Consistent use of Collection.toArray with zero-sized array argument

Includes consistent use of ClassUtils.toClassArray (as non-null variant)

Issue: SPR-16523

spring-aop/src/main/java/org/springframework/aop/config/ConfigBeanDefinitionParser.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -253,8 +253,8 @@ class ConfigBeanDefinitionParser implements BeanDefinitionParser {
 			Element aspectElement, String aspectId, List<BeanDefinition> beanDefs,
 			List<BeanReference> beanRefs, ParserContext parserContext) {
 
-		BeanDefinition[] beanDefArray = beanDefs.toArray(new BeanDefinition[beanDefs.size()]);
-		BeanReference[] beanRefArray = beanRefs.toArray(new BeanReference[beanRefs.size()]);
+		BeanDefinition[] beanDefArray = beanDefs.toArray(new BeanDefinition[0]);
+		BeanReference[] beanRefArray = beanRefs.toArray(new BeanReference[0]);
 		Object source = parserContext.extractSource(aspectElement);
 		return new AspectComponentDefinition(aspectId, beanDefArray, beanRefArray, source);
 	}

spring-aop/src/main/java/org/springframework/aop/framework/AdvisedSupport.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -228,7 +228,7 @@ public class AdvisedSupport extends ProxyConfig implements Advised {
 
 	@Override
 	public Class<?>[] getProxiedInterfaces() {
-		return this.interfaces.toArray(new Class<?>[this.interfaces.size()]);
+		return ClassUtils.toClassArray(this.interfaces);
 	}
 
 	@Override
@@ -372,7 +372,7 @@ public class AdvisedSupport extends ProxyConfig implements Advised {
 	 * Bring the array up to date with the list.
 	 */
 	protected final void updateAdvisorArray() {
-		this.advisorArray = this.advisors.toArray(new Advisor[this.advisors.size()]);
+		this.advisorArray = this.advisors.toArray(new Advisor[0]);
 	}
 
 	/**

spring-aop/src/main/java/org/springframework/aop/framework/adapter/DefaultAdvisorAdapterRegistry.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -90,7 +90,7 @@ public class DefaultAdvisorAdapterRegistry implements AdvisorAdapterRegistry, Se
 		if (interceptors.isEmpty()) {
 			throw new UnknownAdviceTypeException(advisor.getAdvice());
 		}
-		return interceptors.toArray(new MethodInterceptor[interceptors.size()]);
+		return interceptors.toArray(new MethodInterceptor[0]);
 	}
 
 	@Override

spring-aop/src/main/java/org/springframework/aop/framework/autoproxy/AbstractAutoProxyCreator.java

@@ -554,7 +554,7 @@ public abstract class AbstractAutoProxyCreator extends ProxyProcessorSupport
 				advisors.add(this.advisorAdapterRegistry.wrap(next));
 			}
 		}
-		return advisors.toArray(new Advisor[advisors.size()]);
+		return advisors.toArray(new Advisor[0]);
 	}
 
 	/**

spring-aop/src/main/java/org/springframework/aop/support/DefaultIntroductionAdvisor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -105,7 +105,7 @@ public class DefaultIntroductionAdvisor implements IntroductionAdvisor, ClassFil
 
 	@Override
 	public Class<?>[] getInterfaces() {
-		return this.interfaces.toArray(new Class<?>[this.interfaces.size()]);
+		return ClassUtils.toClassArray(this.interfaces);
 	}
 
 	@Override

spring-aop/src/main/java/org/springframework/aop/support/IntroductionInfoSupport.java

@@ -61,7 +61,7 @@ public class IntroductionInfoSupport implements IntroductionInfo, Serializable {
 
 	@Override
 	public Class<?>[] getInterfaces() {
-		return this.publishedInterfaces.toArray(new Class<?>[this.publishedInterfaces.size()]);
+		return ClassUtils.toClassArray(this.publishedInterfaces);
 	}
 
 	/**

spring-beans/src/main/java/org/springframework/beans/AbstractPropertyAccessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -118,8 +118,7 @@ public abstract class AbstractPropertyAccessor extends TypeConverterSupport impl
 
 		// If we encountered individual exceptions, throw the composite exception.
 		if (propertyAccessExceptions != null) {
-			PropertyAccessException[] paeArray =
-					propertyAccessExceptions.toArray(new PropertyAccessException[propertyAccessExceptions.size()]);
+			PropertyAccessException[] paeArray = propertyAccessExceptions.toArray(new PropertyAccessException[0]);
 			throw new PropertyBatchUpdateException(paeArray);
 		}
 	}

spring-beans/src/main/java/org/springframework/beans/ExtendedBeanInfo.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -220,7 +220,7 @@ class ExtendedBeanInfo implements BeanInfo {
 	 */
 	@Override
 	public PropertyDescriptor[] getPropertyDescriptors() {
-		return this.propertyDescriptors.toArray(new PropertyDescriptor[this.propertyDescriptors.size()]);
+		return this.propertyDescriptors.toArray(new PropertyDescriptor[0]);
 	}
 
 	@Override

spring-beans/src/main/java/org/springframework/beans/MutablePropertyValues.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -246,7 +246,7 @@ public class MutablePropertyValues implements PropertyValues, Serializable {
 
 	@Override
 	public PropertyValue[] getPropertyValues() {
-		return this.propertyValueList.toArray(new PropertyValue[this.propertyValueList.size()]);
+		return this.propertyValueList.toArray(new PropertyValue[0]);
 	}
 
 	@Override

spring-beans/src/main/java/org/springframework/beans/factory/BeanCreationException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -149,7 +149,7 @@ public class BeanCreationException extends FatalBeanException {
 		if (this.relatedCauses == null) {
 			return null;
 		}
-		return this.relatedCauses.toArray(new Throwable[this.relatedCauses.size()]);
+		return this.relatedCauses.toArray(new Throwable[0]);
 	}
 
 

spring-beans/src/main/java/org/springframework/beans/factory/annotation/AutowiredAnnotationBeanPostProcessor.java

@@ -342,7 +342,7 @@ public class AutowiredAnnotationBeanPostProcessor extends InstantiationAwareBean
 										"default constructor to fall back to: " + candidates.get(0));
 							}
 						}
-						candidateConstructors = candidates.toArray(new Constructor<?>[candidates.size()]);
+						candidateConstructors = candidates.toArray(new Constructor<?>[0]);
 					}
 					else if (rawCandidates.length == 1 && rawCandidates[0].getParameterCount() > 0) {
 						candidateConstructors = new Constructor<?>[] {rawCandidates[0]};

spring-beans/src/main/java/org/springframework/beans/factory/parsing/BeanComponentDefinition.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -83,8 +83,8 @@ public class BeanComponentDefinition extends BeanDefinitionHolder implements Com
 				references.add((BeanReference) value);
 			}
 		}
-		this.innerBeanDefinitions = innerBeans.toArray(new BeanDefinition[innerBeans.size()]);
-		this.beanReferences = references.toArray(new BeanReference[references.size()]);
+		this.innerBeanDefinitions = innerBeans.toArray(new BeanDefinition[0]);
+		this.beanReferences = references.toArray(new BeanReference[0]);
 	}
 
 

spring-beans/src/main/java/org/springframework/beans/factory/parsing/CompositeComponentDefinition.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -79,7 +79,7 @@ public class CompositeComponentDefinition extends AbstractComponentDefinition {
 	 * @return the array of nested components, or an empty array if none
 	 */
 	public ComponentDefinition[] getNestedComponents() {
-		return this.nestedComponents.toArray(new ComponentDefinition[this.nestedComponents.size()]);
+		return this.nestedComponents.toArray(new ComponentDefinition[0]);
 	}
 
