Specify generic type nullness in spring-context

Also in spring-context-support.

See spring-projectsgh-34140

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -16,6 +16,7 @@
 
 package org.springframework.cache.jcache;
 
+import java.util.Objects;
 import java.util.concurrent.Callable;
 import java.util.function.Function;
 
@@ -134,7 +135,8 @@ private static class PutIfAbsentEntryProcessor implements EntryProcessor<Object,
 		private static final PutIfAbsentEntryProcessor INSTANCE = new PutIfAbsentEntryProcessor();
 
 		@Override
-		public @Nullable Object process(MutableEntry<Object, Object> entry, Object... arguments) throws EntryProcessorException {
+		@SuppressWarnings("NullAway") // Overridden method does not define nullness
+		public @Nullable Object process(MutableEntry<Object, @Nullable Object> entry, @Nullable Object... arguments) throws EntryProcessorException {
 			Object existingValue = entry.getValue();
 			if (existingValue == null) {
 				entry.setValue(arguments[0]);
@@ -146,28 +148,28 @@ private static class PutIfAbsentEntryProcessor implements EntryProcessor<Object,
 
 	private static final class ValueLoaderEntryProcessor implements EntryProcessor<Object, Object, Object> {
 
-		private final Function<Object, Object> fromStoreValue;
+		private final Function<Object, @Nullable Object> fromStoreValue;
 
 		private final Function<Object, Object> toStoreValue;
 
-		private ValueLoaderEntryProcessor(Function<Object, Object> fromStoreValue,
+		private ValueLoaderEntryProcessor(Function<Object, @Nullable Object> fromStoreValue,
 				Function<Object, Object> toStoreValue) {
 
 			this.fromStoreValue = fromStoreValue;
 			this.toStoreValue = toStoreValue;
 		}
 
 		@Override
-		@SuppressWarnings("unchecked")
-		public @Nullable Object process(MutableEntry<Object, Object> entry, Object... arguments) throws EntryProcessorException {
+		@SuppressWarnings({"unchecked","NullAway"}) // Overridden method does not define nullness
+		public @Nullable Object process(MutableEntry<Object, @Nullable Object> entry, @Nullable Object... arguments) throws EntryProcessorException {
 			Callable<Object> valueLoader = (Callable<Object>) arguments[0];
 			if (entry.exists()) {
-				return this.fromStoreValue.apply(entry.getValue());
+				return this.fromStoreValue.apply(Objects.requireNonNull(entry.getValue()));
 			}
 			else {
 				Object value;
 				try {
-					value = valueLoader.call();
+					value = Objects.requireNonNull(valueLoader).call();
 				}
 				catch (Exception ex) {
 					throw new EntryProcessorException("Value loader '" + valueLoader + "' failed " +

spring-context-support/src/main/java/org/springframework/cache/jcache/config/AbstractJCacheConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -41,10 +41,11 @@
 @Configuration(proxyBeanMethods = false)
 public abstract class AbstractJCacheConfiguration extends AbstractCachingConfiguration {
 
-	protected @Nullable Supplier<CacheResolver> exceptionCacheResolver;
+	protected @Nullable Supplier<? extends @Nullable CacheResolver> exceptionCacheResolver;
 
 
 	@Override
+	@SuppressWarnings("NullAway") // https://github.com/uber/NullAway/issues/1126
 	protected void useCachingConfigurer(CachingConfigurerSupplier cachingConfigurerSupplier) {
 		super.useCachingConfigurer(cachingConfigurerSupplier);
 		this.exceptionCacheResolver = cachingConfigurerSupplier.adapt(config -> {

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2024 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -79,8 +79,8 @@ public DefaultJCacheOperationSource() {
 	 * @since 5.1
 	 */
 	public DefaultJCacheOperationSource(
-			@Nullable Supplier<CacheManager> cacheManager, @Nullable Supplier<CacheResolver> cacheResolver,
-			@Nullable Supplier<CacheResolver> exceptionCacheResolver, @Nullable Supplier<KeyGenerator> keyGenerator) {
+			@Nullable Supplier<? extends @Nullable CacheManager> cacheManager, @Nullable Supplier<? extends @Nullable CacheResolver> cacheResolver,
+			@Nullable Supplier<? extends @Nullable CacheResolver> exceptionCacheResolver, @Nullable Supplier<? extends @Nullable KeyGenerator> keyGenerator) {
 
 		this.cacheManager = SingletonSupplier.ofNullable(cacheManager);
 		this.cacheResolver = SingletonSupplier.ofNullable(cacheResolver);

