Refine null-safety based on IDEA warnings

See gh-28797

spring-aop/src/main/java/org/springframework/aop/MethodMatcher.java

@@ -18,6 +18,8 @@ package org.springframework.aop;
 
 import java.lang.reflect.Method;
 
+import org.jspecify.annotations.Nullable;
+
 /**
  * Part of a {@link Pointcut}: Checks whether the target method is eligible for advice.
  *
@@ -94,7 +96,7 @@ public interface MethodMatcher {
 	 * @return whether there's a runtime match
 	 * @see #matches(Method, Class)
 	 */
-	boolean matches(Method method, Class<?> targetClass, Object... args);
+	boolean matches(Method method, Class<?> targetClass, @Nullable Object... args);
 
 
 	/**

spring-aop/src/main/java/org/springframework/aop/TrueMethodMatcher.java

@@ -19,6 +19,8 @@ package org.springframework.aop;
 import java.io.Serializable;
 import java.lang.reflect.Method;
 
+import org.jspecify.annotations.Nullable;
+
 /**
  * Canonical MethodMatcher instance that matches all methods.
  *
@@ -48,7 +50,7 @@ final class TrueMethodMatcher implements MethodMatcher, Serializable {
 	}
 
 	@Override
-	public boolean matches(Method method, Class<?> targetClass, Object... args) {
+	public boolean matches(Method method, Class<?> targetClass, @Nullable Object... args) {
 		// Should never be invoked as isRuntime returns false.
 		throw new UnsupportedOperationException();
 	}

spring-aop/src/main/java/org/springframework/aop/aspectj/AspectJExpressionPointcut.java

@@ -340,7 +340,7 @@ public class AspectJExpressionPointcut extends AbstractExpressionPointcut
 	}
 
 	@Override
-	public boolean matches(Method method, Class<?> targetClass, Object... args) {
+	public boolean matches(Method method, Class<?> targetClass, @Nullable Object... args) {
 		ShadowMatch shadowMatch = getTargetShadowMatch(method, targetClass);
 
 		// Bind Spring AOP proxy to AspectJ "this" and Spring AOP target to AspectJ target,

spring-aop/src/main/java/org/springframework/aop/aspectj/annotation/InstantiationModelAwarePointcutAdvisorImpl.java

@@ -289,7 +289,7 @@ final class InstantiationModelAwarePointcutAdvisorImpl
 		}
 
 		@Override
-		public boolean matches(Method method, Class<?> targetClass, Object... args) {
+		public boolean matches(Method method, Class<?> targetClass, @Nullable Object... args) {
 			// This can match only on declared pointcut.
 			return (isAspectMaterialized() && this.declaredPointcut.matches(method, targetClass, args));
 		}

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

@@ -144,7 +144,7 @@ public class ControlFlowPointcut implements Pointcut, ClassFilter, MethodMatcher
 	}
 
 	@Override
-	public boolean matches(Method method, Class<?> targetClass, Object... args) {
+	public boolean matches(Method method, Class<?> targetClass, @Nullable Object... args) {
 		incrementEvaluationCount();
 
 		for (StackTraceElement element : new Throwable().getStackTrace()) {

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

@@ -151,7 +151,7 @@ public abstract class MethodMatchers {
 		}
 
 		@Override
-		public boolean matches(Method method, Class<?> targetClass, Object... args) {
+		public boolean matches(Method method, Class<?> targetClass, @Nullable Object... args) {
 			return this.mm1.matches(method, targetClass, args) || this.mm2.matches(method, targetClass, args);
 		}
 
@@ -303,7 +303,7 @@ public abstract class MethodMatchers {
 		}
 
 		@Override
-		public boolean matches(Method method, Class<?> targetClass, Object... args) {
+		public boolean matches(Method method, Class<?> targetClass, @Nullable Object... args) {
 			// Because a dynamic intersection may be composed of a static and dynamic part,
 			// we must avoid calling the 3-arg matches method on a dynamic matcher, as
 			// it will probably be an unsupported operation.
@@ -373,7 +373,7 @@ public abstract class MethodMatchers {
 		}
 
 		@Override
-		public boolean matches(Method method, Class<?> targetClass, Object... args) {
+		public boolean matches(Method method, Class<?> targetClass, @Nullable Object... args) {
 			return !this.original.matches(method, targetClass, args);
 		}
 

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

@@ -18,6 +18,8 @@ package org.springframework.aop.support;
 
 import java.lang.reflect.Method;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.aop.MethodMatcher;
 
