Reduce else condition and modernize switch pattern

Author: ngocnhan-tran1996

spring-rabbit/src/main/java/org/springframework/amqp/rabbit/annotation/RabbitListenerAnnotationBeanPostProcessor.java

@@ -76,6 +76,7 @@
 import org.springframework.context.expression.StandardBeanExpressionResolver;
 import org.springframework.core.Ordered;
 import org.springframework.core.annotation.AnnotationUtils;
+import org.springframework.core.annotation.MergedAnnotation;
 import org.springframework.core.annotation.MergedAnnotations;
 import org.springframework.core.annotation.MergedAnnotations.SearchStrategy;
 import org.springframework.core.convert.ConversionService;
@@ -357,7 +358,7 @@ else if (source instanceof Method method) {
 					}
 					return !name.contains("$MockitoMock$");
 				})
-				.map(ann -> ann.synthesize())
+				.map(MergedAnnotation::synthesize)
 				.collect(Collectors.toList());
 	}
 
@@ -893,7 +894,7 @@ private void addToMap(Map<String, Object> map, String key, Object value, Class<?
 			}
 		}
 		else {
-			if (value instanceof String && !StringUtils.hasText((String) value)) {
+			if (value instanceof String string && !StringUtils.hasText(string)) {
 				putEmpty(map, key);
 			}
 			else {

spring-rabbit/src/main/java/org/springframework/amqp/rabbit/batch/SimpleBatchingStrategy.java

@@ -107,13 +107,12 @@ public Date nextRelease() {
 		if (this.messages.isEmpty() || this.timeout <= 0) {
 			return null;
 		}
-		else if (this.currentSize >= this.bufferLimit) {
+		if (this.currentSize >= this.bufferLimit) {
 			// release immediately, we're already over the limit
 			return new Date();
 		}
-		else {
-			return new Date(System.currentTimeMillis() + this.timeout);
-		}
+
+		return new Date(System.currentTimeMillis() + this.timeout);
 	}
 
 	@Override
@@ -122,9 +121,8 @@ public Collection<MessageBatch> releaseBatches() {
 		if (batch == null) {
 			return Collections.emptyList();
 		}
-		else {
-			return Collections.singletonList(batch);
-		}
+
+		return Collections.singletonList(batch);
 	}
 
 	private MessageBatch doReleaseBatch() {

spring-rabbit/src/main/java/org/springframework/amqp/rabbit/config/ListenerContainerFactoryBean.java

@@ -575,14 +575,13 @@ private AbstractMessageListenerContainer createContainer() {
 					.acceptIfNotNull(this.retryDeclarationInterval, container::setRetryDeclarationInterval);
 			return container;
 		}
-		else {
-			DirectMessageListenerContainer container = new DirectMessageListenerContainer(this.connectionFactory);
-			JavaUtils.INSTANCE
-					.acceptIfNotNull(this.consumersPerQueue, container::setConsumersPerQueue)
-					.acceptIfNotNull(this.taskScheduler, container::setTaskScheduler)
-					.acceptIfNotNull(this.monitorInterval, container::setMonitorInterval);
-			return container;
-		}
+
+		DirectMessageListenerContainer container = new DirectMessageListenerContainer(this.connectionFactory);
+		JavaUtils.INSTANCE
+				.acceptIfNotNull(this.consumersPerQueue, container::setConsumersPerQueue)
+				.acceptIfNotNull(this.taskScheduler, container::setTaskScheduler)
+				.acceptIfNotNull(this.monitorInterval, container::setMonitorInterval);
+		return container;
 	}
 
 	@Override

spring-rabbit/src/main/java/org/springframework/amqp/rabbit/config/ListenerContainerParser.java

@@ -101,8 +101,8 @@ public BeanDefinition parse(Element element, ParserContext parserContext) {
 		}
 
