Add EmptyLineSeparator Checkstyle rule

* Support "blank lines around" via `spring-framework.xml` IDEA config
* Fix all the Checkstyle violations

Author: artembilan

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -181,12 +181,12 @@ public void onInit() {
 		this.container.setQueueNames(queue);
 		MessageConverter converter =
 				(getAmqpTemplate() instanceof RabbitTemplate rabbitTemplate)
-				? rabbitTemplate.getMessageConverter()
-				: new SimpleMessageConverter();
+						? rabbitTemplate.getMessageConverter()
+						: new SimpleMessageConverter();
 
 		MessageListener listener =
 				new DispatchingMessageListener(converter, this.dispatcher, this, this.isPubSub,
-				getMessageBuilderFactory(), getInboundHeaderMapper());
+						getMessageBuilderFactory(), getInboundHeaderMapper());
 		this.container.setMessageListener(listener);
 		if (!this.container.isActive()) {
 			this.container.afterPropertiesSet();
@@ -261,7 +261,6 @@ public void destroy() {
 
 	protected abstract String obtainQueueName(String channelName);
 
-
 	private static final class DispatchingMessageListener implements MessageListener {
 
 		private final Log logger = LogFactory.getLog(DispatchingMessageListener.class);
@@ -292,7 +291,6 @@ private DispatchingMessageListener(MessageConverter converter,
 			this.inboundHeaderMapper = inboundHeaderMapper;
 		}
 
-
 		@Override
 		public void onMessage(org.springframework.amqp.core.Message message) {
 			Message<?> messageToSend = null;

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -55,7 +55,6 @@ public PointToPointSubscribableAmqpChannel(String channelName, AbstractMessageLi
 		super(channelName, container, amqpTemplate);
 	}
 
-
 	/**
 	 * Construct an instance with the supplied name, container and template; default header
 	 * mappers will be used if the message is mapped.
@@ -73,7 +72,6 @@ public PointToPointSubscribableAmqpChannel(String channelName, AbstractMessageLi
 		super(channelName, container, amqpTemplate, outboundMapper, inboundMapper);
 	}
 
-
 	/**
 	 * Provide a Queue name to be used. If this is not provided,
 	 * the Queue's name will be the same as the channel name.

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -93,7 +93,6 @@ public PollableAmqpChannel(String channelName, AmqpTemplate amqpTemplate, AmqpHe
 		this.channelName = channelName;
 	}
 
-
 	/**
 	 * Provide an explicitly configured queue name. If this is not provided, then a Queue will be created
 	 * implicitly with the channelName as its name. The implicit creation will require that either an AmqpAdmin
@@ -286,7 +285,6 @@ private CounterFacade buildReceiveCounter(MetricsCaptor metricsCaptor, @Nullable
 		return counterFacade;
 	}
 
-
 	@Override
 	public void setInterceptors(List<ChannelInterceptor> interceptors) {
 		super.setInterceptors(interceptors);

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -77,7 +77,6 @@ public PublishSubscribeAmqpChannel(String channelName, AbstractMessageListenerCo
 		super(channelName, container, amqpTemplate, true, outboundMapper, inboundMapper);
 	}
 
-
 	/**
 	 * Configure the FanoutExchange instance. If this is not provided, then a
 	 * FanoutExchange will be declared implicitly, and its name will be the same

spring-integration-amqp/src/main/java/org/springframework/integration/amqp/config/AbstractAmqpInboundAdapterParser.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -72,16 +72,13 @@ abstract class AbstractAmqpInboundAdapterParser extends AbstractSingleBeanDefini
 			"transaction-manager"
 	};
 
-
 	private final String adapterClassName;
 
-
 	AbstractAmqpInboundAdapterParser(String adapterClassName) {
 		Assert.hasText(adapterClassName, "adapterClassName is required");
 		this.adapterClassName = adapterClassName;
 	}
 
-
 	@Override
 	protected final String getBeanClassName(Element element) {
 		return this.adapterClassName;

spring-integration-amqp/src/main/java/org/springframework/integration/amqp/config/AmqpChannelFactoryBean.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -148,7 +148,6 @@ public AmqpChannelFactoryBean(boolean messageDriven) {
 		this.messageDriven = messageDriven;
 	}
 
-
 	@Override
 	public void setBeanName(@Nullable String name) {
 		this.beanName = name;

spring-integration-amqp/src/main/java/org/springframework/integration/amqp/config/AmqpInboundGatewayParser.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -39,7 +39,6 @@ public class AmqpInboundGatewayParser extends AbstractAmqpInboundAdapterParser {
 		super(AmqpInboundGateway.class.getName());
 	}
 
-
 	@Override
 	protected void configureChannels(Element element, ParserContext parserContext, BeanDefinitionBuilder builder) {
 		String amqpTemplateRef = element.getAttribute("amqp-template");

spring-integration-amqp/src/main/java/org/springframework/integration/amqp/dsl/Amqp.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.
@@ -64,7 +64,6 @@ public static AmqpInboundGatewaySMLCSpec inboundGateway(ConnectionFactory connec
 		return inboundGateway(listenerContainer, amqpTemplate);
 	}
 
-
 	/**
 	 * Create an initial {@link AmqpInboundGatewaySpec}.
 	 * @param connectionFactory the connectionFactory.

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2022 the original author or authors.
+ * Copyright 2016-2024 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.
@@ -271,7 +271,6 @@ public S delayFunction(Function<Message<?>, Integer> delayFunction) {
 		return delayExpression(new FunctionExpression<>(delayFunction));
 	}
 
-
 	/**
 	 * Set the SpEL expression to calculate the {@code x-delay} header when using the
 	 * RabbitMQ delayed message exchange plugin.

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2023 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.
@@ -55,4 +55,5 @@ public AmqpInboundChannelAdapterSMLCSpec batchMode(BatchMode batchMode) {
 		this.target.setBatchMode(batchMode);
 		return this;
 	}
+
 }