Consistent default ClassLoader fallback in hint classes

Closes gh-34470

spring-core/src/main/java/org/springframework/aot/hint/ResourceHints.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.
@@ -27,6 +27,7 @@ import java.util.stream.Stream;
 import org.springframework.core.io.ClassPathResource;
 import org.springframework.core.io.Resource;
 import org.springframework.lang.Nullable;
+import org.springframework.util.ClassUtils;
 
 /**
  * Gather the need for resources available at runtime.
@@ -50,14 +51,14 @@ public class ResourceHints {
 		this.resourceBundleHints = new LinkedHashSet<>();
 	}
 
+
 	/**
 	 * Return the resources that should be made available at runtime.
 	 * @return a stream of {@link ResourcePatternHints}
 	 */
 	public Stream<ResourcePatternHints> resourcePatternHints() {
 		Stream<ResourcePatternHints> patterns = this.resourcePatternHints.stream();
-		return (this.types.isEmpty() ? patterns
-				: Stream.concat(Stream.of(typesPatternResourceHint()), patterns));
+		return (this.types.isEmpty() ? patterns : Stream.concat(Stream.of(typesPatternResourceHint()), patterns));
 	}
 
 	/**
@@ -70,18 +71,18 @@ public class ResourceHints {
 
 	/**
 	 * Register a pattern if the given {@code location} is available on the
-	 * classpath. This delegates to {@link ClassLoader#getResource(String)}
-	 * which validates directories as well. The location is not included in
-	 * the hint.
-	 * @param classLoader the classloader to use
+	 * classpath. This delegates to {@link ClassLoader#getResource(String)} which
+	 * validates directories as well. The location is not included in the hint.
+	 * @param classLoader the ClassLoader to use, or {@code null} for the default
 	 * @param location a '/'-separated path name that should exist
 	 * @param resourceHint a builder to customize the resource pattern
 	 * @return {@code this}, to facilitate method chaining
 	 */
 	public ResourceHints registerPatternIfPresent(@Nullable ClassLoader classLoader, String location,
 			Consumer<ResourcePatternHints.Builder> resourceHint) {
-		ClassLoader classLoaderToUse = (classLoader != null ? classLoader : getClass().getClassLoader());
-		if (classLoaderToUse.getResource(location) != null) {
+
+		ClassLoader classLoaderToUse = (classLoader != null ? classLoader : ClassUtils.getDefaultClassLoader());
+		if (classLoaderToUse != null && classLoaderToUse.getResource(location) != null) {
 			registerPattern(resourceHint);
 		}
 		return this;

spring-core/src/main/java/org/springframework/aot/hint/RuntimeHintsRegistrar.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.
@@ -25,8 +25,9 @@ import org.springframework.lang.Nullable;
  *
  * <p>Implementations of this interface can be registered dynamically by using
  * {@link org.springframework.context.annotation.ImportRuntimeHints @ImportRuntimeHints}
- * or statically in {@code META-INF/spring/aot.factories} by using the FQN of this
- * interface as the key. A standard no-arg constructor is required for implementations.
+ * or statically in {@code META-INF/spring/aot.factories} by using the fully-qualified
+ * class name of this interface as the key. A standard no-arg constructor is required
+ * for implementations.
  *
  * @author Brian Clozel
  * @author Stephane Nicoll
@@ -38,7 +39,7 @@ public interface RuntimeHintsRegistrar {
 	/**
 	 * Contribute hints to the given {@link RuntimeHints} instance.
 	 * @param hints the hints contributed so far for the deployment unit
-	 * @param classLoader the classloader, or {@code null} if even the system ClassLoader isn't accessible
+	 * @param classLoader the ClassLoader to use, or {@code null} for the default
 	 */
 	void registerHints(RuntimeHints hints, @Nullable ClassLoader classLoader);
 

spring-core/src/main/java/org/springframework/aot/hint/support/FilePatternResourceHintsRegistrar.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.
@@ -23,6 +23,7 @@ import java.util.List;
 import org.springframework.aot.hint.ResourceHints;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 import org.springframework.util.ResourceUtils;
 
 /**
@@ -66,7 +67,8 @@ public class FilePatternResourceHintsRegistrar {
 
 	@Deprecated(since = "6.0.12", forRemoval = true)
 	public void registerHints(ResourceHints hints, @Nullable ClassLoader classLoader) {
-		ClassLoader classLoaderToUse = (classLoader != null ? classLoader : getClass().getClassLoader());
+		ClassLoader classLoaderToUse = (classLoader != null ? classLoader : ClassUtils.getDefaultClassLoader());
+		if (classLoaderToUse != null) {
 			List<String> includes = new ArrayList<>();
 			for (String location : this.classpathLocations) {
 				if (classLoaderToUse.getResource(location) != null) {
@@ -81,6 +83,7 @@ public class FilePatternResourceHintsRegistrar {
 				hints.registerPattern(hint -> hint.includes(includes.toArray(String[]::new)));
 			}
 		}
+	}
 
 
 	/**
@@ -246,8 +249,7 @@ public class FilePatternResourceHintsRegistrar {
 		 * classpath location that resolves against the {@code ClassLoader}, files
 		 * with the configured file prefixes and extensions are registered.
 		 * @param hints the hints contributed so far for the deployment unit
-		 * @param classLoader the classloader, or {@code null} if even the system
-		 * ClassLoader isn't accessible
+		 * @param classLoader the ClassLoader to use, or {@code null} for the default
 		 */
 		public void registerHints(ResourceHints hints, @Nullable ClassLoader classLoader) {
 			build().registerHints(hints, classLoader);

spring-core/src/main/java/org/springframework/aot/hint/support/SpringFactoriesLoaderRuntimeHints.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.
@@ -48,12 +48,13 @@ class SpringFactoriesLoaderRuntimeHints implements RuntimeHintsRegistrar {
 
 	@Override
 	public void registerHints(RuntimeHints hints, @Nullable ClassLoader classLoader) {
-		ClassLoader classLoaderToUse = (classLoader != null ? classLoader :
-				SpringFactoriesLoaderRuntimeHints.class.getClassLoader());
+		ClassLoader classLoaderToUse = (classLoader != null ? classLoader : ClassUtils.getDefaultClassLoader());
+		if (classLoaderToUse != null) {
 			for (String resourceLocation : RESOURCE_LOCATIONS) {
 				registerHints(hints, classLoaderToUse, resourceLocation);
 			}
 		}
+	}
 
 	private void registerHints(RuntimeHints hints, ClassLoader classLoader, String resourceLocation) {
 		hints.resources().registerPattern(resourceLocation);