Validate declared annotations before deciding between reflection and ASM

Issue: SPR-16564

Author: jhoeller

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

@@ -18,6 +18,7 @@
 
 import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.lang.annotation.Annotation;
 import java.net.UnknownHostException;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
@@ -55,6 +56,7 @@
 import org.springframework.core.Ordered;
 import org.springframework.core.annotation.AnnotationAttributes;
 import org.springframework.core.annotation.AnnotationAwareOrderComparator;
+import org.springframework.core.annotation.AnnotationUtils;
 import org.springframework.core.env.CompositePropertySource;
 import org.springframework.core.env.ConfigurableEnvironment;
 import org.springframework.core.env.Environment;
@@ -659,8 +661,11 @@ SourceClass asSourceClass(@Nullable Class<?> classType) throws IOException {
 			return new SourceClass(Object.class);
 		}
 		try {
-			// Sanity test that we can read annotations, if not fall back to ASM
-			classType.getAnnotations();
+			// Sanity test that we can reflectively read annotations,
+			// including Class attributes; if not -> fall back to ASM
+			for (Annotation ann : classType.getAnnotations()) {
+				AnnotationUtils.validateAnnotation(ann);
+			}
 			return new SourceClass(classType);
 		}
 		catch (Throwable ex) {

spring-core/src/main/java/org/springframework/core/annotation/AnnotatedElementUtils.java

@@ -60,10 +60,9 @@
  * individual method for details on which search algorithm is used.
  *
  * <p><strong>Get semantics</strong> are limited to searching for annotations
- * that are either <em>present</em> on an {@code AnnotatedElement} (i.e.,
- * declared locally or {@linkplain java.lang.annotation.Inherited inherited})
- * or declared within the annotation hierarchy <em>above</em> the
- * {@code AnnotatedElement}.
+ * that are either <em>present</em> on an {@code AnnotatedElement} (i.e. declared
+ * locally or {@linkplain java.lang.annotation.Inherited inherited}) or declared
+ * within the annotation hierarchy <em>above</em> the {@code AnnotatedElement}.
  *
  * <p><strong>Find semantics</strong> are much more exhaustive, providing
  * <em>get semantics</em> plus support for the following:
@@ -77,14 +76,13 @@
  * </ul>
  *
  * <h3>Support for {@code @Inherited}</h3>
- * <p>Methods following <em>get semantics</em> will honor the contract of
- * Java's {@link java.lang.annotation.Inherited @Inherited} annotation except
- * that locally declared annotations (including custom composed annotations)
- * will be favored over inherited annotations. In contrast, methods following
- * <em>find semantics</em> will completely ignore the presence of
- * {@code @Inherited} since the <em>find</em> search algorithm manually
- * traverses type and method hierarchies and thereby implicitly supports
- * annotation inheritance without the need for {@code @Inherited}.
+ * <p>Methods following <em>get semantics</em> will honor the contract of Java's
+ * {@link java.lang.annotation.Inherited @Inherited} annotation except that locally
+ * declared annotations (including custom composed annotations) will be favored over
+ * inherited annotations. In contrast, methods following <em>find semantics</em>
+ * will completely ignore the presence of {@code @Inherited} since the <em>find</em>
+ * search algorithm manually traverses type and method hierarchies and thereby
+ * implicitly supports annotation inheritance without a need for {@code @Inherited}.
  *
  * @author Phillip Webb
  * @author Juergen Hoeller
@@ -794,7 +792,7 @@ public static <A extends Annotation> Set<A> findMergedRepeatableAnnotations(Anno
 	 * @param annotationName the fully qualified class name of the annotation
 	 * type to find (as an alternative to {@code annotationType})
 	 * @param processor the processor to delegate to
-	 * @return the result of the processor, potentially {@code null}
+	 * @return the result of the processor (potentially {@code null})
 	 */
 	@Nullable
 	private static <T> T searchWithGetSemantics(AnnotatedElement element,
@@ -815,7 +813,7 @@ private static <T> T searchWithGetSemantics(AnnotatedElement element,
 	 * @param containerType the type of the container that holds repeatable
 	 * annotations, or {@code null} if the annotation is not repeatable
 	 * @param processor the processor to delegate to
-	 * @return the result of the processor, potentially {@code null}
+	 * @return the result of the processor (potentially {@code null})
 	 * @since 4.3
 	 */
 	@Nullable
@@ -848,7 +846,7 @@ private static <T> T searchWithGetSemantics(AnnotatedElement element,
 	 * @param processor the processor to delegate to
 	 * @param visited the set of annotated elements that have already been visited
 	 * @param metaDepth the meta-depth of the annotation
-	 * @return the result of the processor, potentially {@code null}
+	 * @return the result of the processor (potentially {@code null})
 	 */
 	@Nullable
 	private static <T> T searchWithGetSemantics(AnnotatedElement element,
@@ -909,7 +907,7 @@ private static <T> T searchWithGetSemantics(AnnotatedElement element,
 	 * @param processor the processor to delegate to
 	 * @param visited the set of annotated elements that have already been visited
 	 * @param metaDepth the meta-depth of the annotation
-	 * @return the result of the processor, potentially {@code null}
+	 * @return the result of the processor (potentially {@code null})
 	 * @since 4.2
 	 */
 	@Nullable
@@ -979,7 +977,7 @@ else if (currentAnnotationType == containerType) {
 	 * @param annotationName the fully qualified class name of the annotation
 	 * type to find (as an alternative to {@code annotationType})
 	 * @param processor the processor to delegate to
-	 * @return the result of the processor, potentially {@code null}
+	 * @return the result of the processor (potentially {@code null})
 	 * @since 4.2
 	 */
 	@Nullable
@@ -1001,7 +999,7 @@ private static <T> T searchWithFindSemantics(AnnotatedElement element,
 	 * @param containerType the type of the container that holds repeatable
 	 * annotations, or {@code null} if the annotation is not repeatable
 	 * @param processor the processor to delegate to
-	 * @return the result of the processor, potentially {@code null}
+	 * @return the result of the processor (potentially {@code null})
 	 * @since 4.3
 	 */
 	@Nullable
@@ -1039,7 +1037,7 @@ private static <T> T searchWithFindSemantics(AnnotatedElement element,
 	 * @param processor the processor to delegate to
 	 * @param visited the set of annotated elements that have already been visited
 	 * @param metaDepth the meta-depth of the annotation
-	 * @return the result of the processor, potentially {@code null}
+	 * @return the result of the processor (potentially {@code null})
 	 * @since 4.2
 	 */
 	@Nullable