 /**
@@ -34,7 +36,7 @@ public abstract class StaticMethodMatcher implements MethodMatcher {
 	}
 
 	@Override
-	public final boolean matches(Method method, Class<?> targetClass, Object... args) {
+	public final boolean matches(Method method, Class<?> targetClass, @Nullable Object... args) {
 		// should never be invoked because isRuntime() returns false
 		throw new UnsupportedOperationException("Illegal MethodMatcher usage");
 	}

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

@@ -77,7 +77,7 @@ public interface ObjectProvider<T> extends ObjectFactory<T>, Iterable<T> {
 	 * @throws BeansException in case of creation errors
 	 * @see #getObject()
 	 */
-	default T getObject(Object... args) throws BeansException {
+	default T getObject(@Nullable Object... args) throws BeansException {
 		throw new UnsupportedOperationException("Retrieval with arguments not supported -" +
 				"for custom ObjectProvider classes, implement getObject(Object...) for your purposes");
 	}

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

@@ -140,7 +140,7 @@ class ConstructorResolver {
 
 		Constructor<?> constructorToUse = null;
 		ArgumentsHolder argsHolderToUse = null;
-		Object[] argsToUse = null;
+		@Nullable Object[] argsToUse = null;
 
 		if (explicitArgs != null) {
 			argsToUse = explicitArgs;
@@ -227,7 +227,7 @@ class ConstructorResolver {
 				Class<?>[] paramTypes = candidate.getParameterTypes();
 				if (resolvedValues != null) {
 					try {
-						String[] paramNames = null;
+						@Nullable String[] paramNames = null;
 						if (resolvedValues.containsNamedArgument()) {
 							paramNames = ConstructorPropertiesChecker.evaluate(candidate, parameterCount);
 							if (paramNames == null) {
@@ -437,7 +437,7 @@ class ConstructorResolver {
 			argsToUse = explicitArgs;
 		}
 		else {
-			Object[] argsToResolve = null;
+			@Nullable Object[] argsToResolve = null;
 			synchronized (mbd.constructorArgumentLock) {
 				factoryMethodToUse = (Method) mbd.resolvedConstructorOrFactoryMethod;
 				if (factoryMethodToUse != null && mbd.constructorArgumentsResolved) {
@@ -536,7 +536,7 @@ class ConstructorResolver {
 					else {
 						// Resolved constructor arguments: type conversion and/or autowiring necessary.
 						try {
-							String[] paramNames = null;
+							@Nullable String[] paramNames = null;
 							if (resolvedValues != null && resolvedValues.containsNamedArgument()) {
 								ParameterNameDiscoverer pnd = this.beanFactory.getParameterNameDiscoverer();
 								if (pnd != null) {
@@ -719,7 +719,7 @@ class ConstructorResolver {
 	 */
 	private ArgumentsHolder createArgumentArray(
 			String beanName, RootBeanDefinition mbd, @Nullable ConstructorArgumentValues resolvedValues,
-			BeanWrapper bw, Class<?>[] paramTypes, String @Nullable [] paramNames, Executable executable,
+			BeanWrapper bw, Class<?>[] paramTypes, @Nullable String @Nullable [] paramNames, Executable executable,
 			boolean autowiring, boolean fallback) throws UnsatisfiedDependencyException {
 
 		TypeConverter customConverter = this.beanFactory.getCustomTypeConverter();

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

@@ -422,7 +422,7 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 				return resolved;
 			}
 			@Override
-			public T getObject(Object... args) throws BeansException {
+			public T getObject(@Nullable Object... args) throws BeansException {
 				T resolved = resolveBean(requiredType, args, false);
 				if (resolved == null) {
 					throw new NoSuchBeanDefinitionException(requiredType);
@@ -2147,7 +2147,7 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 	 * Create an {@link Optional} wrapper for the specified dependency.
 	 */
 	private Optional<?> createOptionalDependency(
-			DependencyDescriptor descriptor, @Nullable String beanName, final Object... args) {
+			DependencyDescriptor descriptor, @Nullable String beanName, final @Nullable Object... args) {
 
 		DependencyDescriptor descriptorToUse = new NestedDependencyDescriptor(descriptor) {
 			@Override
@@ -2317,7 +2317,7 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 		}
 
 		@Override
-		public Object getObject(final Object... args) throws BeansException {
+		public Object getObject(final @Nullable Object... args) throws BeansException {
 			if (this.optional) {
 				return createOptionalDependency(this.descriptor, this.beanName, args);
 			}

