Avoid resizing of fixed-size HashMap/LinkedHashMap variants

Closes spring-projectsgh-25349

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

@@ -21,7 +21,6 @@
 import java.lang.reflect.Modifier;
 import java.lang.reflect.UndeclaredThrowableException;
 import java.util.Collections;
-import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -53,6 +52,7 @@
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
+import org.springframework.util.CollectionUtils;
 import org.springframework.util.ObjectUtils;
 import org.springframework.util.ReflectionUtils;
 
@@ -325,7 +325,7 @@ private Callback[] getCallbacks(Class<?> rootClass) throws Exception {
 		if (isStatic && isFrozen) {
 			Method[] methods = rootClass.getMethods();
 			Callback[] fixedCallbacks = new Callback[methods.length];
-			this.fixedInterceptorMap = new HashMap<>(methods.length);
+			this.fixedInterceptorMap = CollectionUtils.newHashMap(methods.length);
 
 			// TODO: small memory optimization here (can skip creation for methods with no advice)
 			for (int x = 0; x < methods.length; x++) {

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

@@ -49,6 +49,7 @@
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
+import org.springframework.util.CollectionUtils;
 import org.springframework.util.ConcurrentReferenceHashMap;
 import org.springframework.util.ReflectionUtils;
 import org.springframework.util.StringUtils;
@@ -792,7 +793,7 @@ public static <T> T instantiateClass(Constructor<T> ctor, Object... args)
 			}
 
 			List<KParameter> parameters = kotlinConstructor.getParameters();
-			Map<KParameter, Object> argParameters = new HashMap<>(parameters.size());
+			Map<KParameter, Object> argParameters = CollectionUtils.newHashMap(parameters.size());
 			Assert.isTrue(args.length <= parameters.size(),
 					"Number of provided arguments should be less of equals than number of constructor parameters");
 			for (int i = 0 ; i < args.length ; i++) {

spring-beans/src/main/java/org/springframework/beans/factory/config/MapFactoryBean.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -16,13 +16,13 @@
 
 package org.springframework.beans.factory.config;
 
-import java.util.LinkedHashMap;
 import java.util.Map;
 
 import org.springframework.beans.BeanUtils;
 import org.springframework.beans.TypeConverter;
 import org.springframework.core.ResolvableType;
 import org.springframework.lang.Nullable;
+import org.springframework.util.CollectionUtils;
 
 /**
  * Simple factory for shared Map instances. Allows for central setup
@@ -85,7 +85,7 @@ protected Map<Object, Object> createInstance() {
 			result = BeanUtils.instantiateClass(this.targetMapClass);
 		}
 		else {
-			result = new LinkedHashMap<>(this.sourceMap.size());
+			result = CollectionUtils.newLinkedHashMap(this.sourceMap.size());
 		}
 		Class<?> keyType = null;
 		Class<?> valueType = null;

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

@@ -18,7 +18,6 @@
 
 import java.lang.reflect.Array;
 import java.util.ArrayList;
-import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
@@ -42,6 +41,7 @@
 import org.springframework.beans.factory.config.TypedStringValue;
 import org.springframework.lang.Nullable;
 import org.springframework.util.ClassUtils;
+import org.springframework.util.CollectionUtils;
 import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
 
@@ -447,7 +447,7 @@ private Set<?> resolveManagedSet(Object argName, Set<?> ms) {
 	 * For each element in the managed map, resolve reference if necessary.
 	 */
 	private Map<?, ?> resolveManagedMap(Object argName, Map<?, ?> mm) {
-		Map<Object, Object> resolved = new LinkedHashMap<>(mm.size());
+		Map<Object, Object> resolved = CollectionUtils.newLinkedHashMap(mm.size());
 		mm.forEach((key, value) -> {
 			Object resolvedKey = resolveValueIfNecessary(argName, key);
 			Object resolvedValue = resolveValueIfNecessary(new KeyedArgName(argName, key), value);

