Skip plain Java annotations in SourceClass.getAnnotations() upfront

Includes direct reflective introspection of annotations when possible.

Closes gh-22750

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

@@ -531,7 +531,7 @@ class ConfigurationClassParser {
 		if (visited.add(sourceClass)) {
 			for (SourceClass annotation : sourceClass.getAnnotations()) {
 				String annName = annotation.getMetadata().getClassName();
-				if (!annName.startsWith("java") && !annName.equals(Import.class.getName())) {
+				if (!annName.equals(Import.class.getName())) {
 					collectImports(annotation, imports, visited);
 				}
 			}
@@ -539,8 +539,6 @@ class ConfigurationClassParser {
 		}
 	}
 
-
-
 	private void processImports(ConfigurationClass configClass, SourceClass currentSourceClass,
 			Collection<SourceClass> importCandidates, boolean checkForCircularImports) {
 
@@ -562,8 +560,7 @@ class ConfigurationClassParser {
 						ParserStrategyUtils.invokeAwareMethods(
 								selector, this.environment, this.resourceLoader, this.registry);
 						if (selector instanceof DeferredImportSelector) {
-							this.deferredImportSelectorHandler.handle(
-									configClass, (DeferredImportSelector) selector);
+							this.deferredImportSelectorHandler.handle(configClass, (DeferredImportSelector) selector);
 						}
 						else {
 							String[] importClassNames = selector.selectImports(currentSourceClass.getMetadata());
@@ -1016,13 +1013,32 @@ class ConfigurationClassParser {
 
 		public Set<SourceClass> getAnnotations() {
 			Set<SourceClass> result = new LinkedHashSet<>();
-			for (String className : this.metadata.getAnnotationTypes()) {
-				try {
-					result.add(getRelated(className));
+			if (this.source instanceof Class) {
+				Class<?> sourceClass = (Class<?>) this.source;
+				for (Annotation ann : sourceClass.getAnnotations()) {
+					Class<?> annType = ann.annotationType();
+					if (!annType.getName().startsWith("java")) {
+						try {
+							result.add(asSourceClass(annType));
+						}
+						catch (Throwable ex) {
+							// An annotation not present on the classpath is being ignored
+							// by the JVM's class loading -> ignore here as well.
+						}
+					}
 				}
-				catch (Throwable ex) {
-					// An annotation not present on the classpath is being ignored
-					// by the JVM's class loading -> ignore here as well.
+			}
+			else {
+				for (String className : this.metadata.getAnnotationTypes()) {
+					if (!className.startsWith("java")) {
+						try {
+							result.add(getRelated(className));
+						}
+						catch (Throwable ex) {
+							// An annotation not present on the classpath is being ignored
+							// by the JVM's class loading -> ignore here as well.
+						}
+					}
 				}
 			}
 			return result;