 }

spring-beans/src/main/java/org/springframework/beans/factory/support/AbstractAutowireCapableBeanFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -29,7 +29,6 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.LinkedHashSet;
 import java.util.LinkedList;
 import java.util.List;
@@ -1496,15 +1495,9 @@ public abstract class AbstractAutowireCapableBeanFactory extends AbstractBeanFac
 	 * @see #isExcludedFromDependencyCheck
 	 */
 	protected PropertyDescriptor[] filterPropertyDescriptorsForDependencyCheck(BeanWrapper bw) {
-		List<PropertyDescriptor> pds =
-				new LinkedList<>(Arrays.asList(bw.getPropertyDescriptors()));
-		for (Iterator<PropertyDescriptor> it = pds.iterator(); it.hasNext();) {
-			PropertyDescriptor pd = it.next();
-			if (isExcludedFromDependencyCheck(pd)) {
-				it.remove();
-			}
-		}
-		return pds.toArray(new PropertyDescriptor[pds.size()]);
+		List<PropertyDescriptor> pds = new LinkedList<>(Arrays.asList(bw.getPropertyDescriptors()));
+		pds.removeIf(this::isExcludedFromDependencyCheck);
+		return pds.toArray(new PropertyDescriptor[0]);
 	}
 
 	/**

spring-beans/src/main/java/org/springframework/beans/factory/support/ConstructorResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -419,7 +419,7 @@ class ConstructorResolver {
 					candidateSet.add(candidate);
 				}
 			}
-			Method[] candidates = candidateSet.toArray(new Method[candidateSet.size()]);
+			Method[] candidates = candidateSet.toArray(new Method[0]);
 			AutowireUtils.sortFactoryMethods(candidates);
 
 			ConstructorArgumentValues resolvedValues = null;

spring-beans/src/main/java/org/springframework/beans/factory/support/DefaultListableBeanFactory.java

@@ -1780,7 +1780,7 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 			if (targetType != null && targetType != obj.getClass()) {
 				sources.add(targetType);
 			}
-			return sources.toArray(new Object[sources.size()]);
+			return sources.toArray();
 		}
 
 		@Nullable

spring-beans/src/main/java/org/springframework/beans/factory/xml/DefaultBeanDefinitionDocumentReader.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -266,7 +266,7 @@ public class DefaultBeanDefinitionDocumentReader implements BeanDefinitionDocume
 						ele, ex);
 			}
 		}
-		Resource[] actResArray = actualResources.toArray(new Resource[actualResources.size()]);
+		Resource[] actResArray = actualResources.toArray(new Resource[0]);
 		getReaderContext().fireImportProcessed(location, actResArray, extractSource(ele));
 	}
 

spring-context-support/src/main/java/org/springframework/cache/jcache/interceptor/AbstractJCacheKeyOperation.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -82,7 +82,7 @@ abstract class AbstractJCacheKeyOperation<A extends Annotation> extends Abstract
 			}
 			result.add(keyParameterDetail.toCacheInvocationParameter(values[parameterPosition]));
 		}
-		return result.toArray(new CacheInvocationParameter[result.size()]);
+		return result.toArray(new CacheInvocationParameter[0]);
 	}
 
 

spring-context-support/src/main/java/org/springframework/cache/jcache/interceptor/AbstractJCacheOperation.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -110,7 +110,7 @@ abstract class AbstractJCacheOperation<A extends Annotation> implements JCacheOp
 		for (int i = 0; i < this.allParameterDetails.size(); i++) {
 			result.add(this.allParameterDetails.get(i).toCacheInvocationParameter(values[i]));
 		}
-		return result.toArray(new CacheInvocationParameter[result.size()]);
+		return result.toArray(new CacheInvocationParameter[0]);
 	}
 
 	protected ExceptionTypeFilter createExceptionTypeFilter(

spring-context-support/src/main/java/org/springframework/cache/jcache/interceptor/KeyGeneratorAdapter.java

@@ -104,15 +104,14 @@ class KeyGeneratorAdapter implements KeyGenerator {
 				parameters.add(value);
 			}
 		}
-		return keyGenerator.generate(context.getTarget(), context.getMethod(),
-				parameters.toArray(new Object[parameters.size()]));
-
+		return keyGenerator.generate(context.getTarget(), context.getMethod(), parameters.toArray());
 	}
 
 
 	@SuppressWarnings("unchecked")
-	private CacheKeyInvocationContext<?> createCacheKeyInvocationContext(Object target,
-			JCacheOperation<?> operation, Object[] params) {
+	private CacheKeyInvocationContext<?> createCacheKeyInvocationContext(
+			Object target, JCacheOperation<?> operation, Object[] params) {
+
 		AbstractJCacheKeyOperation<Annotation> keyCacheOperation = (AbstractJCacheKeyOperation<Annotation>) operation;
 		return new DefaultCacheKeyInvocationContext<>(keyCacheOperation, target, params);
 	}

spring-context-support/src/main/java/org/springframework/mail/MailSendException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -71,7 +71,7 @@ public class MailSendException extends MailException {
 	public MailSendException(@Nullable String msg, @Nullable Throwable cause, Map<Object, Exception> failedMessages) {
 		super(msg, cause);
 		this.failedMessages = new LinkedHashMap<>(failedMessages);
-		this.messageExceptions = failedMessages.values().toArray(new Exception[failedMessages.size()]);
+		this.messageExceptions = failedMessages.values().toArray(new Exception[0]);
 	}
 
 	/**

spring-context-support/src/main/java/org/springframework/mail/javamail/JavaMailSenderImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -318,7 +318,7 @@ public class JavaMailSenderImpl implements JavaMailSender {
 			simpleMessage.copyTo(message);
 			mimeMessages.add(message.getMimeMessage());
 		}
-		doSend(mimeMessages.toArray(new MimeMessage[mimeMessages.size()]), simpleMessages);
+		doSend(mimeMessages.toArray(new MimeMessage[0]), simpleMessages);
 	}
 
 
@@ -373,7 +373,7 @@ public class JavaMailSenderImpl implements JavaMailSender {
 				preparator.prepare(mimeMessage);
 				mimeMessages.add(mimeMessage);
 			}
-			send(mimeMessages.toArray(new MimeMessage[mimeMessages.size()]));
+			send(mimeMessages.toArray(new MimeMessage[0]));
 		}
 		catch (MailException ex) {
 			throw ex;

spring-context-support/src/main/java/org/springframework/ui/freemarker/FreeMarkerConfigurationFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -390,15 +390,14 @@ public class FreeMarkerConfigurationFactory {
 	 */
 	@Nullable
 	protected TemplateLoader getAggregateTemplateLoader(List<TemplateLoader> templateLoaders) {
-		int loaderCount = templateLoaders.size();
-		switch (loaderCount) {
+		switch (templateLoaders.size()) {
 			case 0:
 				logger.info("No FreeMarker TemplateLoaders specified");
 				return null;
 			case 1:
 				return templateLoaders.get(0);
 			default:
-				TemplateLoader[] loaders = templateLoaders.toArray(new TemplateLoader[loaderCount]);
+				TemplateLoader[] loaders = templateLoaders.toArray(new TemplateLoader[0]);
 				return new MultiTemplateLoader(loaders);
 		}
 	}

spring-context/src/main/java/org/springframework/context/support/AbstractMessageSource.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -337,7 +337,7 @@ public abstract class AbstractMessageSource extends MessageSourceSupport impleme
 				resolvedArgs.add(arg);
 			}
 		}
-		return resolvedArgs.toArray(new Object[resolvedArgs.size()]);
+		return resolvedArgs.toArray();
 	}
 