spring-core/src/main/java/org/springframework/core/annotation/AnnotationUtils.java

@@ -898,6 +898,31 @@ public static boolean isInJavaLangAnnotationPackage(@Nullable String annotationT
 		return (annotationType != null && annotationType.startsWith("java.lang.annotation"));
 	}
 
+	/**
+	 * Check the declared attributes of the given annotation, in particular covering
+	 * Google App Engine's late arrival of {@code TypeNotPresentExceptionProxy} for
+	 * {@code Class} values (instead of early {@code Class.getAnnotations() failure}.
+	 * <p>This method not failing indicates that {@link #getAnnotationAttributes(Annotation)}
+	 * won't failure either (when attempted later on).
+	 * @param annotation the annotation to validate
+	 * @throws IllegalStateException if a declared {@code Class} attribute could not be read
+	 * @since 4.3.15
+	 * @see Class#getAnnotations()
+	 * @see #getAnnotationAttributes(Annotation)
+	 */
+	public static void validateAnnotation(Annotation annotation) {
+		for (Method method : getAttributeMethods(annotation.annotationType())) {
+			if (method.getReturnType() == Class.class) {
+				try {
+					method.invoke(annotation);
+				}
+				catch (Throwable ex) {
+					throw new IllegalStateException("Could not obtain annotation attribute value for " + method, ex);
+				}
+			}
+		}
+	}
+
 	/**
 	 * Retrieve the given annotation's attributes as a {@link Map}, preserving all
 	 * attribute types.
@@ -1835,13 +1860,13 @@ static void handleIntrospectionFailure(@Nullable AnnotatedElement element, Throw
 		if (element instanceof Class && Annotation.class.isAssignableFrom((Class<?>) element)) {
 			// Meta-annotation or (default) value lookup on an annotation type
 			if (loggerToUse.isDebugEnabled()) {
-				loggerToUse.debug("Failed to meta-introspect annotation [" + element + "]: " + ex);
+				loggerToUse.debug("Failed to meta-introspect annotation " + element + ": " + ex);
 			}
 		}
 		else {
 			// Direct annotation lookup on regular Class, Method, Field
 			if (loggerToUse.isInfoEnabled()) {
-				loggerToUse.info("Failed to introspect annotations on [" + element + "]: " + ex);
+				loggerToUse.info("Failed to introspect annotations on " + element + ": " + ex);
 			}
 		}
 	}