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

@@ -33,7 +33,6 @@
 import java.util.Comparator;
 import java.util.IdentityHashMap;
 import java.util.Iterator;
-import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
@@ -81,6 +80,7 @@
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
+import org.springframework.util.CollectionUtils;
 import org.springframework.util.CompositeIterator;
 import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
@@ -476,7 +476,7 @@ public Stream<T> orderedStream() {
 				if (beanNames.length == 0) {
 					return Stream.empty();
 				}
-				Map<String, T> matchingBeans = new LinkedHashMap<>(beanNames.length);
+				Map<String, T> matchingBeans = CollectionUtils.newLinkedHashMap(beanNames.length);
 				for (String beanName : beanNames) {
 					Object beanInstance = getBean(beanName);
 					if (!(beanInstance instanceof NullBean)) {
@@ -665,7 +665,7 @@ public <T> Map<String, T> getBeansOfType(
 			@Nullable Class<T> type, boolean includeNonSingletons, boolean allowEagerInit) throws BeansException {
 
 		String[] beanNames = getBeanNamesForType(type, includeNonSingletons, allowEagerInit);
-		Map<String, T> result = new LinkedHashMap<>(beanNames.length);
+		Map<String, T> result = CollectionUtils.newLinkedHashMap(beanNames.length);
 		for (String beanName : beanNames) {
 			try {
 				Object beanInstance = getBean(beanName);
@@ -715,7 +715,7 @@ public String[] getBeanNamesForAnnotation(Class<? extends Annotation> annotation
 	@Override
 	public Map<String, Object> getBeansWithAnnotation(Class<? extends Annotation> annotationType) {
 		String[] beanNames = getBeanNamesForAnnotation(annotationType);
-		Map<String, Object> result = new LinkedHashMap<>(beanNames.length);
+		Map<String, Object> result = CollectionUtils.newLinkedHashMap(beanNames.length);
 		for (String beanName : beanNames) {
 			Object beanInstance = getBean(beanName);
 			if (!(beanInstance instanceof NullBean)) {
@@ -1235,7 +1235,7 @@ private <T> NamedBeanHolder<T> resolveNamedBean(
 			return new NamedBeanHolder<>(beanName, (T) getBean(beanName, requiredType.toClass(), args));
 		}
 		else if (candidateNames.length > 1) {
-			Map<String, Object> candidates = new LinkedHashMap<>(candidateNames.length);
+			Map<String, Object> candidates = CollectionUtils.newLinkedHashMap(candidateNames.length);
 			for (String beanName : candidateNames) {
 				if (containsSingleton(beanName) && args == null) {
 					Object beanInstance = getBean(beanName);
@@ -1532,7 +1532,7 @@ protected Map<String, Object> findAutowireCandidates(
 
 		String[] candidateNames = BeanFactoryUtils.beanNamesForTypeIncludingAncestors(
 				this, requiredType, true, descriptor.isEager());
-		Map<String, Object> result = new LinkedHashMap<>(candidateNames.length);
+		Map<String, Object> result = CollectionUtils.newLinkedHashMap(candidateNames.length);
 		for (Map.Entry<Class<?>, Object> classObjectEntry : this.resolvableDependencies.entrySet()) {
 			Class<?> autowiringType = classObjectEntry.getKey();
 			if (autowiringType.isAssignableFrom(requiredType)) {

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

@@ -101,7 +101,6 @@ public Object generate(Object target, Method method, Object... params) {
 		}
 	}
 
-	@SuppressWarnings("unchecked")
 	private static Object doGenerate(KeyGenerator keyGenerator, CacheKeyInvocationContext<?> context) {
 		List<Object> parameters = new ArrayList<>();
 		for (CacheInvocationParameter param : context.getKeyParameters()) {

spring-context/src/main/java/org/springframework/jmx/access/MBeanClientInterceptor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -66,6 +66,7 @@
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
+import org.springframework.util.CollectionUtils;
 import org.springframework.util.ReflectionUtils;
 import org.springframework.util.StringUtils;
 
