SPR-15481 Fixed AnnotationUtils.getValue() operation

- Fixed AnnotationUtils.getValue() operation to ensure it re-throws AnnotationConfigurationException instead of swallowing it (as it is done in few other operations in AnnotationUtils)
- Added test
- Removed unnecessary '@SuppressWarnings("unchecked")'

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

@@ -97,6 +97,7 @@ import org.springframework.util.StringUtils;
  * @author Mark Fisher
  * @author Chris Beams
  * @author Phillip Webb
+ * @author Oleg Zhurakousky
  * @since 2.0
  * @see AliasFor
  * @see AnnotationAttributes
@@ -484,7 +485,6 @@ public abstract class AnnotationUtils {
 	 * @return the first matching annotation, or {@code null} if not found
 	 * @since 4.2
 	 */
-	@SuppressWarnings("unchecked")
 	private static <A extends Annotation> A findAnnotation(
 			AnnotatedElement annotatedElement, Class<A> annotationType, Set<Annotation> visited) {
 		try {
@@ -673,7 +673,6 @@ public abstract class AnnotationUtils {
 	 * @param visited the set of annotations that have already been visited
 	 * @return the first matching annotation, or {@code null} if not found
 	 */
-	@SuppressWarnings("unchecked")
 	private static <A extends Annotation> A findAnnotation(Class<?> clazz, Class<A> annotationType, Set<Annotation> visited) {
 		try {
 			A annotation = clazz.getDeclaredAnnotation(annotationType);
@@ -1294,8 +1293,11 @@ public abstract class AnnotationUtils {
 	 * Retrieve the <em>value</em> of a named attribute, given an annotation instance.
 	 * @param annotation the annotation instance from which to retrieve the value
 	 * @param attributeName the name of the attribute value to retrieve
-	 * @return the attribute value, or {@code null} if not found
+	 * @return the attribute value, or {@code null} if not found unless the the attribute value 
+	 * can not be retrieved due to {@link AnnotationConfigurationException}, in which case it
+	 * will be re-thrown
 	 * @see #getValue(Annotation)
+	 * @see #rethrowAnnotationConfigurationException(Throwable)
 	 */
 	public static Object getValue(Annotation annotation, String attributeName) {
 		if (annotation == null || !StringUtils.hasText(attributeName)) {
@@ -1306,6 +1308,10 @@ public abstract class AnnotationUtils {
 			ReflectionUtils.makeAccessible(method);
 			return method.invoke(annotation);
 		}
+		catch (InvocationTargetException ex) {
+			rethrowAnnotationConfigurationException(ex.getTargetException());
+			throw new IllegalStateException("Could not obtain annotation attribute value of " + attributeName, ex);
+		}
 		catch (Exception ex) {
 			return null;
 		}

spring-core/src/test/java/org/springframework/core/annotation/AnnotationUtilsTests.java

@@ -54,6 +54,7 @@ import static org.springframework.core.annotation.AnnotationUtils.*;
  * @author Sam Brannen
  * @author Chris Beams
  * @author Phillip Webb
+ * @author Oleg Zhurakousky
  */
 public class AnnotationUtilsTests {
 
@@ -1240,6 +1241,14 @@ public class AnnotationUtilsTests {
 		assertEquals("location: ", "", contextConfig.location());
 	}
 	
+	@ContextConfig(value="foo", location="bar")
+	@Test(expected=AnnotationConfigurationException.class)
+	public void synthesizeAnnotationWithAttributeAliasesDifferentValues() throws Exception {
+		Method m = AnnotationUtilsTests.class.getDeclaredMethod("synthesizeAnnotationWithAttributeAliasesDifferentValues");
+		Annotation a = synthesizeAnnotation(m.getDeclaredAnnotation(ContextConfig.class));
+		getValue(a);
+	}
+
 	@Test
 	public void synthesizeAnnotationFromMapWithMinimalAttributesWithAttributeAliases() throws Exception {
 		Map<String, Object> map = Collections.singletonMap("location", "test.xml");