Update OpenApiMiddleware.java

This line:
final NormalisedPath openApiPathString = maybeApiPath.get();

Would introduce NoSuchElementException and will be caught as "UnhandledException" by the end, which would respond with 500 Internal Server Error.

The fix is to check if the path is present on the spec, and if not, return a 401 status invalid request path.

Author: syntheshad

src/main/java/com/networknt/aws/lambda/handler/middleware/specification/OpenApiMiddleware.java

@@ -25,6 +25,7 @@ public class OpenApiMiddleware implements MiddlewareHandler {
     public static final String OPENAPI_CONFIG_NAME = "openapi-validator";
     private static final Logger LOG = LoggerFactory.getLogger(OpenApiMiddleware.class);
     private static final String STATUS_METHOD_NOT_ALLOWED = "ERR10008";
+    private static final String STATUS_INVALID_REQUEST_PATH = "ERR10007";
     private static final String CONFIG_NAME = "openapi";
     static ValidatorConfig CONFIG = ValidatorConfig.load();
     private static final String SPEC_INJECT = "openapi-inject";
@@ -58,6 +59,9 @@ public Status execute(LightLambdaExchange exchange) {
         }
         final Optional<NormalisedPath> maybeApiPath = helper.findMatchingApiPath(requestPath);
 
+        if (maybeApiPath.isEmpty()) {
+            return new Status(STATUS_INVALID_REQUEST_PATH, requestPath.normalised());
+        }
         final NormalisedPath openApiPathString = maybeApiPath.get();
         final Path path = helper.openApi3.getPath(openApiPathString.original());