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

@@ -301,7 +301,7 @@ public class StaticListableBeanFactory implements ListableBeanFactory {
 				}
 			}
 			@Override
-			public T getObject(Object... args) throws BeansException {
+			public T getObject(@Nullable Object... args) throws BeansException {
 				String[] beanNames = getBeanNamesForType(requiredType);
 				if (beanNames.length == 1) {
 					return (T) getBean(beanNames[0], args);

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

@@ -63,7 +63,7 @@ final class BeanMethod extends ConfigurationMethod {
 			return;
 		}
 
-		Map<String, Object> attributes =
+		Map<String, @Nullable Object> attributes =
 				getConfigurationClass().getMetadata().getAnnotationAttributes(Configuration.class.getName());
 		if (attributes != null && (Boolean) attributes.get("proxyBeanMethods") && !getMetadata().isOverridable()) {
 			// instance @Bean methods within @Configuration classes must be overridable to accommodate CGLIB

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

@@ -220,7 +220,7 @@ final class ConfigurationClass {
 
 	@SuppressWarnings("NullAway") // Reflection
 	void validate(ProblemReporter problemReporter) {
-		Map<String, Object> attributes = this.metadata.getAnnotationAttributes(Configuration.class.getName());
+		Map<String, @Nullable Object> attributes = this.metadata.getAnnotationAttributes(Configuration.class.getName());
 
 		// A configuration class may not be final (CGLIB limitation) unless it declares proxyBeanMethods=false
 		if (attributes != null && (Boolean) attributes.get("proxyBeanMethods") && this.metadata.isFinal()) {

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

@@ -26,6 +26,7 @@ import java.util.Set;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.jspecify.annotations.Nullable;
 
 import org.springframework.beans.factory.BeanDefinitionStoreException;
 import org.springframework.beans.factory.annotation.AnnotatedBeanDefinition;
@@ -309,7 +310,7 @@ class ConfigurationClassBeanDefinitionReader {
 				ccbd.setNonUniqueFactoryMethodName(ccbd.getFactoryMethodMetadata().getMethodName());
 				return true;
 			}
-			Map<String, Object> attributes =
+			Map<String, @Nullable Object> attributes =
 					configClass.getMetadata().getAnnotationAttributes(Configuration.class.getName());
 			if ((attributes != null && (Boolean) attributes.get("enforceUniqueMethods")) ||
 					!this.registry.isBeanDefinitionOverridable(beanName)) {

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

@@ -16,6 +16,8 @@
 
 package org.springframework.context.annotation;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.core.type.AnnotatedTypeMetadata;
 import org.springframework.util.MultiValueMap;
 
@@ -33,7 +35,7 @@ class ProfileCondition implements Condition {
 	@Override
 	@SuppressWarnings("NullAway") // Reflection
 	public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {
-		MultiValueMap<String, Object> attrs = metadata.getAllAnnotationAttributes(Profile.class.getName());
+		MultiValueMap<String, @Nullable Object> attrs = metadata.getAllAnnotationAttributes(Profile.class.getName());
 		if (attrs != null) {
 			for (Object value : attrs.get("value")) {
 				if (context.getEnvironment().matchesProfiles((String[]) value)) {

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

@@ -139,7 +139,7 @@ public class AnnotationJmxAttributeSource implements JmxAttributeSource, BeanFac
 	}
 
 	@Override
-	public org.springframework.jmx.export.metadata.ManagedOperationParameter[] getManagedOperationParameters(Method method)
+	public org.springframework.jmx.export.metadata.@Nullable ManagedOperationParameter[] getManagedOperationParameters(Method method)
 			throws InvalidMetadataException {
 
 		List<MergedAnnotation<? extends Annotation>> anns = getRepeatableAnnotations(
@@ -149,7 +149,7 @@ public class AnnotationJmxAttributeSource implements JmxAttributeSource, BeanFac
 	}
 
 	@Override
-	public org.springframework.jmx.export.metadata.ManagedNotification[] getManagedNotifications(Class<?> clazz)
+	public org.springframework.jmx.export.metadata.@Nullable ManagedNotification[] getManagedNotifications(Class<?> clazz)
 			throws InvalidMetadataException {
 