@@ -301,13 +302,13 @@ private void retrieveMBeanInfo(MBeanServerConnection server) throws MBeanInfoRet
 			MBeanInfo info = server.getMBeanInfo(this.objectName);
 
 			MBeanAttributeInfo[] attributeInfo = info.getAttributes();
-			this.allowedAttributes = new HashMap<>(attributeInfo.length);
+			this.allowedAttributes = CollectionUtils.newHashMap(attributeInfo.length);
 			for (MBeanAttributeInfo infoEle : attributeInfo) {
 				this.allowedAttributes.put(infoEle.getName(), infoEle);
 			}
 
 			MBeanOperationInfo[] operationInfo = info.getOperations();
-			this.allowedOperations = new HashMap<>(operationInfo.length);
+			this.allowedOperations = CollectionUtils.newHashMap(operationInfo.length);
 			for (MBeanOperationInfo infoEle : operationInfo) {
 				Class<?>[] paramTypes = JmxUtils.parameterInfoToTypes(infoEle.getSignature(), this.beanClassLoader);
 				this.allowedOperations.put(new MethodCacheKey(infoEle.getName(), paramTypes), infoEle);

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

@@ -20,14 +20,14 @@
 import java.lang.reflect.Modifier;
 import java.util.Arrays;
 import java.util.Enumeration;
-import java.util.HashMap;
 import java.util.Map;
 import java.util.Properties;
 
 import org.springframework.beans.factory.BeanClassLoaderAware;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.lang.Nullable;
 import org.springframework.util.ClassUtils;
+import org.springframework.util.CollectionUtils;
 import org.springframework.util.StringUtils;
 
 /**
@@ -126,7 +126,7 @@ public void afterPropertiesSet() {
 	 * @return the resolved interface mappings (with Class objects as values)
 	 */
 	private Map<String, Class<?>[]> resolveInterfaceMappings(Properties mappings) {
-		Map<String, Class<?>[]> resolvedMappings = new HashMap<>(mappings.size());
+		Map<String, Class<?>[]> resolvedMappings = CollectionUtils.newHashMap(mappings.size());
 		for (Enumeration<?> en = mappings.propertyNames(); en.hasMoreElements();) {
 			String beanKey = (String) en.nextElement();
 			String[] classNames = StringUtils.commaDelimitedListToStringArray(mappings.getProperty(beanKey));

spring-core/src/jmh/java/org/springframework/core/convert/support/GenericConversionServiceBenchmark.java

@@ -34,9 +34,11 @@
 import org.openjdk.jmh.infra.Blackhole;
 
 import org.springframework.core.convert.TypeDescriptor;
+import org.springframework.util.CollectionUtils;
 
 /**
  * Benchmarks for {@link GenericConversionService}.
+ *
  * @author Brian Clozel
  */
 @BenchmarkMode(Mode.Throughput)
@@ -78,26 +80,28 @@ public void convertMapOfStringToListOfIntegerWithConversionService(MapBenchmarkS
 
 	@Benchmark
 	public void convertMapOfStringToListOfIntegerBaseline(MapBenchmarkState state, Blackhole bh) {
-		Map<String, Integer> target = new HashMap<>(state.source.size());
+		Map<String, Integer> target = CollectionUtils.newHashMap(state.source.size());
 		state.source.forEach((k, v) -> target.put(k, Integer.valueOf(v)));
 		bh.consume(target);
 	}
 
+
 	@State(Scope.Benchmark)
 	public static class MapBenchmarkState extends BenchmarkState {
 
 		Map<String, String> source;
 
 		@Setup(Level.Trial)
 		public void setup() throws Exception {
-			this.source = new HashMap<>(this.collectionSize);
+			this.source = CollectionUtils.newHashMap(this.collectionSize);
 			Map<String, Integer> target = new HashMap<>();
 			this.targetTypeDesc = TypeDescriptor.forObject(target);
 			this.source = IntStream.rangeClosed(1, collectionSize).mapToObj(String::valueOf)
 					.collect(Collectors.toMap(String::valueOf, String::valueOf));
 		}
 	}
 