 	/**

spring-context/src/main/java/org/springframework/jmx/export/MBeanExporter.java

@@ -383,8 +383,7 @@ public class MBeanExporter extends MBeanRegistrationSupport implements MBeanExpo
 			notificationListeners.add(bean);
 		});
 
-		this.notificationListeners =
-				notificationListeners.toArray(new NotificationListenerBean[notificationListeners.size()]);
+		this.notificationListeners = notificationListeners.toArray(new NotificationListenerBean[0]);
 	}
 
 	@Override

spring-context/src/main/java/org/springframework/jmx/export/assembler/AbstractConfigurableMBeanInfoAssembler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -87,7 +87,7 @@ public abstract class AbstractConfigurableMBeanInfoAssembler extends AbstractRef
 				ManagedNotification mn = (ManagedNotification) colValue;
 				result.add(JmxMetadataUtils.convertToModelMBeanNotificationInfo(mn));
 			}
-			return result.toArray(new ModelMBeanNotificationInfo[result.size()]);
+			return result.toArray(new ModelMBeanNotificationInfo[0]);
 		}
 		else {
 			throw new IllegalArgumentException(

spring-context/src/main/java/org/springframework/jmx/export/assembler/AbstractReflectiveMBeanInfoAssembler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -333,7 +333,7 @@ public abstract class AbstractReflectiveMBeanInfoAssembler extends AbstractMBean
 			}
 		}
 
-		return infos.toArray(new ModelMBeanAttributeInfo[infos.size()]);
+		return infos.toArray(new ModelMBeanAttributeInfo[0]);
 	}
 
 	/**
@@ -401,7 +401,7 @@ public abstract class AbstractReflectiveMBeanInfoAssembler extends AbstractMBean
 			}
 		}
 
-		return infos.toArray(new ModelMBeanOperationInfo[infos.size()]);
+		return infos.toArray(new ModelMBeanOperationInfo[0]);
 	}
 
 	/**

spring-context/src/main/java/org/springframework/jmx/support/MBeanRegistrationSupport.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -228,7 +228,7 @@ public class MBeanRegistrationSupport {
 	 */
 	protected final ObjectName[] getRegisteredObjectNames() {
 		synchronized (this.registeredBeans) {
-			return this.registeredBeans.toArray(new ObjectName[this.registeredBeans.size()]);
+			return this.registeredBeans.toArray(new ObjectName[0]);
 		}
 	}
 

spring-context/src/main/java/org/springframework/validation/beanvalidation/SpringValidatorAdapter.java

@@ -17,9 +17,9 @@
 package org.springframework.validation.beanvalidation;
 
 import java.io.Serializable;
+import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.LinkedHashSet;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -37,6 +37,7 @@ import org.springframework.context.MessageSourceResolvable;
 import org.springframework.context.support.DefaultMessageSourceResolvable;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 import org.springframework.validation.BindingResult;
 import org.springframework.validation.Errors;
 import org.springframework.validation.FieldError;
@@ -116,7 +117,7 @@ public class SpringValidatorAdapter implements SmartValidator, javax.validation.
 				}
 			}
 			processConstraintViolations(
-					this.targetValidator.validate(target, groups.toArray(new Class<?>[groups.size()])), errors);
+					this.targetValidator.validate(target, ClassUtils.toClassArray(groups)), errors);
 		}
 	}
 
@@ -241,7 +242,7 @@ public class SpringValidatorAdapter implements SmartValidator, javax.validation.
 	 * @see org.springframework.validation.DefaultBindingErrorProcessor#getArgumentsForBindError
 	 */
 	protected Object[] getArgumentsForConstraint(String objectName, String field, ConstraintDescriptor<?> descriptor) {
-		List<Object> arguments = new LinkedList<>();
+		List<Object> arguments = new ArrayList<>();
 		arguments.add(getResolvableField(objectName, field));
 		// Using a TreeMap for alphabetical ordering of attribute names
 		Map<String, Object> attributesToExpose = new TreeMap<>();
@@ -254,7 +255,7 @@ public class SpringValidatorAdapter implements SmartValidator, javax.validation.
 			}
 		});
 		arguments.addAll(attributesToExpose.values());
-		return arguments.toArray(new Object[arguments.size()]);
+		return arguments.toArray();
 	}
 
 	/**

spring-core/src/main/java/org/springframework/core/convert/Property.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -211,7 +211,7 @@ public final class Property {
 			addAnnotationsToMap(annotationMap, getReadMethod());
 			addAnnotationsToMap(annotationMap, getWriteMethod());
 			addAnnotationsToMap(annotationMap, getField());
-			annotations = annotationMap.values().toArray(new Annotation[annotationMap.size()]);
+			annotations = annotationMap.values().toArray(new Annotation[0]);
 			annotationCache.put(this, annotations);
 		}
 		return annotations;

spring-core/src/main/java/org/springframework/core/io/support/PathMatchingResourcePatternResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -320,7 +320,7 @@ public class PathMatchingResourcePatternResolver implements ResourcePatternResol
 		if (logger.isDebugEnabled()) {
 			logger.debug("Resolved classpath location [" + location + "] to resources " + result);
 		}
-		return result.toArray(new Resource[result.size()]);
+		return result.toArray(new Resource[0]);
 	}
 
 	/**
@@ -515,7 +515,7 @@ public class PathMatchingResourcePatternResolver implements ResourcePatternResol
 		if (logger.isDebugEnabled()) {
 			logger.debug("Resolved location pattern [" + locationPattern + "] to resources " + result);
 		}
-		return result.toArray(new Resource[result.size()]);
+		return result.toArray(new Resource[0]);
 	}
 
 	/**

spring-core/src/main/java/org/springframework/core/io/support/ResourceArrayPropertyEditor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -162,7 +162,7 @@ public class ResourceArrayPropertyEditor extends PropertyEditorSupport {
 							Resource.class.getName() + "]: only location String and Resource object supported");
 				}
 			}
-			super.setValue(merged.toArray(new Resource[merged.size()]));
+			super.setValue(merged.toArray(new Resource[0]));
 		}
 
 		else {

spring-core/src/main/java/org/springframework/core/type/classreading/RecursiveAnnotationArrayVisitor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -78,8 +78,7 @@ class RecursiveAnnotationArrayVisitor extends AbstractRecursiveAnnotationVisitor
 	@Override
 	public void visitEnd() {
 		if (!this.allNestedAttributes.isEmpty()) {
-			this.attributes.put(this.attributeName,
-					this.allNestedAttributes.toArray(new AnnotationAttributes[this.allNestedAttributes.size()]));
+			this.attributes.put(this.attributeName, this.allNestedAttributes.toArray(new AnnotationAttributes[0]));
 		}
 	}
 

spring-core/src/main/java/org/springframework/util/ClassUtils.java

@@ -1058,18 +1058,15 @@ public abstract class ClassUtils {
 	}
 
 	/**
-	 * Copy the given Collection into a Class array.
-	 * The Collection must contain Class elements only.
-	 * @param collection the Collection to copy
-	 * @return the Class array ({@code null} if the passed-in
-	 * Collection was {@code null})
-	 */
-	@Nullable
-	public static Class<?>[] toClassArray(@Nullable Collection<Class<?>> collection) {
-		if (collection == null) {
-			return null;
-		}
-		return collection.toArray(new Class<?>[collection.size()]);
+	 * Copy the given {@code Collection} into a {@code Class} array.
+	 * <p>The {@code Collection} must contain {@code Class} elements only.
+	 * @param collection the {@code Collection} to copy
+	 * @return the {@code Class} array
+	 * @since 3.1
+	 * @see StringUtils#toStringArray
+	 */
+	public static Class<?>[] toClassArray(Collection<Class<?>> collection) {
+		return collection.toArray(new Class<?>[0]);
 	}
 
