Fix annotation arrays support in ClassFile metadata

As of gh-33616, Spring now supports metadata reading with the ClassFile
API on JDK 24+ runtimes. This commit fixes a bug where
`ArrayStoreException` were thrown when reading annotation attribute
values for arrays.

Fixes gh-35252

Author: bclozel

spring-core/src/main/java24/org/springframework/core/type/classreading/ClassFileAnnotationMetadata.java

@@ -25,6 +25,7 @@
 import java.lang.reflect.Array;
 import java.util.Collections;
 import java.util.LinkedHashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
@@ -86,7 +87,7 @@ static MergedAnnotations createMergedAnnotations(String className, RuntimeVisibl
 				return createMergedAnnotation(className, annotationValue.annotation(), classLoader);
 			}
 			case AnnotationValue.OfClass classValue -> {
-				return fromTypeDescriptor(classValue.className().stringValue());
+				return loadClass(classValue.className().stringValue(), classLoader);
 			}
 			case AnnotationValue.OfEnum enumValue -> {
 				return parseEnum(enumValue, classLoader);
@@ -103,6 +104,16 @@ private static String fromTypeDescriptor(String descriptor) {
 		classDesc.packageName() + "." + classDesc.displayName();
 	}
 
+	private static Class<?> loadClass(String className, @Nullable ClassLoader classLoader) {
+		try {
+			String name = fromTypeDescriptor(className);
+			return ClassUtils.forName(name, classLoader);
+		}
+		catch (ClassNotFoundException ex) {
+			return Object.class;
+		}
+	}
+
 	private static Object parseArrayValue(String className, @Nullable ClassLoader classLoader, AnnotationValue.OfArray arrayValue) {
 		if (arrayValue.values().isEmpty()) {
 			return new Object[0];
@@ -119,10 +130,10 @@ private static Object parseArrayValue(String className, @Nullable ClassLoader cl
 				return stream.map(AnnotationValue.OfLong.class::cast).mapToLong(AnnotationValue.OfLong::longValue).toArray();
 			}
 			default -> {
-				Object firstResolvedValue = readAnnotationValue(className, arrayValue.values().getFirst(), classLoader);
+				Class<?> arrayElementType = resolveArrayElementType(arrayValue.values(), classLoader);
 				return stream
 						.map(rawValue -> readAnnotationValue(className, rawValue, classLoader))
-						.toArray(s -> (Object[]) Array.newInstance(firstResolvedValue.getClass(), s));
+						.toArray(s -> (Object[]) Array.newInstance(arrayElementType, s));
 			}
 		}
 	}
@@ -139,6 +150,28 @@ private static Object parseArrayValue(String className, @Nullable ClassLoader cl
 		}
 	}
 
+	private static Class<?> resolveArrayElementType(List<AnnotationValue> values, @Nullable ClassLoader classLoader) {
+		AnnotationValue firstValue = values.getFirst();
+		switch (firstValue) {
+			case AnnotationValue.OfConstant constantValue -> {
+				return constantValue.resolvedValue().getClass();
+			}
+			case AnnotationValue.OfAnnotation _ -> {
+				return MergedAnnotation.class;
+			}
+			case AnnotationValue.OfClass _ -> {
+				return Class.class;
+			}
+			case AnnotationValue.OfEnum enumValue -> {
+				return loadClass(enumValue.className().stringValue(), classLoader);
+			}
+			default -> {
+				return Object.class;
+			}
+		}
+	}
+
+
 	record Source(Annotation entryName) {
 
 	}

spring-core/src/test/java/org/springframework/core/type/AbstractAnnotationMetadataTests.java

@@ -290,11 +290,11 @@ void getAllAnnotationAttributesReturnsAllAttributes() {
 		void getComplexAttributeTypesReturnsAll() {
 			MultiValueMap<String, Object> attributes =
 					get(WithComplexAttributeTypes.class).getAllAnnotationAttributes(ComplexAttributes.class.getName());
-			assertThat(attributes).containsOnlyKeys("names", "count", "type", "subAnnotation");
+			assertThat(attributes).containsOnlyKeys("names", "count", "types", "subAnnotation");
 			assertThat(attributes.get("names")).hasSize(1);
 			assertThat(attributes.get("names").get(0)).isEqualTo(new String[]{"first", "second"});
-			assertThat(attributes.get("count")).containsExactlyInAnyOrder(TestEnum.ONE);
-			assertThat(attributes.get("type")).containsExactlyInAnyOrder(TestEnum.class);
+			assertThat(attributes.get("count").get(0)).isEqualTo(new TestEnum[]{TestEnum.ONE, TestEnum.TWO});
+			assertThat(attributes.get("types").get(0)).isEqualTo(new Class[]{TestEnum.class});
 			assertThat(attributes.get("subAnnotation")).hasSize(1);
 		}
 
@@ -312,8 +312,8 @@ void getComplexAttributeTypesReturnsAllWithKotlinMetadata() {
 		void getAnnotationAttributeIntType() {
 			MultiValueMap<String, Object> attributes =
 					get(WithIntType.class).getAllAnnotationAttributes(ComplexAttributes.class.getName());
-			assertThat(attributes).containsOnlyKeys("names", "count", "type", "subAnnotation");
-			assertThat(attributes.get("type")).contains(int.class);
+			assertThat(attributes).containsOnlyKeys("names", "count", "types", "subAnnotation");
+			assertThat(attributes.get("types").get(0)).isEqualTo(new Class[]{int.class});
 		}
 
 		@Test
@@ -454,13 +454,13 @@ public static class WithMetaAnnotationAttributes {
 		}
 
 
-		@ComplexAttributes(names = {"first", "second"}, count = TestEnum.ONE,
-				type = TestEnum.class, subAnnotation = @SubAnnotation(name="spring"))
+		@ComplexAttributes(names = {"first", "second"}, count = {TestEnum.ONE, TestEnum.TWO},
+				types = {TestEnum.class}, subAnnotation = @SubAnnotation(name="spring"))
 		@Metadata(mv = {42})
 		public static class WithComplexAttributeTypes {
 		}
 
-		@ComplexAttributes(names = "void", count = TestEnum.ONE, type = int.class,
+		@ComplexAttributes(names = "void", count = TestEnum.ONE, types = int.class,
 				subAnnotation = @SubAnnotation(name="spring"))
 		public static class WithIntType {
 
@@ -471,9 +471,9 @@ public static class WithIntType {
 
 			String[] names();
 
-			TestEnum count();
+			TestEnum[] count();
 
-			Class<?> type();
+			Class<?>[] types();
 
 			SubAnnotation subAnnotation();
 		}
@@ -484,7 +484,15 @@ public static class WithIntType {
 		}
 
 		public enum TestEnum {
-			ONE, TWO, THREE
+			ONE {
+
+			},
+			TWO {
+
+			},
+			THREE {
+
+			}
 		}
 
 		@RepeatableAnnotation(name = "first")