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -96,7 +96,7 @@ public void afterPropertiesSet() {
 	}
 
 
-	protected @Nullable Object execute(CacheOperationInvoker invoker, Object target, Method method, Object[] args) {
+	protected @Nullable Object execute(CacheOperationInvoker invoker, Object target, Method method, @Nullable Object[] args) {
 		// Check whether aspect is enabled to cope with cases where the AJ is pulled in automatically
 		if (this.initialized) {
 			Class<?> targetClass = AopProxyUtils.ultimateTargetClass(target);
@@ -113,7 +113,7 @@ public void afterPropertiesSet() {
 
 	@SuppressWarnings("unchecked")
 	private CacheOperationInvocationContext<?> createCacheOperationInvocationContext(
-			Object target, Object[] args, JCacheOperation<?> operation) {
+			Object target, @Nullable Object[] args, JCacheOperation<?> operation) {
 
 		return new DefaultCacheInvocationContext<>(
 				(JCacheOperation<Annotation>) operation, target, args);

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -60,7 +60,7 @@ public JCacheInterceptor() {
 	 * applying the default error handler if the supplier is not resolvable
 	 * @since 5.1
 	 */
-	public JCacheInterceptor(@Nullable Supplier<CacheErrorHandler> errorHandler) {
+	public JCacheInterceptor(@Nullable Supplier<? extends @Nullable CacheErrorHandler> errorHandler) {
 		this.errorHandler = new SingletonSupplier<>(errorHandler, SimpleCacheErrorHandler::new);
 	}
 

spring-context/src/main/java/org/springframework/cache/annotation/AbstractCachingConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -50,13 +50,13 @@ public abstract class AbstractCachingConfiguration implements ImportAware {
 
 	protected @Nullable AnnotationAttributes enableCaching;
 
-	protected @Nullable Supplier<CacheManager> cacheManager;
+	protected @Nullable Supplier<? extends @Nullable CacheManager> cacheManager;
 
-	protected @Nullable Supplier<CacheResolver> cacheResolver;
+	protected @Nullable Supplier<? extends @Nullable CacheResolver> cacheResolver;
 
-	protected @Nullable Supplier<KeyGenerator> keyGenerator;
+	protected @Nullable Supplier<? extends @Nullable KeyGenerator> keyGenerator;
 
-	protected @Nullable Supplier<CacheErrorHandler> errorHandler;
+	protected @Nullable Supplier<? extends @Nullable CacheErrorHandler> errorHandler;
 
 
 	@Override
@@ -70,8 +70,9 @@ public void setImportMetadata(AnnotationMetadata importMetadata) {
 	}
 
 	@Autowired
+	@SuppressWarnings("NullAway") // https://github.com/uber/NullAway/issues/1126
 	void setConfigurers(ObjectProvider<CachingConfigurer> configurers) {
-		Supplier<CachingConfigurer> configurer = () -> {
+		Supplier<? extends @Nullable CachingConfigurer> configurer = () -> {
 			List<CachingConfigurer> candidates = configurers.stream().toList();
 			if (CollectionUtils.isEmpty(candidates)) {
 				return null;
@@ -90,6 +91,7 @@ void setConfigurers(ObjectProvider<CachingConfigurer> configurers) {
 	/**
 	 * Extract the configuration from the nominated {@link CachingConfigurer}.
 	 */
+	@SuppressWarnings("NullAway") // https://github.com/uber/NullAway/issues/1126
 	protected void useCachingConfigurer(CachingConfigurerSupplier cachingConfigurerSupplier) {
 		this.cacheManager = cachingConfigurerSupplier.adapt(CachingConfigurer::cacheManager);
 		this.cacheResolver = cachingConfigurerSupplier.adapt(CachingConfigurer::cacheResolver);
@@ -100,10 +102,10 @@ protected void useCachingConfigurer(CachingConfigurerSupplier cachingConfigurerS
 
 	protected static class CachingConfigurerSupplier {
 
-		private final Supplier<CachingConfigurer> supplier;
+		private final SingletonSupplier<CachingConfigurer> supplier;
 
-		public CachingConfigurerSupplier(Supplier<CachingConfigurer> supplier) {
-			this.supplier = SingletonSupplier.of(supplier);
+		public CachingConfigurerSupplier(Supplier<? extends @Nullable CachingConfigurer> supplier) {
+			this.supplier = SingletonSupplier.ofNullable(supplier);
 		}
 
