From b7971e2e3da33718bad536df3904aeac923c73db Mon Sep 17 00:00:00 2001
From: William Cheng <wing328hk@gmail.com>
Date: Mon, 7 Jan 2019 23:29:13 +0800
Subject: [PATCH] better error message when parameter ref not defined (#1837)

---
 .../src/main/java/org/openapitools/codegen/DefaultCodegen.java | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
index 1f4f91a10bd..2874cbfd29b 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
@@ -4191,6 +4191,9 @@ public class DefaultCodegen implements CodegenConfig {
     protected Parameter getParameterFromRef(String ref, OpenAPI openAPI) {
         String parameterName = ref.substring(ref.lastIndexOf('/') + 1);
         Map<String, Parameter> parameterMap = openAPI.getComponents().getParameters();
+        if (parameterMap == null ) { // can't find the ref
+            throw new RuntimeException(ref + " not defined in the spec.");
+        }
         return parameterMap.get(parameterName);
     }