 	/**
@@ -1104,8 +1101,7 @@ public abstract class ClassUtils {
 	 * @return all interfaces that the given object implements as an array
 	 */
 	public static Class<?>[] getAllInterfacesForClass(Class<?> clazz, @Nullable ClassLoader classLoader) {
-		Set<Class<?>> ifcs = getAllInterfacesForClassAsSet(clazz, classLoader);
-		return ifcs.toArray(new Class<?>[ifcs.size()]);
+		return toClassArray(getAllInterfacesForClassAsSet(clazz, classLoader));
 	}
 
 	/**

spring-core/src/main/java/org/springframework/util/ReflectionUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -584,7 +584,7 @@ public abstract class ReflectionUtils {
 	public static Method[] getAllDeclaredMethods(Class<?> leafClass) {
 		final List<Method> methods = new ArrayList<>(32);
 		doWithMethods(leafClass, methods::add);
-		return methods.toArray(new Method[methods.size()]);
+		return methods.toArray(new Method[0]);
 	}
 
 	/**
@@ -620,7 +620,7 @@ public abstract class ReflectionUtils {
 				methods.add(method);
 			}
 		});
-		return methods.toArray(new Method[methods.size()]);
+		return methods.toArray(new Method[0]);
 	}
 
 	/**

spring-core/src/main/java/org/springframework/util/StopWatch.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -229,7 +229,7 @@ public class StopWatch {
 		if (!this.keepTaskList) {
 			throw new UnsupportedOperationException("Task info is not being kept!");
 		}
-		return this.taskList.toArray(new TaskInfo[this.taskList.size()]);
+		return this.taskList.toArray(new TaskInfo[0]);
 	}
 
 

spring-core/src/main/java/org/springframework/util/StringUtils.java

@@ -945,7 +945,7 @@ public abstract class StringUtils {
 	 * @return the {@code String} array
 	 */
 	public static String[] toStringArray(Collection<String> collection) {
-		return collection.toArray(new String[collection.size()]);
+		return collection.toArray(new String[0]);
 	}
 
 	/**
@@ -955,8 +955,7 @@ public abstract class StringUtils {
 	 * @return the {@code String} array
 	 */
 	public static String[] toStringArray(Enumeration<String> enumeration) {
-		List<String> list = Collections.list(enumeration);
-		return list.toArray(new String[list.size()]);
+		return toStringArray(Collections.list(enumeration));
 	}
 
 	/**

spring-expression/src/main/java/org/springframework/expression/common/TemplateAwareExpressionParser.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -17,9 +17,9 @@
 package org.springframework.expression.common;
 
 import java.util.ArrayDeque;
+import java.util.Deque;
 import java.util.LinkedList;
 import java.util.List;
-import java.util.Deque;
 
 import org.springframework.expression.Expression;
 import org.springframework.expression.ExpressionParser;
@@ -128,7 +128,7 @@ public abstract class TemplateAwareExpressionParser implements ExpressionParser
 			}
 		}
 
-		return expressions.toArray(new Expression[expressions.size()]);
+		return expressions.toArray(new Expression[0]);
 	}
 
 	/**

spring-expression/src/main/java/org/springframework/expression/spel/standard/InternalSpelExpressionParser.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -365,7 +365,7 @@ class InternalSpelExpressionParser extends TemplateAwareExpressionParser {
 		}
 		return new CompoundExpression(toPos(start.getStartPosition(),
 				nodes.get(nodes.size() - 1).getEndPosition()),
-				nodes.toArray(new SpelNodeImpl[nodes.size()]));
+				nodes.toArray(new SpelNodeImpl[0]));
 	}
 
 	// node : ((DOT dottedNode) | (SAFE_NAVI dottedNode) | nonDottedNode)+;
@@ -443,7 +443,7 @@ class InternalSpelExpressionParser extends TemplateAwareExpressionParser {
 		List<SpelNodeImpl> args = new ArrayList<>();
 		consumeArguments(args);
 		eatToken(TokenKind.RPAREN);
-		return args.toArray(new SpelNodeImpl[args.size()]);
+		return args.toArray(new SpelNodeImpl[0]);
 	}
 
 	private void eatConstructorArgs(List<SpelNodeImpl> accumulatedArguments) {
@@ -646,36 +646,33 @@ class InternalSpelExpressionParser extends TemplateAwareExpressionParser {
 			// ',' - more expressions in this list
 			// ':' - this is a map!
 			if (peekToken(TokenKind.RCURLY)) {  // list with one item in it
-				List<SpelNodeImpl> listElements = new ArrayList<>();
-				listElements.add(firstExpression);
+				List<SpelNodeImpl> elements = new ArrayList<>();
+				elements.add(firstExpression);
 				closingCurly = eatToken(TokenKind.RCURLY);
-				expr = new InlineList(toPos(t.startPos, closingCurly.endPos),
-						listElements.toArray(new SpelNodeImpl[listElements.size()]));
+				expr = new InlineList(toPos(t.startPos, closingCurly.endPos), elements.toArray(new SpelNodeImpl[0]));
 			}
 			else if (peekToken(TokenKind.COMMA, true)) {  // multi-item list
-				List<SpelNodeImpl> listElements = new ArrayList<>();
-				listElements.add(firstExpression);
+				List<SpelNodeImpl> elements = new ArrayList<>();
+				elements.add(firstExpression);
 				do {
-					listElements.add(eatExpression());
+					elements.add(eatExpression());
 				}
 				while (peekToken(TokenKind.COMMA, true));
 				closingCurly = eatToken(TokenKind.RCURLY);
-				expr = new InlineList(toPos(t.startPos, closingCurly.endPos),
-						listElements.toArray(new SpelNodeImpl[listElements.size()]));
+				expr = new InlineList(toPos(t.startPos, closingCurly.endPos), elements.toArray(new SpelNodeImpl[0]));
 
 			}
 			else if (peekToken(TokenKind.COLON, true)) {  // map!
-				List<SpelNodeImpl> mapElements = new ArrayList<>();
-				mapElements.add(firstExpression);
-				mapElements.add(eatExpression());
+				List<SpelNodeImpl> elements = new ArrayList<>();
+				elements.add(firstExpression);
+				elements.add(eatExpression());
 				while (peekToken(TokenKind.COMMA, true)) {
-					mapElements.add(eatExpression());
+					elements.add(eatExpression());
 					eatToken(TokenKind.COLON);
-					mapElements.add(eatExpression());
+					elements.add(eatExpression());
 				}
 				closingCurly = eatToken(TokenKind.RCURLY);
-				expr = new InlineMap(toPos(t.startPos, closingCurly.endPos),
-						mapElements.toArray(new SpelNodeImpl[mapElements.size()]));
+				expr = new InlineMap(toPos(t.startPos, closingCurly.endPos), elements.toArray(new SpelNodeImpl[0]));
 			}
 			else {
 				throw internalException(t.startPos, SpelMessage.OOD);
@@ -743,10 +740,8 @@ class InternalSpelExpressionParser extends TemplateAwareExpressionParser {
 			throw internalException(node.startPos, SpelMessage.NOT_EXPECTED_TOKEN,
 					"qualified ID", node.getKind().toString().toLowerCase());
 		}
-		int pos = toPos(qualifiedIdPieces.getFirst().getStartPosition(),
-				qualifiedIdPieces.getLast().getEndPosition());
-		return new QualifiedIdentifier(pos,
-				qualifiedIdPieces.toArray(new SpelNodeImpl[qualifiedIdPieces.size()]));
+		int pos = toPos(qualifiedIdPieces.getFirst().getStartPosition(), qualifiedIdPieces.getLast().getEndPosition());
+		return new QualifiedIdentifier(pos, qualifiedIdPieces.toArray(new SpelNodeImpl[0]));
 	}
 
