Prefer Collections.addAll call with array over Set.addAll(Arrays.asList)

spring-context/src/main/java/org/springframework/context/annotation/ComponentScanAnnotationParser.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.
@@ -18,7 +18,7 @@ package org.springframework.context.annotation;
 
 import java.lang.annotation.Annotation;
 import java.util.ArrayList;
-import java.util.Arrays;
+import java.util.Collections;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Set;
@@ -114,7 +114,7 @@ class ComponentScanAnnotationParser {
 		for (String pkg : basePackagesArray) {
 			String[] tokenized = StringUtils.tokenizeToStringArray(this.environment.resolvePlaceholders(pkg),
 					ConfigurableApplicationContext.CONFIG_LOCATION_DELIMITERS);
-			basePackages.addAll(Arrays.asList(tokenized));
+			Collections.addAll(basePackages, tokenized);
 		}
 		for (Class<?> clazz : componentScan.getClassArray("basePackageClasses")) {
 			basePackages.add(ClassUtils.getPackageName(clazz));

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

@@ -17,7 +17,7 @@
 package org.springframework.jmx.export;
 
 import java.util.ArrayList;
-import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedHashMap;
@@ -321,7 +321,7 @@ public class MBeanExporter extends MBeanRegistrationSupport implements MBeanExpo
 	 */
 	public void setExcludedBeans(String... excludedBeans) {
 		this.excludedBeans.clear();
-		this.excludedBeans.addAll(Arrays.asList(excludedBeans));
+		Collections.addAll(this.excludedBeans, excludedBeans);
 	}
 
 	/**
@@ -868,9 +868,9 @@ public class MBeanExporter extends MBeanRegistrationSupport implements MBeanExpo
 	private void autodetect(Map<String, Object> beans, AutodetectCallback callback) {
 		Assert.state(this.beanFactory != null, "No BeanFactory set");
 		Set<String> beanNames = new LinkedHashSet<>(this.beanFactory.getBeanDefinitionCount());
-		beanNames.addAll(Arrays.asList(this.beanFactory.getBeanDefinitionNames()));
+		Collections.addAll(beanNames, this.beanFactory.getBeanDefinitionNames());
 		if (this.beanFactory instanceof ConfigurableBeanFactory) {
-			beanNames.addAll(Arrays.asList(((ConfigurableBeanFactory) this.beanFactory).getSingletonNames()));
+			Collections.addAll(beanNames, ((ConfigurableBeanFactory) this.beanFactory).getSingletonNames());
 		}
 
 		for (String beanName : beanNames) {

spring-context/src/main/java/org/springframework/jndi/support/SimpleJndiBeanFactory.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.
@@ -16,7 +16,7 @@
 
 package org.springframework.jndi.support;
 
-import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
@@ -92,7 +92,7 @@ public class SimpleJndiBeanFactory extends JndiLocatorSupport implements BeanFac
 	 * (typically within the "java:comp/env/" namespace)
 	 */
 	public void setShareableResources(String... shareableResources) {
-		this.shareableResources.addAll(Arrays.asList(shareableResources));
+		Collections.addAll(this.shareableResources, shareableResources);
 	}
 
 

spring-core/src/main/java/org/springframework/core/MethodIntrospector.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.
@@ -18,7 +18,7 @@ package org.springframework.core;
 
 import java.lang.reflect.Method;
 import java.lang.reflect.Proxy;
-import java.util.Arrays;
+import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
 import java.util.Map;
@@ -61,7 +61,7 @@ public abstract class MethodIntrospector {
 			handlerTypes.add(targetType);
 			specificHandlerType = targetType;
 		}
-		handlerTypes.addAll(Arrays.asList(targetType.getInterfaces()));
+		Collections.addAll(handlerTypes, targetType.getInterfaces());
 
 		for (Class<?> currentHandlerType : handlerTypes) {
 			final Class<?> targetClass = (specificHandlerType != null ? specificHandlerType : currentHandlerType);