 		List<Element> childElements = DomUtils.getChildElementsByTagName(element, LISTENER_ELEMENT);
-		for (int i = 0; i < childElements.size(); i++) {
-			parseListener(childElements.get(i), element, parserContext, containerList);
+		for (Element childElement : childElements) {
+			parseListener(childElement, element, parserContext, containerList);
 		}
 
 		parserContext.popAndRegisterContainingComponent();
@@ -190,8 +190,8 @@ private void parseListener(Element listenerEle, Element containerEle, ParserCont
 			else {
 				String[] names = StringUtils.commaDelimitedListToStringArray(queues);
 				List<RuntimeBeanReference> values = new ManagedList<>();
-				for (int i = 0; i < names.length; i++) {
-					values.add(new RuntimeBeanReference(names[i].trim()));
+				for (String name : names) {
+					values.add(new RuntimeBeanReference(name.trim()));
 				}
 				containerDef.getPropertyValues().add("queues", values);
 			}

spring-rabbit/src/main/java/org/springframework/amqp/rabbit/config/StatefulRetryOperationsInterceptorFactoryBean.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.
@@ -47,6 +47,7 @@
  *
  * @author Dave Syer
  * @author Gary Russell
+ * @author Ngoc Nhan
  *
  * @see RetryOperations#execute(org.springframework.retry.RetryCallback, org.springframework.retry.RecoveryCallback,
  * org.springframework.retry.RetryState)
@@ -90,9 +91,8 @@ private NewMethodArgumentsIdentifier createNewItemIdentifier() {
 			if (StatefulRetryOperationsInterceptorFactoryBean.this.newMessageIdentifier == null) {
 				return !message.getMessageProperties().isRedelivered();
 			}
-			else {
-				return StatefulRetryOperationsInterceptorFactoryBean.this.newMessageIdentifier.isNew(message);
-			}
+
+			return StatefulRetryOperationsInterceptorFactoryBean.this.newMessageIdentifier.isNew(message);
 		};
 	}
 
@@ -127,23 +127,19 @@ private MethodArgumentsKeyGenerator createKeyGenerator() {
 				}
 				return messageId;
 			}
-			else {
-				return StatefulRetryOperationsInterceptorFactoryBean.this.messageKeyGenerator.getKey(message);
-			}
+			return StatefulRetryOperationsInterceptorFactoryBean.this.messageKeyGenerator.getKey(message);
 		};
 	}
 
-	@SuppressWarnings("unchecked")
 	private Message argToMessage(Object[] args) {
 		Object arg = args[1];
-		Message message = null;
 		if (arg instanceof Message msg) {
-			message = msg;
+			return msg;
 		}
-		else if (arg instanceof List) {
-			message = ((List<Message>) arg).get(0);
+		if (arg instanceof List<?> list) {
+			return (Message) list.get(0);
 		}
-		return message;
+		return null;
 	}
 
 	@Override

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

@@ -69,7 +69,7 @@ public void setTargetConnectionFactories(Map<Object, ConnectionFactory> targetCo
 		Assert.noNullElements(targetConnectionFactories.values().toArray(),
 				"'targetConnectionFactories' cannot have null values.");
 		this.targetConnectionFactories.putAll(targetConnectionFactories);
-		targetConnectionFactories.values().stream().forEach(cf -> checkConfirmsAndReturns(cf));
+		targetConnectionFactories.values().forEach(this::checkConfirmsAndReturns);
 	}
 
 	/**
@@ -293,7 +293,7 @@ public void destroy() {
 
 	@Override
 	public void resetConnection() {
-		this.targetConnectionFactories.values().forEach(factory -> factory.resetConnection());
+		this.targetConnectionFactories.values().forEach(ConnectionFactory::resetConnection);
 		this.defaultTargetConnectionFactory.resetConnection();
 	}
 

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

@@ -84,11 +84,9 @@ public static void unRegisterConsumerChannel() {
 	@Nullable
 	public static Channel getConsumerChannel() {
 		ChannelHolder channelHolder = consumerChannel.get();
-		Channel channel = null;
-		if (channelHolder != null) {
-			channel = channelHolder.getChannel();
-		}
-		return channel;
+		return channelHolder != null
+				? channelHolder.getChannel()
+				: null;
 	}
 