 	private boolean isValidQualifiedId(@Nullable Token node) {
@@ -812,15 +807,13 @@ class InternalSpelExpressionParser extends TemplateAwareExpressionParser {
 					nodes.add(pop());
 				}
 				push(new ConstructorReference(toPos(newToken),
-						dimensions.toArray(new SpelNodeImpl[dimensions.size()]),
-						nodes.toArray(new SpelNodeImpl[nodes.size()])));
+						dimensions.toArray(new SpelNodeImpl[0]), nodes.toArray(new SpelNodeImpl[0])));
 			}
 			else {
 				// regular constructor invocation
 				eatConstructorArgs(nodes);
 				// TODO correct end position?
-				push(new ConstructorReference(toPos(newToken),
-						nodes.toArray(new SpelNodeImpl[nodes.size()])));
+				push(new ConstructorReference(toPos(newToken), nodes.toArray(new SpelNodeImpl[0])));
 			}
 			return true;
 		}

spring-jdbc/src/main/java/org/springframework/jdbc/config/SortedResourcesFactoryBean.java

@@ -84,7 +84,7 @@ public class SortedResourcesFactoryBean extends AbstractFactoryBean<Resource[]>
 			});
 			scripts.addAll(resources);
 		}
-		return scripts.toArray(new Resource[scripts.size()]);
+		return scripts.toArray(new Resource[0]);
 	}
 
 }

spring-jdbc/src/main/java/org/springframework/jdbc/core/simple/AbstractJdbcInsert.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -462,8 +462,8 @@ public abstract class AbstractJdbcInsert {
 			// clause while HSQL uses a second query that has to be executed with the same connection.
 
 			if (keyQuery.toUpperCase().startsWith("RETURNING")) {
-				Long key = getJdbcTemplate().queryForObject(getInsertString() + " " + keyQuery,
-						values.toArray(new Object[values.size()]), Long.class);
+				Long key = getJdbcTemplate().queryForObject(
+						getInsertString() + " " + keyQuery, values.toArray(), Long.class);
 				Map<String, Object> keys = new HashMap<>(1);
 				keys.put(getGeneratedKeyNames()[0], key);
 				keyHolder.getKeyList().add(keys);

spring-jms/src/main/java/org/springframework/jms/connection/CachingConnectionFactory.java

@@ -41,6 +41,7 @@ import javax.jms.TopicSession;
 
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 import org.springframework.util.ObjectUtils;
 
 /**
@@ -254,10 +255,8 @@ public class CachingConnectionFactory extends SingleConnectionFactory {
 		if (target instanceof TopicSession) {
 			classes.add(TopicSession.class);
 		}
-		return (Session) Proxy.newProxyInstance(
-				SessionProxy.class.getClassLoader(),
-				classes.toArray(new Class<?>[classes.size()]),
-				new CachedSessionInvocationHandler(target, sessionList));
+		return (Session) Proxy.newProxyInstance(SessionProxy.class.getClassLoader(),
+				ClassUtils.toClassArray(classes), new CachedSessionInvocationHandler(target, sessionList));
 	}
 
 

spring-jms/src/main/java/org/springframework/jms/connection/ChainedExceptionListener.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -48,7 +48,7 @@ public class ChainedExceptionListener implements ExceptionListener {
 	 * Return all registered ExceptionListener delegates (as array).
 	 */
 	public final ExceptionListener[] getDelegates() {
-		return this.delegates.toArray(new ExceptionListener[this.delegates.size()]);
+		return this.delegates.toArray(new ExceptionListener[0]);
 	}
 
 

spring-jms/src/main/java/org/springframework/jms/connection/SingleConnectionFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -42,6 +42,7 @@ import org.springframework.beans.factory.DisposableBean;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 
 /**
  * A JMS ConnectionFactory adapter that returns the same Connection
@@ -519,10 +520,8 @@ public class SingleConnectionFactory implements ConnectionFactory, QueueConnecti
 		if (target instanceof TopicConnection) {
 			classes.add(TopicConnection.class);
 		}
-		return (Connection) Proxy.newProxyInstance(
-				Connection.class.getClassLoader(),
-				classes.toArray(new Class<?>[classes.size()]),
-				new SharedConnectionInvocationHandler());
+		return (Connection) Proxy.newProxyInstance(Connection.class.getClassLoader(),
+				ClassUtils.toClassArray(classes), new SharedConnectionInvocationHandler());
 	}
 
 

spring-jms/src/main/java/org/springframework/jms/connection/TransactionAwareConnectionFactoryProxy.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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 +37,7 @@ import javax.jms.TransactionInProgressException;
 
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 
 /**
  * Proxy for a target JMS {@link javax.jms.ConnectionFactory}, adding awareness of
@@ -229,10 +230,8 @@ public class TransactionAwareConnectionFactoryProxy
 		if (target instanceof TopicConnection) {
 			classes.add(TopicConnection.class);
 		}
-		return (Connection) Proxy.newProxyInstance(
-				Connection.class.getClassLoader(),
-				classes.toArray(new Class<?>[classes.size()]),
-				new TransactionAwareConnectionInvocationHandler(target));
+		return (Connection) Proxy.newProxyInstance(Connection.class.getClassLoader(),
+				ClassUtils.toClassArray(classes), new TransactionAwareConnectionInvocationHandler(target));
 	}
 
 
@@ -301,10 +300,8 @@ public class TransactionAwareConnectionFactoryProxy
 			if (target instanceof TopicSession) {
 				classes.add(TopicSession.class);
 			}
-			return (Session) Proxy.newProxyInstance(
-					SessionProxy.class.getClassLoader(),
-					classes.toArray(new Class<?>[classes.size()]),
-					new CloseSuppressingSessionInvocationHandler(target));
+			return (Session) Proxy.newProxyInstance(SessionProxy.class.getClassLoader(),
+					ClassUtils.toClassArray(classes), new CloseSuppressingSessionInvocationHandler(target));
 		}
 	}
 

spring-orm/src/main/java/org/springframework/orm/jpa/AbstractEntityManagerFactoryBean.java

@@ -418,9 +418,8 @@ public abstract class AbstractEntityManagerFactoryBean implements
 		}
 		ifcs.add(EntityManagerFactoryInfo.class);
 		try {
-			return (EntityManagerFactory) Proxy.newProxyInstance(
-					this.beanClassLoader, ifcs.toArray(new Class<?>[ifcs.size()]),
-					new ManagedEntityManagerFactoryInvocationHandler(this));
+			return (EntityManagerFactory) Proxy.newProxyInstance(this.beanClassLoader,
+					ClassUtils.toClassArray(ifcs), new ManagedEntityManagerFactoryInvocationHandler(this));
 		}
 		catch (IllegalArgumentException ex) {
 			if (entityManagerFactoryInterface != null) {

spring-orm/src/main/java/org/springframework/orm/jpa/ExtendedEntityManagerCreator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -232,7 +232,7 @@ public abstract class ExtendedEntityManagerCreator {
 		ifcs.add(EntityManagerProxy.class);
 		return (EntityManager) Proxy.newProxyInstance(
 				(cl != null ? cl : ExtendedEntityManagerCreator.class.getClassLoader()),
-				ifcs.toArray(new Class<?>[ifcs.size()]),
+				ClassUtils.toClassArray(ifcs),
 				new ExtendedEntityManagerInvocationHandler(
 						rawEm, exceptionTranslator, jta, containerManaged, synchronizedWithTransaction));
 	}

spring-orm/src/main/java/org/springframework/orm/jpa/persistenceunit/PersistenceUnitReader.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -150,7 +150,7 @@ final class PersistenceUnitReader {
 			throw new IllegalArgumentException("Internal error parsing persistence unit from " + resourceLocation);
 		}
 