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

@@ -125,8 +125,8 @@ public abstract class ClassUtils {
 
 		Set<Class<?>> primitiveTypes = new HashSet<>(32);
 		primitiveTypes.addAll(primitiveWrapperTypeMap.values());
-		primitiveTypes.addAll(Arrays.asList(boolean[].class, byte[].class, char[].class,
+		Collections.addAll(primitiveTypes, boolean[].class, byte[].class, char[].class,
-				double[].class, float[].class, int[].class, long[].class, short[].class));
+				double[].class, float[].class, int[].class, long[].class, short[].class);
 		primitiveTypes.add(void.class);
 		for (Class<?> primitiveType : primitiveTypes) {
 			primitiveTypeNameMap.put(primitiveType.getName(), primitiveType);

spring-expression/src/main/java/org/springframework/expression/spel/support/ReflectiveMethodResolver.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.
@@ -22,6 +22,7 @@ import java.lang.reflect.Proxy;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.LinkedHashSet;
 import java.util.List;
@@ -137,7 +138,7 @@ public class ReflectiveMethodResolver implements MethodResolver {
 							return 0;
 						}
 					}
-					return (m1pl < m2pl ? -1 : (m1pl > m2pl ? 1 : 0));
+					return Integer.compare(m1pl, m2pl);
 				});
 			}
 
@@ -228,14 +229,14 @@ public class ReflectiveMethodResolver implements MethodResolver {
 				}
 			}
 			// Also expose methods from java.lang.Class itself
-			result.addAll(Arrays.asList(getMethods(Class.class)));
+			Collections.addAll(result, getMethods(Class.class));
 			return result;
 		}
 		else if (Proxy.isProxyClass(type)) {
 			Set<Method> result = new LinkedHashSet<>();
 			// Expose interface methods (not proxy-declared overrides) for proper vararg introspection
 			for (Class<?> ifc : type.getInterfaces()) {
-				result.addAll(Arrays.asList(getMethods(ifc)));
+				Collections.addAll(result, getMethods(ifc));
 			}
 			return result;
 		}

spring-test/src/main/java/org/springframework/test/context/support/ApplicationContextInitializerUtils.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.
@@ -16,8 +16,8 @@
 
 package org.springframework.test.context.support;
 
-import java.util.Arrays;
+import java.util.Collections;
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Set;
 
@@ -30,8 +30,8 @@ import org.springframework.test.context.ContextConfigurationAttributes;
 import org.springframework.util.Assert;
 
 /**
- * Utility methods for working with {@link ApplicationContextInitializer
+ * Utility methods for working with
- * ApplicationContextInitializers}.
+ * {@link ApplicationContextInitializer ApplicationContextInitializers}.
  *
  * <p>Although {@code ApplicationContextInitializerUtils} was first introduced
  * in Spring Framework 4.1, the initial implementations of methods in this class
@@ -46,21 +46,15 @@ abstract class ApplicationContextInitializerUtils {
 	private static final Log logger = LogFactory.getLog(ApplicationContextInitializerUtils.class);
 
 
-	private ApplicationContextInitializerUtils() {
-		/* no-op */
-	}
-
 	/**
 	 * Resolve the set of merged {@code ApplicationContextInitializer} classes for the
 	 * supplied list of {@code ContextConfigurationAttributes}.
-	 *
 	 * <p>Note that the {@link ContextConfiguration#inheritInitializers inheritInitializers}
 	 * flag of {@link ContextConfiguration @ContextConfiguration} will be taken into
 	 * consideration. Specifically, if the {@code inheritInitializers} flag is set to
 	 * {@code true} for a given level in the class hierarchy represented by the provided
 	 * configuration attributes, context initializer classes defined at the given level
 	 * will be merged with those defined in higher levels of the class hierarchy.
-	 *
 	 * @param configAttributesList the list of configuration attributes to process; must
 	 * not be {@code null} or <em>empty</em>; must be ordered <em>bottom-up</em>
 	 * (i.e., as if we were traversing up the class hierarchy)
@@ -70,19 +64,15 @@ abstract class ApplicationContextInitializerUtils {
 	 */
 	static Set<Class<? extends ApplicationContextInitializer<?>>> resolveInitializerClasses(
 			List<ContextConfigurationAttributes> configAttributesList) {
-		Assert.notEmpty(configAttributesList, "ContextConfigurationAttributes list must not be empty");
 
