DATACMNS-1108 - Prefer regular methods in ReflectionUtils.findRequiredMethod(…).

findRequiredMethod(…) now prefers regular methods over synthetic/bridge methods. This refinement is required for newer Java versions that create synthetic bridge methods using the interface's return type. For SpEL extension introspection we're looking for the most specific return type that may be declared in the extension.

Original Pull Request: #454

src/main/java/org/springframework/data/util/ReflectionUtils.java

@@ -247,17 +247,34 @@ public final class ReflectionUtils {
 	}
 
 	/**
-	 * Returns the method with the given name of the given class and parameter types.
+	 * Returns the method with the given name of the given class and parameter types. Prefers regular methods over
+	 * {@link Method#isBridge() bridge} and {@link Method#isSynthetic() synthetic} ones.
 	 *
 	 * @param type must not be {@literal null}.
 	 * @param name must not be {@literal null}.
 	 * @param parameterTypes must not be {@literal null}.
-	 * @return
+	 * @return the method object.
 	 * @throws IllegalArgumentException in case the method cannot be resolved.
 	 */
 	public static Method findRequiredMethod(Class<?> type, String name, Class<?>... parameterTypes) {
 
-		Method result = org.springframework.util.ReflectionUtils.findMethod(type, name, parameterTypes);
+		Assert.notNull(type, "Class must not be null");
+		Assert.notNull(name, "Method name must not be null");
+
+		Method result = null;
+		Class<?> searchType = type;
+		while (searchType != null) {
+			Method[] methods = (searchType.isInterface() ? searchType.getMethods()
+					: org.springframework.util.ReflectionUtils.getDeclaredMethods(searchType));
+			for (Method method : methods) {
+				if (name.equals(method.getName()) && hasSameParams(method, parameterTypes)) {
+					if (result == null || result.isSynthetic() || result.isBridge()) {
+						result = method;
+					}
+				}
+			}
+			searchType = searchType.getSuperclass();
+		}
 
 		if (result == null) {
 
@@ -272,6 +289,10 @@ public final class ReflectionUtils {
 		return result;
 	}
 
+	private static boolean hasSameParams(Method method, Class<?>[] paramTypes) {
+		return (paramTypes.length == method.getParameterCount() && Arrays.equals(paramTypes, method.getParameterTypes()));
+	}
+
 	/**
 	 * Returns a {@link Stream} of the return and parameters types of the given {@link Method}.
 	 *