 	}
 
 	/**
-	 * Create an initial AmqpInboundPolledChannelAdapterSpec
+	 * Create an initial AmqpInboundPolledChannelAdapterSpec.
 	 * @param connectionFactory the connectionFactory.
 	 * @param queue the queue.
 	 * @return the AmqpInboundPolledChannelAdapterSpec.
@@ -168,7 +168,7 @@ public final class Amqp {
 	}
 
 	/**
-	 * Create an initial AmqpInboundPolledChannelAdapterSpec
+	 * Create an initial AmqpInboundPolledChannelAdapterSpec.
 	 * @param connectionFactory the connectionFactory.
 	 * @param ackCallbackFactory the ackCallbackFactory
 	 * @param queue the queue.

spring-integration-amqp/src/main/java/org/springframework/integration/amqp/dsl/AmqpMessageChannelSpec.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2020 the original author or authors.
+ * Copyright 2014-2021 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.
@@ -36,6 +36,7 @@ import org.springframework.util.ErrorHandler;
  * {@link org.springframework.integration.amqp.channel.PointToPointSubscribableAmqpChannel}.
  *
  * @param <S> the target {@link AmqpMessageChannelSpec} implementation type.
+ * @param <T> the target channel type.
  *
  * @author Artem Bilan
  * @author Gary Russell

spring-integration-amqp/src/main/java/org/springframework/integration/amqp/dsl/AmqpOutboundChannelAdapterSpec.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2020 the original author or authors.
+ * Copyright 2020-2021 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.
@@ -19,7 +19,7 @@ package org.springframework.integration.amqp.dsl;
 import org.springframework.amqp.core.AmqpTemplate;
 
 /**
- * Spec for an outbound AMQP channel adapter
+ * Spec for an outbound AMQP channel adapter.
  *
  * @author Gary Russell
  * @author Artme Bilan

spring-integration-amqp/src/main/java/org/springframework/integration/amqp/dsl/AmqpPollableMessageChannelSpec.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2020 the original author or authors.
+ * Copyright 2014-2021 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.
@@ -33,6 +33,7 @@ import org.springframework.util.Assert;
  * A {@link MessageChannelSpec} for a {@link AbstractAmqpChannel}s.
  *
  * @param <S> the target {@link AmqpPollableMessageChannelSpec} implementation type.
+ * @param <T> the target channel type.
  *
  * @author Artem Bilan
  * @author Gary Russell

spring-integration-amqp/src/main/java/org/springframework/integration/amqp/dsl/SimpleMessageListenerContainerSpec.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2020 the original author or authors.
+ * Copyright 2017-2021 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.
@@ -111,8 +111,8 @@ public class SimpleMessageListenerContainerSpec extends
 	 * The batch size to use.
 	 * @param batchSize the batchSize.
 	 * @return the spec.
-	 * @see SimpleMessageListenerContainer#setBatchSize(int)
 	 * @since 5.2
+	 * @see SimpleMessageListenerContainer#setBatchSize(int)
 	 */
 	public SimpleMessageListenerContainerSpec batchSize(int batchSize) {
 		this.listenerContainer.setBatchSize(batchSize);

spring-integration-amqp/src/main/java/org/springframework/integration/amqp/support/DefaultAmqpHeaderMapper.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -340,9 +340,9 @@ public class DefaultAmqpHeaderMapper extends AbstractHeaderMapper<MessagePropert
 	/**
 	 * Construct a default inbound header mapper.
 	 * @return the mapper.
+	 * @since 4.3
 	 * @see #inboundRequestHeaders()
 	 * @see #inboundReplyHeaders()
-	 * @since 4.3
 	 */
 	public static DefaultAmqpHeaderMapper inboundMapper() {
 		return new DefaultAmqpHeaderMapper(inboundRequestHeaders(), inboundReplyHeaders());
@@ -351,9 +351,9 @@ public class DefaultAmqpHeaderMapper extends AbstractHeaderMapper<MessagePropert
 	/**
 	 * Construct a default outbound header mapper.
 	 * @return the mapper.
+	 * @since 4.3
 	 * @see #outboundRequestHeaders()
 	 * @see #outboundReplyHeaders()
-	 * @since 4.3
 	 */
 	public static DefaultAmqpHeaderMapper outboundMapper() {
 		return new DefaultAmqpHeaderMapper(outboundRequestHeaders(), outboundReplyHeaders());