 		/**
@@ -115,7 +117,7 @@ public CachingConfigurerSupplier(Supplier<CachingConfigurer> supplier) {
 		 * @param <T> the type of the supplier
 		 * @return another supplier mapped by the specified function
 		 */
-		public <T> @Nullable Supplier<T> adapt(Function<CachingConfigurer, T> provider) {
+		public <T> Supplier<@Nullable T> adapt(Function<CachingConfigurer, ? extends @Nullable T> provider) {
 			return () -> {
 				CachingConfigurer cachingConfigurer = this.supplier.get();
 				return (cachingConfigurer != null ? provider.apply(cachingConfigurer) : null);

spring-context/src/main/java/org/springframework/cache/interceptor/CacheAspectSupport.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2024 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -154,8 +154,8 @@ protected CacheAspectSupport() {
 	 * @since 5.1
 	 */
 	public void configure(
-			@Nullable Supplier<CacheErrorHandler> errorHandler, @Nullable Supplier<KeyGenerator> keyGenerator,
-			@Nullable Supplier<CacheResolver> cacheResolver, @Nullable Supplier<CacheManager> cacheManager) {
+			@Nullable Supplier<? extends @Nullable CacheErrorHandler> errorHandler, @Nullable Supplier<? extends @Nullable KeyGenerator> keyGenerator,
+			@Nullable Supplier<? extends @Nullable CacheResolver> cacheResolver, @Nullable Supplier<? extends @Nullable CacheManager> cacheManager) {
 
 		this.errorHandler = new SingletonSupplier<>(errorHandler, SimpleCacheErrorHandler::new);
 		this.keyGenerator = new SingletonSupplier<>(keyGenerator, SimpleKeyGenerator::new);
@@ -317,7 +317,7 @@ protected Collection<? extends Cache> getCaches(
 	}
 
 	protected CacheOperationContext getOperationContext(
-			CacheOperation operation, Method method, Object[] args, Object target, Class<?> targetClass) {
+			CacheOperation operation, Method method, @Nullable Object[] args, Object target, Class<?> targetClass) {
 
 		CacheOperationMetadata metadata = getCacheOperationMetadata(operation, method, targetClass);
 		return new CacheOperationContext(metadata, args, target);
@@ -391,7 +391,7 @@ protected void clearMetadataCache() {
 		this.evaluator.clear();
 	}
 
-	protected @Nullable Object execute(CacheOperationInvoker invoker, Object target, Method method, Object[] args) {
+	protected @Nullable Object execute(CacheOperationInvoker invoker, Object target, Method method, @Nullable Object[] args) {
 		// Check whether aspect is enabled (to cope with cases where the AJ is pulled in automatically)
 		if (this.initialized) {
 			Class<?> targetClass = AopProxyUtils.ultimateTargetClass(target);
@@ -726,7 +726,7 @@ private class CacheOperationContexts {
 		boolean processed;
 
 		public CacheOperationContexts(Collection<? extends CacheOperation> operations, Method method,
-				Object[] args, Object target, Class<?> targetClass) {
+				@Nullable Object[] args, Object target, Class<?> targetClass) {
 
 			this.contexts = new LinkedMultiValueMap<>(operations.size());
 			for (CacheOperation op : operations) {

spring-context/src/main/java/org/springframework/cache/interceptor/SimpleCacheResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2025 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 org.springframework.cache.Cache;
 import org.springframework.cache.CacheManager;
+import org.springframework.lang.Contract;
 
 /**
  * A simple {@link CacheResolver} that resolves the {@link Cache} instance(s)
@@ -63,6 +64,7 @@ protected Collection<String> getCacheNames(CacheOperationInvocationContext<?> co
 	 * @return the SimpleCacheResolver ({@code null} if the CacheManager was {@code null})
 	 * @since 5.1
 	 */
+	@Contract("null -> null; !null -> !null")
 	static @Nullable SimpleCacheResolver of(@Nullable CacheManager cacheManager) {
 		return (cacheManager != null ? new SimpleCacheResolver(cacheManager) : null);
 	}

spring-context/src/main/java/org/springframework/context/annotation/AnnotationBeanNameGenerator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2024 the original author or authors.
+ * Copyright 2002-2025 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 @@ private Set<String> getMetaAnnotationTypes(MergedAnnotation<Annotation> mergedAn
 	 * @return whether the annotation qualifies as a stereotype with component name
 	 */
 	protected boolean isStereotypeWithNameValue(String annotationType,
-			Set<String> metaAnnotationTypes, Map<String, Object> attributes) {
+			Set<String> metaAnnotationTypes, Map<String, @Nullable Object> attributes) {
 
 		boolean isStereotype = metaAnnotationTypes.contains(COMPONENT_ANNOTATION_CLASSNAME) ||
 				annotationType.equals("jakarta.inject.Named");

spring-context/src/main/java/org/springframework/context/annotation/ConditionEvaluator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2024 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -129,7 +129,7 @@ List<Condition> collectConditions(@Nullable AnnotatedTypeMetadata metadata) {
 
