Spring 4 incompatibility using springdoc-openapi 1.2.30+. Fixes #563.

Author: bnasslahsen

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

@@ -266,7 +266,8 @@ private Schema getFileSchema(RequestBodyInfo requestBodyInfo) {
 
 	private boolean isFile(ParameterizedType parameterizedType) {
 		Type type = parameterizedType.getActualTypeArguments()[0];
-		if (isFile(ResolvableType.forType(type).getRawClass()))
+		Class fileClass = ResolvableType.forType(type).getRawClass();
+		if (fileClass!=null && isFile(fileClass))
 			return true;
 		else if (type instanceof WildcardType) {
 			WildcardType wildcardType = (WildcardType) type;