Fix some compiler smells for Java 21

Author: artembilan

gradle/wrapper/gradle-wrapper.jar

@@ -1,7 +1,7 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionSha256Sum=d725d707bfabd4dfdc958c624003b3c80accc03f7037b5122c4b1d0ef15cecab
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.9-bin.zip
+distributionSha256Sum=1541fa36599e12857140465f3c91a97409b4512501c26f9631fb113e392c5bd1
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.10.1-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME

gradle/wrapper/gradle-wrapper.properties

@@ -114,6 +114,7 @@ public AmqpInboundGateway(MessageListenerContainer listenerContainer, AmqpTempla
 
 	private AmqpInboundGateway(MessageListenerContainer listenerContainer, AmqpTemplate amqpTemplate,
 			boolean amqpTemplateExplicitlySet) {
+
 		Assert.notNull(listenerContainer, "listenerContainer must not be null");
 		Assert.notNull(amqpTemplate, "'amqpTemplate' must not be null");
 		Assert.isNull(listenerContainer.getMessageListener(),
@@ -194,7 +195,7 @@ public void setRetryTemplate(RetryTemplate retryTemplate) {
 	 * @since 4.3.10
 	 * @see #setRetryTemplate(RetryTemplate)
 	 */
-	public void setRecoveryCallback(RecoveryCallback<? extends Object> recoveryCallback) {
+	public void setRecoveryCallback(RecoveryCallback<?> recoveryCallback) {
 		this.recoveryCallback = recoveryCallback;
 	}
 
@@ -341,6 +342,9 @@ protected AttributeAccessor getErrorMessageAttributes(org.springframework.messag
 
 	protected class Listener implements ChannelAwareMessageListener {
 
+		protected Listener() {
+		}
+
 		@SuppressWarnings("unchecked")
 		@Override
 		public void onMessage(final Message message, final Channel channel) {

spring-integration-amqp/src/main/java/org/springframework/integration/amqp/inbound/AmqpInboundGateway.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2022 the original author or authors.
+ * Copyright 2019-2024 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.
@@ -38,7 +38,7 @@ public class ManualAckListenerExecutionFailedException extends ListenerExecution
 	@Serial
 	private static final long serialVersionUID = 1L;
 
-	private final Channel channel;
+	private final transient Channel channel;
 
 	private final long deliveryTag;
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2019 the original author or authors.
+ * Copyright 2017-2024 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.
@@ -25,17 +25,20 @@
  * publisher confirm.
  *
  * @author Gary Russell
+ * @author Artem Bilan
+ *
  * @since 4.3.12
  *
  */
 public class NackedAmqpMessageException extends MessagingException {
 
 	private static final long serialVersionUID = 1L;
 
-	private final Object correlationData;
-
 	private final String nackReason;
 
+	@SuppressWarnings("serial")
+	private final Object correlationData;
+
 	public NackedAmqpMessageException(Message<?> message, @Nullable Object correlationData, String nackReason) {
 		super(message);
 		this.correlationData = correlationData;

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2022 the original author or authors.
+ * Copyright 2014-2024 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.
@@ -32,6 +32,7 @@ public class MessageGroupExpiredEvent extends IntegrationEvent {
 
 	private static final long serialVersionUID = -7126221042599333919L;
 
+	@SuppressWarnings("serial")
 	private final Object groupId;
 
 	private final int messageCount;
@@ -44,6 +45,7 @@ public class MessageGroupExpiredEvent extends IntegrationEvent {
 
 	public MessageGroupExpiredEvent(Object source, Object groupId, int messageCount, Date lastModified, Date expired,
 			boolean discarded) {
+
 		super(source);
 		this.groupId = groupId;
 		this.messageCount = messageCount;

spring-integration-core/src/main/java/org/springframework/integration/aggregator/MessageGroupExpiredEvent.java

@@ -45,7 +45,7 @@ public EventDrivenConsumer(SubscribableChannel inputChannel, MessageHandler hand
 		Assert.notNull(handler, "handler must not be null");
 		this.inputChannel = inputChannel;
 		this.handler = handler;
-		this.setPhase(Integer.MIN_VALUE);
+		setPhase(Integer.MIN_VALUE);
 	}
 
 	@Override
@@ -55,11 +55,11 @@ public MessageChannel getInputChannel() {
 
 	@Override
 	public MessageChannel getOutputChannel() {
-		if (this.handler instanceof MessageProducer) {
-			return ((MessageProducer) this.handler).getOutputChannel();
+		if (this.handler instanceof MessageProducer messageProducer) {
+			return messageProducer.getOutputChannel();
 		}
-		else if (this.handler instanceof MessageRouter) {
-			return ((MessageRouter) this.handler).getDefaultOutputChannel();
+		else if (this.handler instanceof MessageRouter messageRouter) {
+			return messageRouter.getDefaultOutputChannel();
 		}
 		else {
 			return null;
@@ -75,24 +75,25 @@ public MessageHandler getHandler() {
 	protected void doStart() {
 		this.logComponentSubscriptionEvent(true);
 		this.inputChannel.subscribe(this.handler);
-		if (this.handler instanceof Lifecycle) {
-			((Lifecycle) this.handler).start();
+		if (this.handler instanceof Lifecycle lifecycle) {
+			lifecycle.start();
 		}
 	}
 