 		List<MergedAnnotation<? extends Annotation>> anns = getRepeatableAnnotations(

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

@@ -18,6 +18,7 @@ package org.springframework.jmx.export.assembler;
 
 import java.beans.PropertyDescriptor;
 import java.lang.reflect.Method;
+import java.util.Objects;
 
 import javax.management.Descriptor;
 import javax.management.MBeanParameterInfo;
@@ -259,7 +260,7 @@ public class MetadataMBeanInfoAssembler extends AbstractReflectiveMBeanInfoAssem
 	 */
 	@Override
 	protected MBeanParameterInfo[] getOperationParameters(Method method, String beanKey) {
-		ManagedOperationParameter[] params = obtainAttributeSource().getManagedOperationParameters(method);
+		@Nullable ManagedOperationParameter[] params = obtainAttributeSource().getManagedOperationParameters(method);
 		if (ObjectUtils.isEmpty(params)) {
 			return super.getOperationParameters(method, beanKey);
 		}
@@ -267,7 +268,7 @@ public class MetadataMBeanInfoAssembler extends AbstractReflectiveMBeanInfoAssem
 		MBeanParameterInfo[] parameterInfo = new MBeanParameterInfo[params.length];
 		Class<?>[] methodParameters = method.getParameterTypes();
 		for (int i = 0; i < params.length; i++) {
-			ManagedOperationParameter param = params[i];
+			ManagedOperationParameter param = Objects.requireNonNull(params[i]);
 			parameterInfo[i] =
 					new MBeanParameterInfo(param.getName(), methodParameters[i].getName(), param.getDescription());
 		}
@@ -280,14 +281,14 @@ public class MetadataMBeanInfoAssembler extends AbstractReflectiveMBeanInfoAssem
 	 */
 	@Override
 	protected ModelMBeanNotificationInfo[] getNotificationInfo(Object managedBean, String beanKey) {
-		ManagedNotification[] notificationAttributes =
+		@Nullable ManagedNotification[] notificationAttributes =
 				obtainAttributeSource().getManagedNotifications(getClassToExpose(managedBean));
 		ModelMBeanNotificationInfo[] notificationInfos =
 				new ModelMBeanNotificationInfo[notificationAttributes.length];
 
 		for (int i = 0; i < notificationAttributes.length; i++) {
 			ManagedNotification attribute = notificationAttributes[i];
-			notificationInfos[i] = JmxMetadataUtils.convertToModelMBeanNotificationInfo(attribute);
+			notificationInfos[i] = JmxMetadataUtils.convertToModelMBeanNotificationInfo(Objects.requireNonNull(attribute));
 		}
 
 		return notificationInfos;

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

@@ -80,7 +80,7 @@ public interface JmxAttributeSource {
 	 * @return the parameter information.
 	 * @throws InvalidMetadataException in the case of invalid attributes.
 	 */
-	ManagedOperationParameter[] getManagedOperationParameters(Method method) throws InvalidMetadataException;
+	@Nullable ManagedOperationParameter[] getManagedOperationParameters(Method method) throws InvalidMetadataException;
 
 	/**
 	 * Implementations should return an array of {@link ManagedNotification ManagedNotifications}
@@ -90,7 +90,7 @@ public interface JmxAttributeSource {
 	 * @return the notification information
 	 * @throws InvalidMetadataException in the case of invalid metadata
 	 */
-	ManagedNotification[] getManagedNotifications(Class<?> clazz) throws InvalidMetadataException;
+	@Nullable ManagedNotification[] getManagedNotifications(Class<?> clazz) throws InvalidMetadataException;
 
 
 

spring-context/src/main/java/org/springframework/jndi/support/SimpleJndiBeanFactory.java

@@ -162,7 +162,7 @@ public class SimpleJndiBeanFactory extends JndiLocatorSupport implements BeanFac
 				return getBean(requiredType);
 			}
 			@Override
-			public T getObject(Object... args) throws BeansException {
+			public T getObject(@Nullable Object... args) throws BeansException {
 				return getBean(requiredType, args);
 			}
 			@Override

spring-expression/src/main/java/org/springframework/expression/ConstructorExecutor.java

@@ -16,6 +16,8 @@
 
 package org.springframework.expression;
 
+import org.jspecify.annotations.Nullable;
+
 /**
  * A {@code ConstructorExecutor} is built by a {@link ConstructorResolver} and
  * can be cached by the infrastructure to repeat an operation quickly without
@@ -49,6 +51,6 @@ public interface ConstructorExecutor {
 	 * @throws AccessException if there is a problem executing the constructor or
 	 * if this {@code ConstructorExecutor} has become stale
 	 */
-	TypedValue execute(EvaluationContext context, Object... arguments) throws AccessException;
+	TypedValue execute(EvaluationContext context, @Nullable Object... arguments) throws AccessException;
 
