Avoids NPEs

Author: João Dias

springdoc-openapi-common/src/main/java/org/springdoc/core/AbstractRequestBuilder.java

@@ -60,6 +60,9 @@ public Operation build(Components components, HandlerMethod handlerMethod, Reque
         String[] pNames = d.getParameterNames(handlerMethod.getMethod());
         java.lang.reflect.Parameter[] parameters = handlerMethod.getMethod().getParameters();
         String[] reflectionParametersNames = Arrays.stream(parameters).map(java.lang.reflect.Parameter::getName).toArray(String[]::new);
+        if (pNames == null) {
+            pNames = reflectionParametersNames;
+        }
         RequestBodyInfo requestBodyInfo = new RequestBodyInfo(methodAttributes);
         List<Parameter> operationParameters = (operation.getParameters() != null) ? operation.getParameters()
                 : new ArrayList<>();