-		return infos.toArray(new SpringPersistenceUnitInfo[infos.size()]);
+		return infos.toArray(new SpringPersistenceUnitInfo[0]);
 	}
 
 

spring-oxm/src/main/java/org/springframework/oxm/jaxb/ClassPathJaxb2TypeScanner.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -94,7 +94,7 @@ class ClassPathJaxb2TypeScanner {
 					}
 				}
 			}
-			return jaxb2Classes.toArray(new Class<?>[jaxb2Classes.size()]);
+			return ClassUtils.toClassArray(jaxb2Classes);
 		}
 		catch (IOException ex) {
 			throw new UncategorizedMappingException("Failed to scan classpath for unlisted classes", ex);

spring-test/src/main/java/org/springframework/mock/web/MockHttpServletResponse.java

@@ -357,7 +357,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 	}
 
 	public Cookie[] getCookies() {
-		return this.cookies.toArray(new Cookie[this.cookies.size()]);
+		return this.cookies.toArray(new Cookie[0]);
 	}
 
 	@Nullable

spring-test/src/main/java/org/springframework/test/context/TestContextManager.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -149,7 +149,7 @@ public class TestContextManager {
 	 * @see #registerTestExecutionListeners(TestExecutionListener...)
 	 */
 	public void registerTestExecutionListeners(List<TestExecutionListener> testExecutionListeners) {
-		registerTestExecutionListeners(testExecutionListeners.toArray(new TestExecutionListener[testExecutionListeners.size()]));
+		registerTestExecutionListeners(testExecutionListeners.toArray(new TestExecutionListener[0]));
 	}
 
 	/**

spring-test/src/main/java/org/springframework/test/context/jdbc/SqlScriptsTestExecutionListener.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -185,7 +185,7 @@ public class SqlScriptsTestExecutionListener extends AbstractTestExecutionListen
 				scriptResources.add(new ByteArrayResource(stmt.getBytes(), "from inlined SQL statement: " + stmt));
 			}
 		}
-		populator.setScripts(scriptResources.toArray(new Resource[scriptResources.size()]));
+		populator.setScripts(scriptResources.toArray(new Resource[0]));
 		if (logger.isDebugEnabled()) {
 			logger.debug("Executing SQL scripts: " + ObjectUtils.nullSafeToString(scriptResources));
 		}

spring-test/src/main/java/org/springframework/test/context/support/AbstractTestContextBootstrapper.java

@@ -385,8 +385,7 @@ public abstract class AbstractTestContextBootstrapper implements TestContextBoot
 		MergedTestPropertySources mergedTestPropertySources =
 				TestPropertySourceUtils.buildMergedTestPropertySources(testClass);
 		MergedContextConfiguration mergedConfig = new MergedContextConfiguration(testClass,
-				StringUtils.toStringArray(locations),
-				ClassUtils.toClassArray(classes),
+				StringUtils.toStringArray(locations), ClassUtils.toClassArray(classes),
 				ApplicationContextInitializerUtils.resolveInitializerClasses(configAttributesList),
 				ActiveProfilesUtils.resolveActiveProfiles(testClass),
 				mergedTestPropertySources.getLocations(),

spring-test/src/main/java/org/springframework/test/context/support/AnnotationConfigContextLoaderUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -28,6 +28,7 @@ import org.springframework.core.annotation.AnnotatedElementUtils;
 import org.springframework.lang.Nullable;
 import org.springframework.test.context.SmartContextLoader;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 
 /**
  * Utility methods for {@link SmartContextLoader SmartContextLoaders} that deal
@@ -85,7 +86,7 @@ public abstract class AnnotationConfigContextLoaderUtils {
 			}
 		}
 
-		return configClasses.toArray(new Class<?>[configClasses.size()]);
+		return ClassUtils.toClassArray(configClasses);
 	}
 
 	/**

spring-test/src/main/java/org/springframework/test/context/support/DefaultTestContext.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -29,6 +29,7 @@ import org.springframework.test.context.CacheAwareContextLoaderDelegate;
 import org.springframework.test.context.MergedContextConfiguration;
 import org.springframework.test.context.TestContext;
 import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
 
 /**
  * Default implementation of the {@link TestContext} interface.
@@ -195,7 +196,7 @@ public class DefaultTestContext implements TestContext {
 	@Override
 	public String[] attributeNames() {
 		synchronized (this.attributes) {
-			return this.attributes.keySet().stream().toArray(String[]::new);
+			return StringUtils.toStringArray(this.attributes.keySet());
 		}
 	}
 

spring-test/src/main/java/org/springframework/test/web/servlet/htmlunit/HtmlUnitRequestBuilder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -295,7 +295,7 @@ final class HtmlUnitRequestBuilder implements RequestBuilder, Mergeable {
 		}
 
 		if (!ObjectUtils.isEmpty(cookies)) {
-			request.setCookies(cookies.toArray(new Cookie[cookies.size()]));
+			request.setCookies(cookies.toArray(new Cookie[0]));
 		}
 	}
 

spring-test/src/main/java/org/springframework/test/web/servlet/request/MockHttpServletRequestBuilder.java

@@ -652,7 +652,7 @@ public class MockHttpServletRequestBuilder
 		}
 
 		if (!ObjectUtils.isEmpty(this.cookies)) {
-			request.setCookies(this.cookies.toArray(new Cookie[this.cookies.size()]));
+			request.setCookies(this.cookies.toArray(new Cookie[0]));
 		}
 		if (!ObjectUtils.isEmpty(this.locales)) {
 			request.setPreferredLocales(this.locales);

spring-test/src/main/java/org/springframework/test/web/servlet/setup/AbstractMockMvcBuilder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -25,6 +25,7 @@ import org.springframework.lang.Nullable;
 import org.springframework.mock.web.MockServletConfig;
 import org.springframework.test.web.servlet.DispatcherServletCustomizer;
 import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.MockMvcBuilder;
 import org.springframework.test.web.servlet.MockMvcBuilderSupport;
 import org.springframework.test.web.servlet.RequestBuilder;
 import org.springframework.test.web.servlet.ResultHandler;
@@ -34,7 +35,6 @@ import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
 import org.springframework.test.web.servlet.request.RequestPostProcessor;
 import org.springframework.util.Assert;
 import org.springframework.web.context.WebApplicationContext;
-import org.springframework.test.web.servlet.MockMvcBuilder;
 
 /**
  * Abstract implementation of {@link MockMvcBuilder} with common methods for
@@ -144,7 +144,7 @@ public abstract class AbstractMockMvcBuilder<B extends AbstractMockMvcBuilder<B>
 			}
 		}
 
-		Filter[] filterArray = this.filters.toArray(new Filter[this.filters.size()]);
+		Filter[] filterArray = this.filters.toArray(new Filter[0]);
 
 		return super.createMockMvc(filterArray, mockServletConfig, wac, this.defaultRequestBuilder,
 				this.globalResultMatchers, this.globalResultHandlers, this.dispatcherServletCustomizers);

spring-tx/src/main/java/org/springframework/dao/support/ChainedPersistenceExceptionTranslator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -50,7 +50,7 @@ public class ChainedPersistenceExceptionTranslator implements PersistenceExcepti
 	 * Return all registered PersistenceExceptionTranslator delegates (as array).
 	 */
 	public final PersistenceExceptionTranslator[] getDelegates() {
-		return this.delegates.toArray(new PersistenceExceptionTranslator[this.delegates.size()]);
+		return this.delegates.toArray(new PersistenceExceptionTranslator[0]);
 	}
 