 	/**

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 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.
@@ -27,6 +27,7 @@
  * expired. It also holds {@link CorrelationData} for
  * the client to correlate a confirm with a sent message.
  * @author Gary Russell
+ * @author Ngoc Nhan
  * @since 1.0.1
  *
  */
@@ -115,7 +116,7 @@ public void setReturned(boolean isReturned) {
 	 * @since 2.2.10
 	 */
 	public boolean waitForReturnIfNeeded() throws InterruptedException {
-		return this.returned ? this.latch.await(RETURN_CALLBACK_TIMEOUT, TimeUnit.SECONDS) : true;
+		return !this.returned || this.latch.await(RETURN_CALLBACK_TIMEOUT, TimeUnit.SECONDS);
 	}
 
 	/**

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

@@ -55,6 +55,7 @@
  * @author Gary Russell
  * @author Leonardo Ferreira
  * @author Christian Tzolov
+ * @author Ngoc Nhan
  * @since 2.3
  *
  */
@@ -255,23 +256,21 @@ private Channel createProxy(Channel channel, boolean transacted) {
 			Advice advice =
 					(MethodInterceptor) invocation -> {
 						String method = invocation.getMethod().getName();
-						switch (method) {
-						case "close":
-							handleClose(channel, transacted, proxy);
-							return null;
-						case "getTargetChannel":
-							return channel;
-						case "isTransactional":
-							return transacted;
-						case "confirmSelect":
-							confirmSelected.set(true);
-							return channel.confirmSelect();
-						case "isConfirmSelected":
-							return confirmSelected.get();
-						case "isPublisherConfirms":
-							return false;
-						}
-						return null;
+						return switch (method) {
+							case "close" -> {
+								handleClose(channel, transacted, proxy);
+								yield null;
+							}
+							case "getTargetChannel" -> channel;
+							case "isTransactional" -> transacted;
+							case "confirmSelect" -> {
+								confirmSelected.set(true);
+								yield channel.confirmSelect();
+							}
+							case "isConfirmSelected" -> confirmSelected.get();
+							case "isPublisherConfirms" -> false;
+							default -> null;
+						};
 					};
 			NameMatchMethodPointcutAdvisor advisor = new NameMatchMethodPointcutAdvisor(advice);
 			advisor.addMethodName("close");

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

@@ -922,27 +922,26 @@ public Collection<PendingConfirm> expire(Listener listener, long cutoffTime) {
 		try {
 			SortedMap<Long, PendingConfirm> pendingConfirmsForListener = this.pendingConfirms.get(listener);
 			if (pendingConfirmsForListener == null) {
-				return Collections.<PendingConfirm>emptyList();
+				return Collections.emptyList();
 			}
-			else {
-				List<PendingConfirm> expired = new ArrayList<>();
-				Iterator<Entry<Long, PendingConfirm>> iterator = pendingConfirmsForListener.entrySet().iterator();
-				while (iterator.hasNext()) {
-					PendingConfirm pendingConfirm = iterator.next().getValue();
-					if (pendingConfirm.getTimestamp() < cutoffTime) {
-						expired.add(pendingConfirm);
-						iterator.remove();
-						CorrelationData correlationData = pendingConfirm.getCorrelationData();
-						if (correlationData != null && StringUtils.hasText(correlationData.getId())) {
-							this.pendingReturns.remove(correlationData.getId()); // NOSONAR never null
-						}
-					}
-					else {
-						break;
+
+			List<PendingConfirm> expired = new ArrayList<>();
+			Iterator<Entry<Long, PendingConfirm>> iterator = pendingConfirmsForListener.entrySet().iterator();
+			while (iterator.hasNext()) {
+				PendingConfirm pendingConfirm = iterator.next().getValue();
+				if (pendingConfirm.getTimestamp() < cutoffTime) {
+					expired.add(pendingConfirm);
+					iterator.remove();
+					CorrelationData correlationData = pendingConfirm.getCorrelationData();
+					if (correlationData != null && StringUtils.hasText(correlationData.getId())) {
+						this.pendingReturns.remove(correlationData.getId()); // NOSONAR never null
 					}
 				}
-				return expired;
+				else {
+					break;
+				}
 			}
+			return expired;
 		}
 		finally {
 			this.lock.unlock();