-		final Set<Class<? extends ApplicationContextInitializer<?>>> initializerClasses = //
+		Assert.notEmpty(configAttributesList, "ContextConfigurationAttributes List must not be empty");
-				new HashSet<>();
+		Set<Class<? extends ApplicationContextInitializer<?>>> initializerClasses = new LinkedHashSet<>();
 
 		for (ContextConfigurationAttributes configAttributes : configAttributesList) {
 			if (logger.isTraceEnabled()) {
-				logger.trace(String.format("Processing context initializers for context configuration attributes %s",
+				logger.trace("Processing context initializers for configuration attributes " + configAttributes);
-					configAttributes));
 			}
-
+			Collections.addAll(initializerClasses, configAttributes.getInitializers());
-			initializerClasses.addAll(Arrays.asList(configAttributes.getInitializers()));
-
 			if (!configAttributes.isInheritInitializers()) {
 				break;
 			}

spring-test/src/main/java/org/springframework/test/web/servlet/htmlunit/HostRequestMatcher.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.
@@ -17,7 +17,7 @@
 package org.springframework.test.web.servlet.htmlunit;
 
 import java.net.URL;
-import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashSet;
 import java.util.Set;
 
@@ -65,9 +65,10 @@ public final class HostRequestMatcher implements WebRequestMatcher {
 	 * @param hosts the hosts to match on
 	 */
 	public HostRequestMatcher(String... hosts) {
-		this.hosts.addAll(Arrays.asList(hosts));
+		Collections.addAll(this.hosts, hosts);
 	}
 
+
 	@Override
 	public boolean matches(WebRequest request) {
 		URL url = request.getUrl();

spring-web/src/main/java/org/springframework/remoting/jaxws/AbstractJaxWsServiceExporter.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.
@@ -16,7 +16,7 @@
 
 package org.springframework.remoting.jaxws;
 
-import java.util.Arrays;
+import java.util.Collections;
 import java.util.LinkedHashSet;
 import java.util.Map;
 import java.util.Set;
@@ -137,9 +137,9 @@ public abstract class AbstractJaxWsServiceExporter implements BeanFactoryAware,
 		Assert.state(this.beanFactory != null, "No BeanFactory set");
 
 		Set<String> beanNames = new LinkedHashSet<>(this.beanFactory.getBeanDefinitionCount());
-		beanNames.addAll(Arrays.asList(this.beanFactory.getBeanDefinitionNames()));
+		Collections.addAll(beanNames, this.beanFactory.getBeanDefinitionNames());
 		if (this.beanFactory instanceof ConfigurableBeanFactory) {
-			beanNames.addAll(Arrays.asList(((ConfigurableBeanFactory) this.beanFactory).getSingletonNames()));
+			Collections.addAll(beanNames, ((ConfigurableBeanFactory) this.beanFactory).getSingletonNames());
 		}
 
 		for (String beanName : beanNames) {

spring-web/src/main/java/org/springframework/web/accept/ContentNegotiationManager.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.
@@ -118,7 +118,7 @@ public class ContentNegotiationManager implements ContentNegotiationStrategy, Me
 	 * @param resolvers the resolvers to add
 	 */
 	public void addFileExtensionResolvers(MediaTypeFileExtensionResolver... resolvers) {
-		this.resolvers.addAll(Arrays.asList(resolvers));
+		Collections.addAll(this.resolvers, resolvers);
 	}
 
 	@Override

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

@@ -16,7 +16,7 @@
 
 package org.springframework.web.context.support;
 
-import java.util.Arrays;
+import java.util.Collections;
 import java.util.LinkedHashSet;
 import java.util.Set;
 