 

spring-web/src/main/java/org/springframework/http/server/reactive/DefaultSslInfo.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -103,7 +103,7 @@ final class DefaultSslInfo implements SslInfo {
 				result.add((X509Certificate) certificate);
 			}
 		}
-		return !result.isEmpty() ? result.toArray(new X509Certificate[result.size()]) : null;
+		return (!result.isEmpty() ? result.toArray(new X509Certificate[0]) : null);
 	}
 
 }

spring-web/src/main/java/org/springframework/web/context/support/AnnotationConfigWebApplicationContext.java

@@ -213,7 +213,7 @@ public class AnnotationConfigWebApplicationContext extends AbstractRefreshableWe
 				logger.info("Registering annotated classes: [" +
 						StringUtils.collectionToCommaDelimitedString(this.annotatedClasses) + "]");
 			}
-			reader.register(this.annotatedClasses.toArray(new Class<?>[this.annotatedClasses.size()]));
+			reader.register(ClassUtils.toClassArray(this.annotatedClasses));
 		}
 
 		if (!this.basePackages.isEmpty()) {

spring-web/src/main/java/org/springframework/web/multipart/support/MultipartResolutionDelegate.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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 +93,7 @@ public abstract class MultipartResolutionDelegate {
 			}
 			if (multipartRequest != null) {
 				List<MultipartFile> multipartFiles = multipartRequest.getFiles(name);
-				return multipartFiles.toArray(new MultipartFile[multipartFiles.size()]);
+				return multipartFiles.toArray(new MultipartFile[0]);
 			}
 			else {
 				return null;
@@ -164,7 +164,7 @@ public abstract class MultipartResolutionDelegate {
 				result.add(part);
 			}
 		}
-		return result.toArray(new Part[result.size()]);
+		return result.toArray(new Part[0]);
 	}
 
 }

spring-web/src/main/java/org/springframework/web/server/handler/FilteringWebHandler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -21,14 +21,13 @@ import java.util.List;
 
 import reactor.core.publisher.Mono;
 
-import org.springframework.util.CollectionUtils;
 import org.springframework.web.server.ServerWebExchange;
 import org.springframework.web.server.WebFilter;
 import org.springframework.web.server.WebHandler;
 
 /**
- * WebHandler decorator that invokes a chain of {@link WebFilter}s before the
- * delegate {@link WebHandler}.
+ * {@link WebHandler} decorator that invokes a chain of {@link WebFilter}s
+ * before the delegate {@link WebHandler}.
  *
  * @author Rossen Stoyanchev
  * @since 5.0
@@ -44,8 +43,7 @@ public class FilteringWebHandler extends WebHandlerDecorator {
 	 */
 	public FilteringWebHandler(WebHandler webHandler, List<WebFilter> filters) {
 		super(webHandler);
-		this.filters = !CollectionUtils.isEmpty(filters) ?
-				filters.toArray(new WebFilter[filters.size()]) : new WebFilter[0];
+		this.filters = filters.toArray(new WebFilter[0]);
 	}
 
 

spring-web/src/test/java/org/springframework/mock/web/test/MockHttpServletResponse.java

@@ -349,7 +349,7 @@ public class MockHttpServletResponse implements HttpServletResponse {
 	}
 
 	public Cookie[] getCookies() {
-		return this.cookies.toArray(new Cookie[this.cookies.size()]);
+		return this.cookies.toArray(new Cookie[0]);
 	}
 
 	public Cookie getCookie(String name) {

spring-webflux/src/main/java/org/springframework/web/reactive/resource/ResourceWebHandler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -223,7 +223,7 @@ public class ResourceWebHandler implements WebHandler, InitializingBean {
 			if (getResourceResolvers().get(i) instanceof PathResourceResolver) {
 				PathResourceResolver resolver = (PathResourceResolver) getResourceResolvers().get(i);
 				if (ObjectUtils.isEmpty(resolver.getAllowedLocations())) {
-					resolver.setAllowedLocations(getLocations().toArray(new Resource[getLocations().size()]));
+					resolver.setAllowedLocations(getLocations().toArray(new Resource[0]));
 				}
 				break;
 			}

spring-webmvc/src/main/java/org/springframework/web/servlet/HandlerExecutionChain.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -116,7 +116,7 @@ public class HandlerExecutionChain {
 	@Nullable
 	public HandlerInterceptor[] getInterceptors() {
 		if (this.interceptors == null && this.interceptorList != null) {
-			this.interceptors = this.interceptorList.toArray(new HandlerInterceptor[this.interceptorList.size()]);
+			this.interceptors = this.interceptorList.toArray(new HandlerInterceptor[0]);
 		}
 		return this.interceptors;
 	}

spring-webmvc/src/main/java/org/springframework/web/servlet/handler/AbstractHandlerMapping.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -317,8 +317,8 @@ public abstract class AbstractHandlerMapping extends WebApplicationObjectSupport
 	 */
 	@Nullable
 	protected final HandlerInterceptor[] getAdaptedInterceptors() {
-		int count = this.adaptedInterceptors.size();
-		return (count > 0 ? this.adaptedInterceptors.toArray(new HandlerInterceptor[count]) : null);
+		return (!this.adaptedInterceptors.isEmpty() ?
+				this.adaptedInterceptors.toArray(new HandlerInterceptor[0]) : null);
 	}
 
 	/**
@@ -327,14 +327,13 @@ public abstract class AbstractHandlerMapping extends WebApplicationObjectSupport
 	 */
 	@Nullable
 	protected final MappedInterceptor[] getMappedInterceptors() {
-		List<MappedInterceptor> mappedInterceptors = new ArrayList<>();
+		List<MappedInterceptor> mappedInterceptors = new ArrayList<>(this.adaptedInterceptors.size());
 		for (HandlerInterceptor interceptor : this.adaptedInterceptors) {
 			if (interceptor instanceof MappedInterceptor) {
 				mappedInterceptors.add((MappedInterceptor) interceptor);
 			}
 		}
-		int count = mappedInterceptors.size();
-		return (count > 0 ? mappedInterceptors.toArray(new MappedInterceptor[count]) : null);
+		return (!mappedInterceptors.isEmpty() ? mappedInterceptors.toArray(new MappedInterceptor[0]) : null);
 	}
 
 

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerAdapter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -47,7 +47,6 @@ import org.springframework.http.converter.support.AllEncompassingFormHttpMessage
 import org.springframework.http.converter.xml.SourceHttpMessageConverter;
 import org.springframework.lang.Nullable;
 import org.springframework.ui.ModelMap;
-import org.springframework.util.Assert;
 import org.springframework.util.CollectionUtils;
 import org.springframework.util.ReflectionUtils.MethodFilter;
 import org.springframework.web.accept.ContentNegotiationManager;
@@ -151,7 +150,7 @@ public class RequestMappingHandlerAdapter extends AbstractHandlerMethodAdapter
 
 	private DeferredResultProcessingInterceptor[] deferredResultInterceptors = new DeferredResultProcessingInterceptor[0];
 
-	private ReactiveAdapterRegistry reactiveRegistry = ReactiveAdapterRegistry.getSharedInstance();
+	private ReactiveAdapterRegistry reactiveAdapterRegistry = ReactiveAdapterRegistry.getSharedInstance();
 
 	private boolean ignoreDefaultModelOnRedirect = false;
 