 }

spring-expression/src/main/java/org/springframework/expression/MethodExecutor.java

@@ -16,6 +16,8 @@
 
 package org.springframework.expression;
 
+import org.jspecify.annotations.Nullable;
+
 /**
  * A {@code MethodExecutor} is built by a {@link MethodResolver} and can be cached
  * by the infrastructure to repeat an operation quickly without going back to the
@@ -50,6 +52,6 @@ public interface MethodExecutor {
 	 * @throws AccessException if there is a problem executing the method or
 	 * if this {@code MethodExecutor} has become stale
 	 */
-	TypedValue execute(EvaluationContext context, Object target, Object... arguments) throws AccessException;
+	TypedValue execute(EvaluationContext context, Object target, @Nullable Object... arguments) throws AccessException;
 
 }

spring-web/src/jmh/java/org/springframework/http/support/HeadersAdaptersBaseline.java

@@ -69,12 +69,12 @@ class HeadersAdaptersBaseline {
 		}
 
 		@Override
-		public void addAll(String key, List<? extends String> values) {
+		public void addAll(String key, List<? extends @Nullable String> values) {
 			values.forEach(value -> add(key, value));
 		}
 
 		@Override
-		public void addAll(MultiValueMap<String, String> values) {
+		public void addAll(MultiValueMap<String, @Nullable String> values) {
 			values.forEach(this::addAll);
 		}
 
@@ -84,12 +84,12 @@ class HeadersAdaptersBaseline {
 		}
 
 		@Override
-		public void setAll(Map<String, String> values) {
+		public void setAll(Map<String, @Nullable String> values) {
 			values.forEach(this::set);
 		}
 
 		@Override
-		public Map<String, String> toSingleValueMap() {
+		public Map<String, @Nullable String> toSingleValueMap() {
 			Map<String, String> map = CollectionUtils.newLinkedHashMap(size());
 			this.message.headerIterator().forEachRemaining(h -> map.putIfAbsent(h.getName(), h.getValue()));
 			return map;
@@ -274,12 +274,12 @@ class HeadersAdaptersBaseline {
 		}
 
 		@Override
-		public void addAll(String key, List<? extends String> values) {
+		public void addAll(String key, List<? extends @Nullable String> values) {
 			values.forEach(value -> add(key, value));
 		}
 
 		@Override
-		public void addAll(MultiValueMap<String, String> values) {
+		public void addAll(MultiValueMap<String, @Nullable String> values) {
 			values.forEach(this::addAll);
 		}
 
@@ -295,7 +295,7 @@ class HeadersAdaptersBaseline {
 		}
 
 		@Override
-		public void setAll(Map<String, String> values) {
+		public void setAll(Map<String, @Nullable String> values) {
 			values.forEach(this::set);
 		}
 
@@ -566,12 +566,12 @@ class HeadersAdaptersBaseline {
 		}
 
 		@Override
-		public void addAll(String key, List<? extends String> values) {
+		public void addAll(String key, List<? extends @Nullable String> values) {
 			this.headers.add(key, values);
 		}
 
 		@Override
-		public void addAll(MultiValueMap<String, String> values) {
+		public void addAll(MultiValueMap<String, @Nullable String> values) {
 			values.forEach(this.headers::add);
 		}
 
@@ -583,7 +583,7 @@ class HeadersAdaptersBaseline {
 		}
 
 		@Override
-		public void setAll(Map<String, String> values) {
+		public void setAll(Map<String, @Nullable String> values) {
 			values.forEach(this.headers::set);
 		}
 
@@ -809,12 +809,12 @@ class HeadersAdaptersBaseline {
 		}
 
 		@Override
-		public void addAll(String key, List<? extends String> values) {
+		public void addAll(String key, List<? extends @Nullable String> values) {
 			this.headers.add(key, values);
 		}
 
 		@Override
-		public void addAll(MultiValueMap<String, String> values) {
+		public void addAll(MultiValueMap<String, @Nullable String> values) {
 			values.forEach(this.headers::add);
 		}
 
@@ -826,7 +826,7 @@ class HeadersAdaptersBaseline {
 		}
 
 		@Override
-		public void setAll(Map<String, String> values) {
+		public void setAll(Map<String, @Nullable String> values) {
 			values.forEach(this.headers::set);
 		}