+
 	@State(Scope.Benchmark)
 	public static class BenchmarkState {
 
@@ -107,6 +111,6 @@ public static class BenchmarkState {
 		int collectionSize;
 
 		TypeDescriptor targetTypeDesc;
-
 	}
+
 }

spring-core/src/main/java/org/springframework/core/annotation/AnnotationUtils.java

@@ -24,7 +24,6 @@
 import java.lang.reflect.Modifier;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.NoSuchElementException;
@@ -35,6 +34,7 @@
 import org.springframework.core.annotation.MergedAnnotation.Adapt;
 import org.springframework.core.annotation.MergedAnnotations.SearchStrategy;
 import org.springframework.lang.Nullable;
+import org.springframework.util.CollectionUtils;
 import org.springframework.util.ConcurrentReferenceHashMap;
 import org.springframework.util.ReflectionUtils;
 import org.springframework.util.StringUtils;
@@ -905,7 +905,7 @@ private static Map<String, DefaultValueHolder> computeDefaultValues(
 		if (!methods.hasDefaultValueMethod()) {
 			return Collections.emptyMap();
 		}
-		Map<String, DefaultValueHolder> result = new LinkedHashMap<>(methods.size());
+		Map<String, DefaultValueHolder> result = CollectionUtils.newLinkedHashMap(methods.size());
 		if (!methods.hasNestedAnnotation()) {
 			// Use simpler method if there are no nested annotations
 			for (int i = 0; i < methods.size(); i++) {

spring-core/src/main/java/org/springframework/core/codec/Hints.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -17,12 +17,12 @@
 package org.springframework.core.codec;
 
 import java.util.Collections;
-import java.util.HashMap;
 import java.util.Map;
 
 import org.apache.commons.logging.Log;
 
 import org.springframework.lang.Nullable;
+import org.springframework.util.CollectionUtils;
 
 /**
  * Constants and convenience methods for working with hints.
@@ -120,7 +120,7 @@ else if (hints1.isEmpty()) {
 			return hints2;
 		}
 		else {
-			Map<String, Object> result = new HashMap<>(hints1.size() + hints2.size());
+			Map<String, Object> result = CollectionUtils.newHashMap(hints1.size() + hints2.size());
 			result.putAll(hints1);
 			result.putAll(hints2);
 			return result;
@@ -141,7 +141,7 @@ public static Map<String, Object> merge(Map<String, Object> hints, String hintNa
 			return Collections.singletonMap(hintName, hintValue);
 		}
 		else {
-			Map<String, Object> result = new HashMap<>(hints.size() + 1);
+			Map<String, Object> result = CollectionUtils.newHashMap(hints.size() + 1);
 			result.putAll(hints);
 			result.put(hintName, hintValue);
 			return result;

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

@@ -68,7 +68,7 @@ public class AnnotationMetadataReadingVisitor extends ClassMetadataReadingVisito
 	 * to ensure that the hierarchical ordering of the entries is preserved.
 	 * @see AnnotationReadingVisitorUtils#getMergedAnnotationAttributes
 	 */
-	protected final LinkedMultiValueMap<String, AnnotationAttributes> attributesMap = new LinkedMultiValueMap<>(4);
+	protected final LinkedMultiValueMap<String, AnnotationAttributes> attributesMap = new LinkedMultiValueMap<>(3);
 
 	protected final Set<MethodMetadata> methodMetadataSet = new LinkedHashSet<>(4);
 

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

@@ -66,7 +66,7 @@ public class MethodMetadataReadingVisitor extends MethodVisitor implements Metho
 
 	protected final Map<String, Set<String>> metaAnnotationMap = new LinkedHashMap<>(4);
 
-	protected final LinkedMultiValueMap<String, AnnotationAttributes> attributesMap = new LinkedMultiValueMap<>(4);
+	protected final LinkedMultiValueMap<String, AnnotationAttributes> attributesMap = new LinkedMultiValueMap<>(3);
 
 
 	public MethodMetadataReadingVisitor(String methodName, int access, String declaringClassName,