 	@SuppressWarnings("unchecked")
 	private List<String[]> getConditionClasses(AnnotatedTypeMetadata metadata) {
-		MultiValueMap<String, Object> attributes = metadata.getAllAnnotationAttributes(Conditional.class.getName(), true);
+		MultiValueMap<String, @Nullable Object> attributes = metadata.getAllAnnotationAttributes(Conditional.class.getName(), true);
 		Object values = (attributes != null ? attributes.get("value") : null);
 		return (List<String[]>) (values != null ? values : Collections.emptyList());
 	}

spring-context/src/main/java/org/springframework/context/annotation/ConfigurationClassParser.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2024 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -1077,7 +1077,7 @@ public Set<SourceClass> getAnnotations() {
 		}
 
 		public Collection<SourceClass> getAnnotationAttributes(String annType, String attribute) throws IOException {
-			Map<String, Object> annotationAttributes = this.metadata.getAnnotationAttributes(annType, true);
+			Map<String, @Nullable Object> annotationAttributes = this.metadata.getAnnotationAttributes(annType, true);
 			if (annotationAttributes == null || !annotationAttributes.containsKey(attribute)) {
 				return Collections.emptySet();
 			}

spring-context/src/main/java/org/springframework/context/annotation/ConfigurationClassPostProcessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2024 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -658,9 +658,9 @@ private static class PropertySourcesAotContribution implements BeanFactoryInitia
 
 		private final List<PropertySourceDescriptor> descriptors;
 
-		private final Function<String, Resource> resourceResolver;
+		private final Function<String, @Nullable Resource> resourceResolver;
 
-		PropertySourcesAotContribution(List<PropertySourceDescriptor> descriptors, Function<String, Resource> resourceResolver) {
+		PropertySourcesAotContribution(List<PropertySourceDescriptor> descriptors, Function<String, @Nullable Resource> resourceResolver) {
 			this.descriptors = descriptors;
 			this.resourceResolver = resourceResolver;
 		}

spring-context/src/main/java/org/springframework/context/annotation/ConfigurationClassUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -143,7 +143,7 @@ else if (beanDef instanceof AbstractBeanDefinition abstractBd && abstractBd.hasB
 			}
 		}
 
-		Map<String, Object> config = metadata.getAnnotationAttributes(Configuration.class.getName());
+		Map<String, @Nullable Object> config = metadata.getAnnotationAttributes(Configuration.class.getName());
 		if (config != null && !Boolean.FALSE.equals(config.get("proxyBeanMethods"))) {
 			beanDef.setAttribute(CONFIGURATION_CLASS_ATTRIBUTE, CONFIGURATION_CLASS_FULL);
 		}
@@ -208,7 +208,7 @@ static boolean hasBeanMethods(AnnotationMetadata metadata) {
 	 * @since 5.0
 	 */
 	public static @Nullable Integer getOrder(AnnotationMetadata metadata) {
-		Map<String, Object> orderAttributes = metadata.getAnnotationAttributes(Order.class.getName());
+		Map<String, @Nullable Object> orderAttributes = metadata.getAnnotationAttributes(Order.class.getName());
 		return (orderAttributes != null ? ((Integer) orderAttributes.get(AnnotationUtils.VALUE)) : null);
 	}
 

spring-context/src/main/java/org/springframework/context/annotation/MBeanExportConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -60,7 +60,7 @@ public class MBeanExportConfiguration implements ImportAware, EnvironmentAware,
 
 	@Override
 	public void setImportMetadata(AnnotationMetadata importMetadata) {
-		Map<String, Object> map = importMetadata.getAnnotationAttributes(EnableMBeanExport.class.getName());
+		Map<String, @Nullable Object> map = importMetadata.getAnnotationAttributes(EnableMBeanExport.class.getName());
 		this.enableMBeanExport = AnnotationAttributes.fromMap(map);
 		if (this.enableMBeanExport == null) {
 			throw new IllegalArgumentException(