Sonar: Add Nullable to Possibly Null Parameters

spring-rabbit/src/main/java/org/springframework/amqp/rabbit/connection/CachingConnectionFactory.java

@@ -529,7 +529,7 @@ private Channel getChannel(ChannelCachingConnectionProxy connection, boolean tra
 		LinkedList<ChannelProxy> channelList = determineChannelList(connection, transactional);
 		ChannelProxy channel = null;
 		if (connection.isOpen()) {
-			channel = findOpenChannel(channelList, channel);
+			channel = findOpenChannel(channelList);
 			if (channel != null && logger.isTraceEnabled()) {
 				logger.trace("Found cached Rabbit Channel: " + channel.toString());
 			}
@@ -576,9 +576,10 @@ private Semaphore obtainPermits(ChannelCachingConnectionProxy connection) {
 		return permits;
 	}
 
-	private ChannelProxy findOpenChannel(LinkedList<ChannelProxy> channelList, // NOSONAR LinkedList.removeFirst()
-			ChannelProxy channelArg) {
-		ChannelProxy channel = channelArg;
+	@Nullable
+	private ChannelProxy findOpenChannel(LinkedList<ChannelProxy> channelList) {
+
+		ChannelProxy channel = null;
 		synchronized (channelList) {
 			while (!channelList.isEmpty()) {
 				channel = channelList.removeFirst();

spring-rabbit/src/main/java/org/springframework/amqp/rabbit/core/RabbitAdmin.java

@@ -769,7 +769,7 @@ private void declareBindings(final Channel channel, final Binding... bindings) t
 		}
 	}
 
-	private <T extends Throwable> void logOrRethrowDeclarationException(@Nullable Declarable element,
+	private <T extends Throwable> void logOrRethrowDeclarationException(Declarable element,
 			String elementType, T t) throws T {
 
 		publishDeclarationExceptionEvent(element, t);
@@ -794,7 +794,7 @@ else if (this.logger.isWarnEnabled()) {
 		}
 	}
 
-	private <T extends Throwable> void publishDeclarationExceptionEvent(Declarable element, T t) {
+	private <T extends Throwable> void publishDeclarationExceptionEvent(@Nullable Declarable element, T t) {
 		DeclarationExceptionEvent event = new DeclarationExceptionEvent(this, element, t);
 		this.lastDeclarationExceptionEvent = event;
 		if (this.applicationEventPublisher != null) {

spring-rabbit/src/main/java/org/springframework/amqp/rabbit/core/RabbitTemplate.java

@@ -1444,7 +1444,7 @@ private Delivery consumeDelivery(Channel channel, String queueName, long timeout
 		return delivery;
 	}
 
-	private void logReceived(Message message) {
+	private void logReceived(@Nullable Message message) {
 		if (message == null) {
 			logger.debug("Received no message");
 		}
@@ -2161,8 +2161,8 @@ private <T> T doExecute(ChannelCallback<T> action, ConnectionFactory connectionF
 		}
 	}
 
-	private void cleanUpAfterAction(Channel channel, boolean invokeScope, RabbitResourceHolder resourceHolder,
-			Connection connection) {
+	private void cleanUpAfterAction(@Nullable Channel channel, boolean invokeScope,
+			@Nullable RabbitResourceHolder resourceHolder, @Nullable Connection connection) {
 
 		if (!invokeScope) {
 			if (resourceHolder != null) {
@@ -2257,8 +2257,8 @@ private ConfirmListener addConfirmListener(@Nullable com.rabbitmq.client.Confirm
 		return listener;
 	}
 
-	private void cleanUpAfterAction(RabbitResourceHolder resourceHolder, Connection connection, Channel channel,
-			ConfirmListener listener) {
+	private void cleanUpAfterAction(@Nullable RabbitResourceHolder resourceHolder, @Nullable Connection connection,
+			@Nullable Channel channel, @Nullable ConfirmListener listener) {
 
 		if (listener != null) {
 			channel.removeConfirmListener(listener);