ConfigurationClassParser falls back to ASM-based resolution of member classes in case of NoClassDefFoundError

Issue: SPR-11844

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

@@ -537,6 +537,7 @@ class ConfigurationClassParser {
 			return new SourceClass(classType);
 		}
 		catch (Throwable ex) {
+			// Enforce ASM via class name resolution
 			return asSourceClass(classType.getName());
 		}
 	}
@@ -693,10 +694,14 @@ class ConfigurationClassParser {
 		}
 
 		public Collection<SourceClass> getMemberClasses() throws IOException {
-			List<SourceClass> members = new ArrayList<SourceClass>();
+			Object sourceToProcess = this.source;
-			if (this.source instanceof Class<?>) {
+
-				Class<?> sourceClass = (Class<?>) this.source;
+			if (sourceToProcess instanceof Class<?>) {
-				for (Class<?> declaredClass : sourceClass.getDeclaredClasses()) {
+				Class<?> sourceClass = (Class<?>) sourceToProcess;
+				try {
+					Class<?>[] declaredClasses = sourceClass.getDeclaredClasses();
+					List<SourceClass> members = new ArrayList<SourceClass>(declaredClasses.length);
+					for (Class<?> declaredClass : declaredClasses) {
 						try {
 							members.add(asSourceClass(declaredClass));
 						}
@@ -704,10 +709,20 @@ class ConfigurationClassParser {
 							// ignore
 						}
 					}
+					return members;
 				}
-			else {
+				catch (NoClassDefFoundError err) {
-				MetadataReader sourceReader = (MetadataReader) source;
+					// getDeclaredClasses() failed because of non-resolvable dependencies
-				for (String memberClassName : sourceReader.getClassMetadata().getMemberClassNames()) {
+					// -> fall back to ASM below
+					sourceToProcess = metadataReaderFactory.getMetadataReader(sourceClass.getName());
+				}
+			}
+
+			// ASM-based resolution - safe for non-resolvable classes as well
+			MetadataReader sourceReader = (MetadataReader) sourceToProcess;
+			String[] memberClassNames = sourceReader.getClassMetadata().getMemberClassNames();
+			List<SourceClass> members = new ArrayList<SourceClass>(memberClassNames.length);
+			for (String memberClassName : memberClassNames) {
 				try {
 					members.add(asSourceClass(memberClassName));
 				}
@@ -715,7 +730,6 @@ class ConfigurationClassParser {
 					// ignore
 				}
 			}
-			}
 			return members;
 		}