 	@Override
 	protected void doStop() {
 		this.logComponentSubscriptionEvent(false);
 		this.inputChannel.unsubscribe(this.handler);
-		if (this.handler instanceof Lifecycle) {
-			((Lifecycle) this.handler).stop();
+		if (this.handler instanceof Lifecycle lifecycle) {
+			lifecycle.stop();
 		}
 	}
 
 	private void logComponentSubscriptionEvent(boolean add) {
-		if (this.handler instanceof NamedComponent && this.inputChannel instanceof NamedComponent) {
-			String channelName = ((NamedComponent) this.inputChannel).getComponentName();
-			String componentType = ((NamedComponent) this.handler).getComponentType();
+		if (this.handler instanceof NamedComponent namedHandler
+				&& this.inputChannel instanceof NamedComponent namedChannel) {
+
+			String componentType = namedHandler.getComponentType();
 			componentType = StringUtils.hasText(componentType) ? componentType : "";
 			String componentName = getComponentName();
 			componentName =
@@ -102,7 +103,7 @@ private void logComponentSubscriptionEvent(boolean add) {
 					.append(componentType)
 					.append(componentName)
 					.append("} as a subscriber to the '")
-					.append(channelName)
+					.append(namedChannel.getComponentName())
 					.append("' channel");
 			if (add) {
 				buffer.insert(0, "Adding ");

spring-integration-core/src/main/java/org/springframework/integration/endpoint/EventDrivenConsumer.java

@@ -81,7 +81,7 @@ public abstract class MessageProducerSupport extends AbstractEndpoint
 	private volatile Subscription subscription;
 
 	protected MessageProducerSupport() {
-		this.setPhase(Integer.MAX_VALUE / 2);
+		setPhase(Integer.MAX_VALUE / 2);
 	}
 
 	@Override
@@ -222,7 +222,6 @@ protected void onInit() {
 		if (beanFactory != null) {
 			this.messagingTemplate.setBeanFactory(beanFactory);
 		}
-
 	}
 
 	/**
@@ -278,8 +277,8 @@ protected void subscribeToPublisher(Publisher<? extends Message<?>> publisher) {
 						.doOnCancel(this::stop)
 						.doOnSubscribe((subs) -> this.subscription = subs);
 
-		if (channelForSubscription instanceof ReactiveStreamsSubscribableChannel) {
-			((ReactiveStreamsSubscribableChannel) channelForSubscription).subscribeTo(messageFlux);
+		if (channelForSubscription instanceof ReactiveStreamsSubscribableChannel reactiveStreamsSubscribableChannel) {
+			reactiveStreamsSubscribableChannel.subscribeTo(messageFlux);
 		}
 		else {
 			messageFlux

spring-integration-core/src/main/java/org/springframework/integration/endpoint/MessageProducerSupport.java

@@ -686,6 +686,7 @@ public static final class DelayedMessageWrapper implements Serializable {
 
 		private final long requestDate;
 
+		@SuppressWarnings("serial")
 		private final Message<?> original;
 
 		DelayedMessageWrapper(Message<?> original, long requestDate) {

spring-integration-core/src/main/java/org/springframework/integration/handler/DelayHandler.java

@@ -23,6 +23,7 @@
 import java.util.function.Function;
 import java.util.stream.Collectors;
 
+import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.SmartInitializingSingleton;
 import org.springframework.cache.CacheManager;
 import org.springframework.cache.interceptor.CacheAspectSupport;
@@ -49,7 +50,7 @@
  * The {@link AbstractRequestHandlerAdvice} implementation for caching
  * {@code AbstractReplyProducingMessageHandler.RequestHandler#handleRequestMessage(Message)} results.
  * Supports all the cache operations - cacheable, put, evict.
- * By default only cacheable is applied for the provided {@code cacheNames}.
+ * By default, only cacheable is applied for the provided {@code cacheNames}.
  * The default cache {@code key} is {@code payload} of the request message.
  *
  * @author Artem Bilan
@@ -103,9 +104,6 @@ public class CacheRequestHandlerAdvice extends AbstractRequestHandlerAdvice
 	 */
 	public CacheRequestHandlerAdvice(String... cacheNamesArg) {
 		this.cacheNames = cacheNamesArg != null ? Arrays.copyOf(cacheNamesArg, cacheNamesArg.length) : null;
-		CacheableOperation.Builder builder = new CacheableOperation.Builder();
-		builder.setName(toString());
-		this.cacheOperations.add(builder.build());
 	}
 
 	/**
@@ -192,6 +190,11 @@ public void afterSingletonsInstantiated() {
 
 	@Override
 	protected void onInit() {
+		if (this.cacheOperations.isEmpty()) {
+			CacheableOperation.Builder builder = new CacheableOperation.Builder();
+			builder.setName(toString());
+			this.cacheOperations.add(builder.build());
+		}
 		List<CacheOperation> cacheOperationsToUse;
 		if (!ObjectUtils.isEmpty(this.cacheNames)) {
 			cacheOperationsToUse =
@@ -232,14 +235,15 @@ else if (operation instanceof CacheEvictOperation cacheEvictOperation) {
 								builder.setKeyGenerator(operation.getKeyGenerator());
 								return builder.build();
 							})
-							.collect(Collectors.toList());
+							.toList();
 		}
 		else {
 			cacheOperationsToUse = this.cacheOperations;
 		}
 
-		this.delegate.setBeanFactory(getBeanFactory());
-		EvaluationContext evaluationContext = ExpressionUtils.createStandardEvaluationContext(getBeanFactory());
+		BeanFactory beanFactory = getBeanFactory();
+		this.delegate.setBeanFactory(beanFactory);
+		EvaluationContext evaluationContext = ExpressionUtils.createStandardEvaluationContext(beanFactory);
 		this.delegate.setKeyGenerator((target, method, params) ->
 				this.keyExpression.getValue(evaluationContext, params[0])); // NOSONAR
 		this.delegate.setCacheOperationSources((method, targetClass) -> cacheOperationsToUse);
@@ -260,7 +264,6 @@ protected Object doInvoke(ExecutionCallback callback, Object target, Message<?>
 					else {
 						return result;
 					}
-
 				};
 
 		return this.delegate.invoke(operationInvoker, target, message);