@@ -410,8 +409,7 @@ public class RequestMappingHandlerAdapter extends AbstractHandlerMethodAdapter
 	 * @param interceptors the interceptors to register
 	 */
 	public void setCallableInterceptors(List<CallableProcessingInterceptor> interceptors) {
-		Assert.notNull(interceptors, "CallableProcessingInterceptor List must not be null");
-		this.callableInterceptors = interceptors.toArray(new CallableProcessingInterceptor[interceptors.size()]);
+		this.callableInterceptors = interceptors.toArray(new CallableProcessingInterceptor[0]);
 	}
 
 	/**
@@ -419,18 +417,27 @@ public class RequestMappingHandlerAdapter extends AbstractHandlerMethodAdapter
 	 * @param interceptors the interceptors to register
 	 */
 	public void setDeferredResultInterceptors(List<DeferredResultProcessingInterceptor> interceptors) {
-		Assert.notNull(interceptors, "DeferredResultProcessingInterceptor List must not be null");
-		this.deferredResultInterceptors = interceptors.toArray(new DeferredResultProcessingInterceptor[interceptors.size()]);
+		this.deferredResultInterceptors = interceptors.toArray(new DeferredResultProcessingInterceptor[0]);
 	}
 
 	/**
 	 * Configure the registry for reactive library types to be supported as
 	 * return values from controller methods.
 	 * @since 5.0
+	 * @deprecated as of 5.0.5, in favor of {@link #setReactiveAdapterRegistry}
 	 */
+	@Deprecated
 	public void setReactiveRegistry(ReactiveAdapterRegistry reactiveRegistry) {
-		Assert.notNull(reactiveRegistry, "ReactiveAdapterRegistry is required");
-		this.reactiveRegistry = reactiveRegistry;
+		this.reactiveAdapterRegistry = reactiveRegistry;
+	}
+
+	/**
+	 * Configure the registry for reactive library types to be supported as
+	 * return values from controller methods.
+	 * @since 5.0.5
+	 */
+	public void setReactiveAdapterRegistry(ReactiveAdapterRegistry reactiveAdapterRegistry) {
+		this.reactiveAdapterRegistry = reactiveAdapterRegistry;
 	}
 
 	/**
@@ -438,7 +445,7 @@ public class RequestMappingHandlerAdapter extends AbstractHandlerMethodAdapter
 	 * @since 5.0
 	 */
 	public ReactiveAdapterRegistry getReactiveAdapterRegistry() {
-		return this.reactiveRegistry;
+		return this.reactiveAdapterRegistry;
 	}
 
 	/**
@@ -702,7 +709,7 @@ public class RequestMappingHandlerAdapter extends AbstractHandlerMethodAdapter
 		handlers.add(new ModelMethodProcessor());
 		handlers.add(new ViewMethodReturnValueHandler());
 		handlers.add(new ResponseBodyEmitterReturnValueHandler(getMessageConverters(),
-				this.reactiveRegistry, this.taskExecutor, this.contentNegotiationManager));
+				this.reactiveAdapterRegistry, this.taskExecutor, this.contentNegotiationManager));
 		handlers.add(new StreamingResponseBodyReturnValueHandler());
 		handlers.add(new HttpEntityMethodProcessor(getMessageConverters(),
 				this.contentNegotiationManager, this.requestResponseBodyAdvice));

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/ResourceHttpRequestHandler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -387,7 +387,7 @@ public class ResourceHttpRequestHandler extends WebContentGenerator
 			if (getResourceResolvers().get(i) instanceof PathResourceResolver) {
 				PathResourceResolver pathResolver = (PathResourceResolver) getResourceResolvers().get(i);
 				if (ObjectUtils.isEmpty(pathResolver.getAllowedLocations())) {
-					pathResolver.setAllowedLocations(getLocations().toArray(new Resource[getLocations().size()]));
+					pathResolver.setAllowedLocations(getLocations().toArray(new Resource[0]));
 				}
 				if (this.urlPathHelper != null) {
 					pathResolver.setLocationCharsets(this.locationCharsets);

spring-webmvc/src/main/java/org/springframework/web/servlet/view/groovy/GroovyMarkupConfigurer.java

@@ -180,7 +180,7 @@ public class GroovyMarkupConfigurer extends TemplateConfiguration
 		}
 		ClassLoader classLoader = getApplicationContext().getClassLoader();
 		Assert.state(classLoader != null, "No ClassLoader");
-		return (!urls.isEmpty() ? new URLClassLoader(urls.toArray(new URL[urls.size()]), classLoader) : classLoader);
+		return (!urls.isEmpty() ? new URLClassLoader(urls.toArray(new URL[0]), classLoader) : classLoader);
 	}
 
 	/**

spring-websocket/src/main/java/org/springframework/web/socket/config/annotation/AbstractWebSocketHandlerRegistration.java

@@ -135,7 +135,7 @@ public abstract class AbstractWebSocketHandlerRegistration<M> implements WebSock
 		List<HandshakeInterceptor> interceptors = new ArrayList<>(this.interceptors.size() + 1);
 		interceptors.addAll(this.interceptors);
 		interceptors.add(new OriginHandshakeInterceptor(this.allowedOrigins));
-		return interceptors.toArray(new HandshakeInterceptor[interceptors.size()]);
+		return interceptors.toArray(new HandshakeInterceptor[0]);
 	}
 
 	/**

spring-websocket/src/main/java/org/springframework/web/socket/config/annotation/WebMvcStompWebSocketEndpointRegistration.java

@@ -62,8 +62,8 @@ public class WebMvcStompWebSocketEndpointRegistration implements StompWebSocketE
 	private SockJsServiceRegistration registration;
 
 
-	public WebMvcStompWebSocketEndpointRegistration(String[] paths, WebSocketHandler webSocketHandler,
-			TaskScheduler sockJsTaskScheduler) {
+	public WebMvcStompWebSocketEndpointRegistration(
+			String[] paths, WebSocketHandler webSocketHandler, TaskScheduler sockJsTaskScheduler) {
 
 		Assert.notEmpty(paths, "No paths specified");
 		Assert.notNull(webSocketHandler, "WebSocketHandler must not be null");
@@ -76,7 +76,6 @@ public class WebMvcStompWebSocketEndpointRegistration implements StompWebSocketE
 
 	@Override
 	public StompWebSocketEndpointRegistration setHandshakeHandler(HandshakeHandler handshakeHandler) {
-		Assert.notNull(handshakeHandler, "'handshakeHandler' must not be null");
 		this.handshakeHandler = handshakeHandler;
 		return this;
 	}
@@ -117,10 +116,10 @@ public class WebMvcStompWebSocketEndpointRegistration implements StompWebSocketE
 	}
 
 	protected HandshakeInterceptor[] getInterceptors() {
-		List<HandshakeInterceptor> interceptors = new ArrayList<>();
+		List<HandshakeInterceptor> interceptors = new ArrayList<>(this.interceptors.size() + 1);
 		interceptors.addAll(this.interceptors);
 		interceptors.add(new OriginHandshakeInterceptor(this.allowedOrigins));
-		return interceptors.toArray(new HandshakeInterceptor[interceptors.size()]);
+		return interceptors.toArray(new HandshakeInterceptor[0]);
 	}
 
 	public final MultiValueMap<HttpRequestHandler, String> getMappings() {
@@ -128,7 +127,7 @@ public class WebMvcStompWebSocketEndpointRegistration implements StompWebSocketE
 		if (this.registration != null) {
 			SockJsService sockJsService = this.registration.getSockJsService();
 			for (String path : this.paths) {
-				String pattern = path.endsWith("/") ? path + "**" : path + "/**";
+				String pattern = (path.endsWith("/") ? path + "**" : path + "/**");
 				SockJsHttpRequestHandler handler = new SockJsHttpRequestHandler(sockJsService, this.webSocketHandler);
 				mappings.add(handler, pattern);
 			}