@@ -149,7 +149,7 @@ public class AnnotationConfigWebApplicationContext extends AbstractRefreshableWe
 	 */
 	public void register(Class<?>... annotatedClasses) {
 		Assert.notEmpty(annotatedClasses, "At least one annotated class must be specified");
-		this.annotatedClasses.addAll(Arrays.asList(annotatedClasses));
+		Collections.addAll(this.annotatedClasses, annotatedClasses);
 	}
 
 	/**
@@ -164,7 +164,7 @@ public class AnnotationConfigWebApplicationContext extends AbstractRefreshableWe
 	 */
 	public void scan(String... basePackages) {
 		Assert.notEmpty(basePackages, "At least one base package must be specified");
-		this.basePackages.addAll(Arrays.asList(basePackages));
+		Collections.addAll(this.basePackages, basePackages);
 	}
 
 

spring-web/src/main/java/org/springframework/web/method/annotation/SessionAttributesHandler.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.
@@ -16,7 +16,6 @@
 
 package org.springframework.web.method.annotation;
 
-import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -59,9 +58,9 @@ public class SessionAttributesHandler {
 
 
 	/**
-	 * Create a new instance for a controller type. Session attribute names and
+	 * Create a new session attributes handler. Session attribute names and types
-	 * types are extracted from the {@code @SessionAttributes} annotation, if
+	 * are extracted from the {@code @SessionAttributes} annotation, if present,
-	 * present, on the given type.
+	 * on the given type.
 	 * @param handlerType the controller type
 	 * @param sessionAttributeStore used for session access
 	 */
@@ -69,15 +68,15 @@ public class SessionAttributesHandler {
 		Assert.notNull(sessionAttributeStore, "SessionAttributeStore may not be null");
 		this.sessionAttributeStore = sessionAttributeStore;
 
-		SessionAttributes annotation =
+		SessionAttributes ann = AnnotatedElementUtils.findMergedAnnotation(handlerType, SessionAttributes.class);
-				AnnotatedElementUtils.findMergedAnnotation(handlerType, SessionAttributes.class);
+		if (ann != null) {
-		if (annotation != null) {
+			Collections.addAll(this.attributeNames, ann.names());
-			this.attributeNames.addAll(Arrays.asList(annotation.names()));
+			Collections.addAll(this.attributeTypes, ann.types());
-			this.attributeTypes.addAll(Arrays.asList(annotation.types()));
 		}
 		this.knownAttributeNames.addAll(this.attributeNames);
 	}
 
+
 	/**
 	 * Whether the controller represented by this instance has declared any
 	 * session attributes through an {@link SessionAttributes} annotation.

spring-webflux/src/main/java/org/springframework/web/reactive/result/method/annotation/SessionAttributesHandler.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.
@@ -15,7 +15,6 @@
  */
 package org.springframework.web.reactive.result.method.annotation;
 
-import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -46,17 +45,16 @@ class SessionAttributesHandler {
 
 
 	/**
-	 * Create a new instance for a controller type. Session attribute names and
+	 * Create a new session attributes handler. Session attribute names and types
-	 * types are extracted from the {@code @SessionAttributes} annotation, if
+	 * are extracted from the {@code @SessionAttributes} annotation, if present,
-	 * present, on the given type.
+	 * on the given type.
 	 * @param handlerType the controller type
 	 */
 	public SessionAttributesHandler(Class<?> handlerType) {
-		SessionAttributes annotation =
+		SessionAttributes ann = AnnotatedElementUtils.findMergedAnnotation(handlerType, SessionAttributes.class);
-				AnnotatedElementUtils.findMergedAnnotation(handlerType, SessionAttributes.class);
+		if (ann != null) {
-		if (annotation != null) {
+			Collections.addAll(this.attributeNames, ann.names());
-			this.attributeNames.addAll(Arrays.asList(annotation.names()));
+			Collections.addAll(this.attributeTypes, ann.types());
-			this.attributeTypes.addAll(Arrays.asList(annotation.types()));
 		}
 		this.knownAttributeNames.addAll(this.attributeNames);
 	}